From 55d94d412d4269d93e9c71a2ce59d1b9631b8957 Mon Sep 17 00:00:00 2001 From: Manuel Bentele Date: Wed, 9 Sep 2020 17:32:57 +0200 Subject: Renamed files from loop to xloop and generate package only in Release mode --- CMakeLists.txt | 42 +- kernel/CMakeLists.txt | 31 +- kernel/Kbuild | 8 +- kernel/Makefile | 12 - kernel/loop_file_fmt.c | 347 ------ kernel/loop_file_fmt.h | 380 ------ kernel/loop_file_fmt_qcow_cache.c | 218 ---- kernel/loop_file_fmt_qcow_cache.h | 51 - kernel/loop_file_fmt_qcow_cluster.c | 270 ----- kernel/loop_file_fmt_qcow_cluster.h | 23 - kernel/loop_file_fmt_qcow_main.c | 953 --------------- kernel/loop_file_fmt_qcow_main.h | 419 ------- kernel/loop_file_fmt_raw.c | 465 ------- kernel/loop_main.c | 2221 ---------------------------------- kernel/loop_main.h | 105 -- kernel/uapi/linux/loop.h | 125 -- kernel/uapi/linux/xloop.h | 125 ++ kernel/xloop_file_fmt.c | 347 ++++++ kernel/xloop_file_fmt.h | 380 ++++++ kernel/xloop_file_fmt_qcow_cache.c | 218 ++++ kernel/xloop_file_fmt_qcow_cache.h | 51 + kernel/xloop_file_fmt_qcow_cluster.c | 270 +++++ kernel/xloop_file_fmt_qcow_cluster.h | 23 + kernel/xloop_file_fmt_qcow_main.c | 953 +++++++++++++++ kernel/xloop_file_fmt_qcow_main.h | 419 +++++++ kernel/xloop_file_fmt_raw.c | 465 +++++++ kernel/xloop_main.c | 2221 ++++++++++++++++++++++++++++++++++ kernel/xloop_main.h | 105 ++ utils/CMakeLists.txt | 2 +- utils/bash-completion/losetup | 85 -- utils/bash-completion/xlosetup | 85 ++ utils/lib/loopdev.c | 56 +- utils/sys-utils/CMakeLists.txt | 4 +- utils/sys-utils/losetup.8 | 215 ---- utils/sys-utils/losetup.c | 955 --------------- utils/sys-utils/xlosetup.8 | 215 ++++ utils/sys-utils/xlosetup.c | 955 +++++++++++++++ 37 files changed, 6906 insertions(+), 6913 deletions(-) delete mode 100644 kernel/Makefile delete mode 100644 kernel/loop_file_fmt.c delete mode 100644 kernel/loop_file_fmt.h delete mode 100644 kernel/loop_file_fmt_qcow_cache.c delete mode 100644 kernel/loop_file_fmt_qcow_cache.h delete mode 100644 kernel/loop_file_fmt_qcow_cluster.c delete mode 100644 kernel/loop_file_fmt_qcow_cluster.h delete mode 100644 kernel/loop_file_fmt_qcow_main.c delete mode 100644 kernel/loop_file_fmt_qcow_main.h delete mode 100644 kernel/loop_file_fmt_raw.c delete mode 100644 kernel/loop_main.c delete mode 100644 kernel/loop_main.h delete mode 100644 kernel/uapi/linux/loop.h create mode 100644 kernel/uapi/linux/xloop.h create mode 100644 kernel/xloop_file_fmt.c create mode 100644 kernel/xloop_file_fmt.h create mode 100644 kernel/xloop_file_fmt_qcow_cache.c create mode 100644 kernel/xloop_file_fmt_qcow_cache.h create mode 100644 kernel/xloop_file_fmt_qcow_cluster.c create mode 100644 kernel/xloop_file_fmt_qcow_cluster.h create mode 100644 kernel/xloop_file_fmt_qcow_main.c create mode 100644 kernel/xloop_file_fmt_qcow_main.h create mode 100644 kernel/xloop_file_fmt_raw.c create mode 100644 kernel/xloop_main.c create mode 100644 kernel/xloop_main.h delete mode 100644 utils/bash-completion/losetup create mode 100644 utils/bash-completion/xlosetup delete mode 100644 utils/sys-utils/losetup.8 delete mode 100644 utils/sys-utils/losetup.c create mode 100644 utils/sys-utils/xlosetup.8 create mode 100644 utils/sys-utils/xlosetup.c diff --git a/CMakeLists.txt b/CMakeLists.txt index 3a9f07a..ba17bf4 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -8,26 +8,28 @@ if(NOT CMAKE_BUILD_TYPE) endif() # define packaging -set(CPACK_GENERATOR "DEB") -set(CPACK_SOURCE_GENERATOR "TGZ") -set(CPACK_IGNORE_FILES "*.gitignore") -set(CPACK_PACKAGE_NAME "xloop") -set(CPACK_PACKAGE_DESCRIPTION "xloop Kernel modules and utility") -set(CPACK_PACKAGE_VERSION_MAJOR 0) -set(CPACK_PACKAGE_VERSION_MINOR 1) -set(CPACK_PACKAGE_SECTION admin) -set(CPACK_PACKAGE_VENDOR "University of Freiburg") -set(CPACK_PACKAGE_CONTACT "Christian Rößler ") -set(CPACK_PACKAGE_HOMEPAGE_URL "https://git.openslx.org/openslx-ng/xloop.git/") -set(CPACK_PACKAGE_CHECKSUM SHA256) -set(CPACK_STRIP_FILES TRUE) -set(CPACK_DEBIAN_FILE_NAME DEB-DEFAULT) -set(CPACK_DEBIAN_PACKAGE_DEPENDS "libc6") -file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postinst "depmod -a\n") -file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postrm "depmod -a\n") -set(CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postinst - ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postrm) -include(CPack) +if(NOT CMAKE_BUILD_TYPE MATCHES Debug) + set(CPACK_GENERATOR "DEB") + set(CPACK_SOURCE_GENERATOR "TGZ") + set(CPACK_IGNORE_FILES "*.gitignore") + set(CPACK_PACKAGE_NAME "xloop") + set(CPACK_PACKAGE_DESCRIPTION "xloop Kernel modules and utility") + set(CPACK_PACKAGE_VERSION_MAJOR 0) + set(CPACK_PACKAGE_VERSION_MINOR 1) + set(CPACK_PACKAGE_SECTION admin) + set(CPACK_PACKAGE_VENDOR "University of Freiburg") + set(CPACK_PACKAGE_CONTACT "Christian Rößler ") + set(CPACK_PACKAGE_HOMEPAGE_URL "https://git.openslx.org/openslx-ng/xloop.git/") + set(CPACK_PACKAGE_CHECKSUM SHA256) + set(CPACK_STRIP_FILES TRUE) + set(CPACK_DEBIAN_FILE_NAME DEB-DEFAULT) + set(CPACK_DEBIAN_PACKAGE_DEPENDS "libc6") + file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postinst "depmod -a\n") + file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postrm "depmod -a\n") + set(CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postinst + ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postrm) + include(CPack) +endif() # add subprojects add_subdirectory(kernel) diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt index c850f0a..7cc79dd 100644 --- a/kernel/CMakeLists.txt +++ b/kernel/CMakeLists.txt @@ -15,14 +15,17 @@ set(BLK_DEV_XLOOP_MIN_COUNT 8 CACHE STRING "Number of xloop devices to pre-create at init time") set(XLOOP_MAJOR 120 CACHE STRING "Major number for xloop devices") +set(XLOOP_CTRL_MINOR 15 + CACHE STRING "Minor number for xloop-control device") # print configured settings message(STATUS "Kernel module path is " ${KERNEL_DIR}) message(STATUS "Number of xloop devices to pre-create at init time is " ${BLK_DEV_XLOOP_MIN_COUNT}) message(STATUS "Major number for xloop devices is " ${XLOOP_MAJOR}) +message(STATUS "Minor number for xloop-control device is " ${XLOOP_CTRL_MINOR}) # set C flags for a Linux kernel module -set(KERNEL_C_FLAGS "-DCONFIG_BLK_DEV_XLOOP_MIN_COUNT=${BLK_DEV_XLOOP_MIN_COUNT} -DXLOOP_MAJOR=${XLOOP_MAJOR}" +set(KERNEL_C_FLAGS "-DCONFIG_BLK_DEV_XLOOP_MIN_COUNT=${BLK_DEV_XLOOP_MIN_COUNT} -DXLOOP_MAJOR=${XLOOP_MAJOR} -DXLOOP_CTRL_MINOR=${XLOOP_CTRL_MINOR}" CACHE STRING "C flags to be used for building the kernel module") # set C flags for the debug mode of a Linux kernel module set(KERNEL_C_FLAGS_DEBUG "-g -DDEBUG" @@ -37,10 +40,10 @@ endif(CMAKE_BUILD_TYPE MATCHES Debug) add_kernel_build(prepare ${CMAKE_CURRENT_SOURCE_DIR}/Kbuild) # xloop main Linux kernel module -set(KERNEL_MODULE_XLOOP_SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt.c - ${CMAKE_CURRENT_SOURCE_DIR}/loop_main.c) -set(KERNEL_MODULE_XLOOP_HEADER_FILES ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt.h - ${CMAKE_CURRENT_SOURCE_DIR}/loop_main.h +set(KERNEL_MODULE_XLOOP_SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt.c + ${CMAKE_CURRENT_SOURCE_DIR}/xloop_main.c) +set(KERNEL_MODULE_XLOOP_HEADER_FILES ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt.h + ${CMAKE_CURRENT_SOURCE_DIR}/xloop_main.h ${CMAKE_CURRENT_SOURCE_DIR}/uapi) add_kernel_module(xloop "${KERNEL_DIR}" "CONFIG_BLK_DEV_XLOOP=m" @@ -49,9 +52,9 @@ add_kernel_module(xloop "${KERNEL_DIR}" ${CMAKE_CURRENT_BINARY_DIR}/Kbuild) # xloop_file_fmt_raw Linux kernel module -set(KERNEL_MODULE_XLOOP_RAW_SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_raw.c) +set(KERNEL_MODULE_XLOOP_RAW_SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_raw.c) set(KERNEL_MODULE_XLOOP_RAW_HEADER_FILES ) -add_kernel_module(loop_file_fmt_raw "${KERNEL_DIR}" +add_kernel_module(xloop_file_fmt_raw "${KERNEL_DIR}" "CONFIG_BLK_DEV_XLOOP_FILE_FMT_RAW=m" "${KERNEL_MODULE_XLOOP_RAW_SOURCE_FILES}" "${KERNEL_MODULE_XLOOP_RAW_HEADER_FILES}" @@ -59,13 +62,13 @@ add_kernel_module(loop_file_fmt_raw "${KERNEL_DIR}" xloop) # xloop_file_fmt_qcow Linux kernel module -set(KERNEL_MODULE_XLOOP_QCOW_SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_qcow_cache.c - ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_qcow_cluster.c - ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_qcow_main.c) -set(KERNEL_MODULE_XLOOP_QCOW_HEADER_FILES ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_qcow_cache.h - ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_qcow_cluster.h - ${CMAKE_CURRENT_SOURCE_DIR}/loop_file_fmt_qcow_main.h) -add_kernel_module(loop_file_fmt_qcow "${KERNEL_DIR}" +set(KERNEL_MODULE_XLOOP_QCOW_SOURCE_FILES ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_qcow_cache.c + ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_qcow_cluster.c + ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_qcow_main.c) +set(KERNEL_MODULE_XLOOP_QCOW_HEADER_FILES ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_qcow_cache.h + ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_qcow_cluster.h + ${CMAKE_CURRENT_SOURCE_DIR}/xloop_file_fmt_qcow_main.h) +add_kernel_module(xloop_file_fmt_qcow "${KERNEL_DIR}" "CONFIG_BLK_DEV_XLOOP_FILE_FMT_QCOW=m" "${KERNEL_MODULE_XLOOP_QCOW_SOURCE_FILES}" "${KERNEL_MODULE_XLOOP_QCOW_HEADER_FILES}" diff --git a/kernel/Kbuild b/kernel/Kbuild index a216066..e3b34ac 100644 --- a/kernel/Kbuild +++ b/kernel/Kbuild @@ -2,11 +2,11 @@ # Linux kernel module xloop obj-$(CONFIG_BLK_DEV_XLOOP) += xloop.o -xloop-objs += loop_main.o loop_file_fmt.o +xloop-objs += xloop_main.o xloop_file_fmt.o # Linux kernel module loop_file_fmt_raw -obj-$(CONFIG_BLK_DEV_XLOOP_FILE_FMT_RAW) += loop_file_fmt_raw.o +obj-$(CONFIG_BLK_DEV_XLOOP_FILE_FMT_RAW) += xloop_file_fmt_raw.o # Linux kernel module loop_file_fmt_qcow -obj-$(CONFIG_BLK_DEV_XLOOP_FILE_FMT_QCOW) += loop_file_fmt_qcow.o -loop_file_fmt_qcow-objs += loop_file_fmt_qcow_main.o loop_file_fmt_qcow_cluster.o loop_file_fmt_qcow_cache.o \ No newline at end of file +obj-$(CONFIG_BLK_DEV_XLOOP_FILE_FMT_QCOW) += xloop_file_fmt_qcow.o +xloop_file_fmt_qcow-objs += xloop_file_fmt_qcow_main.o xloop_file_fmt_qcow_cluster.o xloop_file_fmt_qcow_cache.o \ No newline at end of file diff --git a/kernel/Makefile b/kernel/Makefile deleted file mode 100644 index ca9019a..0000000 --- a/kernel/Makefile +++ /dev/null @@ -1,12 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -include $(PWD)/Kbuild - -ifndef KDIR - KDIR = /lib/modules/$(shell uname -r)/build -endif - -all: - make -C "$(KDIR)" "M=$(PWD)" modules - -clean: - make -C "$(KDIR)" "M=$(PWD)" clean diff --git a/kernel/loop_file_fmt.c b/kernel/loop_file_fmt.c deleted file mode 100644 index 062ea0d..0000000 --- a/kernel/loop_file_fmt.c +++ /dev/null @@ -1,347 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * loop_file_fmt.c - * - * File format subsystem for the xloop device module. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#include -#include - -#include "loop_file_fmt.h" - -/* storage for all registered file format drivers */ -static struct xloop_file_fmt_driver *xloop_file_fmt_drivers[MAX_XLO_FILE_FMT] = { - NULL -}; - -int xloop_file_fmt_register_driver(struct xloop_file_fmt_driver *drv) -{ - int ret = 0; - - if (drv == NULL) - return -EFAULT; - - if (drv->file_fmt_type > MAX_XLO_FILE_FMT) - return -EINVAL; - - if (xloop_file_fmt_drivers[drv->file_fmt_type] == NULL) { - xloop_file_fmt_drivers[drv->file_fmt_type] = drv; - printk(KERN_INFO "xloop_file_fmt: successfully registered file " - "format driver %s", drv->name); - } else { - printk(KERN_WARNING "xloop_file_fmt: driver for file format " - "already registered"); - ret = -EBUSY; - } - - return ret; -} -EXPORT_SYMBOL(xloop_file_fmt_register_driver); - -void xloop_file_fmt_unregister_driver(struct xloop_file_fmt_driver *drv) -{ - if (drv == NULL) - return; - - if (drv->file_fmt_type > MAX_XLO_FILE_FMT) - return; - - xloop_file_fmt_drivers[drv->file_fmt_type] = NULL; - printk(KERN_INFO "xloop_file_fmt: successfully unregistered file " - "format driver %s", drv->name); -} -EXPORT_SYMBOL(xloop_file_fmt_unregister_driver); - -struct xloop_file_fmt *xloop_file_fmt_alloc(void) -{ - return kzalloc(sizeof(struct xloop_file_fmt), GFP_KERNEL); -} - -void xloop_file_fmt_free(struct xloop_file_fmt *xlo_fmt) -{ - kfree(xlo_fmt); -} - -int xloop_file_fmt_set_xlo(struct xloop_file_fmt *xlo_fmt, struct xloop_device *xlo) -{ - if (xlo_fmt == NULL) - return -EINVAL; - - xlo_fmt->xlo = xlo; - - return 0; -} -EXPORT_SYMBOL(xloop_file_fmt_set_xlo); - -struct xloop_device *xloop_file_fmt_get_xlo(struct xloop_file_fmt *xlo_fmt) -{ - return xlo_fmt->xlo; -} -EXPORT_SYMBOL(xloop_file_fmt_get_xlo); - -int xloop_file_fmt_init(struct xloop_file_fmt *xlo_fmt, - u32 file_fmt_type) -{ - struct xloop_file_fmt_ops *ops; - struct module *drv; - int ret = 0; - - if (file_fmt_type > MAX_XLO_FILE_FMT) - return -EINVAL; - - xlo_fmt->file_fmt_type = file_fmt_type; - - if (xlo_fmt->file_fmt_state != file_fmt_uninitialized) { - printk(KERN_WARNING "xloop_file_fmt: file format is " - "initialized already"); - return -EINVAL; - } - - /* check if new file format driver is registered */ - if (xloop_file_fmt_drivers[xlo_fmt->file_fmt_type] == NULL) { - printk(KERN_ERR "xloop_file_fmt: file format driver is not " - "available"); - return -ENODEV; - } - - printk(KERN_INFO "xloop_file_fmt: use file format driver %s", - xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->name); - - drv = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->owner; - if (!try_module_get(drv)) { - printk(KERN_ERR "xloop_file_fmt: file format driver %s can not " - "be accessed", - xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->name); - return -ENODEV; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->init)) { - ret = ops->init(xlo_fmt); - if (ret < 0) - goto free_drv; - } - - /* after increasing the refcount of file format driver module and - * the successful initialization, the file format is initialized */ - xlo_fmt->file_fmt_state = file_fmt_initialized; - - return ret; - -free_drv: - module_put(drv); - xlo_fmt->file_fmt_state = file_fmt_uninitialized; - return ret; -} - -void xloop_file_fmt_exit(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_ops *ops; - struct module *drv; - - if (xlo_fmt->file_fmt_state != file_fmt_initialized) { - printk(KERN_WARNING "xloop_file_fmt: file format is " - "uninitialized already"); - return; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->exit)) - ops->exit(xlo_fmt); - - drv = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->owner; - module_put(drv); - - /* after decreasing the refcount of file format driver module, - * the file format is uninitialized */ - xlo_fmt->file_fmt_state = file_fmt_uninitialized; -} - -int xloop_file_fmt_read(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not read"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->read)) - return ops->read(xlo_fmt, rq); - else - return -EIO; -} - -int xloop_file_fmt_read_aio(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not read aio"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->read_aio)) - return ops->read_aio(xlo_fmt, rq); - else - return -EIO; -} - -int xloop_file_fmt_write(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not write"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->write)) - return ops->write(xlo_fmt, rq); - else - return -EIO; -} - -int xloop_file_fmt_write_aio(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not write aio"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->write_aio)) - return ops->write_aio(xlo_fmt, rq); - else - return -EIO; -} - -int xloop_file_fmt_write_zeros(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not write zeros"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->write_zeros)) - return ops->write_zeros(xlo_fmt, rq); - else - return -EIO; -} - -int xloop_file_fmt_discard(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not discard"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->discard)) - return ops->discard(xlo_fmt, rq); - else - return -EIO; -} - -int xloop_file_fmt_flush(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not flush"); - return -EINVAL; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->flush)) - return ops->flush(xlo_fmt); - - return 0; -} - -loff_t xloop_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, - struct file *file, loff_t offset, loff_t sizelimit) -{ - struct xloop_file_fmt_ops *ops; - - if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { - printk(KERN_ERR "xloop_file_fmt: file format is " - "not initialized, can not read sector size"); - return 0; - } - - ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; - if (likely(ops->sector_size)) - return ops->sector_size(xlo_fmt, file, offset, sizelimit); - else - return 0; -} - -int xloop_file_fmt_change(struct xloop_file_fmt *xlo_fmt, - u32 file_fmt_type_new) -{ - if (file_fmt_type_new > MAX_XLO_FILE_FMT) - return -EINVAL; - - /* Unload the old file format driver if the file format is - * initialized */ - if (xlo_fmt->file_fmt_state == file_fmt_initialized) - xloop_file_fmt_exit(xlo_fmt); - - /* Load the new file format driver because the file format is - * uninitialized now */ - return xloop_file_fmt_init(xlo_fmt, file_fmt_type_new); -} - -ssize_t xloop_file_fmt_print_type(u32 file_fmt_type, char *file_fmt_name) -{ - ssize_t len = 0; - - switch (file_fmt_type) { - case XLO_FILE_FMT_RAW: - len = sprintf(file_fmt_name, "%s", "RAW"); - break; - case XLO_FILE_FMT_QCOW: - len = sprintf(file_fmt_name, "%s", "QCOW"); - break; - case XLO_FILE_FMT_VDI: - len = sprintf(file_fmt_name, "%s", "VDI"); - break; - case XLO_FILE_FMT_VMDK: - len = sprintf(file_fmt_name, "%s", "VMDK"); - break; - default: - len = sprintf(file_fmt_name, "%s", "ERROR: Unsupported xloop " - "file format!"); - break; - } - - return len; -} -EXPORT_SYMBOL(xloop_file_fmt_print_type); diff --git a/kernel/loop_file_fmt.h b/kernel/loop_file_fmt.h deleted file mode 100644 index 38d6a3b..0000000 --- a/kernel/loop_file_fmt.h +++ /dev/null @@ -1,380 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * loop_file_fmt.h - * - * File format subsystem for the xloop device module. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#ifndef _LINUX_XLOOP_FILE_FMT_H -#define _LINUX_XLOOP_FILE_FMT_H - -#include "loop_main.h" - -struct xloop_file_fmt; - -#define XLO_FILE_FMT_RAW 0 -#define XLO_FILE_FMT_QCOW 1 -#define XLO_FILE_FMT_VDI 2 -#define XLO_FILE_FMT_VMDK 3 -#define MAX_XLO_FILE_FMT (XLO_FILE_FMT_VMDK + 1) - -/** - * struct xloop_file_fmt_ops - File format subsystem operations - * - * Data structure representing the file format subsystem interface. - */ -struct xloop_file_fmt_ops { - /** - * @init: Initialization callback function - */ - int (*init) (struct xloop_file_fmt *xlo_fmt); - - /** - * @exit: Release callback function - */ - void (*exit) (struct xloop_file_fmt *xlo_fmt); - - /** - * @read: Read IO callback function - */ - int (*read) (struct xloop_file_fmt *xlo_fmt, - struct request *rq); - - /** - * @write: Write IO callback function - */ - int (*write) (struct xloop_file_fmt *xlo_fmt, - struct request *rq); - - /** - * @read_aio: Asynchronous read IO callback function - */ - int (*read_aio) (struct xloop_file_fmt *xlo_fmt, - struct request *rq); - - /** - * @write_aio: Asynchronous write IO callback function - */ - int (*write_aio) (struct xloop_file_fmt *xlo_fmt, - struct request *rq); - - /** - * @zero: Zero (discard) IO callback function - */ - int (*write_zeros) (struct xloop_file_fmt *xlo_fmt, - struct request *rq); - - /** - * @discard: Discard IO callback function - */ - int (*discard) (struct xloop_file_fmt *xlo_fmt, - struct request *rq); - - /** - * @flush: Flush callback function - */ - int (*flush) (struct xloop_file_fmt *xlo_fmt); - - /** - * @sector_size: Get sector size callback function - */ - loff_t (*sector_size) (struct xloop_file_fmt *xlo_fmt, - struct file *file, loff_t offset, loff_t sizelimit); -}; - -/** - * struct xloop_file_fmt_driver - File format subsystem driver - * - * Data structure to implement file format drivers for the file format - * subsystem. - */ -struct xloop_file_fmt_driver { - /** - * @name: Name of the file format driver - */ - const char *name; - - /** - * @file_fmt_type: xloop file format type of the file format driver - */ - const u32 file_fmt_type; - - /** - * @ops: Driver's implemented file format operations - */ - struct xloop_file_fmt_ops *ops; - - /** - * @ops: Owner of the file format driver - */ - struct module *owner; -}; - -/* - * states of the file format - * - * transitions: - * xloop_file_fmt_init(...) - * ---> uninitialized ------------------------------> initialized - * xloop_file_fmt_exit(...) - * initialized ------------------------------> uninitialized - * xloop_file_fmt_read(...) - * initialized ------------------------------> initialized - * xloop_file_fmt_read_aio(...) - * initialized ------------------------------> initialized - * xloop_file_fmt_write(...) - * initialized ------------------------------> initialized - * xloop_file_fmt_write_aio(...) - * initialized ------------------------------> initialized - * xloop_file_fmt_discard(...) - * initialized ------------------------------> initialized - * xloop_file_fmt_flush(...) - * initialized ------------------------------> initialized - * xloop_file_fmt_sector_size(...) - * initialized ------------------------------> initialized - * - * xloop_file_fmt_change(...) - * +-----------------------------------------------------------+ - * | exit(...) init(...) | - * | initialized -------> uninitialized -------> initialized | - * +-----------------------------------------------------------+ - */ -enum { - file_fmt_uninitialized = 0, - file_fmt_initialized -}; - -/** - * struct xloop_file_fmt - xloop file format - * - * Data structure to use with the file format the xloop file format subsystem. - */ -struct xloop_file_fmt { - /** - * @file_fmt_type: Current type of the xloop file format - */ - u32 file_fmt_type; - - /** - * @file_fmt_state: Current state of the xloop file format - */ - int file_fmt_state; - - /** - * @xlo: Link to a file format's xloop device - */ - struct xloop_device *xlo; - - /** - * @private_data: Optional link to a file format's driver specific data - */ - void *private_data; -}; - - -/* subsystem functions for the driver implementation */ - -/** - * xloop_file_fmt_register_driver - Register a xloop file format driver - * @drv: File format driver - * - * Registers the specified xloop file format driver @drv by the xloop file format - * subsystem. - */ -extern int xloop_file_fmt_register_driver(struct xloop_file_fmt_driver *drv); - -/** - * xloop_file_fmt_unregister_driver - Unregister a xloop file format driver - * @drv: File format driver - * - * Unregisters the specified xloop file format driver @drv from the xloop file - * format subsystem. - */ -extern void xloop_file_fmt_unregister_driver(struct xloop_file_fmt_driver *drv); - - -/* subsystem functions for subsystem usage */ - -/** - * xloop_file_fmt_alloc - Allocate a xloop file format - * - * Dynamically allocates a xloop file format and returns a pointer to the - * created xloop file format. - */ -extern struct xloop_file_fmt *xloop_file_fmt_alloc(void); - -/** - * xloop_file_fmt_free - Free an allocated xloop file format - * @xlo_fmt: xloop file format - * - * Frees the already allocated xloop file format @xlo_fmt. - */ -extern void xloop_file_fmt_free(struct xloop_file_fmt *xlo_fmt); - -/** - * xloop_file_fmt_set_xlo - Set the xloop file format's xloop device - * @xlo_fmt: xloop file format - * @xlo: xloop device - * - * The link to the xloop device @xlo is set in the xloop file format @xlo_fmt. - */ -extern int xloop_file_fmt_set_xlo(struct xloop_file_fmt *xlo_fmt, - struct xloop_device *xlo); - -/** - * xloop_file_fmt_get_xlo - Get the xloop file format's xloop device - * @xlo_fmt: xloop file format - * - * Returns a pointer to the xloop device of the xloop file format @xlo_fmt. - */ -extern struct xloop_device *xloop_file_fmt_get_xlo(struct xloop_file_fmt *xlo_fmt); - -/** - * xloop_file_fmt_init - Initialize a xloop file format - * @xlo_fmt: xloop file format - * @file_fmt_type: Type of the file format - * - * Initializes the specified xloop file format @xlo_fmt and sets up the correct - * file format type @file_fmt_type. Depending on @file_fmt_type, the correct - * xloop file format driver is loaded in the subsystems backend. If no xloop file - * format driver for the specified file format is available an error is - * returned. - */ -extern int xloop_file_fmt_init(struct xloop_file_fmt *xlo_fmt, - u32 file_fmt_type); - -/** - * xloop_file_fmt_exit - Release a xloop file format - * @xlo_fmt: xloop file format - * - * Releases the specified xloop file format @xlo_fmt and all its resources. - */ -extern void xloop_file_fmt_exit(struct xloop_file_fmt *xlo_fmt); - -/** - * xloop_file_fmt_read - Read IO from a xloop file format - * @xlo_fmt: xloop file format - * @rq: IO Request - * - * Reads IO from the file format's xloop device by sending the IO read request - * @rq to the xloop file format subsystem. The subsystem calls the registered - * callback function of the suitable xloop file format driver. - */ -extern int xloop_file_fmt_read(struct xloop_file_fmt *xlo_fmt, - struct request *rq); - -/** - * xloop_file_fmt_read_aio - Read IO from a xloop file format asynchronously - * @xlo_fmt: xloop file format - * @rq: IO Request - * - * Reads IO from the file format's xloop device asynchronously by sending the - * IO read aio request @rq to the xloop file format subsystem. The subsystem - * calls the registered callback function of the suitable xloop file format - * driver. - */ -extern int xloop_file_fmt_read_aio(struct xloop_file_fmt *xlo_fmt, - struct request *rq); - -/** - * xloop_file_fmt_write - Write IO to a xloop file format - * @xlo_fmt: xloop file format - * @rq: IO Request - * - * Write IO to the file format's xloop device by sending the IO write request - * @rq to the xloop file format subsystem. The subsystem calls the registered - * callback function of the suitable xloop file format driver. - */ -extern int xloop_file_fmt_write(struct xloop_file_fmt *xlo_fmt, - struct request *rq); - -/** - * xloop_file_fmt_write_aio - Write IO to a xloop file format asynchronously - * @xlo_fmt: xloop file format - * @rq: IO Request - * - * Write IO to the file format's xloop device asynchronously by sending the - * IO write aio request @rq to the xloop file format subsystem. The subsystem - * calls the registered callback function of the suitable xloop file format - * driver. - */ -extern int xloop_file_fmt_write_aio(struct xloop_file_fmt *xlo_fmt, - struct request *rq); - -/** - * xloop_file_fmt_write_zeros - Zero (discard) IO on a xloop file format - * @xlo_fmt: xloop file format - * @rq: IO Request - * - * Zero (discard) IO on the file format's xloop device by sending the IO write - * zeros request @rq to the xloop file format subsystem. The subsystem calls the - * registered callback function of the suitable xloop file format driver. - */ -extern int xloop_file_fmt_write_zeros(struct xloop_file_fmt *xlo_fmt, - struct request *rq); - -/** - * xloop_file_fmt_discard - Discard IO on a xloop file format - * @xlo_fmt: xloop file format - * @rq: IO Request - * - * Discard IO on the file format's xloop device by sending the IO discard - * request @rq to the xloop file format subsystem. The subsystem calls the - * registered callback function of the suitable xloop file format driver. - */ -extern int xloop_file_fmt_discard(struct xloop_file_fmt *xlo_fmt, - struct request *rq); - -/** - * xloop_file_fmt_flush - Flush a xloop file format - * @xlo_fmt: xloop file format - * - * Flush the file format's xloop device by calling the registered callback - * function of the suitable xloop file format driver. - */ -extern int xloop_file_fmt_flush(struct xloop_file_fmt *xlo_fmt); - -/** - * xloop_file_fmt_sector_size - Get sector size of a xloop file format - * @xlo_fmt: xloop file format - * @file: xloop file formats file for sector size calculation - * @offset: Offset within the file for sector size calculation - * @sizelimit: Sizelimit of the file for sector size calculation - * - * Returns the physical sector size of the given xloop file format's file. - * If the xloop file format implements a sparse disk image format, then this - * function returns the virtual sector size. - */ -extern loff_t xloop_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, - struct file *file, loff_t offset, loff_t sizelimit); - -/** - * xloop_file_fmt_change - Change the xloop file format's type - * @xlo_fmt: xloop file format - * @file_fmt_type_new: xloop file format type - * - * Changes the file format type of the already initialized xloop file format - * @xlo_fmt. Therefore, the function releases the old file format and frees all - * of its resources before the xloop file format @xlo_fmt is initialized and set - * up with the new file format @file_fmt_type_new. - */ -extern int xloop_file_fmt_change(struct xloop_file_fmt *xlo_fmt, - u32 file_fmt_type_new); - - -/* helper functions of the subsystem */ - -/** - * xloop_file_fmt_print_type - Convert file format type to string - * @file_fmt_type: xloop file format type - * @file_fmt_name: xloop file format type string - * - * Converts the specified numeric @file_fmt_type value into a human readable - * string stating the file format as string in @file_fmt_name. - */ -extern ssize_t xloop_file_fmt_print_type(u32 file_fmt_type, - char *file_fmt_name); - -#endif diff --git a/kernel/loop_file_fmt_qcow_cache.c b/kernel/loop_file_fmt_qcow_cache.c deleted file mode 100644 index 4ef772a..0000000 --- a/kernel/loop_file_fmt_qcow_cache.c +++ /dev/null @@ -1,218 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * loop_file_fmt_qcow_cache.c - * - * QCOW file format driver for the xloop device module. - * - * Ported QCOW2 implementation of the QEMU project (GPL-2.0): - * L2/refcount table cache for the QCOW2 format. - * - * The copyright (C) 2010 of the original code is owned by - * Kevin Wolf - * - * Copyright (C) 2019 Manuel Bentele - */ - -#include -#include -#include -#include -#include -#include - -#include "loop_file_fmt_qcow_main.h" -#include "loop_file_fmt_qcow_cache.h" - -static inline void *__xloop_file_fmt_qcow_cache_get_table_addr( - struct xloop_file_fmt_qcow_cache *c, int table) -{ - return (u8 *) c->table_array + (size_t) table * c->table_size; -} - -static inline int __xloop_file_fmt_qcow_cache_get_table_idx( - struct xloop_file_fmt_qcow_cache *c, void *table) -{ - ptrdiff_t table_offset = (u8 *) table - (u8 *) c->table_array; - int idx = table_offset / c->table_size; - ASSERT(idx >= 0 && idx < c->size && table_offset % c->table_size == 0); - return idx; -} - -static inline const char *__xloop_file_fmt_qcow_cache_get_name( - struct xloop_file_fmt *xlo_fmt, struct xloop_file_fmt_qcow_cache *c) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - - if (c == qcow_data->refcount_block_cache) { - return "refcount block"; - } else if (c == qcow_data->l2_table_cache) { - return "L2 table"; - } else { - /* do not abort, because this is not critical */ - return "unknown"; - } -} - -struct xloop_file_fmt_qcow_cache *xloop_file_fmt_qcow_cache_create( - struct xloop_file_fmt *xlo_fmt, int num_tables, unsigned table_size) -{ -#ifdef CONFIG_DEBUG_DRIVER - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; -#endif - struct xloop_file_fmt_qcow_cache *c; - - ASSERT(num_tables > 0); - ASSERT(is_power_of_2(table_size)); - ASSERT(table_size >= (1 << QCOW_MIN_CLUSTER_BITS)); - ASSERT(table_size <= qcow_data->cluster_size); - - c = kzalloc(sizeof(*c), GFP_KERNEL); - if (!c) { - return NULL; - } - - c->size = num_tables; - c->table_size = table_size; - c->entries = vzalloc(sizeof(struct xloop_file_fmt_qcow_cache_table) * - num_tables); - c->table_array = vzalloc(num_tables * c->table_size); - - if (!c->entries || !c->table_array) { - vfree(c->table_array); - vfree(c->entries); - kfree(c); - c = NULL; - } - - return c; -} - -void xloop_file_fmt_qcow_cache_destroy(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - struct xloop_file_fmt_qcow_cache *c = qcow_data->l2_table_cache; - int i; - - for (i = 0; i < c->size; i++) { - ASSERT(c->entries[i].ref == 0); - } - - vfree(c->table_array); - vfree(c->entries); - kfree(c); -} - -static int __xloop_file_fmt_qcow_cache_entry_flush( - struct xloop_file_fmt_qcow_cache *c, int i) -{ - if (!c->entries[i].dirty || !c->entries[i].offset) { - return 0; - } else { - printk(KERN_ERR "xloop_file_fmt_qcow: Flush dirty cache tables " - "is not supported yet\n"); - return -ENOSYS; - } -} - -static int __xloop_file_fmt_qcow_cache_do_get(struct xloop_file_fmt *xlo_fmt, - struct xloop_file_fmt_qcow_cache *c, u64 offset, void **table, - bool read_from_disk) -{ - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - int i; - int ret; - int lookup_index; - u64 min_lru_counter = U64_MAX; - int min_lru_index = -1; - u64 read_offset; - size_t len; - - ASSERT(offset != 0); - - if (!IS_ALIGNED(offset, c->table_size)) { - printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: Cannot get " - "entry from %s cache: offset %llx is unaligned\n", - __xloop_file_fmt_qcow_cache_get_name(xlo_fmt, c), - offset); - return -EIO; - } - - /* Check if the table is already cached */ - i = lookup_index = (offset / c->table_size * 4) % c->size; - do { - const struct xloop_file_fmt_qcow_cache_table *t = - &c->entries[i]; - if (t->offset == offset) { - goto found; - } - if (t->ref == 0 && t->lru_counter < min_lru_counter) { - min_lru_counter = t->lru_counter; - min_lru_index = i; - } - if (++i == c->size) { - i = 0; - } - } while (i != lookup_index); - - if (min_lru_index == -1) { - BUG(); - panic("Oops: This can't happen in current synchronous code, " - "but leave the check here as a reminder for whoever " - "starts using AIO with the QCOW cache"); - } - - /* Cache miss: write a table back and replace it */ - i = min_lru_index; - - ret = __xloop_file_fmt_qcow_cache_entry_flush(c, i); - if (ret < 0) { - return ret; - } - - c->entries[i].offset = 0; - if (read_from_disk) { - read_offset = offset; - len = kernel_read(xlo->xlo_backing_file, - __xloop_file_fmt_qcow_cache_get_table_addr(c, i), - c->table_size, &read_offset); - if (len < 0) { - len = ret; - return ret; - } - } - - c->entries[i].offset = offset; - - /* And return the right table */ -found: - c->entries[i].ref++; - *table = __xloop_file_fmt_qcow_cache_get_table_addr(c, i); - - return 0; -} - -int xloop_file_fmt_qcow_cache_get(struct xloop_file_fmt *xlo_fmt, u64 offset, - void **table) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - struct xloop_file_fmt_qcow_cache *c = qcow_data->l2_table_cache; - - return __xloop_file_fmt_qcow_cache_do_get(xlo_fmt, c, offset, table, - true); -} - -void xloop_file_fmt_qcow_cache_put(struct xloop_file_fmt *xlo_fmt, void **table) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - struct xloop_file_fmt_qcow_cache *c = qcow_data->l2_table_cache; - int i = __xloop_file_fmt_qcow_cache_get_table_idx(c, *table); - - c->entries[i].ref--; - *table = NULL; - - if (c->entries[i].ref == 0) { - c->entries[i].lru_counter = ++c->lru_counter; - } - - ASSERT(c->entries[i].ref >= 0); -} diff --git a/kernel/loop_file_fmt_qcow_cache.h b/kernel/loop_file_fmt_qcow_cache.h deleted file mode 100644 index d2f1010..0000000 --- a/kernel/loop_file_fmt_qcow_cache.h +++ /dev/null @@ -1,51 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * xloop_file_fmt_qcow_cache.h - * - * Ported QCOW2 implementation of the QEMU project (GPL-2.0): - * L2/refcount table cache for the QCOW2 format. - * - * The copyright (C) 2010 of the original code is owned by - * Kevin Wolf - * - * Copyright (C) 2019 Manuel Bentele - */ - -#ifndef _LINUX_XLOOP_FILE_FMT_QCOW_CACHE_H -#define _LINUX_XLOOP_FILE_FMT_QCOW_CACHE_H - -#include "loop_file_fmt.h" - -struct xloop_file_fmt_qcow_cache_table { - s64 offset; - u64 lru_counter; - int ref; - bool dirty; -}; - -struct xloop_file_fmt_qcow_cache { - struct xloop_file_fmt_qcow_cache_table *entries; - struct xloop_file_fmt_qcow_cache *depends; - int size; - int table_size; - bool depends_on_flush; - void *table_array; - u64 lru_counter; - u64 cache_clean_lru_counter; -}; - -extern struct xloop_file_fmt_qcow_cache *xloop_file_fmt_qcow_cache_create( - struct xloop_file_fmt *xlo_fmt, - int num_tables, - unsigned table_size); - -extern void xloop_file_fmt_qcow_cache_destroy(struct xloop_file_fmt *xlo_fmt); - -extern int xloop_file_fmt_qcow_cache_get(struct xloop_file_fmt *xlo_fmt, - u64 offset, - void **table); - -extern void xloop_file_fmt_qcow_cache_put(struct xloop_file_fmt *xlo_fmt, - void **table); - -#endif diff --git a/kernel/loop_file_fmt_qcow_cluster.c b/kernel/loop_file_fmt_qcow_cluster.c deleted file mode 100644 index 593a173..0000000 --- a/kernel/loop_file_fmt_qcow_cluster.c +++ /dev/null @@ -1,270 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * xloop_file_fmt_qcow_cluster.c - * - * Ported QCOW2 implementation of the QEMU project (GPL-2.0): - * Cluster calculation and lookup for the QCOW2 format. - * - * The copyright (C) 2004-2006 of the original code is owned by Fabrice Bellard. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#include -#include - -#include "loop_file_fmt.h" -#include "loop_file_fmt_qcow_main.h" -#include "loop_file_fmt_qcow_cache.h" -#include "loop_file_fmt_qcow_cluster.h" - -/* - * Loads a L2 slice into memory (L2 slices are the parts of L2 tables - * that are loaded by the qcow2 cache). If the slice is in the cache, - * the cache is used; otherwise the L2 slice is loaded from the image - * file. - */ -static int __xloop_file_fmt_qcow_cluster_l2_load(struct xloop_file_fmt *xlo_fmt, - u64 offset, u64 l2_offset, u64 **l2_slice) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - - int start_of_slice = sizeof(u64) * ( - xloop_file_fmt_qcow_offset_to_l2_index(qcow_data, offset) - - xloop_file_fmt_qcow_offset_to_l2_slice_index(qcow_data, offset) - ); - - ASSERT(qcow_data->l2_table_cache != NULL); - return xloop_file_fmt_qcow_cache_get(xlo_fmt, l2_offset + start_of_slice, - (void **) l2_slice); -} - -/* - * Checks how many clusters in a given L2 slice are contiguous in the image - * file. As soon as one of the flags in the bitmask stop_flags changes compared - * to the first cluster, the search is stopped and the cluster is not counted - * as contiguous. (This allows it, for example, to stop at the first compressed - * cluster which may require a different handling) - */ -static int __xloop_file_fmt_qcow_cluster_count_contiguous( - struct xloop_file_fmt *xlo_fmt, int nb_clusters, int cluster_size, - u64 *l2_slice, u64 stop_flags) -{ - int i; - enum xloop_file_fmt_qcow_cluster_type first_cluster_type; - u64 mask = stop_flags | L2E_OFFSET_MASK | QCOW_OFLAG_COMPRESSED; - u64 first_entry = be64_to_cpu(l2_slice[0]); - u64 offset = first_entry & mask; - - first_cluster_type = xloop_file_fmt_qcow_get_cluster_type(xlo_fmt, - first_entry); - if (first_cluster_type == QCOW_CLUSTER_UNALLOCATED) { - return 0; - } - - /* must be allocated */ - ASSERT(first_cluster_type == QCOW_CLUSTER_NORMAL || - first_cluster_type == QCOW_CLUSTER_ZERO_ALLOC); - - for (i = 0; i < nb_clusters; i++) { - u64 l2_entry = be64_to_cpu(l2_slice[i]) & mask; - if (offset + (u64) i * cluster_size != l2_entry) { - break; - } - } - - return i; -} - -/* - * Checks how many consecutive unallocated clusters in a given L2 - * slice have the same cluster type. - */ -static int __xloop_file_fmt_qcow_cluster_count_contiguous_unallocated( - struct xloop_file_fmt *xlo_fmt, int nb_clusters, u64 *l2_slice, - enum xloop_file_fmt_qcow_cluster_type wanted_type) -{ - int i; - - ASSERT(wanted_type == QCOW_CLUSTER_ZERO_PLAIN || - wanted_type == QCOW_CLUSTER_UNALLOCATED); - - for (i = 0; i < nb_clusters; i++) { - u64 entry = be64_to_cpu(l2_slice[i]); - enum xloop_file_fmt_qcow_cluster_type type = - xloop_file_fmt_qcow_get_cluster_type(xlo_fmt, entry); - - if (type != wanted_type) { - break; - } - } - - return i; -} - -/* - * For a given offset of the virtual disk, find the cluster type and offset in - * the qcow2 file. The offset is stored in *cluster_offset. - * - * On entry, *bytes is the maximum number of contiguous bytes starting at - * offset that we are interested in. - * - * On exit, *bytes is the number of bytes starting at offset that have the same - * cluster type and (if applicable) are stored contiguously in the image file. - * Compressed clusters are always returned one by one. - * - * Returns the cluster type (QCOW2_CLUSTER_*) on success, -errno in error - * cases. - */ -int xloop_file_fmt_qcow_cluster_get_offset(struct xloop_file_fmt *xlo_fmt, - u64 offset, unsigned int *bytes, u64 *cluster_offset) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - unsigned int l2_index; - u64 l1_index, l2_offset, *l2_slice; - int c; - unsigned int offset_in_cluster; - u64 bytes_available, bytes_needed, nb_clusters; - enum xloop_file_fmt_qcow_cluster_type type; - int ret; - - offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster(qcow_data, - offset); - bytes_needed = (u64) *bytes + offset_in_cluster; - - /* compute how many bytes there are between the start of the cluster - * containing offset and the end of the l2 slice that contains - * the entry pointing to it */ - bytes_available = ((u64)( - qcow_data->l2_slice_size - - xloop_file_fmt_qcow_offset_to_l2_slice_index(qcow_data, offset)) - ) << qcow_data->cluster_bits; - - if (bytes_needed > bytes_available) { - bytes_needed = bytes_available; - } - - *cluster_offset = 0; - - /* seek to the l2 offset in the l1 table */ - l1_index = xloop_file_fmt_qcow_offset_to_l1_index(qcow_data, offset); - if (l1_index >= qcow_data->l1_size) { - type = QCOW_CLUSTER_UNALLOCATED; - goto out; - } - - l2_offset = qcow_data->l1_table[l1_index] & L1E_OFFSET_MASK; - if (!l2_offset) { - type = QCOW_CLUSTER_UNALLOCATED; - goto out; - } - - if (xloop_file_fmt_qcow_offset_into_cluster(qcow_data, l2_offset)) { - printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: L2 table " - "offset %llx unaligned (L1 index: %llx)", l2_offset, - l1_index); - return -EIO; - } - - /* load the l2 slice in memory */ - ret = __xloop_file_fmt_qcow_cluster_l2_load(xlo_fmt, offset, l2_offset, - &l2_slice); - if (ret < 0) { - return ret; - } - - /* find the cluster offset for the given disk offset */ - l2_index = xloop_file_fmt_qcow_offset_to_l2_slice_index(qcow_data, - offset); - *cluster_offset = be64_to_cpu(l2_slice[l2_index]); - - nb_clusters = xloop_file_fmt_qcow_size_to_clusters(qcow_data, - bytes_needed); - /* bytes_needed <= *bytes + offset_in_cluster, both of which are - * unsigned integers; the minimum cluster size is 512, so this - * assertion is always true */ - ASSERT(nb_clusters <= INT_MAX); - - type = xloop_file_fmt_qcow_get_cluster_type(xlo_fmt, *cluster_offset); - if (qcow_data->qcow_version < 3 && ( - type == QCOW_CLUSTER_ZERO_PLAIN || - type == QCOW_CLUSTER_ZERO_ALLOC)) { - printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: zero cluster " - "entry found in pre-v3 image (L2 offset: %llx, " - "L2 index: %x)\n", l2_offset, l2_index); - ret = -EIO; - goto fail; - } - switch (type) { - case QCOW_CLUSTER_COMPRESSED: - if (xloop_file_fmt_qcow_has_data_file(xlo_fmt)) { - printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: " - "compressed cluster entry found in image with " - "external data file (L2 offset: %llx, " - "L2 index: %x)", l2_offset, l2_index); - ret = -EIO; - goto fail; - } - /* Compressed clusters can only be processed one by one */ - c = 1; - *cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK; - break; - case QCOW_CLUSTER_ZERO_PLAIN: - case QCOW_CLUSTER_UNALLOCATED: - /* how many empty clusters ? */ - c = __xloop_file_fmt_qcow_cluster_count_contiguous_unallocated( - xlo_fmt, nb_clusters, &l2_slice[l2_index], type); - *cluster_offset = 0; - break; - case QCOW_CLUSTER_ZERO_ALLOC: - case QCOW_CLUSTER_NORMAL: - /* how many allocated clusters ? */ - c = __xloop_file_fmt_qcow_cluster_count_contiguous(xlo_fmt, - nb_clusters, qcow_data->cluster_size, - &l2_slice[l2_index], QCOW_OFLAG_ZERO); - *cluster_offset &= L2E_OFFSET_MASK; - if (xloop_file_fmt_qcow_offset_into_cluster(qcow_data, - *cluster_offset)) { - printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: " - "cluster allocation offset %llx unaligned " - "(L2 offset: %llx, L2 index: %x)\n", - *cluster_offset, l2_offset, l2_index); - ret = -EIO; - goto fail; - } - if (xloop_file_fmt_qcow_has_data_file(xlo_fmt) && - *cluster_offset != offset - offset_in_cluster) { - printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: " - "external data file host cluster offset %llx " - "does not match guest cluster offset: %llx, " - "L2 index: %x)", *cluster_offset, - offset - offset_in_cluster, l2_index); - ret = -EIO; - goto fail; - } - break; - default: - BUG(); - } - - xloop_file_fmt_qcow_cache_put(xlo_fmt, (void **) &l2_slice); - - bytes_available = (s64) c * qcow_data->cluster_size; - -out: - if (bytes_available > bytes_needed) { - bytes_available = bytes_needed; - } - - /* bytes_available <= bytes_needed <= *bytes + offset_in_cluster; - * subtracting offset_in_cluster will therefore definitely yield - * something not exceeding UINT_MAX */ - ASSERT(bytes_available - offset_in_cluster <= UINT_MAX); - *bytes = bytes_available - offset_in_cluster; - - return type; - -fail: - xloop_file_fmt_qcow_cache_put(xlo_fmt, (void **) &l2_slice); - return ret; -} diff --git a/kernel/loop_file_fmt_qcow_cluster.h b/kernel/loop_file_fmt_qcow_cluster.h deleted file mode 100644 index 5078f29..0000000 --- a/kernel/loop_file_fmt_qcow_cluster.h +++ /dev/null @@ -1,23 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * xloop_file_fmt_qcow_cluster.h - * - * Ported QCOW2 implementation of the QEMU project (GPL-2.0): - * Cluster calculation and lookup for the QCOW2 format. - * - * The copyright (C) 2004-2006 of the original code is owned by Fabrice Bellard. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#ifndef _LINUX_XLOOP_FILE_FMT_QCOW_CLUSTER_H -#define _LINUX_XLOOP_FILE_FMT_QCOW_CLUSTER_H - -#include "loop_file_fmt.h" - -extern int xloop_file_fmt_qcow_cluster_get_offset(struct xloop_file_fmt *xlo_fmt, - u64 offset, - unsigned int *bytes, - u64 *cluster_offset); - -#endif diff --git a/kernel/loop_file_fmt_qcow_main.c b/kernel/loop_file_fmt_qcow_main.c deleted file mode 100644 index 7c3e360..0000000 --- a/kernel/loop_file_fmt_qcow_main.c +++ /dev/null @@ -1,953 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * xloop_file_fmt_qcow.c - * - * QCOW file format driver for the xloop device module. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "loop_file_fmt.h" -#include "loop_file_fmt_qcow_main.h" -#include "loop_file_fmt_qcow_cache.h" -#include "loop_file_fmt_qcow_cluster.h" - -static int __qcow_file_fmt_header_read(struct file *file, - struct xloop_file_fmt_qcow_header *header) -{ - ssize_t len; - loff_t offset; - int ret = 0; - - /* read QCOW header */ - offset = 0; - len = kernel_read(file, header, sizeof(*header), &offset); - if (len < 0) { - printk(KERN_ERR "xloop_file_fmt_qcow: could not read QCOW " - "header"); - return len; - } - - header->magic = be32_to_cpu(header->magic); - header->version = be32_to_cpu(header->version); - header->backing_file_offset = be64_to_cpu(header->backing_file_offset); - header->backing_file_size = be32_to_cpu(header->backing_file_size); - header->cluster_bits = be32_to_cpu(header->cluster_bits); - header->size = be64_to_cpu(header->size); - header->crypt_method = be32_to_cpu(header->crypt_method); - header->l1_size = be32_to_cpu(header->l1_size); - header->l1_table_offset = be64_to_cpu(header->l1_table_offset); - header->refcount_table_offset = - be64_to_cpu(header->refcount_table_offset); - header->refcount_table_clusters = - be32_to_cpu(header->refcount_table_clusters); - header->nb_snapshots = be32_to_cpu(header->nb_snapshots); - header->snapshots_offset = be64_to_cpu(header->snapshots_offset); - - /* check QCOW file format and header version */ - if (header->magic != QCOW_MAGIC) { - printk(KERN_ERR "xloop_file_fmt_qcow: image is not in QCOW " - "format"); - return -EINVAL; - } - - if (header->version < 2 || header->version > 3) { - printk(KERN_ERR "xloop_file_fmt_qcow: unsupported QCOW version " - "%d", header->version); - return -ENOTSUPP; - } - - /* initialize version 3 header fields */ - if (header->version == 2) { - header->incompatible_features = 0; - header->compatible_features = 0; - header->autoclear_features = 0; - header->refcount_order = 4; - header->header_length = 72; - } else { - header->incompatible_features = - be64_to_cpu(header->incompatible_features); - header->compatible_features = - be64_to_cpu(header->compatible_features); - header->autoclear_features = - be64_to_cpu(header->autoclear_features); - header->refcount_order = be32_to_cpu(header->refcount_order); - header->header_length = be32_to_cpu(header->header_length); - - if (header->header_length < 104) { - printk(KERN_ERR "xloop_file_fmt_qcow: QCOW header too " - "short"); - return -EINVAL; - } - } - - return ret; -} - -static int __qcow_file_fmt_validate_table(struct xloop_file_fmt *xlo_fmt, - u64 offset, u64 entries, size_t entry_len, s64 max_size_bytes, - const char *table_name) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - - if (entries > max_size_bytes / entry_len) { - printk(KERN_INFO "xloop_file_fmt_qcow: %s too large", - table_name); - return -EFBIG; - } - - /* Use signed S64_MAX as the maximum even for u64 header fields, - * because values will be passed to qemu functions taking s64. */ - if ((S64_MAX - entries * entry_len < offset) || ( - xloop_file_fmt_qcow_offset_into_cluster(qcow_data, offset) != 0) - ) { - printk(KERN_INFO "xloop_file_fmt_qcow: %s offset invalid", - table_name); - return -EINVAL; - } - - return 0; -} - -static inline loff_t __qcow_file_fmt_rq_get_pos(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - return ((loff_t) blk_rq_pos(rq) << 9) + xlo->xlo_offset; -} - -static int __qcow_file_fmt_compression_init(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - int ret = 0; - - qcow_data->strm = kzalloc(sizeof(*qcow_data->strm), GFP_KERNEL); - if (!qcow_data->strm) { - ret = -ENOMEM; - goto out; - } - - qcow_data->strm->workspace = vzalloc(zlib_inflate_workspacesize()); - if (!qcow_data->strm->workspace) { - ret = -ENOMEM; - goto out_free_strm; - } - - qcow_data->cmp_last_coffset = ULLONG_MAX; - qcow_data->cmp_out_buf = vmalloc(qcow_data->cluster_size); - if (!qcow_data->cmp_out_buf) { - ret = -ENOMEM; - goto out_free_workspace; - } - - return ret; - -out_free_workspace: - vfree(qcow_data->strm->workspace); -out_free_strm: - kfree(qcow_data->strm); -out: - return ret; -} - -static void __qcow_file_fmt_compression_exit(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - - vfree(qcow_data->strm->workspace); - kfree(qcow_data->strm); - vfree(qcow_data->cmp_out_buf); -} - -#ifdef CONFIG_DEBUG_FS -static void __qcow_file_fmt_header_to_buf(struct xloop_file_fmt *xlo_fmt, - const struct xloop_file_fmt_qcow_header *header) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - char *header_buf = qcow_data->dbgfs_file_qcow_header_buf; - ssize_t len = 0; - - len += sprintf(header_buf + len, "magic: %d\n", - header->magic); - len += sprintf(header_buf + len, "version: %d\n", - header->version); - len += sprintf(header_buf + len, "backing_file_offset: %lld\n", - header->backing_file_offset); - len += sprintf(header_buf + len, "backing_file_size: %d\n", - header->backing_file_size); - len += sprintf(header_buf + len, "cluster_bits: %d\n", - header->cluster_bits); - len += sprintf(header_buf + len, "size: %lld\n", - header->size); - len += sprintf(header_buf + len, "crypt_method: %d\n", - header->crypt_method); - len += sprintf(header_buf + len, "l1_size: %d\n", - header->l1_size); - len += sprintf(header_buf + len, "l1_table_offset: %lld\n", - header->l1_table_offset); - len += sprintf(header_buf + len, "refcount_table_offset: %lld\n", - header->refcount_table_offset); - len += sprintf(header_buf + len, "refcount_table_clusters: %d\n", - header->refcount_table_clusters); - len += sprintf(header_buf + len, "nb_snapshots: %d\n", - header->nb_snapshots); - len += sprintf(header_buf + len, "snapshots_offset: %lld\n", - header->snapshots_offset); - - if (header->version == 3) { - len += sprintf(header_buf + len, - "incompatible_features: %lld\n", - header->incompatible_features); - len += sprintf(header_buf + len, - "compatible_features: %lld\n", - header->compatible_features); - len += sprintf(header_buf + len, - "autoclear_features: %lld\n", - header->autoclear_features); - len += sprintf(header_buf + len, - "refcount_order: %d\n", - header->refcount_order); - len += sprintf(header_buf + len, - "header_length: %d\n", - header->header_length); - } - - ASSERT(len < QCOW_HEADER_BUF_LEN); -} - -static ssize_t __qcow_file_fmt_dbgfs_hdr_read(struct file *file, - char __user *buf, size_t size, loff_t *ppos) -{ - struct xloop_file_fmt *xlo_fmt = file->private_data; - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - char *header_buf = qcow_data->dbgfs_file_qcow_header_buf; - - return simple_read_from_buffer(buf, size, ppos, header_buf, - strlen(header_buf)); -} - -static const struct file_operations qcow_file_fmt_dbgfs_hdr_fops = { - .open = simple_open, - .read = __qcow_file_fmt_dbgfs_hdr_read -}; - -static ssize_t __qcow_file_fmt_dbgfs_ofs_read(struct file *file, - char __user *buf, size_t size, loff_t *ppos) -{ - struct xloop_file_fmt *xlo_fmt = file->private_data; - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - unsigned int cur_bytes = 1; - u64 offset = 0; - u64 cluster_offset = 0; - s64 offset_in_cluster = 0; - ssize_t len = 0; - int ret = 0; - - /* read the share debugfs offset */ - ret = mutex_lock_interruptible(&qcow_data->dbgfs_qcow_offset_mutex); - if (ret) - return ret; - - offset = qcow_data->dbgfs_qcow_offset; - mutex_unlock(&qcow_data->dbgfs_qcow_offset_mutex); - - /* calculate and print the cluster offset */ - ret = xloop_file_fmt_qcow_cluster_get_offset(xlo_fmt, - offset, &cur_bytes, &cluster_offset); - if (ret < 0) - return -EINVAL; - - offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster(qcow_data, - offset); - - len = sprintf(qcow_data->dbgfs_file_qcow_cluster_buf, - "offset: %lld\ncluster_offset: %lld\noffset_in_cluster: %lld\n", - offset, cluster_offset, offset_in_cluster); - - ASSERT(len < QCOW_CLUSTER_BUF_LEN); - - return simple_read_from_buffer(buf, size, ppos, - qcow_data->dbgfs_file_qcow_cluster_buf, len); -} - -static ssize_t __qcow_file_fmt_dbgfs_ofs_write(struct file *file, - const char __user *buf, size_t size, loff_t *ppos) -{ - struct xloop_file_fmt *xlo_fmt = file->private_data; - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - ssize_t len = 0; - int ret = 0; - - if (*ppos > QCOW_OFFSET_BUF_LEN || size > QCOW_OFFSET_BUF_LEN) - return -EINVAL; - - len = simple_write_to_buffer(qcow_data->dbgfs_file_qcow_offset_buf, - QCOW_OFFSET_BUF_LEN, ppos, buf, size); - if (len < 0) - return len; - - qcow_data->dbgfs_file_qcow_offset_buf[len] = '\0'; - - ret = mutex_lock_interruptible(&qcow_data->dbgfs_qcow_offset_mutex); - if (ret) - return ret; - - ret = kstrtou64(qcow_data->dbgfs_file_qcow_offset_buf, 10, - &qcow_data->dbgfs_qcow_offset); - if (ret < 0) - goto out; - - ret = len; -out: - mutex_unlock(&qcow_data->dbgfs_qcow_offset_mutex); - return ret; -} - -static const struct file_operations qcow_file_fmt_dbgfs_ofs_fops = { - .open = simple_open, - .read = __qcow_file_fmt_dbgfs_ofs_read, - .write = __qcow_file_fmt_dbgfs_ofs_write -}; - -static int __qcow_file_fmt_dbgfs_init(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - int ret = 0; - - qcow_data->dbgfs_dir = debugfs_create_dir("QCOW", xlo->xlo_dbgfs_dir); - if (IS_ERR_OR_NULL(qcow_data->dbgfs_dir)) { - ret = -ENODEV; - goto out; - } - - qcow_data->dbgfs_file_qcow_header = debugfs_create_file("header", - S_IRUGO, qcow_data->dbgfs_dir, xlo_fmt, - &qcow_file_fmt_dbgfs_hdr_fops); - if (IS_ERR_OR_NULL(qcow_data->dbgfs_file_qcow_header)) { - ret = -ENODEV; - goto out_free_dbgfs_dir; - } - - qcow_data->dbgfs_file_qcow_offset = debugfs_create_file("offset", - S_IRUGO | S_IWUSR, qcow_data->dbgfs_dir, xlo_fmt, - &qcow_file_fmt_dbgfs_ofs_fops); - if (IS_ERR_OR_NULL(qcow_data->dbgfs_file_qcow_offset)) { - qcow_data->dbgfs_file_qcow_offset = NULL; - ret = -ENODEV; - goto out_free_dbgfs_hdr; - } - - qcow_data->dbgfs_qcow_offset = 0; - mutex_init(&qcow_data->dbgfs_qcow_offset_mutex); - - return ret; - -out_free_dbgfs_hdr: - debugfs_remove(qcow_data->dbgfs_file_qcow_header); - qcow_data->dbgfs_file_qcow_header = NULL; -out_free_dbgfs_dir: - debugfs_remove(qcow_data->dbgfs_dir); - qcow_data->dbgfs_dir = NULL; -out: - return ret; -} - -static void __qcow_file_fmt_dbgfs_exit(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - - if (qcow_data->dbgfs_file_qcow_offset) - debugfs_remove(qcow_data->dbgfs_file_qcow_offset); - - mutex_destroy(&qcow_data->dbgfs_qcow_offset_mutex); - - if (qcow_data->dbgfs_file_qcow_header) - debugfs_remove(qcow_data->dbgfs_file_qcow_header); - - if (qcow_data->dbgfs_dir) - debugfs_remove(qcow_data->dbgfs_dir); -} -#endif - -static int qcow_file_fmt_init(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data; - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - struct xloop_file_fmt_qcow_header header; - u64 l1_vm_state_index; - u64 l2_cache_size; - u64 l2_cache_entry_size; - ssize_t len; - unsigned int i; - int ret = 0; - - /* allocate memory for saving QCOW file format data */ - qcow_data = kzalloc(sizeof(*qcow_data), GFP_KERNEL); - if (!qcow_data) - return -ENOMEM; - - xlo_fmt->private_data = qcow_data; - - /* read the QCOW file header */ - ret = __qcow_file_fmt_header_read(xlo->xlo_backing_file, &header); - if (ret) - goto free_qcow_data; - - /* save information of the header fields in human readable format in - * a file buffer to access it with debugfs */ -#ifdef CONFIG_DEBUG_FS - __qcow_file_fmt_header_to_buf(xlo_fmt, &header); -#endif - - qcow_data->qcow_version = header.version; - - /* Initialise cluster size */ - if (header.cluster_bits < QCOW_MIN_CLUSTER_BITS - || header.cluster_bits > QCOW_MAX_CLUSTER_BITS) { - printk(KERN_ERR "xloop_file_fmt_qcow: unsupported cluster " - "size: 2^%d", header.cluster_bits); - ret = -EINVAL; - goto free_qcow_data; - } - - qcow_data->cluster_bits = header.cluster_bits; - qcow_data->cluster_size = 1 << qcow_data->cluster_bits; - qcow_data->cluster_sectors = 1 << - (qcow_data->cluster_bits - SECTOR_SHIFT); - - if (header.header_length > qcow_data->cluster_size) { - printk(KERN_ERR "xloop_file_fmt_qcow: QCOW header exceeds " - "cluster size"); - ret = -EINVAL; - goto free_qcow_data; - } - - if (header.backing_file_offset > qcow_data->cluster_size) { - printk(KERN_ERR "xloop_file_fmt_qcow: invalid backing file " - "offset"); - ret = -EINVAL; - goto free_qcow_data; - } - - if (header.backing_file_offset) { - printk(KERN_ERR "xloop_file_fmt_qcow: backing file support not " - "available"); - ret = -ENOTSUPP; - goto free_qcow_data; - } - - /* handle feature bits */ - qcow_data->incompatible_features = header.incompatible_features; - qcow_data->compatible_features = header.compatible_features; - qcow_data->autoclear_features = header.autoclear_features; - - if (qcow_data->incompatible_features & QCOW_INCOMPAT_DIRTY) { - printk(KERN_ERR "xloop_file_fmt_qcow: image contains " - "inconsistent refcounts"); - ret = -EACCES; - goto free_qcow_data; - } - - if (qcow_data->incompatible_features & QCOW_INCOMPAT_CORRUPT) { - printk(KERN_ERR "xloop_file_fmt_qcow: image is corrupt; cannot " - "be opened read/write"); - ret = -EACCES; - goto free_qcow_data; - } - - if (qcow_data->incompatible_features & QCOW_INCOMPAT_DATA_FILE) { - printk(KERN_ERR "xloop_file_fmt_qcow: clusters in the external " - "data file are not refcounted"); - ret = -EACCES; - goto free_qcow_data; - } - - /* Check support for various header values */ - if (header.refcount_order > 6) { - printk(KERN_ERR "xloop_file_fmt_qcow: reference count entry " - "width too large; may not exceed 64 bits"); - ret = -EINVAL; - goto free_qcow_data; - } - qcow_data->refcount_order = header.refcount_order; - qcow_data->refcount_bits = 1 << qcow_data->refcount_order; - qcow_data->refcount_max = U64_C(1) << (qcow_data->refcount_bits - 1); - qcow_data->refcount_max += qcow_data->refcount_max - 1; - - qcow_data->crypt_method_header = header.crypt_method; - if (qcow_data->crypt_method_header) { - printk(KERN_ERR "xloop_file_fmt_qcow: encryption support not " - "available"); - ret = -ENOTSUPP; - goto free_qcow_data; - } - - /* L2 is always one cluster */ - qcow_data->l2_bits = qcow_data->cluster_bits - 3; - qcow_data->l2_size = 1 << qcow_data->l2_bits; - /* 2^(qcow_data->refcount_order - 3) is the refcount width in bytes */ - qcow_data->refcount_block_bits = qcow_data->cluster_bits - - (qcow_data->refcount_order - 3); - qcow_data->refcount_block_size = 1 << qcow_data->refcount_block_bits; - qcow_data->size = header.size; - qcow_data->csize_shift = (62 - (qcow_data->cluster_bits - 8)); - qcow_data->csize_mask = (1 << (qcow_data->cluster_bits - 8)) - 1; - qcow_data->cluster_offset_mask = (1LL << qcow_data->csize_shift) - 1; - - qcow_data->refcount_table_offset = header.refcount_table_offset; - qcow_data->refcount_table_size = header.refcount_table_clusters << - (qcow_data->cluster_bits - 3); - - if (header.refcount_table_clusters == 0) { - printk(KERN_ERR "xloop_file_fmt_qcow: image does not contain a " - "reference count table"); - ret = -EINVAL; - goto free_qcow_data; - } - - ret = __qcow_file_fmt_validate_table(xlo_fmt, - qcow_data->refcount_table_offset, - header.refcount_table_clusters, qcow_data->cluster_size, - QCOW_MAX_REFTABLE_SIZE, "Reference count table"); - if (ret < 0) { - goto free_qcow_data; - } - - /* The total size in bytes of the snapshot table is checked in - * qcow2_read_snapshots() because the size of each snapshot is - * variable and we don't know it yet. - * Here we only check the offset and number of snapshots. */ - ret = __qcow_file_fmt_validate_table(xlo_fmt, header.snapshots_offset, - header.nb_snapshots, - sizeof(struct xloop_file_fmt_qcow_snapshot_header), - sizeof(struct xloop_file_fmt_qcow_snapshot_header) * - QCOW_MAX_SNAPSHOTS, "Snapshot table"); - if (ret < 0) { - goto free_qcow_data; - } - - /* read the level 1 table */ - ret = __qcow_file_fmt_validate_table(xlo_fmt, header.l1_table_offset, - header.l1_size, sizeof(u64), QCOW_MAX_L1_SIZE, - "Active L1 table"); - if (ret < 0) { - goto free_qcow_data; - } - qcow_data->l1_size = header.l1_size; - qcow_data->l1_table_offset = header.l1_table_offset; - - l1_vm_state_index = xloop_file_fmt_qcow_size_to_l1(qcow_data, - header.size); - if (l1_vm_state_index > INT_MAX) { - printk(KERN_ERR "xloop_file_fmt_qcow: image is too big"); - ret = -EFBIG; - goto free_qcow_data; - } - qcow_data->l1_vm_state_index = l1_vm_state_index; - - /* the L1 table must contain at least enough entries to put header.size - * bytes */ - if (qcow_data->l1_size < qcow_data->l1_vm_state_index) { - printk(KERN_ERR "xloop_file_fmt_qcow: L1 table is too small"); - ret = -EINVAL; - goto free_qcow_data; - } - - if (qcow_data->l1_size > 0) { - qcow_data->l1_table = vzalloc(round_up(qcow_data->l1_size * - sizeof(u64), 512)); - if (qcow_data->l1_table == NULL) { - printk(KERN_ERR "xloop_file_fmt_qcow: could not " - "allocate L1 table"); - ret = -ENOMEM; - goto free_qcow_data; - } - len = kernel_read(xlo->xlo_backing_file, qcow_data->l1_table, - qcow_data->l1_size * sizeof(u64), - &qcow_data->l1_table_offset); - if (len < 0) { - printk(KERN_ERR "xloop_file_fmt_qcow: could not read L1 " - "table"); - ret = len; - goto free_l1_table; - } - for (i = 0; i < qcow_data->l1_size; i++) { - qcow_data->l1_table[i] = - be64_to_cpu(qcow_data->l1_table[i]); - } - } - - /* Internal snapshots */ - qcow_data->snapshots_offset = header.snapshots_offset; - qcow_data->nb_snapshots = header.nb_snapshots; - - if (qcow_data->nb_snapshots > 0) { - printk(KERN_ERR "xloop_file_fmt_qcow: snapshots support not " - "available"); - ret = -ENOTSUPP; - goto free_l1_table; - } - - - /* create cache for L2 */ - l2_cache_size = qcow_data->size / (qcow_data->cluster_size / 8); - l2_cache_entry_size = min(qcow_data->cluster_size, (int)4096); - - /* limit the L2 size to maximum QCOW_DEFAULT_L2_CACHE_MAX_SIZE */ - l2_cache_size = min(l2_cache_size, (u64)QCOW_DEFAULT_L2_CACHE_MAX_SIZE); - - /* calculate the number of cache tables */ - l2_cache_size /= l2_cache_entry_size; - if (l2_cache_size < QCOW_MIN_L2_CACHE_SIZE) { - l2_cache_size = QCOW_MIN_L2_CACHE_SIZE; - } - - if (l2_cache_size > INT_MAX) { - printk(KERN_ERR "xloop_file_fmt_qcow: L2 cache size too big"); - ret = -EINVAL; - goto free_l1_table; - } - - qcow_data->l2_slice_size = l2_cache_entry_size / sizeof(u64); - - qcow_data->l2_table_cache = xloop_file_fmt_qcow_cache_create(xlo_fmt, - l2_cache_size, l2_cache_entry_size); - if (!qcow_data->l2_table_cache) { - ret = -ENOMEM; - goto free_l1_table; - } - - /* initialize compression support */ - ret = __qcow_file_fmt_compression_init(xlo_fmt); - if (ret < 0) - goto free_l2_cache; - - /* initialize debugfs entries */ -#ifdef CONFIG_DEBUG_FS - ret = __qcow_file_fmt_dbgfs_init(xlo_fmt); - if (ret < 0) - goto free_l2_cache; -#endif - - return ret; - -free_l2_cache: - xloop_file_fmt_qcow_cache_destroy(xlo_fmt); -free_l1_table: - vfree(qcow_data->l1_table); -free_qcow_data: - kfree(qcow_data); - xlo_fmt->private_data = NULL; - return ret; -} - -static void qcow_file_fmt_exit(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - -#ifdef CONFIG_DEBUG_FS - __qcow_file_fmt_dbgfs_exit(xlo_fmt); -#endif - - __qcow_file_fmt_compression_exit(xlo_fmt); - - if (qcow_data->l1_table) { - vfree(qcow_data->l1_table); - } - - if (qcow_data->l2_table_cache) { - xloop_file_fmt_qcow_cache_destroy(xlo_fmt); - } - - if (qcow_data) { - kfree(qcow_data); - xlo_fmt->private_data = NULL; - } -} - -static ssize_t __qcow_file_fmt_buffer_decompress(struct xloop_file_fmt *xlo_fmt, - void *dest, - size_t dest_size, - const void *src, - size_t src_size) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - int ret = 0; - - qcow_data->strm->avail_in = src_size; - qcow_data->strm->next_in = (void *) src; - qcow_data->strm->avail_out = dest_size; - qcow_data->strm->next_out = dest; - - ret = zlib_inflateInit2(qcow_data->strm, -12); - if (ret != Z_OK) { - return -1; - } - - ret = zlib_inflate(qcow_data->strm, Z_FINISH); - if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) - || qcow_data->strm->avail_out != 0) { - /* We approve Z_BUF_ERROR because we need @dest buffer to be - * filled, but @src buffer may be processed partly (because in - * qcow2 we know size of compressed data with precision of one - * sector) */ - ret = -1; - } else { - ret = 0; - } - return ret; -} - -static int __qcow_file_fmt_read_compressed(struct xloop_file_fmt *xlo_fmt, - struct bio_vec *bvec, - u64 file_cluster_offset, - u64 offset, - u64 bytes, - u64 bytes_done) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - int ret = 0, csize, nb_csectors; - u64 coffset; - u8 *in_buf = NULL; - ssize_t len; - void *data; - unsigned long irq_flags; - int offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster( - qcow_data, offset); - - coffset = file_cluster_offset & qcow_data->cluster_offset_mask; - nb_csectors = ((file_cluster_offset >> qcow_data->csize_shift) & - qcow_data->csize_mask) + 1; - csize = nb_csectors * QCOW_COMPRESSED_SECTOR_SIZE - - (coffset & ~QCOW_COMPRESSED_SECTOR_MASK); - - - if (qcow_data->cmp_last_coffset != coffset) { - in_buf = vmalloc(csize); - if (!in_buf) { - qcow_data->cmp_last_coffset = ULLONG_MAX; - return -ENOMEM; - } - qcow_data->cmp_last_coffset = coffset; - len = kernel_read(xlo->xlo_backing_file, in_buf, csize, &coffset); - if (len < 0) { - qcow_data->cmp_last_coffset = ULLONG_MAX; - ret = len; - goto out_free_in_buf; - } - - if (__qcow_file_fmt_buffer_decompress(xlo_fmt, qcow_data->cmp_out_buf, - qcow_data->cluster_size, in_buf, csize) < 0) { - qcow_data->cmp_last_coffset = ULLONG_MAX; - ret = -EIO; - goto out_free_in_buf; - } - } - - ASSERT(bytes <= bvec->bv_len); - data = bvec_kmap_irq(bvec, &irq_flags) + bytes_done; - memcpy(data, qcow_data->cmp_out_buf + offset_in_cluster, bytes); - flush_dcache_page(bvec->bv_page); - bvec_kunmap_irq(data, &irq_flags); - -out_free_in_buf: - vfree(in_buf); - - return ret; -} - -static int __qcow_file_fmt_read_bvec(struct xloop_file_fmt *xlo_fmt, - struct bio_vec *bvec, - loff_t *ppos) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - int offset_in_cluster; - int ret; - unsigned int cur_bytes; /* number of bytes in current iteration */ - u64 bytes; - u64 cluster_offset = 0; - u64 bytes_done = 0; - void *data; - unsigned long irq_flags; - ssize_t len; - loff_t pos_read; - - bytes = bvec->bv_len; - - while (bytes != 0) { - - /* prepare next request */ - cur_bytes = bytes; - - ret = xloop_file_fmt_qcow_cluster_get_offset(xlo_fmt, *ppos, - &cur_bytes, &cluster_offset); - if (ret < 0) { - goto fail; - } - - offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster( - qcow_data, *ppos); - - switch (ret) { - case QCOW_CLUSTER_UNALLOCATED: - case QCOW_CLUSTER_ZERO_PLAIN: - case QCOW_CLUSTER_ZERO_ALLOC: - data = bvec_kmap_irq(bvec, &irq_flags) + bytes_done; - memset(data, 0, cur_bytes); - flush_dcache_page(bvec->bv_page); - bvec_kunmap_irq(data, &irq_flags); - break; - - case QCOW_CLUSTER_COMPRESSED: - ret = __qcow_file_fmt_read_compressed(xlo_fmt, bvec, - cluster_offset, *ppos, cur_bytes, bytes_done); - if (ret < 0) { - goto fail; - } - - break; - - case QCOW_CLUSTER_NORMAL: - if ((cluster_offset & 511) != 0) { - ret = -EIO; - goto fail; - } - - pos_read = cluster_offset + offset_in_cluster; - - data = bvec_kmap_irq(bvec, &irq_flags) + bytes_done; - len = kernel_read(xlo->xlo_backing_file, data, cur_bytes, - &pos_read); - flush_dcache_page(bvec->bv_page); - bvec_kunmap_irq(data, &irq_flags); - - if (len < 0) - return len; - - break; - - default: - ret = -EIO; - goto fail; - } - - bytes -= cur_bytes; - *ppos += cur_bytes; - bytes_done += cur_bytes; - } - - ret = 0; - -fail: - return ret; -} - -static int qcow_file_fmt_read(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct bio_vec bvec; - struct req_iterator iter; - loff_t pos; - int ret = 0; - - pos = __qcow_file_fmt_rq_get_pos(xlo_fmt, rq); - - rq_for_each_segment(bvec, rq, iter) { - ret = __qcow_file_fmt_read_bvec(xlo_fmt, &bvec, &pos); - if (ret) - return ret; - - cond_resched(); - } - - return ret; -} - -static loff_t qcow_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, - struct file *file, loff_t offset, loff_t sizelimit) -{ - struct xloop_file_fmt_qcow_header header; - loff_t xloopsize; - int ret; - - /* temporary read the QCOW file header of other QCOW image file */ - ret = __qcow_file_fmt_header_read(file, &header); - if (ret) - return 0; - - /* compute xloopsize in bytes */ - xloopsize = header.size; - if (offset > 0) - xloopsize -= offset; - /* offset is beyond i_size, weird but possible */ - if (xloopsize < 0) - return 0; - - if (sizelimit > 0 && sizelimit < xloopsize) - xloopsize = sizelimit; - /* - * Unfortunately, if we want to do I/O on the device, - * the number of 512-byte sectors has to fit into a sector_t. - */ - return xloopsize >> 9; -} - -static struct xloop_file_fmt_ops qcow_file_fmt_ops = { - .init = qcow_file_fmt_init, - .exit = qcow_file_fmt_exit, - .read = qcow_file_fmt_read, - .write = NULL, - .read_aio = NULL, - .write_aio = NULL, - .write_zeros = NULL, - .discard = NULL, - .flush = NULL, - .sector_size = qcow_file_fmt_sector_size, -}; - -static struct xloop_file_fmt_driver qcow_file_fmt_driver = { - .name = "QCOW", - .file_fmt_type = XLO_FILE_FMT_QCOW, - .ops = &qcow_file_fmt_ops, - .owner = THIS_MODULE, -}; - -static int __init xloop_file_fmt_qcow_init(void) -{ - printk(KERN_INFO "xloop_file_fmt_qcow: init xloop device QCOW file " - "format driver"); - return xloop_file_fmt_register_driver(&qcow_file_fmt_driver); -} - -static void __exit xloop_file_fmt_qcow_exit(void) -{ - printk(KERN_INFO "xloop_file_fmt_qcow: exit xloop device QCOW file " - "format driver"); - xloop_file_fmt_unregister_driver(&qcow_file_fmt_driver); -} - -module_init(xloop_file_fmt_qcow_init); -module_exit(xloop_file_fmt_qcow_exit); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Manuel Bentele "); -MODULE_DESCRIPTION("xloop device QCOW file format driver"); -MODULE_SOFTDEP("pre: xloop"); diff --git a/kernel/loop_file_fmt_qcow_main.h b/kernel/loop_file_fmt_qcow_main.h deleted file mode 100644 index 54b94c3..0000000 --- a/kernel/loop_file_fmt_qcow_main.h +++ /dev/null @@ -1,419 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * xloop_file_fmt_qcow.h - * - * QCOW file format driver for the xloop device module. - * - * Ported QCOW2 implementation of the QEMU project (GPL-2.0): - * Declarations for the QCOW2 file format. - * - * The copyright (C) 2004-2006 of the original code is owned by Fabrice Bellard. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#ifndef _LINUX_XLOOP_FILE_FMT_QCOW_H -#define _LINUX_XLOOP_FILE_FMT_QCOW_H - -#include -#include -#include -#include - -#ifdef CONFIG_DEBUG_FS -#include -#endif - -#include "loop_file_fmt.h" - -#ifdef CONFIG_DEBUG_DRIVER -#define ASSERT(x) \ -do { \ - if (!(x)) { \ - printk(KERN_EMERG "assertion failed %s: %d: %s\n", \ - __FILE__, __LINE__, #x); \ - BUG(); \ - } \ -} while (0) -#else -#define ASSERT(x) do { } while (0) -#endif - -#define KiB (1024) -#define MiB (1024 * 1024) - -#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) - -#define QCOW_CRYPT_NONE 0 -#define QCOW_CRYPT_AES 1 -#define QCOW_CRYPT_LUKS 2 - -#define QCOW_MAX_CRYPT_CLUSTERS 32 -#define QCOW_MAX_SNAPSHOTS 65536 - -/* Field widths in QCOW mean normal cluster offsets cannot reach - * 64PB; depending on cluster size, compressed clusters can have a - * smaller limit (64PB for up to 16k clusters, then ramps down to - * 512TB for 2M clusters). */ -#define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) - -/* 8 MB refcount table is enough for 2 PB images at 64k cluster size - * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ -#define QCOW_MAX_REFTABLE_SIZE (8 * MiB) - -/* 32 MB L1 table is enough for 2 PB images at 64k cluster size - * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ -#define QCOW_MAX_L1_SIZE (32 * MiB) - -/* Allow for an average of 1k per snapshot table entry, should be plenty of - * space for snapshot names and IDs */ -#define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) - -/* Bitmap header extension constraints */ -#define QCOW_MAX_BITMAPS 65535 -#define QCOW_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW_MAX_BITMAPS) - -/* indicate that the refcount of the referenced cluster is exactly one. */ -#define QCOW_OFLAG_COPIED (1ULL << 63) -/* indicate that the cluster is compressed (they never have the copied flag) */ -#define QCOW_OFLAG_COMPRESSED (1ULL << 62) -/* The cluster reads as all zeros */ -#define QCOW_OFLAG_ZERO (1ULL << 0) - -#define QCOW_MIN_CLUSTER_BITS 9 -#define QCOW_MAX_CLUSTER_BITS 21 - -/* Defined in the qcow2 spec (compressed cluster descriptor) */ -#define QCOW_COMPRESSED_SECTOR_SIZE 512U -#define QCOW_COMPRESSED_SECTOR_MASK (~(QCOW_COMPRESSED_SECTOR_SIZE - 1)) - -/* Must be at least 2 to cover COW */ -#define QCOW_MIN_L2_CACHE_SIZE 2 /* cache entries */ - -/* Must be at least 4 to cover all cases of refcount table growth */ -#define QCOW_MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ - -#define QCOW_DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB) -#define QCOW_DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */ - -#define QCOW_DEFAULT_CLUSTER_SIZE 65536 - -/* Buffer size for debugfs file buffer to display QCOW header information */ -#define QCOW_HEADER_BUF_LEN 1024 - -/* Buffer size for debugfs file buffer to receive and display offset and - * cluster offset information */ -#define QCOW_OFFSET_BUF_LEN 32 -#define QCOW_CLUSTER_BUF_LEN 128 - -struct xloop_file_fmt_qcow_header { - u32 magic; - u32 version; - u64 backing_file_offset; - u32 backing_file_size; - u32 cluster_bits; - u64 size; /* in bytes */ - u32 crypt_method; - u32 l1_size; - u64 l1_table_offset; - u64 refcount_table_offset; - u32 refcount_table_clusters; - u32 nb_snapshots; - u64 snapshots_offset; - - /* The following fields are only valid for version >= 3 */ - u64 incompatible_features; - u64 compatible_features; - u64 autoclear_features; - - u32 refcount_order; - u32 header_length; -} __attribute__((packed)); - -struct xloop_file_fmt_qcow_snapshot_header { - /* header is 8 byte aligned */ - u64 l1_table_offset; - - u32 l1_size; - u16 id_str_size; - u16 name_size; - - u32 date_sec; - u32 date_nsec; - - u64 vm_clock_nsec; - - u32 vm_state_size; - /* for extension */ - u32 extra_data_size; - /* extra data follows */ - /* id_str follows */ - /* name follows */ -} __attribute__((packed)); - -enum { - QCOW_FEAT_TYPE_INCOMPATIBLE = 0, - QCOW_FEAT_TYPE_COMPATIBLE = 1, - QCOW_FEAT_TYPE_AUTOCLEAR = 2, -}; - -/* incompatible feature bits */ -enum { - QCOW_INCOMPAT_DIRTY_BITNR = 0, - QCOW_INCOMPAT_CORRUPT_BITNR = 1, - QCOW_INCOMPAT_DATA_FILE_BITNR = 2, - QCOW_INCOMPAT_DIRTY = 1 << QCOW_INCOMPAT_DIRTY_BITNR, - QCOW_INCOMPAT_CORRUPT = 1 << QCOW_INCOMPAT_CORRUPT_BITNR, - QCOW_INCOMPAT_DATA_FILE = 1 << QCOW_INCOMPAT_DATA_FILE_BITNR, - - QCOW_INCOMPAT_MASK = QCOW_INCOMPAT_DIRTY - | QCOW_INCOMPAT_CORRUPT - | QCOW_INCOMPAT_DATA_FILE, -}; - -/* compatible feature bits */ -enum { - QCOW_COMPAT_LAZY_REFCOUNTS_BITNR = 0, - QCOW_COMPAT_LAZY_REFCOUNTS = 1 << QCOW_COMPAT_LAZY_REFCOUNTS_BITNR, - - QCOW_COMPAT_FEAT_MASK = QCOW_COMPAT_LAZY_REFCOUNTS, -}; - -/* autoclear feature bits */ -enum { - QCOW_AUTOCLEAR_BITMAPS_BITNR = 0, - QCOW_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1, - QCOW_AUTOCLEAR_BITMAPS = 1 << QCOW_AUTOCLEAR_BITMAPS_BITNR, - QCOW_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW_AUTOCLEAR_DATA_FILE_RAW_BITNR, - - QCOW_AUTOCLEAR_MASK = QCOW_AUTOCLEAR_BITMAPS | - QCOW_AUTOCLEAR_DATA_FILE_RAW, -}; - -struct xloop_file_fmt_qcow_data { - u64 size; - int cluster_bits; - int cluster_size; - int cluster_sectors; - int l2_slice_size; - int l2_bits; - int l2_size; - int l1_size; - int l1_vm_state_index; - int refcount_block_bits; - int refcount_block_size; - int csize_shift; - int csize_mask; - u64 cluster_offset_mask; - u64 l1_table_offset; - u64 *l1_table; - - struct xloop_file_fmt_qcow_cache *l2_table_cache; - struct xloop_file_fmt_qcow_cache *refcount_block_cache; - - u64 *refcount_table; - u64 refcount_table_offset; - u32 refcount_table_size; - u32 max_refcount_table_index; /* Last used entry in refcount_table */ - u64 free_cluster_index; - u64 free_byte_offset; - - u32 crypt_method_header; - u64 snapshots_offset; - int snapshots_size; - unsigned int nb_snapshots; - - u32 nb_bitmaps; - u64 bitmap_directory_size; - u64 bitmap_directory_offset; - - int qcow_version; - bool use_lazy_refcounts; - int refcount_order; - int refcount_bits; - u64 refcount_max; - - u64 incompatible_features; - u64 compatible_features; - u64 autoclear_features; - - struct z_stream_s *strm; - u8 *cmp_out_buf; - u64 cmp_last_coffset; - - /* debugfs entries */ -#ifdef CONFIG_DEBUG_FS - struct dentry *dbgfs_dir; - struct dentry *dbgfs_file_qcow_header; - char dbgfs_file_qcow_header_buf[QCOW_HEADER_BUF_LEN]; - struct dentry *dbgfs_file_qcow_offset; - char dbgfs_file_qcow_offset_buf[QCOW_OFFSET_BUF_LEN]; - char dbgfs_file_qcow_cluster_buf[QCOW_CLUSTER_BUF_LEN]; - u64 dbgfs_qcow_offset; - struct mutex dbgfs_qcow_offset_mutex; -#endif -}; - -struct xloop_file_fmt_qcow_cow_region { - /** - * Offset of the COW region in bytes from the start of the first - * cluster touched by the request. - */ - unsigned offset; - - /** Number of bytes to copy */ - unsigned nb_bytes; -}; - -enum xloop_file_fmt_qcow_cluster_type { - QCOW_CLUSTER_UNALLOCATED, - QCOW_CLUSTER_ZERO_PLAIN, - QCOW_CLUSTER_ZERO_ALLOC, - QCOW_CLUSTER_NORMAL, - QCOW_CLUSTER_COMPRESSED, -}; - -enum xloop_file_fmt_qcow_metadata_overlap { - QCOW_OL_MAIN_HEADER_BITNR = 0, - QCOW_OL_ACTIVE_L1_BITNR = 1, - QCOW_OL_ACTIVE_L2_BITNR = 2, - QCOW_OL_REFCOUNT_TABLE_BITNR = 3, - QCOW_OL_REFCOUNT_BLOCK_BITNR = 4, - QCOW_OL_SNAPSHOT_TABLE_BITNR = 5, - QCOW_OL_INACTIVE_L1_BITNR = 6, - QCOW_OL_INACTIVE_L2_BITNR = 7, - QCOW_OL_BITMAP_DIRECTORY_BITNR = 8, - - QCOW_OL_MAX_BITNR = 9, - - QCOW_OL_NONE = 0, - QCOW_OL_MAIN_HEADER = (1 << QCOW_OL_MAIN_HEADER_BITNR), - QCOW_OL_ACTIVE_L1 = (1 << QCOW_OL_ACTIVE_L1_BITNR), - QCOW_OL_ACTIVE_L2 = (1 << QCOW_OL_ACTIVE_L2_BITNR), - QCOW_OL_REFCOUNT_TABLE = (1 << QCOW_OL_REFCOUNT_TABLE_BITNR), - QCOW_OL_REFCOUNT_BLOCK = (1 << QCOW_OL_REFCOUNT_BLOCK_BITNR), - QCOW_OL_SNAPSHOT_TABLE = (1 << QCOW_OL_SNAPSHOT_TABLE_BITNR), - QCOW_OL_INACTIVE_L1 = (1 << QCOW_OL_INACTIVE_L1_BITNR), - /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv - * reads. */ - QCOW_OL_INACTIVE_L2 = (1 << QCOW_OL_INACTIVE_L2_BITNR), - QCOW_OL_BITMAP_DIRECTORY = (1 << QCOW_OL_BITMAP_DIRECTORY_BITNR), -}; - -/* Perform all overlap checks which can be done in constant time */ -#define QCOW_OL_CONSTANT \ - (QCOW_OL_MAIN_HEADER | QCOW_OL_ACTIVE_L1 | QCOW_OL_REFCOUNT_TABLE | \ - QCOW_OL_SNAPSHOT_TABLE | QCOW_OL_BITMAP_DIRECTORY) - -/* Perform all overlap checks which don't require disk access */ -#define QCOW_OL_CACHED \ - (QCOW_OL_CONSTANT | QCOW_OL_ACTIVE_L2 | QCOW_OL_REFCOUNT_BLOCK | \ - QCOW_OL_INACTIVE_L1) - -/* Perform all overlap checks */ -#define QCOW_OL_ALL \ - (QCOW_OL_CACHED | QCOW_OL_INACTIVE_L2) - -#define L1E_OFFSET_MASK 0x00fffffffffffe00ULL -#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL -#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL - -#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL - -#define INV_OFFSET (-1ULL) - -static inline bool xloop_file_fmt_qcow_has_data_file( - struct xloop_file_fmt *xlo_fmt) -{ - /* At the moment, there is no support for copy on write! */ - return false; -} - -static inline bool xloop_file_fmt_qcow_data_file_is_raw( - struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; - return !!(qcow_data->autoclear_features & - QCOW_AUTOCLEAR_DATA_FILE_RAW); -} - -static inline s64 xloop_file_fmt_qcow_start_of_cluster( - struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) -{ - return offset & ~(qcow_data->cluster_size - 1); -} - -static inline s64 xloop_file_fmt_qcow_offset_into_cluster( - struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) -{ - return offset & (qcow_data->cluster_size - 1); -} - -static inline s64 xloop_file_fmt_qcow_size_to_clusters( - struct xloop_file_fmt_qcow_data *qcow_data, u64 size) -{ - return (size + (qcow_data->cluster_size - 1)) >> - qcow_data->cluster_bits; -} - -static inline s64 xloop_file_fmt_qcow_size_to_l1( - struct xloop_file_fmt_qcow_data *qcow_data, s64 size) -{ - int shift = qcow_data->cluster_bits + qcow_data->l2_bits; - return (size + (1ULL << shift) - 1) >> shift; -} - -static inline int xloop_file_fmt_qcow_offset_to_l1_index( - struct xloop_file_fmt_qcow_data *qcow_data, u64 offset) -{ - return offset >> (qcow_data->l2_bits + qcow_data->cluster_bits); -} - -static inline int xloop_file_fmt_qcow_offset_to_l2_index( - struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) -{ - return (offset >> qcow_data->cluster_bits) & (qcow_data->l2_size - 1); -} - -static inline int xloop_file_fmt_qcow_offset_to_l2_slice_index( - struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) -{ - return (offset >> qcow_data->cluster_bits) & - (qcow_data->l2_slice_size - 1); -} - -static inline s64 xloop_file_fmt_qcow_vm_state_offset( - struct xloop_file_fmt_qcow_data *qcow_data) -{ - return (s64)qcow_data->l1_vm_state_index << - (qcow_data->cluster_bits + qcow_data->l2_bits); -} - -static inline enum xloop_file_fmt_qcow_cluster_type -xloop_file_fmt_qcow_get_cluster_type(struct xloop_file_fmt *xlo_fmt, u64 l2_entry) -{ - if (l2_entry & QCOW_OFLAG_COMPRESSED) { - return QCOW_CLUSTER_COMPRESSED; - } else if (l2_entry & QCOW_OFLAG_ZERO) { - if (l2_entry & L2E_OFFSET_MASK) { - return QCOW_CLUSTER_ZERO_ALLOC; - } - return QCOW_CLUSTER_ZERO_PLAIN; - } else if (!(l2_entry & L2E_OFFSET_MASK)) { - /* Offset 0 generally means unallocated, but it is ambiguous - * with external data files because 0 is a valid offset there. - * However, all clusters in external data files always have - * refcount 1, so we can rely on QCOW_OFLAG_COPIED to - * disambiguate. */ - if (xloop_file_fmt_qcow_has_data_file(xlo_fmt) && - (l2_entry & QCOW_OFLAG_COPIED)) { - return QCOW_CLUSTER_NORMAL; - } else { - return QCOW_CLUSTER_UNALLOCATED; - } - } else { - return QCOW_CLUSTER_NORMAL; - } -} - -#endif diff --git a/kernel/loop_file_fmt_raw.c b/kernel/loop_file_fmt_raw.c deleted file mode 100644 index 11cc8cd..0000000 --- a/kernel/loop_file_fmt_raw.c +++ /dev/null @@ -1,465 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * xloop_file_fmt_raw.c - * - * RAW file format driver for the xloop device module. - * - * Copyright (C) 2019 Manuel Bentele - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "loop_file_fmt.h" - -static inline loff_t __raw_file_fmt_rq_get_pos(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - return ((loff_t) blk_rq_pos(rq) << 9) + xlo->xlo_offset; -} - -/* transfer function for DEPRECATED cryptoxloop support */ -static inline int __raw_file_fmt_do_transfer(struct xloop_device *xlo, int cmd, - struct page *rpage, unsigned roffs, - struct page *lpage, unsigned loffs, - int size, sector_t rblock) -{ - int ret; - - ret = xlo->transfer(xlo, cmd, rpage, roffs, lpage, loffs, size, rblock); - if (likely(!ret)) - return 0; - - printk_ratelimited(KERN_ERR - "xloop_file_fmt_raw: Transfer error at byte offset %llu, length %i.\n", - (unsigned long long)rblock << 9, size); - return ret; -} - -static int __raw_file_fmt_read_transfer(struct xloop_device *xlo, - struct request *rq, loff_t pos) -{ - struct bio_vec bvec, b; - struct req_iterator iter; - struct iov_iter i; - struct page *page; - ssize_t len; - int ret = 0; - - page = alloc_page(GFP_NOIO); - if (unlikely(!page)) - return -ENOMEM; - - rq_for_each_segment(bvec, rq, iter) { - loff_t offset = pos; - - b.bv_page = page; - b.bv_offset = 0; - b.bv_len = bvec.bv_len; - - iov_iter_bvec(&i, READ, &b, 1, b.bv_len); - len = vfs_iter_read(xlo->xlo_backing_file, &i, &pos, 0); - if (len < 0) { - ret = len; - goto out_free_page; - } - - ret = __raw_file_fmt_do_transfer(xlo, READ, page, 0, bvec.bv_page, - bvec.bv_offset, len, offset >> 9); - if (ret) - goto out_free_page; - - flush_dcache_page(bvec.bv_page); - - if (len != bvec.bv_len) { - struct bio *bio; - - __rq_for_each_bio(bio, rq) - zero_fill_bio(bio); - break; - } - } - - ret = 0; -out_free_page: - __free_page(page); - return ret; -} - -static int raw_file_fmt_read(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct bio_vec bvec; - struct req_iterator iter; - struct iov_iter i; - ssize_t len; - struct xloop_device *xlo; - loff_t pos; - - xlo = xloop_file_fmt_get_xlo(xlo_fmt); - pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); - - if (xlo->transfer) - return __raw_file_fmt_read_transfer(xlo, rq, pos); - - rq_for_each_segment(bvec, rq, iter) { - iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len); - len = vfs_iter_read(xlo->xlo_backing_file, &i, &pos, 0); - if (len < 0) - return len; - - flush_dcache_page(bvec.bv_page); - - if (len != bvec.bv_len) { - struct bio *bio; - - __rq_for_each_bio(bio, rq) - zero_fill_bio(bio); - break; - } - cond_resched(); - } - - return 0; -} - -static void __raw_file_fmt_rw_aio_do_completion(struct xloop_cmd *cmd) -{ - struct request *rq = blk_mq_rq_from_pdu(cmd); - - if (!atomic_dec_and_test(&cmd->ref)) - return; - kfree(cmd->bvec); - cmd->bvec = NULL; -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) - if (likely(!blk_should_fake_timeout(rq->q))) - blk_mq_complete_request(rq); -#else - blk_mq_complete_request(rq); -#endif -} - -static void __raw_file_fmt_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) -{ - struct xloop_cmd *cmd = container_of(iocb, struct xloop_cmd, iocb); - - if (cmd->css) - css_put(cmd->css); - cmd->ret = ret; - __raw_file_fmt_rw_aio_do_completion(cmd); -} - -static int __raw_file_fmt_rw_aio(struct xloop_device *xlo, - struct xloop_cmd *cmd, loff_t pos, bool rw) -{ - struct iov_iter iter; - struct req_iterator rq_iter; - struct bio_vec *bvec; - struct request *rq = blk_mq_rq_from_pdu(cmd); - struct bio *bio = rq->bio; - struct file *file = xlo->xlo_backing_file; - struct bio_vec tmp; - unsigned int offset; - int nr_bvec = 0; - int ret; - - rq_for_each_bvec(tmp, rq, rq_iter) - nr_bvec++; - - if (rq->bio != rq->biotail) { - - bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), - GFP_NOIO); - if (!bvec) - return -EIO; - cmd->bvec = bvec; - - /* - * The bios of the request may be started from the middle of - * the 'bvec' because of bio splitting, so we can't directly - * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec - * API will take care of all details for us. - */ - rq_for_each_bvec(tmp, rq, rq_iter) { - *bvec = tmp; - bvec++; - } - bvec = cmd->bvec; - offset = 0; - } else { - /* - * Same here, this bio may be started from the middle of the - * 'bvec' because of bio splitting, so offset from the bvec - * must be passed to iov iterator - */ - offset = bio->bi_iter.bi_bvec_done; - bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); - } - atomic_set(&cmd->ref, 2); - - iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq)); - iter.iov_offset = offset; - - cmd->iocb.ki_pos = pos; - cmd->iocb.ki_filp = file; - cmd->iocb.ki_complete = __raw_file_fmt_rw_aio_complete; - cmd->iocb.ki_flags = IOCB_DIRECT; - cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); - if (cmd->css) - kthread_associate_blkcg(cmd->css); - - if (rw == WRITE) - ret = call_write_iter(file, &cmd->iocb, &iter); - else - ret = call_read_iter(file, &cmd->iocb, &iter); - - __raw_file_fmt_rw_aio_do_completion(cmd); - kthread_associate_blkcg(NULL); - - if (ret != -EIOCBQUEUED) - cmd->iocb.ki_complete(&cmd->iocb, ret, 0); - return 0; -} - -static int raw_file_fmt_read_aio(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); - loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); - - return __raw_file_fmt_rw_aio(xlo, cmd, pos, READ); -} - -static int __raw_file_fmt_write_bvec(struct file *file, - struct bio_vec *bvec, - loff_t *ppos) -{ - struct iov_iter i; - ssize_t bw; - - iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len); - - file_start_write(file); - bw = vfs_iter_write(file, &i, ppos, 0); - file_end_write(file); - - if (likely(bw == bvec->bv_len)) - return 0; - - printk_ratelimited(KERN_ERR - "xloop_file_fmt_raw: Write error at byte offset %llu, length " - "%i.\n", (unsigned long long)*ppos, bvec->bv_len); - if (bw >= 0) - bw = -EIO; - return bw; -} - -/* - * This is the slow, transforming version that needs to double buffer the - * data as it cannot do the transformations in place without having direct - * access to the destination pages of the backing file. - */ -static int __raw_file_fmt_write_transfer(struct xloop_device *xlo, - struct request *rq, loff_t pos) -{ -struct bio_vec bvec, b; - struct req_iterator iter; - struct page *page; - int ret = 0; - - page = alloc_page(GFP_NOIO); - if (unlikely(!page)) - return -ENOMEM; - - rq_for_each_segment(bvec, rq, iter) { - ret = __raw_file_fmt_do_transfer(xlo, WRITE, page, 0, bvec.bv_page, - bvec.bv_offset, bvec.bv_len, pos >> 9); - if (unlikely(ret)) - break; - - b.bv_page = page; - b.bv_offset = 0; - b.bv_len = bvec.bv_len; - ret = __raw_file_fmt_write_bvec(xlo->xlo_backing_file, &b, &pos); - if (ret < 0) - break; - } - - __free_page(page); - return ret; -} - -static int raw_file_fmt_write(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct bio_vec bvec; - struct req_iterator iter; - int ret = 0; - struct xloop_device *xlo; - loff_t pos; - - xlo = xloop_file_fmt_get_xlo(xlo_fmt); - pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); - - if (xlo->transfer) - return __raw_file_fmt_write_transfer(xlo, rq, pos); - - rq_for_each_segment(bvec, rq, iter) { - ret = __raw_file_fmt_write_bvec(xlo->xlo_backing_file, &bvec, &pos); - if (ret < 0) - break; - cond_resched(); - } - - return ret; -} - -static int raw_file_fmt_write_aio(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); - loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); - - return __raw_file_fmt_rw_aio(xlo, cmd, pos, WRITE); -} - -static int __raw_file_fmt_fallocate(struct xloop_device *xlo, - struct request *rq, loff_t pos, int mode) -{ - /* - * We use fallocate to manipulate the space mappings used by the image - * a.k.a. discard/zerorange. However we do not support this if - * encryption is enabled, because it may give an attacker useful - * information. - */ - struct file *file = xlo->xlo_backing_file; - struct request_queue *q = xlo->xlo_queue; - int ret; - - mode |= FALLOC_FL_KEEP_SIZE; - - if (!blk_queue_discard(q)) { - ret = -EOPNOTSUPP; - goto out; - } - - ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); - if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) - ret = -EIO; -out: - return ret; -} - -static int raw_file_fmt_write_zeros(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - - /* - * If the caller doesn't want deallocation, call zeroout to - * write zeroes the range. Otherwise, punch them out. - */ - return __raw_file_fmt_fallocate(xlo, rq, pos, - (rq->cmd_flags & REQ_NOUNMAP) ? - FALLOC_FL_ZERO_RANGE : - FALLOC_FL_PUNCH_HOLE); -} - -static int raw_file_fmt_discard(struct xloop_file_fmt *xlo_fmt, - struct request *rq) -{ - loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - - return __raw_file_fmt_fallocate(xlo, rq, pos, FALLOC_FL_PUNCH_HOLE); -} - -static int raw_file_fmt_flush(struct xloop_file_fmt *xlo_fmt) -{ - struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); - struct file *file = xlo->xlo_backing_file; - int ret = vfs_fsync(file, 0); - if (unlikely(ret && ret != -EINVAL)) - ret = -EIO; - - return ret; -} - -static loff_t raw_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, - struct file *file, loff_t offset, loff_t sizelimit) -{ - loff_t xloopsize; - - /* Compute xloopsize in bytes */ - xloopsize = i_size_read(file->f_mapping->host); - if (offset > 0) - xloopsize -= offset; - /* offset is beyond i_size, weird but possible */ - if (xloopsize < 0) - return 0; - - if (sizelimit > 0 && sizelimit < xloopsize) - xloopsize = sizelimit; - /* - * Unfortunately, if we want to do I/O on the device, - * the number of 512-byte sectors has to fit into a sector_t. - */ - return xloopsize >> 9; -} - -static struct xloop_file_fmt_ops raw_file_fmt_ops = { - .init = NULL, - .exit = NULL, - .read = raw_file_fmt_read, - .write = raw_file_fmt_write, - .read_aio = raw_file_fmt_read_aio, - .write_aio = raw_file_fmt_write_aio, - .write_zeros = raw_file_fmt_write_zeros, - .discard = raw_file_fmt_discard, - .flush = raw_file_fmt_flush, - .sector_size = raw_file_fmt_sector_size, -}; - -static struct xloop_file_fmt_driver raw_file_fmt_driver = { - .name = "RAW", - .file_fmt_type = XLO_FILE_FMT_RAW, - .ops = &raw_file_fmt_ops, - .owner = THIS_MODULE, -}; - -static int __init xloop_file_fmt_raw_init(void) -{ - printk(KERN_INFO "xloop_file_fmt_raw: init xloop device RAW file format " - "driver"); - return xloop_file_fmt_register_driver(&raw_file_fmt_driver); -} - -static void __exit xloop_file_fmt_raw_exit(void) -{ - printk(KERN_INFO "xloop_file_fmt_raw: exit xloop device RAW file format " - "driver"); - xloop_file_fmt_unregister_driver(&raw_file_fmt_driver); -} - -module_init(xloop_file_fmt_raw_init); -module_exit(xloop_file_fmt_raw_exit); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Manuel Bentele "); -MODULE_DESCRIPTION("xloop device RAW file format driver"); -MODULE_SOFTDEP("pre: xloop"); diff --git a/kernel/loop_main.c b/kernel/loop_main.c deleted file mode 100644 index 221b59f..0000000 --- a/kernel/loop_main.c +++ /dev/null @@ -1,2221 +0,0 @@ -/* - * loop_main.c - * - * Written by Theodore Ts'o, 3/29/93 - * - * Copyright 1993 by Theodore Ts'o. Redistribution of this file is - * permitted under the GNU General Public License. - * - * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 - * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 - * - * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 - * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 - * - * Fixed do_xloop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 - * - * Added devfs support - Richard Gooch 16-Jan-1998 - * - * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 - * - * Loadable modules and other fixes by AK, 1998 - * - * Make real block number available to downstream transfer functions, enables - * CBC (and relatives) mode encryption requiring unique IVs per data block. - * Reed H. Petty, rhp@draper.net - * - * Maximum number of xloop devices now dynamic via max_xloop module parameter. - * Russell Kroll 19990701 - * - * Maximum number of xloop devices when compiled-in now selectable by passing - * max_xloop=<1-255> to the kernel on boot. - * Erik I. Bolsø, , Oct 31, 1999 - * - * Completely rewrite request handling to be make_request_fn style and - * non blocking, pushing work to a helper thread. Lots of fixes from - * Al Viro too. - * Jens Axboe , Nov 2000 - * - * Support up to 256 xloop devices - * Heinz Mauelshagen , Feb 2002 - * - * Support for falling back on the write file operation when the address space - * operations write_begin is not available on the backing filesystem. - * Anton Altaparmakov, 16 Feb 2005 - * - * Support for using file formats. - * Manuel Bentele , 2019 - * - * Still To Fix: - * - Advisory locking is ignored here. - * - Should use an own CAP_* category instead of CAP_SYS_ADMIN - * - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#ifdef CONFIG_DEBUG_FS -#include -#endif - -#include "loop_file_fmt.h" -#include "loop_main.h" - -#include - -static DEFINE_IDR(xloop_index_idr); -static DEFINE_MUTEX(xloop_ctl_mutex); - -static int max_part; -static int part_shift; - -static int transfer_xor(struct xloop_device *xlo, int cmd, - struct page *raw_page, unsigned raw_off, - struct page *xloop_page, unsigned xloop_off, - int size, sector_t real_block) -{ - char *raw_buf = kmap_atomic(raw_page) + raw_off; - char *xloop_buf = kmap_atomic(xloop_page) + xloop_off; - char *in, *out, *key; - int i, keysize; - - if (cmd == READ) { - in = raw_buf; - out = xloop_buf; - } else { - in = xloop_buf; - out = raw_buf; - } - - key = xlo->xlo_encrypt_key; - keysize = xlo->xlo_encrypt_key_size; - for (i = 0; i < size; i++) - *out++ = *in++ ^ key[(i & 511) % keysize]; - - kunmap_atomic(xloop_buf); - kunmap_atomic(raw_buf); - cond_resched(); - return 0; -} - -static int xor_init(struct xloop_device *xlo, const struct xloop_info64 *info) -{ - if (unlikely(info->xlo_encrypt_key_size <= 0)) - return -EINVAL; - return 0; -} - -static struct xloop_func_table none_funcs = { - .number = XLO_CRYPT_NONE, -}; - -static struct xloop_func_table xor_funcs = { - .number = XLO_CRYPT_XOR, - .transfer = transfer_xor, - .init = xor_init -}; - -/* xfer_funcs[0] is special - its release function is never called */ -static struct xloop_func_table *xfer_funcs[MAX_XLO_CRYPT] = { - &none_funcs, - &xor_funcs -}; - -static loff_t get_xloop_size(struct xloop_device *xlo, struct file *file) -{ - return xloop_file_fmt_sector_size(xlo->xlo_fmt, file, xlo->xlo_offset, - xlo->xlo_sizelimit); -} - -static void __xloop_update_dio(struct xloop_device *xlo, bool dio) -{ - struct file *file = xlo->xlo_backing_file; - struct address_space *mapping = file->f_mapping; - struct inode *inode = mapping->host; - unsigned short sb_bsize = 0; - unsigned dio_align = 0; - bool use_dio; - - if (inode->i_sb->s_bdev) { - sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); - dio_align = sb_bsize - 1; - } - - /* - * We support direct I/O only if xlo_offset is aligned with the - * logical I/O size of backing device, and the logical block - * size of xloop is bigger than the backing device's and the xloop - * needn't transform transfer. - * - * TODO: the above condition may be loosed in the future, and - * direct I/O may be switched runtime at that time because most - * of requests in sane applications should be PAGE_SIZE aligned - */ - if (dio) { - if (queue_logical_block_size(xlo->xlo_queue) >= sb_bsize && - !(xlo->xlo_offset & dio_align) && - mapping->a_ops->direct_IO && - !xlo->transfer) - use_dio = true; - else - use_dio = false; - } else { - use_dio = false; - } - - if (xlo->use_dio == use_dio) - return; - - /* flush dirty pages before changing direct IO */ - xloop_file_fmt_flush(xlo->xlo_fmt); - - /* - * The flag of XLO_FLAGS_DIRECT_IO is handled similarly with - * XLO_FLAGS_READ_ONLY, both are set from kernel, and losetup - * will get updated by ioctl(XLOOP_GET_STATUS) - */ - if (xlo->xlo_state == Xlo_bound) - blk_mq_freeze_queue(xlo->xlo_queue); - xlo->use_dio = use_dio; - if (use_dio) { - blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); - xlo->xlo_flags |= XLO_FLAGS_DIRECT_IO; - } else { - blk_queue_flag_set(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); - xlo->xlo_flags &= ~XLO_FLAGS_DIRECT_IO; - } - if (xlo->xlo_state == Xlo_bound) - blk_mq_unfreeze_queue(xlo->xlo_queue); -} - -/** - * xloop_validate_block_size() - validates the passed in block size - * @bsize: size to validate - */ -static int -xloop_validate_block_size(unsigned short bsize) -{ - if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize)) - return -EINVAL; - - return 0; -} - -/** - * xloop_set_size() - sets device size and notifies userspace - * @xlo: struct xloop_device to set the size for - * @size: new size of the xloop device - * - * Callers must validate that the size passed into this function fits into - * a sector_t, eg using xloop_validate_size() - */ -static void xloop_set_size(struct xloop_device *xlo, loff_t size) -{ - struct block_device *bdev = xlo->xlo_device; -#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 7, 0) - sector_t capacity; -#endif - - bd_set_size(bdev, size << SECTOR_SHIFT); - -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 7, 0) - set_capacity_revalidate_and_notify(xlo->xlo_disk, size, false); -#else - capacity = get_capacity(xlo->xlo_disk); - set_capacity(xlo->xlo_disk, size); - if (capacity != size && capacity != 0 && size != 0) { - char *envp[] = { "RESIZE=1", NULL }; - kobject_uevent_env(&disk_to_dev(xlo->xlo_disk)->kobj, KOBJ_CHANGE, - envp); - } -#endif -} - -static void xlo_complete_rq(struct request *rq) -{ - struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); - blk_status_t ret = BLK_STS_OK; - - if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || - req_op(rq) != REQ_OP_READ) { - if (cmd->ret < 0) - ret = errno_to_blk_status(cmd->ret); - goto end_io; - } - - /* - * Short READ - if we got some data, advance our request and - * retry it. If we got no data, end the rest with EIO. - */ - if (cmd->ret) { - blk_update_request(rq, BLK_STS_OK, cmd->ret); - cmd->ret = 0; - blk_mq_requeue_request(rq, true); - } else { - if (cmd->use_aio) { - struct bio *bio = rq->bio; - - while (bio) { - zero_fill_bio(bio); - bio = bio->bi_next; - } - } - ret = BLK_STS_IOERR; -end_io: - blk_mq_end_request(rq, ret); - } -} - -static int do_req_filebacked(struct xloop_device *xlo, struct request *rq) -{ - struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); - - /* - * xlo_write_simple and xlo_read_simple should have been covered - * by io submit style function like xlo_rw_aio(), one blocker - * is that xlo_read_simple() need to call flush_dcache_page after - * the page is written from kernel, and it isn't easy to handle - * this in io submit style function which submits all segments - * of the req at one time. And direct read IO doesn't need to - * run flush_dcache_page(). - */ - switch (req_op(rq)) { - case REQ_OP_FLUSH: - return xloop_file_fmt_flush(xlo->xlo_fmt); - case REQ_OP_WRITE_ZEROES: - return xloop_file_fmt_write_zeros(xlo->xlo_fmt, rq); - case REQ_OP_DISCARD: - return xloop_file_fmt_discard(xlo->xlo_fmt, rq); - case REQ_OP_WRITE: - if (cmd->use_aio) - return xloop_file_fmt_write_aio(xlo->xlo_fmt, rq); - else - return xloop_file_fmt_write(xlo->xlo_fmt, rq); - case REQ_OP_READ: - if (cmd->use_aio) - return xloop_file_fmt_read_aio(xlo->xlo_fmt, rq); - else - return xloop_file_fmt_read(xlo->xlo_fmt, rq); - default: - WARN_ON_ONCE(1); - return -EIO; - } -} - -static inline void xloop_update_dio(struct xloop_device *xlo) -{ - __xloop_update_dio(xlo, (xlo->xlo_backing_file->f_flags & O_DIRECT) | - xlo->use_dio); -} - -static void xloop_reread_partitions(struct xloop_device *xlo, - struct block_device *bdev) -{ - int rc; - - mutex_lock(&bdev->bd_mutex); -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0) - rc = bdev_disk_changed(bdev, false); -#else - rc = blkdev_reread_part(bdev); -#endif - mutex_unlock(&bdev->bd_mutex); - if (rc) - pr_warn("%s: partition scan of xloop%d (%s) failed (rc=%d)\n", - __func__, xlo->xlo_number, xlo->xlo_file_name, rc); -} - -static inline int is_xloop_device(struct file *file) -{ - struct inode *i = file->f_mapping->host; - - return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == XLOOP_MAJOR; -} - -static int xloop_validate_file(struct file *file, struct block_device *bdev) -{ - struct inode *inode = file->f_mapping->host; - struct file *f = file; - - /* Avoid recursion */ - while (is_xloop_device(f)) { - struct xloop_device *l; - - if (f->f_mapping->host->i_bdev == bdev) - return -EBADF; - - l = f->f_mapping->host->i_bdev->bd_disk->private_data; - if (l->xlo_state != Xlo_bound) { - return -EINVAL; - } - f = l->xlo_backing_file; - } - if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) - return -EINVAL; - return 0; -} - -/* - * xloop_change_fd switched the backing store of a xloopback device to - * a new file. This is useful for operating system installers to free up - * the original file and in High Availability environments to switch to - * an alternative location for the content in case of server meltdown. - * This can only work if the xloop device is used read-only, and if the - * new backing store is the same size and type as the old backing store. - */ -static int xloop_change_fd(struct xloop_device *xlo, struct block_device *bdev, - unsigned int arg) -{ - struct file *file = NULL, *old_file; - int error; - bool partscan; - - error = mutex_lock_killable(&xloop_ctl_mutex); - if (error) - return error; - error = -ENXIO; - if (xlo->xlo_state != Xlo_bound) - goto out_err; - - /* the xloop device has to be read-only */ - error = -EINVAL; - if (!(xlo->xlo_flags & XLO_FLAGS_READ_ONLY)) - goto out_err; - - error = -EBADF; - file = fget(arg); - if (!file) - goto out_err; - - error = xloop_validate_file(file, bdev); - if (error) - goto out_err; - - old_file = xlo->xlo_backing_file; - - error = -EINVAL; - - /* size of the new backing store needs to be the same */ - if (get_xloop_size(xlo, file) != get_xloop_size(xlo, old_file)) - goto out_err; - - /* and ... switch */ - blk_mq_freeze_queue(xlo->xlo_queue); - mapping_set_gfp_mask(old_file->f_mapping, xlo->old_gfp_mask); - xlo->xlo_backing_file = file; - xlo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); - mapping_set_gfp_mask(file->f_mapping, - xlo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); - xloop_update_dio(xlo); - blk_mq_unfreeze_queue(xlo->xlo_queue); - partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN; - mutex_unlock(&xloop_ctl_mutex); - /* - * We must drop file reference outside of xloop_ctl_mutex as dropping - * the file ref can take bd_mutex which creates circular locking - * dependency. - */ - fput(old_file); - if (partscan) - xloop_reread_partitions(xlo, bdev); - return 0; - -out_err: - mutex_unlock(&xloop_ctl_mutex); - if (file) - fput(file); - return error; -} - -/* xloop sysfs attributes */ - -static ssize_t xloop_attr_show(struct device *dev, char *page, - ssize_t (*callback)(struct xloop_device *, char *)) -{ - struct gendisk *disk = dev_to_disk(dev); - struct xloop_device *xlo = disk->private_data; - - return callback(xlo, page); -} - -#define XLOOP_ATTR_RO(_name) \ -static ssize_t xloop_attr_##_name##_show(struct xloop_device *, char *); \ -static ssize_t xloop_attr_do_show_##_name(struct device *d, \ - struct device_attribute *attr, char *b) \ -{ \ - return xloop_attr_show(d, b, xloop_attr_##_name##_show); \ -} \ -static struct device_attribute xloop_attr_##_name = \ - __ATTR(_name, 0444, xloop_attr_do_show_##_name, NULL); - -static ssize_t xloop_attr_backing_file_show(struct xloop_device *xlo, char *buf) -{ - ssize_t ret; - char *p = NULL; - - spin_lock_irq(&xlo->xlo_lock); - if (xlo->xlo_backing_file) - p = file_path(xlo->xlo_backing_file, buf, PAGE_SIZE - 1); - spin_unlock_irq(&xlo->xlo_lock); - - if (IS_ERR_OR_NULL(p)) - ret = PTR_ERR(p); - else { - ret = strlen(p); - memmove(buf, p, ret); - buf[ret++] = '\n'; - buf[ret] = 0; - } - - return ret; -} - -static ssize_t xloop_attr_file_fmt_type_show(struct xloop_device *xlo, - char *buf) -{ - ssize_t len = 0; - - len = xloop_file_fmt_print_type(xlo->xlo_fmt->file_fmt_type, buf); - len += sprintf(buf + len, "\n"); - - return len; -} - -static ssize_t xloop_attr_offset_show(struct xloop_device *xlo, char *buf) -{ - return sprintf(buf, "%llu\n", (unsigned long long)xlo->xlo_offset); -} - -static ssize_t xloop_attr_sizelimit_show(struct xloop_device *xlo, char *buf) -{ - return sprintf(buf, "%llu\n", (unsigned long long)xlo->xlo_sizelimit); -} - -static ssize_t xloop_attr_autoclear_show(struct xloop_device *xlo, char *buf) -{ - int autoclear = (xlo->xlo_flags & XLO_FLAGS_AUTOCLEAR); - - return sprintf(buf, "%s\n", autoclear ? "1" : "0"); -} - -static ssize_t xloop_attr_partscan_show(struct xloop_device *xlo, char *buf) -{ - int partscan = (xlo->xlo_flags & XLO_FLAGS_PARTSCAN); - - return sprintf(buf, "%s\n", partscan ? "1" : "0"); -} - -static ssize_t xloop_attr_dio_show(struct xloop_device *xlo, char *buf) -{ - int dio = (xlo->xlo_flags & XLO_FLAGS_DIRECT_IO); - - return sprintf(buf, "%s\n", dio ? "1" : "0"); -} - -XLOOP_ATTR_RO(backing_file); -XLOOP_ATTR_RO(file_fmt_type); -XLOOP_ATTR_RO(offset); -XLOOP_ATTR_RO(sizelimit); -XLOOP_ATTR_RO(autoclear); -XLOOP_ATTR_RO(partscan); -XLOOP_ATTR_RO(dio); - -static struct attribute *xloop_attrs[] = { - &xloop_attr_backing_file.attr, - &xloop_attr_file_fmt_type.attr, - &xloop_attr_offset.attr, - &xloop_attr_sizelimit.attr, - &xloop_attr_autoclear.attr, - &xloop_attr_partscan.attr, - &xloop_attr_dio.attr, - NULL, -}; - -static struct attribute_group xloop_attribute_group = { - .name = "xloop", - .attrs= xloop_attrs, -}; - -static void xloop_sysfs_init(struct xloop_device *xlo) -{ - xlo->sysfs_inited = !sysfs_create_group(&disk_to_dev(xlo->xlo_disk)->kobj, - &xloop_attribute_group); -} - -static void xloop_sysfs_exit(struct xloop_device *xlo) -{ - if (xlo->sysfs_inited) - sysfs_remove_group(&disk_to_dev(xlo->xlo_disk)->kobj, - &xloop_attribute_group); -} - -static void xloop_config_discard(struct xloop_device *xlo) -{ - struct file *file = xlo->xlo_backing_file; - struct inode *inode = file->f_mapping->host; - struct request_queue *q = xlo->xlo_queue; - u32 granularity, max_discard_sectors; - - /* - * If the backing device is a block device, mirror its zeroing - * capability. Set the discard sectors to the block device's zeroing - * capabilities because xloop discards result in blkdev_issue_zeroout(), - * not blkdev_issue_discard(). This maintains consistent behavior with - * file-backed xloop devices: discarded regions read back as zero. - */ - if (S_ISBLK(inode->i_mode) && !xlo->xlo_encrypt_key_size) { - struct request_queue *backingq; - - backingq = bdev_get_queue(inode->i_bdev); - - max_discard_sectors = backingq->limits.max_write_zeroes_sectors; - granularity = backingq->limits.discard_granularity ?: - queue_physical_block_size(backingq); - - /* - * We use punch hole to reclaim the free space used by the - * image a.k.a. discard. However we do not support discard if - * encryption is enabled, because it may give an attacker - * useful information. - */ - } else if (!file->f_op->fallocate || xlo->xlo_encrypt_key_size) { - max_discard_sectors = 0; - granularity = 0; - - } else { - max_discard_sectors = UINT_MAX >> 9; - granularity = inode->i_sb->s_blocksize; - } - - if (max_discard_sectors) { - q->limits.discard_granularity = granularity; - blk_queue_max_discard_sectors(q, max_discard_sectors); - blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); - blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); - } else { - q->limits.discard_granularity = 0; - blk_queue_max_discard_sectors(q, 0); - blk_queue_max_write_zeroes_sectors(q, 0); - blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); - } - q->limits.discard_alignment = 0; -} - -static void xloop_unprepare_queue(struct xloop_device *xlo) -{ - kthread_flush_worker(&xlo->worker); - kthread_stop(xlo->worker_task); -} - -static int xloop_kthread_worker_fn(void *worker_ptr) -{ -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0) - current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; -#else - current->flags |= PF_LESS_THROTTLE | PF_MEMALLOC_NOIO; -#endif - return kthread_worker_fn(worker_ptr); -} - -static int xloop_prepare_queue(struct xloop_device *xlo) -{ - kthread_init_worker(&xlo->worker); - xlo->worker_task = kthread_run(xloop_kthread_worker_fn, - &xlo->worker, "xloop%d", xlo->xlo_number); - if (IS_ERR(xlo->worker_task)) - return -ENOMEM; - set_user_nice(xlo->worker_task, MIN_NICE); - return 0; -} - -static void xloop_update_rotational(struct xloop_device *xlo) -{ - struct file *file = xlo->xlo_backing_file; - struct inode *file_inode = file->f_mapping->host; - struct block_device *file_bdev = file_inode->i_sb->s_bdev; - struct request_queue *q = xlo->xlo_queue; - bool nonrot = true; - - /* not all filesystems (e.g. tmpfs) have a sb->s_bdev */ - if (file_bdev) - nonrot = blk_queue_nonrot(bdev_get_queue(file_bdev)); - - if (nonrot) - blk_queue_flag_set(QUEUE_FLAG_NONROT, q); - else - blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); -} - -static int -xloop_release_xfer(struct xloop_device *xlo) -{ - int err = 0; - struct xloop_func_table *xfer = xlo->xlo_encryption; - - if (xfer) { - if (xfer->release) - err = xfer->release(xlo); - xlo->transfer = NULL; - xlo->xlo_encryption = NULL; - module_put(xfer->owner); - } - return err; -} - -static int -xloop_init_xfer(struct xloop_device *xlo, struct xloop_func_table *xfer, - const struct xloop_info64 *i) -{ - int err = 0; - - if (xfer) { - struct module *owner = xfer->owner; - - if (!try_module_get(owner)) - return -EINVAL; - if (xfer->init) - err = xfer->init(xlo, i); - if (err) - module_put(owner); - else - xlo->xlo_encryption = xfer; - } - return err; -} - -/** - * xloop_set_status_from_info - configure device from xloop_info - * @xlo: struct xloop_device to configure - * @info: struct xloop_info64 to configure the device with - * - * Configures the xloop device parameters according to the passed - * in xloop_info64 configuration. - */ -static int -xloop_set_status_from_info(struct xloop_device *xlo, - const struct xloop_info64 *info) -{ - int err; - struct xloop_func_table *xfer; - kuid_t uid = current_uid(); - - if ((unsigned int) info->xlo_encrypt_key_size > XLO_KEY_SIZE) - return -EINVAL; - - err = xloop_release_xfer(xlo); - if (err) - return err; - - if (info->xlo_encrypt_type) { - unsigned int type = info->xlo_encrypt_type; - - if (type >= MAX_XLO_CRYPT) - return -EINVAL; - xfer = xfer_funcs[type]; - if (xfer == NULL) - return -EINVAL; - } else - xfer = NULL; - - err = xloop_init_xfer(xlo, xfer, info); - if (err) - return err; - - xlo->xlo_offset = info->xlo_offset; - xlo->xlo_sizelimit = info->xlo_sizelimit; - memcpy(xlo->xlo_file_name, info->xlo_file_name, XLO_NAME_SIZE); - memcpy(xlo->xlo_crypt_name, info->xlo_crypt_name, XLO_NAME_SIZE); - xlo->xlo_file_name[XLO_NAME_SIZE-1] = 0; - xlo->xlo_crypt_name[XLO_NAME_SIZE-1] = 0; - - if (!xfer) - xfer = &none_funcs; - xlo->transfer = xfer->transfer; - xlo->ioctl = xfer->ioctl; - - xlo->xlo_flags = info->xlo_flags; - - xlo->xlo_encrypt_key_size = info->xlo_encrypt_key_size; - xlo->xlo_init[0] = info->xlo_init[0]; - xlo->xlo_init[1] = info->xlo_init[1]; - if (info->xlo_encrypt_key_size) { - memcpy(xlo->xlo_encrypt_key, info->xlo_encrypt_key, - info->xlo_encrypt_key_size); - xlo->xlo_key_owner = uid; - } - - return 0; -} - -static int xloop_configure(struct xloop_device *xlo, fmode_t mode, - struct block_device *bdev, - const struct xloop_config *config) -{ - struct file *file; - struct inode *inode; - struct address_space *mapping; - struct block_device *claimed_bdev = NULL; - int error; - loff_t size; - bool partscan; - unsigned short bsize; - - /* This is safe, since we have a reference from open(). */ - __module_get(THIS_MODULE); - - error = -EBADF; - file = fget(config->fd); - if (!file) - goto out; - - /* - * If we don't hold exclusive handle for the device, upgrade to it - * here to avoid changing device under exclusive owner. - */ - if (!(mode & FMODE_EXCL)) { -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) - claimed_bdev = bdev->bd_contains; - error = bd_prepare_to_claim(bdev, claimed_bdev, xloop_configure); - if (error) - goto out_putf; -#else - claimed_bdev = bd_start_claiming(bdev, xloop_configure); - if (IS_ERR(claimed_bdev)) { - error = PTR_ERR(claimed_bdev); - goto out_putf; - } -#endif - } - - error = mutex_lock_killable(&xloop_ctl_mutex); - if (error) - goto out_bdev; - - error = -EBUSY; - if (xlo->xlo_state != Xlo_unbound) - goto out_unlock; - - error = xloop_validate_file(file, bdev); - if (error) - goto out_unlock; - - mapping = file->f_mapping; - inode = mapping->host; - - if ((config->info.xlo_flags & ~XLOOP_CONFIGURE_SETTABLE_FLAGS) != 0) { - error = -EINVAL; - goto out_unlock; - } - - if (config->block_size) { - error = xloop_validate_block_size(config->block_size); - if (error) - goto out_unlock; - } - - error = xloop_set_status_from_info(xlo, &config->info); - if (error) - goto out_unlock; - - if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || - !file->f_op->write_iter) - xlo->xlo_flags |= XLO_FLAGS_READ_ONLY; - - error = xloop_prepare_queue(xlo); - if (error) - goto out_unlock; - - error = xloop_file_fmt_init(xlo->xlo_fmt, - config->info.xlo_file_fmt_type); - if (error) - goto out_unlock; - - set_device_ro(bdev, (xlo->xlo_flags & XLO_FLAGS_READ_ONLY) != 0); - - xlo->use_dio = xlo->xlo_flags & XLO_FLAGS_DIRECT_IO; - xlo->xlo_device = bdev; - xlo->xlo_backing_file = file; - xlo->old_gfp_mask = mapping_gfp_mask(mapping); - mapping_set_gfp_mask(mapping, xlo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); - - if (!(xlo->xlo_flags & XLO_FLAGS_READ_ONLY) && file->f_op->fsync) - blk_queue_write_cache(xlo->xlo_queue, true, false); - - if (config->block_size) - bsize = config->block_size; - else if ((xlo->xlo_backing_file->f_flags & O_DIRECT) && inode->i_sb->s_bdev) - /* In case of direct I/O, match underlying block size */ - bsize = bdev_logical_block_size(inode->i_sb->s_bdev); - else - bsize = 512; - - blk_queue_logical_block_size(xlo->xlo_queue, bsize); - blk_queue_physical_block_size(xlo->xlo_queue, bsize); - blk_queue_io_min(xlo->xlo_queue, bsize); - - xloop_update_rotational(xlo); - xloop_update_dio(xlo); - xloop_sysfs_init(xlo); - - size = get_xloop_size(xlo, file); - xloop_set_size(xlo, size); - - set_blocksize(bdev, S_ISBLK(inode->i_mode) ? - block_size(inode->i_bdev) : PAGE_SIZE); - - xlo->xlo_state = Xlo_bound; - if (part_shift) - xlo->xlo_flags |= XLO_FLAGS_PARTSCAN; - partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN; - if (partscan) - xlo->xlo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; - - /* Grab the block_device to prevent its destruction after we - * put /dev/xloopXX inode. Later in __xloop_clr_fd() we bdput(bdev). - */ - bdgrab(bdev); - mutex_unlock(&xloop_ctl_mutex); - if (partscan) - xloop_reread_partitions(xlo, bdev); - if (claimed_bdev) - bd_abort_claiming(bdev, claimed_bdev, xloop_configure); - return 0; - -out_unlock: - mutex_unlock(&xloop_ctl_mutex); -out_bdev: - if (claimed_bdev) - bd_abort_claiming(bdev, claimed_bdev, xloop_configure); -out_putf: - fput(file); -out: - /* This is safe: open() is still holding a reference. */ - module_put(THIS_MODULE); - return error; -} - -static int __xloop_clr_fd(struct xloop_device *xlo, bool release) -{ - struct file *filp = NULL; - gfp_t gfp = xlo->old_gfp_mask; - struct block_device *bdev = xlo->xlo_device; - int err = 0; - bool partscan = false; - int xlo_number; - - mutex_lock(&xloop_ctl_mutex); - if (WARN_ON_ONCE(xlo->xlo_state != Xlo_rundown)) { - err = -ENXIO; - goto out_unlock; - } - - filp = xlo->xlo_backing_file; - if (filp == NULL) { - err = -EINVAL; - goto out_unlock; - } - - /* freeze request queue during the transition */ - blk_mq_freeze_queue(xlo->xlo_queue); - - xloop_file_fmt_exit(xlo->xlo_fmt); - - spin_lock_irq(&xlo->xlo_lock); - xlo->xlo_backing_file = NULL; - spin_unlock_irq(&xlo->xlo_lock); - - xloop_release_xfer(xlo); - xlo->transfer = NULL; - xlo->ioctl = NULL; - xlo->xlo_device = NULL; - xlo->xlo_encryption = NULL; - xlo->xlo_offset = 0; - xlo->xlo_sizelimit = 0; - xlo->xlo_encrypt_key_size = 0; - memset(xlo->xlo_encrypt_key, 0, XLO_KEY_SIZE); - memset(xlo->xlo_crypt_name, 0, XLO_NAME_SIZE); - memset(xlo->xlo_file_name, 0, XLO_NAME_SIZE); - blk_queue_logical_block_size(xlo->xlo_queue, 512); - blk_queue_physical_block_size(xlo->xlo_queue, 512); - blk_queue_io_min(xlo->xlo_queue, 512); - if (bdev) { - bdput(bdev); - invalidate_bdev(bdev); - bdev->bd_inode->i_mapping->wb_err = 0; - } - set_capacity(xlo->xlo_disk, 0); - xloop_sysfs_exit(xlo); - if (bdev) { - bd_set_size(bdev, 0); - /* let user-space know about this change */ - kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); - } - mapping_set_gfp_mask(filp->f_mapping, gfp); - /* This is safe: open() is still holding a reference. */ - module_put(THIS_MODULE); - blk_mq_unfreeze_queue(xlo->xlo_queue); - - partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN && bdev; - xlo_number = xlo->xlo_number; - xloop_unprepare_queue(xlo); -out_unlock: - mutex_unlock(&xloop_ctl_mutex); - if (partscan) { - /* - * bd_mutex has been held already in release path, so don't - * acquire it if this function is called in such case. - * - * If the reread partition isn't from release path, xlo_refcnt - * must be at least one and it can only become zero when the - * current holder is released. - */ - if (!release) - mutex_lock(&bdev->bd_mutex); -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0) - err = bdev_disk_changed(bdev, false); -#else - err = blkdev_reread_part(bdev); -#endif - if (!release) - mutex_unlock(&bdev->bd_mutex); - if (err) - pr_warn("%s: partition scan of xloop%d failed (rc=%d)\n", - __func__, xlo_number, err); - /* Device is gone, no point in returning error */ - err = 0; - } - - /* - * xlo->xlo_state is set to Xlo_unbound here after above partscan has - * finished. - * - * There cannot be anybody else entering __xloop_clr_fd() as - * xlo->xlo_backing_file is already cleared and Xlo_rundown state - * protects us from all the other places trying to change the 'xlo' - * device. - */ - mutex_lock(&xloop_ctl_mutex); - xlo->xlo_flags = 0; - if (!part_shift) - xlo->xlo_disk->flags |= GENHD_FL_NO_PART_SCAN; - xlo->xlo_state = Xlo_unbound; - mutex_unlock(&xloop_ctl_mutex); - - /* - * Need not hold xloop_ctl_mutex to fput backing file. - * Calling fput holding xloop_ctl_mutex triggers a circular - * lock dependency possibility warning as fput can take - * bd_mutex which is usually taken before xloop_ctl_mutex. - */ - if (filp) - fput(filp); - return err; -} - -static int xloop_clr_fd(struct xloop_device *xlo) -{ - int err; - - err = mutex_lock_killable(&xloop_ctl_mutex); - if (err) - return err; - if (xlo->xlo_state != Xlo_bound) { - mutex_unlock(&xloop_ctl_mutex); - return -ENXIO; - } - /* - * If we've explicitly asked to tear down the xloop device, - * and it has an elevated reference count, set it for auto-teardown when - * the last reference goes away. This stops $!~#$@ udev from - * preventing teardown because it decided that it needs to run blkid on - * the xloopback device whenever they appear. xfstests is notorious for - * failing tests because blkid via udev races with a losetup - * /do something like mkfs/losetup -d causing the losetup -d - * command to fail with EBUSY. - */ - if (atomic_read(&xlo->xlo_refcnt) > 1) { - xlo->xlo_flags |= XLO_FLAGS_AUTOCLEAR; - mutex_unlock(&xloop_ctl_mutex); - return 0; - } - xlo->xlo_state = Xlo_rundown; - mutex_unlock(&xloop_ctl_mutex); - - return __xloop_clr_fd(xlo, false); -} - -static int -xloop_set_status(struct xloop_device *xlo, const struct xloop_info64 *info) -{ - int err; - struct block_device *bdev; - kuid_t uid = current_uid(); - int prev_xlo_flags; - bool partscan = false; - bool size_changed = false; - - err = mutex_lock_killable(&xloop_ctl_mutex); - if (err) - return err; - if (xlo->xlo_encrypt_key_size && - !uid_eq(xlo->xlo_key_owner, uid) && - !capable(CAP_SYS_ADMIN)) { - err = -EPERM; - goto out_unlock; - } - if (xlo->xlo_state != Xlo_bound) { - err = -ENXIO; - goto out_unlock; - } - - if (xlo->xlo_offset != info->xlo_offset || - xlo->xlo_sizelimit != info->xlo_sizelimit) { - size_changed = true; - sync_blockdev(xlo->xlo_device); - invalidate_bdev(xlo->xlo_device); - } - - /* I/O need to be drained during transfer transition */ - blk_mq_freeze_queue(xlo->xlo_queue); - - if (size_changed && xlo->xlo_device->bd_inode->i_mapping->nrpages) { - /* If any pages were dirtied after invalidate_bdev(), try again */ - err = -EAGAIN; - pr_warn("%s: xloop%d (%s) has still dirty pages (nrpages=%lu)\n", - __func__, xlo->xlo_number, xlo->xlo_file_name, - xlo->xlo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - - prev_xlo_flags = xlo->xlo_flags; - - err = xloop_set_status_from_info(xlo, info); - if (err) - goto out_unfreeze; - - /* Mask out flags that can't be set using XLOOP_SET_STATUS. */ - xlo->xlo_flags &= XLOOP_SET_STATUS_SETTABLE_FLAGS; - /* For those flags, use the previous values instead */ - xlo->xlo_flags |= prev_xlo_flags & ~XLOOP_SET_STATUS_SETTABLE_FLAGS; - /* For flags that can't be cleared, use previous values too */ - xlo->xlo_flags |= prev_xlo_flags & ~XLOOP_SET_STATUS_CLEARABLE_FLAGS; - - if (xlo->xlo_fmt->file_fmt_type != info->xlo_file_fmt_type) { - /* xloop file format has changed, so change file format driver */ - err = xloop_file_fmt_change(xlo->xlo_fmt, info->xlo_file_fmt_type); - if (err) - goto out_unfreeze; - - /* After change of the file format, recalculate the capacity of - * the loop device. */ - size_changed = true; - } - - if (size_changed) { - loff_t new_size = get_xloop_size(xlo, xlo->xlo_backing_file); - xloop_set_size(xlo, new_size); - } - - xloop_config_discard(xlo); - - /* update dio if xlo_offset or transfer is changed */ - __xloop_update_dio(xlo, xlo->use_dio); - -out_unfreeze: - blk_mq_unfreeze_queue(xlo->xlo_queue); - - if (!err && (xlo->xlo_flags & XLO_FLAGS_PARTSCAN) && - !(prev_xlo_flags & XLO_FLAGS_PARTSCAN)) { - xlo->xlo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; - bdev = xlo->xlo_device; - partscan = true; - } -out_unlock: - mutex_unlock(&xloop_ctl_mutex); - if (partscan) - xloop_reread_partitions(xlo, bdev); - - return err; -} - -static int -xloop_get_status(struct xloop_device *xlo, struct xloop_info64 *info) -{ - struct path path; - struct kstat stat; - int ret; - - ret = mutex_lock_killable(&xloop_ctl_mutex); - if (ret) - return ret; - if (xlo->xlo_state != Xlo_bound) { - mutex_unlock(&xloop_ctl_mutex); - return -ENXIO; - } - - memset(info, 0, sizeof(*info)); - info->xlo_number = xlo->xlo_number; - info->xlo_offset = xlo->xlo_offset; - info->xlo_sizelimit = xlo->xlo_sizelimit; - info->xlo_flags = xlo->xlo_flags; - memcpy(info->xlo_file_name, xlo->xlo_file_name, XLO_NAME_SIZE); - memcpy(info->xlo_crypt_name, xlo->xlo_crypt_name, XLO_NAME_SIZE); - info->xlo_encrypt_type = - xlo->xlo_encryption ? xlo->xlo_encryption->number : 0; - if (xlo->xlo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { - info->xlo_encrypt_key_size = xlo->xlo_encrypt_key_size; - memcpy(info->xlo_encrypt_key, xlo->xlo_encrypt_key, - xlo->xlo_encrypt_key_size); - } - - /* Drop xloop_ctl_mutex while we call into the filesystem. */ - path = xlo->xlo_backing_file->f_path; - path_get(&path); - mutex_unlock(&xloop_ctl_mutex); - ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT); - if (!ret) { - info->xlo_device = huge_encode_dev(stat.dev); - info->xlo_inode = stat.ino; - info->xlo_rdevice = huge_encode_dev(stat.rdev); - } - path_put(&path); - return ret; -} - -static void -xloop_info64_from_old(const struct xloop_info *info, struct xloop_info64 *info64) -{ - memset(info64, 0, sizeof(*info64)); - info64->xlo_number = info->xlo_number; - info64->xlo_device = info->xlo_device; - info64->xlo_inode = info->xlo_inode; - info64->xlo_rdevice = info->xlo_rdevice; - info64->xlo_offset = info->xlo_offset; - info64->xlo_sizelimit = 0; - info64->xlo_encrypt_type = info->xlo_encrypt_type; - info64->xlo_encrypt_key_size = info->xlo_encrypt_key_size; - info64->xlo_flags = info->xlo_flags; - info64->xlo_init[0] = info->xlo_init[0]; - info64->xlo_init[1] = info->xlo_init[1]; - info64->xlo_file_fmt_type = info->xlo_file_fmt_type; - if (info->xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) - memcpy(info64->xlo_crypt_name, info->xlo_name, XLO_NAME_SIZE); - else - memcpy(info64->xlo_file_name, info->xlo_name, XLO_NAME_SIZE); - memcpy(info64->xlo_encrypt_key, info->xlo_encrypt_key, XLO_KEY_SIZE); -} - -static int -xloop_info64_to_old(const struct xloop_info64 *info64, struct xloop_info *info) -{ - memset(info, 0, sizeof(*info)); - info->xlo_number = info64->xlo_number; - info->xlo_device = info64->xlo_device; - info->xlo_inode = info64->xlo_inode; - info->xlo_rdevice = info64->xlo_rdevice; - info->xlo_offset = info64->xlo_offset; - info->xlo_encrypt_type = info64->xlo_encrypt_type; - info->xlo_encrypt_key_size = info64->xlo_encrypt_key_size; - info->xlo_flags = info64->xlo_flags; - info->xlo_init[0] = info64->xlo_init[0]; - info->xlo_init[1] = info64->xlo_init[1]; - info->xlo_file_fmt_type = info64->xlo_file_fmt_type; - if (info->xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) - memcpy(info->xlo_name, info64->xlo_crypt_name, XLO_NAME_SIZE); - else - memcpy(info->xlo_name, info64->xlo_file_name, XLO_NAME_SIZE); - memcpy(info->xlo_encrypt_key, info64->xlo_encrypt_key, XLO_KEY_SIZE); - - /* error in case values were truncated */ - if (info->xlo_device != info64->xlo_device || - info->xlo_rdevice != info64->xlo_rdevice || - info->xlo_inode != info64->xlo_inode || - info->xlo_offset != info64->xlo_offset) - return -EOVERFLOW; - - return 0; -} - -static int -xloop_set_status_old(struct xloop_device *xlo, const struct xloop_info __user *arg) -{ - struct xloop_info info; - struct xloop_info64 info64; - - if (copy_from_user(&info, arg, sizeof (struct xloop_info))) - return -EFAULT; - xloop_info64_from_old(&info, &info64); - return xloop_set_status(xlo, &info64); -} - -static int -xloop_set_status64(struct xloop_device *xlo, const struct xloop_info64 __user *arg) -{ - struct xloop_info64 info64; - - if (copy_from_user(&info64, arg, sizeof (struct xloop_info64))) - return -EFAULT; - return xloop_set_status(xlo, &info64); -} - -static int -xloop_get_status_old(struct xloop_device *xlo, struct xloop_info __user *arg) { - struct xloop_info info; - struct xloop_info64 info64; - int err; - - if (!arg) - return -EINVAL; - err = xloop_get_status(xlo, &info64); - if (!err) - err = xloop_info64_to_old(&info64, &info); - if (!err && copy_to_user(arg, &info, sizeof(info))) - err = -EFAULT; - - return err; -} - -static int -xloop_get_status64(struct xloop_device *xlo, struct xloop_info64 __user *arg) { - struct xloop_info64 info64; - int err; - - if (!arg) - return -EINVAL; - err = xloop_get_status(xlo, &info64); - if (!err && copy_to_user(arg, &info64, sizeof(info64))) - err = -EFAULT; - - return err; -} - -static int xloop_set_capacity(struct xloop_device *xlo) -{ - loff_t size; - - if (unlikely(xlo->xlo_state != Xlo_bound)) - return -ENXIO; - - size = get_xloop_size(xlo, xlo->xlo_backing_file); - xloop_set_size(xlo, size); - - return 0; -} - -static int xloop_set_dio(struct xloop_device *xlo, unsigned long arg) -{ - int error = -ENXIO; - if (xlo->xlo_state != Xlo_bound) - goto out; - - __xloop_update_dio(xlo, !!arg); - if (xlo->use_dio == !!arg) - return 0; - error = -EINVAL; - out: - return error; -} - -static int xloop_set_block_size(struct xloop_device *xlo, unsigned long arg) -{ - int err = 0; - - if (xlo->xlo_state != Xlo_bound) - return -ENXIO; - - err = xloop_validate_block_size(arg); - if (err) - return err; - - if (xlo->xlo_queue->limits.logical_block_size == arg) - return 0; - - sync_blockdev(xlo->xlo_device); - invalidate_bdev(xlo->xlo_device); - - blk_mq_freeze_queue(xlo->xlo_queue); - - /* invalidate_bdev should have truncated all the pages */ - if (xlo->xlo_device->bd_inode->i_mapping->nrpages) { - err = -EAGAIN; - pr_warn("%s: xloop%d (%s) has still dirty pages (nrpages=%lu)\n", - __func__, xlo->xlo_number, xlo->xlo_file_name, - xlo->xlo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - - blk_queue_logical_block_size(xlo->xlo_queue, arg); - blk_queue_physical_block_size(xlo->xlo_queue, arg); - blk_queue_io_min(xlo->xlo_queue, arg); - xloop_update_dio(xlo); -out_unfreeze: - blk_mq_unfreeze_queue(xlo->xlo_queue); - - return err; -} - -static int xlo_simple_ioctl(struct xloop_device *xlo, unsigned int cmd, - unsigned long arg) -{ - int err; - - err = mutex_lock_killable(&xloop_ctl_mutex); - if (err) - return err; - switch (cmd) { - case XLOOP_SET_CAPACITY: - err = xloop_set_capacity(xlo); - break; - case XLOOP_SET_DIRECT_IO: - err = xloop_set_dio(xlo, arg); - break; - case XLOOP_SET_BLOCK_SIZE: - err = xloop_set_block_size(xlo, arg); - break; - default: - err = xlo->ioctl ? xlo->ioctl(xlo, cmd, arg) : -EINVAL; - } - mutex_unlock(&xloop_ctl_mutex); - return err; -} - -static int xlo_ioctl(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) -{ - struct xloop_device *xlo = bdev->bd_disk->private_data; - void __user *argp = (void __user *) arg; - int err; - - switch (cmd) { - case XLOOP_SET_FD: { - /* - * Legacy case - pass in a zeroed out struct xloop_config with - * only the file descriptor set , which corresponds with the - * default parameters we'd have used otherwise. - */ - struct xloop_config config; - - memset(&config, 0, sizeof(config)); - config.fd = arg; - - return xloop_configure(xlo, mode, bdev, &config); - } - case XLOOP_CONFIGURE: { - struct xloop_config config; - - if (copy_from_user(&config, argp, sizeof(config))) - return -EFAULT; - - return xloop_configure(xlo, mode, bdev, &config); - } - case XLOOP_CHANGE_FD: - return xloop_change_fd(xlo, bdev, arg); - case XLOOP_CLR_FD: - return xloop_clr_fd(xlo); - case XLOOP_SET_STATUS: - err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { - err = xloop_set_status_old(xlo, argp); - } - break; - case XLOOP_GET_STATUS: - return xloop_get_status_old(xlo, argp); - case XLOOP_SET_STATUS64: - err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { - err = xloop_set_status64(xlo, argp); - } - break; - case XLOOP_GET_STATUS64: - return xloop_get_status64(xlo, argp); - case XLOOP_SET_CAPACITY: - case XLOOP_SET_DIRECT_IO: - case XLOOP_SET_BLOCK_SIZE: - if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN)) - return -EPERM; - fallthrough; - default: - err = xlo_simple_ioctl(xlo, cmd, arg); - break; - } - - return err; -} - -#ifdef CONFIG_COMPAT -struct compat_xloop_info { - compat_int_t xlo_number; /* ioctl r/o */ - compat_dev_t xlo_device; /* ioctl r/o */ - compat_ulong_t xlo_inode; /* ioctl r/o */ - compat_dev_t xlo_rdevice; /* ioctl r/o */ - compat_int_t xlo_offset; - compat_int_t xlo_encrypt_type; - compat_int_t xlo_encrypt_key_size; /* ioctl w/o */ - compat_int_t xlo_flags; /* ioctl r/o */ - char xlo_name[XLO_NAME_SIZE]; - unsigned char xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ - compat_ulong_t xlo_init[2]; - char reserved[4]; - compat_int_t xlo_file_fmt_type; -}; - -/* - * Transfer 32-bit compatibility structure in userspace to 64-bit xloop info - * - noinlined to reduce stack space usage in main part of driver - */ -static noinline int -xloop_info64_from_compat(const struct compat_xloop_info __user *arg, - struct xloop_info64 *info64) -{ - struct compat_xloop_info info; - - if (copy_from_user(&info, arg, sizeof(info))) - return -EFAULT; - - memset(info64, 0, sizeof(*info64)); - info64->xlo_number = info.xlo_number; - info64->xlo_device = info.xlo_device; - info64->xlo_inode = info.xlo_inode; - info64->xlo_rdevice = info.xlo_rdevice; - info64->xlo_offset = info.xlo_offset; - info64->xlo_sizelimit = 0; - info64->xlo_encrypt_type = info.xlo_encrypt_type; - info64->xlo_encrypt_key_size = info.xlo_encrypt_key_size; - info64->xlo_flags = info.xlo_flags; - info64->xlo_init[0] = info.xlo_init[0]; - info64->xlo_init[1] = info.xlo_init[1]; - info64->xlo_file_fmt_type = info.xlo_file_fmt_type; - if (info.xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) - memcpy(info64->xlo_crypt_name, info.xlo_name, XLO_NAME_SIZE); - else - memcpy(info64->xlo_file_name, info.xlo_name, XLO_NAME_SIZE); - memcpy(info64->xlo_encrypt_key, info.xlo_encrypt_key, XLO_KEY_SIZE); - return 0; -} - -/* - * Transfer 64-bit xloop info to 32-bit compatibility structure in userspace - * - noinlined to reduce stack space usage in main part of driver - */ -static noinline int -xloop_info64_to_compat(const struct xloop_info64 *info64, - struct compat_xloop_info __user *arg) -{ - struct compat_xloop_info info; - - memset(&info, 0, sizeof(info)); - info.xlo_number = info64->xlo_number; - info.xlo_device = info64->xlo_device; - info.xlo_inode = info64->xlo_inode; - info.xlo_rdevice = info64->xlo_rdevice; - info.xlo_offset = info64->xlo_offset; - info.xlo_encrypt_type = info64->xlo_encrypt_type; - info.xlo_encrypt_key_size = info64->xlo_encrypt_key_size; - info.xlo_flags = info64->xlo_flags; - info.xlo_init[0] = info64->xlo_init[0]; - info.xlo_init[1] = info64->xlo_init[1]; - if (info.xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) - memcpy(info.xlo_name, info64->xlo_crypt_name, XLO_NAME_SIZE); - else - memcpy(info.xlo_name, info64->xlo_file_name, XLO_NAME_SIZE); - memcpy(info.xlo_encrypt_key, info64->xlo_encrypt_key, XLO_KEY_SIZE); - - /* error in case values were truncated */ - if (info.xlo_device != info64->xlo_device || - info.xlo_rdevice != info64->xlo_rdevice || - info.xlo_inode != info64->xlo_inode || - info.xlo_offset != info64->xlo_offset || - info.xlo_init[0] != info64->xlo_init[0] || - info.xlo_init[1] != info64->xlo_init[1]) - return -EOVERFLOW; - - if (copy_to_user(arg, &info, sizeof(info))) - return -EFAULT; - return 0; -} - -static int -xloop_set_status_compat(struct xloop_device *xlo, - const struct compat_xloop_info __user *arg) -{ - struct xloop_info64 info64; - int ret; - - ret = xloop_info64_from_compat(arg, &info64); - if (ret < 0) - return ret; - return xloop_set_status(xlo, &info64); -} - -static int -xloop_get_status_compat(struct xloop_device *xlo, - struct compat_xloop_info __user *arg) -{ - struct xloop_info64 info64; - int err; - - if (!arg) - return -EINVAL; - err = xloop_get_status(xlo, &info64); - if (!err) - err = xloop_info64_to_compat(&info64, arg); - return err; -} - -static int xlo_compat_ioctl(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) -{ - struct xloop_device *xlo = bdev->bd_disk->private_data; - int err; - - switch(cmd) { - case XLOOP_SET_STATUS: - err = xloop_set_status_compat(xlo, - (const struct compat_xloop_info __user *)arg); - break; - case XLOOP_GET_STATUS: - err = xloop_get_status_compat(xlo, - (struct compat_xloop_info __user *)arg); - break; - case XLOOP_SET_CAPACITY: - case XLOOP_CLR_FD: - case XLOOP_GET_STATUS64: - case XLOOP_SET_STATUS64: - case XLOOP_CONFIGURE: - arg = (unsigned long) compat_ptr(arg); - fallthrough; - case XLOOP_SET_FD: - case XLOOP_CHANGE_FD: - case XLOOP_SET_BLOCK_SIZE: - case XLOOP_SET_DIRECT_IO: - err = xlo_ioctl(bdev, mode, cmd, arg); - break; - default: - err = -ENOIOCTLCMD; - break; - } - return err; -} -#endif - -static int xlo_open(struct block_device *bdev, fmode_t mode) -{ - struct xloop_device *xlo; - int err; - - err = mutex_lock_killable(&xloop_ctl_mutex); - if (err) - return err; - xlo = bdev->bd_disk->private_data; - if (!xlo) { - err = -ENXIO; - goto out; - } - - atomic_inc(&xlo->xlo_refcnt); -out: - mutex_unlock(&xloop_ctl_mutex); - return err; -} - -static void xlo_release(struct gendisk *disk, fmode_t mode) -{ - struct xloop_device *xlo; - - mutex_lock(&xloop_ctl_mutex); - xlo = disk->private_data; - if (atomic_dec_return(&xlo->xlo_refcnt)) - goto out_unlock; - - if (xlo->xlo_flags & XLO_FLAGS_AUTOCLEAR) { - if (xlo->xlo_state != Xlo_bound) - goto out_unlock; - xlo->xlo_state = Xlo_rundown; - mutex_unlock(&xloop_ctl_mutex); - /* - * In autoclear mode, stop the xloop thread - * and remove configuration after last close. - */ - __xloop_clr_fd(xlo, true); - return; - } else if (xlo->xlo_state == Xlo_bound) { - /* - * Otherwise keep thread (if running) and config, - * but flush possible ongoing bios in thread. - */ - blk_mq_freeze_queue(xlo->xlo_queue); - blk_mq_unfreeze_queue(xlo->xlo_queue); - } - -out_unlock: - mutex_unlock(&xloop_ctl_mutex); -} - -static const struct block_device_operations xlo_fops = { - .owner = THIS_MODULE, - .open = xlo_open, - .release = xlo_release, - .ioctl = xlo_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = xlo_compat_ioctl, -#endif -}; - -/* - * And now the modules code and kernel interface. - */ -static int max_xloop; -module_param(max_xloop, int, 0444); -MODULE_PARM_DESC(max_xloop, "Maximum number of xloop devices"); -module_param(max_part, int, 0444); -MODULE_PARM_DESC(max_part, "Maximum number of partitions per xloop device"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS_BLOCKDEV_MAJOR(XLOOP_MAJOR); - -int xloop_register_transfer(struct xloop_func_table *funcs) -{ - unsigned int n = funcs->number; - - if (n >= MAX_XLO_CRYPT || xfer_funcs[n]) - return -EINVAL; - xfer_funcs[n] = funcs; - return 0; -} - -static int unregister_transfer_cb(int id, void *ptr, void *data) -{ - struct xloop_device *xlo = ptr; - struct xloop_func_table *xfer = data; - - mutex_lock(&xloop_ctl_mutex); - if (xlo->xlo_encryption == xfer) - xloop_release_xfer(xlo); - mutex_unlock(&xloop_ctl_mutex); - return 0; -} - -int xloop_unregister_transfer(int number) -{ - unsigned int n = number; - struct xloop_func_table *xfer; - - if (n == 0 || n >= MAX_XLO_CRYPT || (xfer = xfer_funcs[n]) == NULL) - return -EINVAL; - - xfer_funcs[n] = NULL; - idr_for_each(&xloop_index_idr, &unregister_transfer_cb, xfer); - return 0; -} - -EXPORT_SYMBOL(xloop_register_transfer); -EXPORT_SYMBOL(xloop_unregister_transfer); - -static blk_status_t xloop_queue_rq(struct blk_mq_hw_ctx *hctx, - const struct blk_mq_queue_data *bd) -{ - struct request *rq = bd->rq; - struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); - struct xloop_device *xlo = rq->q->queuedata; - - blk_mq_start_request(rq); - - if (xlo->xlo_state != Xlo_bound) - return BLK_STS_IOERR; - - switch (req_op(rq)) { - case REQ_OP_FLUSH: - case REQ_OP_DISCARD: - case REQ_OP_WRITE_ZEROES: - cmd->use_aio = false; - break; - default: - cmd->use_aio = xlo->use_dio; - break; - } - - /* always use the first bio's css */ -#ifdef CONFIG_BLK_CGROUP - if (cmd->use_aio && rq->bio && rq->bio->bi_blkg) { - cmd->css = &bio_blkcg(rq->bio)->css; - css_get(cmd->css); - } else -#endif - cmd->css = NULL; - kthread_queue_work(&xlo->worker, &cmd->work); - - return BLK_STS_OK; -} - -static void xloop_handle_cmd(struct xloop_cmd *cmd) -{ - struct request *rq = blk_mq_rq_from_pdu(cmd); - const bool write = op_is_write(req_op(rq)); - struct xloop_device *xlo = rq->q->queuedata; - int ret = 0; - - if (write && (xlo->xlo_flags & XLO_FLAGS_READ_ONLY)) { - ret = -EIO; - goto failed; - } - - ret = do_req_filebacked(xlo, rq); - failed: - /* complete non-aio request */ - if (!cmd->use_aio || ret) { - if (ret == -EOPNOTSUPP) - cmd->ret = ret; - else - cmd->ret = ret ? -EIO : 0; -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) - if (likely(!blk_should_fake_timeout(rq->q))) - blk_mq_complete_request(rq); -#else - blk_mq_complete_request(rq); -#endif - } -} - -static void xloop_queue_work(struct kthread_work *work) -{ - struct xloop_cmd *cmd = - container_of(work, struct xloop_cmd, work); - - xloop_handle_cmd(cmd); -} - -static int xloop_init_request(struct blk_mq_tag_set *set, struct request *rq, - unsigned int hctx_idx, unsigned int numa_node) -{ - struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); - - kthread_init_work(&cmd->work, xloop_queue_work); - return 0; -} - -static const struct blk_mq_ops xloop_mq_ops = { - .queue_rq = xloop_queue_rq, - .init_request = xloop_init_request, - .complete = xlo_complete_rq, -}; - -static struct dentry *xloop_dbgfs_dir; - -static int xloop_add(struct xloop_device **l, int i) -{ - struct xloop_device *xlo; - struct gendisk *disk; - int err; - - err = -ENOMEM; - xlo = kzalloc(sizeof(*xlo), GFP_KERNEL); - if (!xlo) - goto out; - - xlo->xlo_state = Xlo_unbound; - - /* allocate id, if @id >= 0, we're requesting that specific id */ - if (i >= 0) { - err = idr_alloc(&xloop_index_idr, xlo, i, i + 1, GFP_KERNEL); - if (err == -ENOSPC) - err = -EEXIST; - } else { - err = idr_alloc(&xloop_index_idr, xlo, 0, 0, GFP_KERNEL); - } - if (err < 0) - goto out_free_dev; - i = err; - - err = -ENOMEM; - xlo->tag_set.ops = &xloop_mq_ops; - xlo->tag_set.nr_hw_queues = 1; - xlo->tag_set.queue_depth = 128; - xlo->tag_set.numa_node = NUMA_NO_NODE; - xlo->tag_set.cmd_size = sizeof(struct xloop_cmd); -#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0) - xlo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING; -#else - xlo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; -#endif - xlo->tag_set.driver_data = xlo; - - err = blk_mq_alloc_tag_set(&xlo->tag_set); - if (err) - goto out_free_idr; - - xlo->xlo_queue = blk_mq_init_queue(&xlo->tag_set); - if (IS_ERR(xlo->xlo_queue)) { - err = PTR_ERR(xlo->xlo_queue); - goto out_cleanup_tags; - } - xlo->xlo_queue->queuedata = xlo; - - blk_queue_max_hw_sectors(xlo->xlo_queue, BLK_DEF_MAX_SECTORS); - - /* - * By default, we do buffer IO, so it doesn't make sense to enable - * merge because the I/O submitted to backing file is handled page by - * page. For directio mode, merge does help to dispatch bigger request - * to underlayer disk. We will enable merge once directio is enabled. - */ - blk_queue_flag_set(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); - - err = -ENOMEM; - xlo->xlo_fmt = xloop_file_fmt_alloc(); - if (!xlo->xlo_fmt) - goto out_free_queue; - - xloop_file_fmt_set_xlo(xlo->xlo_fmt, xlo); - - err = -ENOMEM; - disk = xlo->xlo_disk = alloc_disk(1 << part_shift); - if (!disk) - goto out_free_file_fmt; - - /* - * Disable partition scanning by default. The in-kernel partition - * scanning can be requested individually per-device during its - * setup. Userspace can always add and remove partitions from all - * devices. The needed partition minors are allocated from the - * extended minor space, the main xloop device numbers will continue - * to match the xloop minors, regardless of the number of partitions - * used. - * - * If max_part is given, partition scanning is globally enabled for - * all xloop devices. The minors for the main xloop devices will be - * multiples of max_part. - * - * Note: Global-for-all-devices, set-only-at-init, read-only module - * parameteters like 'max_xloop' and 'max_part' make things needlessly - * complicated, are too static, inflexible and may surprise - * userspace tools. Parameters like this in general should be avoided. - */ - if (!part_shift) - disk->flags |= GENHD_FL_NO_PART_SCAN; - disk->flags |= GENHD_FL_EXT_DEVT; - atomic_set(&xlo->xlo_refcnt, 0); - xlo->xlo_number = i; - spin_lock_init(&xlo->xlo_lock); - disk->major = XLOOP_MAJOR; - disk->first_minor = i << part_shift; - disk->fops = &xlo_fops; - disk->private_data = xlo; - disk->queue = xlo->xlo_queue; - sprintf(disk->disk_name, "xloop%d", i); - add_disk(disk); - *l = xlo; - - /* initialize debugfs entries */ - /* create for each loop device a debugfs directory under 'loop' if - * the 'block' directory exists, otherwise create the loop directory in - * the root directory */ -#ifdef CONFIG_DEBUG_FS - xlo->xlo_dbgfs_dir = debugfs_create_dir(disk->disk_name, xloop_dbgfs_dir); - - if (IS_ERR_OR_NULL(xlo->xlo_dbgfs_dir)) { - err = -ENODEV; - xlo->xlo_dbgfs_dir = NULL; - goto out_free_file_fmt; - } -#endif - - return xlo->xlo_number; - -out_free_file_fmt: - xloop_file_fmt_free(xlo->xlo_fmt); -out_free_queue: - blk_cleanup_queue(xlo->xlo_queue); -out_cleanup_tags: - blk_mq_free_tag_set(&xlo->tag_set); -out_free_idr: - idr_remove(&xloop_index_idr, i); -out_free_dev: - kfree(xlo); -out: - return err; -} - -static void xloop_remove(struct xloop_device *xlo) -{ - xloop_file_fmt_free(xlo->xlo_fmt); - debugfs_remove(xlo->xlo_dbgfs_dir); - del_gendisk(xlo->xlo_disk); - blk_cleanup_queue(xlo->xlo_queue); - blk_mq_free_tag_set(&xlo->tag_set); - put_disk(xlo->xlo_disk); - kfree(xlo); -} - -static int find_free_cb(int id, void *ptr, void *data) -{ - struct xloop_device *xlo = ptr; - struct xloop_device **l = data; - - if (xlo->xlo_state == Xlo_unbound) { - *l = xlo; - return 1; - } - return 0; -} - -static int xloop_lookup(struct xloop_device **l, int i) -{ - struct xloop_device *xlo; - int ret = -ENODEV; - - if (i < 0) { - int err; - - err = idr_for_each(&xloop_index_idr, &find_free_cb, &xlo); - if (err == 1) { - *l = xlo; - ret = xlo->xlo_number; - } - goto out; - } - - /* lookup and return a specific i */ - xlo = idr_find(&xloop_index_idr, i); - if (xlo) { - *l = xlo; - ret = xlo->xlo_number; - } -out: - return ret; -} - -static struct kobject *xloop_probe(dev_t dev, int *part, void *data) -{ - struct xloop_device *xlo; - struct kobject *kobj; - int err; - - mutex_lock(&xloop_ctl_mutex); - err = xloop_lookup(&xlo, MINOR(dev) >> part_shift); - if (err < 0) - err = xloop_add(&xlo, MINOR(dev) >> part_shift); - if (err < 0) - kobj = NULL; - else - kobj = get_disk_and_module(xlo->xlo_disk); - mutex_unlock(&xloop_ctl_mutex); - - *part = 0; - return kobj; -} - -static long xloop_control_ioctl(struct file *file, unsigned int cmd, - unsigned long parm) -{ - struct xloop_device *xlo; - int ret; - - ret = mutex_lock_killable(&xloop_ctl_mutex); - if (ret) - return ret; - - ret = -ENOSYS; - switch (cmd) { - case XLOOP_CTL_ADD: - ret = xloop_lookup(&xlo, parm); - if (ret >= 0) { - ret = -EEXIST; - break; - } - ret = xloop_add(&xlo, parm); - break; - case XLOOP_CTL_REMOVE: - ret = xloop_lookup(&xlo, parm); - if (ret < 0) - break; - if (xlo->xlo_state != Xlo_unbound) { - ret = -EBUSY; - break; - } - if (atomic_read(&xlo->xlo_refcnt) > 0) { - ret = -EBUSY; - break; - } - xlo->xlo_disk->private_data = NULL; - idr_remove(&xloop_index_idr, xlo->xlo_number); - xloop_remove(xlo); - break; - case XLOOP_CTL_GET_FREE: - ret = xloop_lookup(&xlo, -1); - if (ret >= 0) - break; - ret = xloop_add(&xlo, -1); - } - mutex_unlock(&xloop_ctl_mutex); - - return ret; -} - -static const struct file_operations xloop_ctl_fops = { - .open = nonseekable_open, - .unlocked_ioctl = xloop_control_ioctl, - .compat_ioctl = xloop_control_ioctl, - .owner = THIS_MODULE, - .llseek = noop_llseek, -}; - -static struct miscdevice xloop_misc = { - .minor = LOOP_CTRL_MINOR, - .name = "xloop-control", - .fops = &xloop_ctl_fops, -}; - -MODULE_ALIAS_MISCDEV(LOOP_CTRL_MINOR); -MODULE_ALIAS("devname:xloop-control"); - -static int __init xloop_init(void) -{ - int i, nr; - unsigned long range; - struct xloop_device *xlo; - int err; - - part_shift = 0; - if (max_part > 0) { - part_shift = fls(max_part); - - /* - * Adjust max_part according to part_shift as it is exported - * to user space so that user can decide correct minor number - * if [s]he want to create more devices. - * - * Note that -1 is required because partition 0 is reserved - * for the whole disk. - */ - max_part = (1UL << part_shift) - 1; - } - - if ((1UL << part_shift) > DISK_MAX_PARTS) { - err = -EINVAL; - goto err_out; - } - - if (max_xloop > 1UL << (MINORBITS - part_shift)) { - err = -EINVAL; - goto err_out; - } - - /* - * If max_xloop is specified, create that many devices upfront. - * This also becomes a hard limit. If max_xloop is not specified, - * create CONFIG_BLK_DEV_XLOOP_MIN_COUNT xloop devices at module - * init time. xloop devices can be requested on-demand with the - * /dev/xloop-control interface, or be instantiated by accessing - * a 'dead' device node. - */ - if (max_xloop) { - nr = CONFIG_BLK_DEV_XLOOP_MIN_COUNT; - range = 1UL << MINORBITS; - } - - err = misc_register(&xloop_misc); - if (err < 0) - goto err_out; - - - if (register_blkdev(XLOOP_MAJOR, "xloop")) { - err = -EIO; - goto misc_out; - } - -#ifdef CONFIG_DEBUG_FS - xloop_dbgfs_dir = debugfs_create_dir("xloop", NULL); - if (IS_ERR_OR_NULL(xloop_dbgfs_dir)) { - err = -ENODEV; - goto misc_out; - } -#endif - - blk_register_region(MKDEV(XLOOP_MAJOR, 0), range, - THIS_MODULE, xloop_probe, NULL, NULL); - - /* pre-create number of devices given by config or max_xloop */ - mutex_lock(&xloop_ctl_mutex); - for (i = 0; i < nr; i++) - xloop_add(&xlo, i); - mutex_unlock(&xloop_ctl_mutex); - - printk(KERN_INFO "xloop: module loaded\n"); - return 0; - -misc_out: - misc_deregister(&xloop_misc); -err_out: - return err; -} - -static int xloop_exit_cb(int id, void *ptr, void *data) -{ - struct xloop_device *xlo = ptr; - - xloop_remove(xlo); - return 0; -} - -static void __exit xloop_exit(void) -{ - unsigned long range; - - range = max_xloop ? max_xloop << part_shift : 1UL << MINORBITS; - - mutex_lock(&xloop_ctl_mutex); - - idr_for_each(&xloop_index_idr, &xloop_exit_cb, NULL); - idr_destroy(&xloop_index_idr); - - blk_unregister_region(MKDEV(XLOOP_MAJOR, 0), range); - unregister_blkdev(XLOOP_MAJOR, "xloop"); - -#ifdef CONFIG_DEBUG_FS - debugfs_remove(xloop_dbgfs_dir); -#endif - - misc_deregister(&xloop_misc); - - mutex_unlock(&xloop_ctl_mutex); -} - -module_init(xloop_init); -module_exit(xloop_exit); - -#ifndef MODULE -static int __init max_xloop_setup(char *str) -{ - max_xloop = simple_strtol(str, NULL, 0); - return 1; -} - -__setup("max_xloop=", max_xloop_setup); -#endif diff --git a/kernel/loop_main.h b/kernel/loop_main.h deleted file mode 100644 index 1b5851a..0000000 --- a/kernel/loop_main.h +++ /dev/null @@ -1,105 +0,0 @@ -/* - * loop_main.h - * - * Written by Theodore Ts'o, 3/29/93. - * - * Copyright 1993 by Theodore Ts'o. Redistribution of this file is - * permitted under the GNU General Public License. - */ -#ifndef _LINUX_XLOOP_H -#define _LINUX_XLOOP_H - -#include -#include -#include -#include -#include -#include -#include "uapi/linux/loop.h" -#ifdef CONFIG_DEBUG_FS -#include -#endif - -#include "loop_file_fmt.h" - -/* Possible states of device */ -enum { - Xlo_unbound, - Xlo_bound, - Xlo_rundown, -}; - -struct xloop_func_table; - -struct xloop_device { - int xlo_number; - atomic_t xlo_refcnt; - loff_t xlo_offset; - loff_t xlo_sizelimit; - int xlo_flags; - int (*transfer)(struct xloop_device *, int cmd, - struct page *raw_page, unsigned raw_off, - struct page *xloop_page, unsigned xloop_off, - int size, sector_t real_block); - char xlo_file_name[XLO_NAME_SIZE]; - char xlo_crypt_name[XLO_NAME_SIZE]; - char xlo_encrypt_key[XLO_KEY_SIZE]; - int xlo_encrypt_key_size; - struct xloop_func_table *xlo_encryption; - __u32 xlo_init[2]; - kuid_t xlo_key_owner; /* Who set the key */ - int (*ioctl)(struct xloop_device *, int cmd, - unsigned long arg); - - struct xloop_file_fmt *xlo_fmt; - - struct file * xlo_backing_file; - struct block_device *xlo_device; - void *key_data; - - gfp_t old_gfp_mask; - - spinlock_t xlo_lock; - int xlo_state; - struct kthread_worker worker; - struct task_struct *worker_task; - bool use_dio; - bool sysfs_inited; - - struct request_queue *xlo_queue; - struct blk_mq_tag_set tag_set; - struct gendisk *xlo_disk; - -#ifdef CONFIG_DEBUG_FS - struct dentry *xlo_dbgfs_dir; -#endif -}; - -struct xloop_cmd { - struct kthread_work work; - bool use_aio; /* use AIO interface to handle I/O */ - atomic_t ref; /* only for aio */ - long ret; - struct kiocb iocb; - struct bio_vec *bvec; - struct cgroup_subsys_state *css; -}; - -/* Support for loadable transfer modules */ -struct xloop_func_table { - int number; /* filter type */ - int (*transfer)(struct xloop_device *xlo, int cmd, - struct page *raw_page, unsigned raw_off, - struct page *xloop_page, unsigned xloop_off, - int size, sector_t real_block); - int (*init)(struct xloop_device *, const struct xloop_info64 *); - /* release is called from xloop_unregister_transfer or clr_fd */ - int (*release)(struct xloop_device *); - int (*ioctl)(struct xloop_device *, int cmd, unsigned long arg); - struct module *owner; -}; - -int xloop_register_transfer(struct xloop_func_table *funcs); -int xloop_unregister_transfer(int number); - -#endif diff --git a/kernel/uapi/linux/loop.h b/kernel/uapi/linux/loop.h deleted file mode 100644 index f93f6ad..0000000 --- a/kernel/uapi/linux/loop.h +++ /dev/null @@ -1,125 +0,0 @@ -/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */ -/* - * include/linux/loop.h - * - * Written by Theodore Ts'o, 3/29/93. - * - * Copyright 1993 by Theodore Ts'o. Redistribution of this file is - * permitted under the GNU General Public License. - */ -#ifndef _UAPI_LINUX_XLOOP_H -#define _UAPI_LINUX_XLOOP_H - - -#define XLO_NAME_SIZE 64 -#define XLO_KEY_SIZE 32 - - -/* - * xloop flags - */ -enum { - XLO_FLAGS_READ_ONLY = 1, - XLO_FLAGS_AUTOCLEAR = 4, - XLO_FLAGS_PARTSCAN = 8, - XLO_FLAGS_DIRECT_IO = 16, -}; - -/* XLO_FLAGS that can be set using XLOOP_SET_STATUS(64) */ -#define XLOOP_SET_STATUS_SETTABLE_FLAGS (XLO_FLAGS_AUTOCLEAR | XLO_FLAGS_PARTSCAN) - -/* XLO_FLAGS that can be cleared using XLOOP_SET_STATUS(64) */ -#define XLOOP_SET_STATUS_CLEARABLE_FLAGS (XLO_FLAGS_AUTOCLEAR) - -/* XLO_FLAGS that can be set using XLOOP_CONFIGURE */ -#define XLOOP_CONFIGURE_SETTABLE_FLAGS (XLO_FLAGS_READ_ONLY | XLO_FLAGS_AUTOCLEAR \ - | XLO_FLAGS_PARTSCAN | XLO_FLAGS_DIRECT_IO) - -#include /* for __kernel_old_dev_t */ -#include /* for __u64 */ - -/* Backwards compatibility version */ -struct xloop_info { - int xlo_number; /* ioctl r/o */ - __kernel_old_dev_t xlo_device; /* ioctl r/o */ - unsigned long xlo_inode; /* ioctl r/o */ - __kernel_old_dev_t xlo_rdevice; /* ioctl r/o */ - int xlo_offset; - int xlo_encrypt_type; - int xlo_encrypt_key_size; /* ioctl w/o */ - int xlo_flags; - char xlo_name[XLO_NAME_SIZE]; - unsigned char xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ - unsigned long xlo_init[2]; - char reserved[4]; - int xlo_file_fmt_type; -}; - -struct xloop_info64 { - __u64 xlo_device; /* ioctl r/o */ - __u64 xlo_inode; /* ioctl r/o */ - __u64 xlo_rdevice; /* ioctl r/o */ - __u64 xlo_offset; - __u64 xlo_sizelimit; /* bytes, 0 == max available */ - __u32 xlo_number; /* ioctl r/o */ - __u32 xlo_encrypt_type; - __u32 xlo_encrypt_key_size; /* ioctl w/o */ - __u32 xlo_flags; - __u8 xlo_file_name[XLO_NAME_SIZE]; - __u8 xlo_crypt_name[XLO_NAME_SIZE]; - __u8 xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ - __u64 xlo_init[2]; - __u32 xlo_file_fmt_type; -}; - -/** - * struct xloop_config - Complete configuration for a xloop device. - * @fd: fd of the file to be used as a backing file for the xloop device. - * @block_size: block size to use; ignored if 0. - * @info: struct xloop_info64 to configure the xloop device with. - * - * This structure is used with the XLOOP_CONFIGURE ioctl, and can be used to - * atomically setup and configure all xloop device parameters at once. - */ -struct xloop_config { - __u32 fd; - __u32 block_size; - struct xloop_info64 info; - __u64 __reserved[8]; -}; - -/* - * xloop filter types - */ -#define XLO_CRYPT_NONE 0 -#define XLO_CRYPT_XOR 1 -#define XLO_CRYPT_DES 2 -#define XLO_CRYPT_FISH2 3 /* Twofish encryption */ -#define XLO_CRYPT_BLOW 4 -#define XLO_CRYPT_CAST128 5 -#define XLO_CRYPT_IDEA 6 -#define XLO_CRYPT_DUMMY 9 -#define XLO_CRYPT_SKIPJACK 10 -#define XLO_CRYPT_CRYPTOAPI 18 -#define MAX_XLO_CRYPT 20 - -/* - * IOCTL commands --- we will commandeer 0x4C ('L') - */ -#define XLOOP_SET_FD 0x4C00 -#define XLOOP_CLR_FD 0x4C01 -#define XLOOP_SET_STATUS 0x4C02 -#define XLOOP_GET_STATUS 0x4C03 -#define XLOOP_SET_STATUS64 0x4C04 -#define XLOOP_GET_STATUS64 0x4C05 -#define XLOOP_CHANGE_FD 0x4C06 -#define XLOOP_SET_CAPACITY 0x4C07 -#define XLOOP_SET_DIRECT_IO 0x4C08 -#define XLOOP_SET_BLOCK_SIZE 0x4C09 -#define XLOOP_CONFIGURE 0x4C0A - -/* /dev/xloop-control interface */ -#define XLOOP_CTL_ADD 0x4C80 -#define XLOOP_CTL_REMOVE 0x4C81 -#define XLOOP_CTL_GET_FREE 0x4C82 -#endif /* _UAPI_LINUX_XLOOP_H */ diff --git a/kernel/uapi/linux/xloop.h b/kernel/uapi/linux/xloop.h new file mode 100644 index 0000000..1bf13c6 --- /dev/null +++ b/kernel/uapi/linux/xloop.h @@ -0,0 +1,125 @@ +/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */ +/* + * include/linux/xloop.h + * + * Written by Theodore Ts'o, 3/29/93. + * + * Copyright 1993 by Theodore Ts'o. Redistribution of this file is + * permitted under the GNU General Public License. + */ +#ifndef _UAPI_LINUX_XLOOP_H +#define _UAPI_LINUX_XLOOP_H + + +#define XLO_NAME_SIZE 64 +#define XLO_KEY_SIZE 32 + + +/* + * xloop flags + */ +enum { + XLO_FLAGS_READ_ONLY = 1, + XLO_FLAGS_AUTOCLEAR = 4, + XLO_FLAGS_PARTSCAN = 8, + XLO_FLAGS_DIRECT_IO = 16, +}; + +/* XLO_FLAGS that can be set using XLOOP_SET_STATUS(64) */ +#define XLOOP_SET_STATUS_SETTABLE_FLAGS (XLO_FLAGS_AUTOCLEAR | XLO_FLAGS_PARTSCAN) + +/* XLO_FLAGS that can be cleared using XLOOP_SET_STATUS(64) */ +#define XLOOP_SET_STATUS_CLEARABLE_FLAGS (XLO_FLAGS_AUTOCLEAR) + +/* XLO_FLAGS that can be set using XLOOP_CONFIGURE */ +#define XLOOP_CONFIGURE_SETTABLE_FLAGS (XLO_FLAGS_READ_ONLY | XLO_FLAGS_AUTOCLEAR \ + | XLO_FLAGS_PARTSCAN | XLO_FLAGS_DIRECT_IO) + +#include /* for __kernel_old_dev_t */ +#include /* for __u64 */ + +/* Backwards compatibility version */ +struct xloop_info { + int xlo_number; /* ioctl r/o */ + __kernel_old_dev_t xlo_device; /* ioctl r/o */ + unsigned long xlo_inode; /* ioctl r/o */ + __kernel_old_dev_t xlo_rdevice; /* ioctl r/o */ + int xlo_offset; + int xlo_encrypt_type; + int xlo_encrypt_key_size; /* ioctl w/o */ + int xlo_flags; + char xlo_name[XLO_NAME_SIZE]; + unsigned char xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ + unsigned long xlo_init[2]; + char reserved[4]; + int xlo_file_fmt_type; +}; + +struct xloop_info64 { + __u64 xlo_device; /* ioctl r/o */ + __u64 xlo_inode; /* ioctl r/o */ + __u64 xlo_rdevice; /* ioctl r/o */ + __u64 xlo_offset; + __u64 xlo_sizelimit; /* bytes, 0 == max available */ + __u32 xlo_number; /* ioctl r/o */ + __u32 xlo_encrypt_type; + __u32 xlo_encrypt_key_size; /* ioctl w/o */ + __u32 xlo_flags; + __u8 xlo_file_name[XLO_NAME_SIZE]; + __u8 xlo_crypt_name[XLO_NAME_SIZE]; + __u8 xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ + __u64 xlo_init[2]; + __u32 xlo_file_fmt_type; +}; + +/** + * struct xloop_config - Complete configuration for a xloop device. + * @fd: fd of the file to be used as a backing file for the xloop device. + * @block_size: block size to use; ignored if 0. + * @info: struct xloop_info64 to configure the xloop device with. + * + * This structure is used with the XLOOP_CONFIGURE ioctl, and can be used to + * atomically setup and configure all xloop device parameters at once. + */ +struct xloop_config { + __u32 fd; + __u32 block_size; + struct xloop_info64 info; + __u64 __reserved[8]; +}; + +/* + * xloop filter types + */ +#define XLO_CRYPT_NONE 0 +#define XLO_CRYPT_XOR 1 +#define XLO_CRYPT_DES 2 +#define XLO_CRYPT_FISH2 3 /* Twofish encryption */ +#define XLO_CRYPT_BLOW 4 +#define XLO_CRYPT_CAST128 5 +#define XLO_CRYPT_IDEA 6 +#define XLO_CRYPT_DUMMY 9 +#define XLO_CRYPT_SKIPJACK 10 +#define XLO_CRYPT_CRYPTOAPI 18 +#define MAX_XLO_CRYPT 20 + +/* + * IOCTL commands --- we will commandeer 0x4C ('L') + */ +#define XLOOP_SET_FD 0x4C00 +#define XLOOP_CLR_FD 0x4C01 +#define XLOOP_SET_STATUS 0x4C02 +#define XLOOP_GET_STATUS 0x4C03 +#define XLOOP_SET_STATUS64 0x4C04 +#define XLOOP_GET_STATUS64 0x4C05 +#define XLOOP_CHANGE_FD 0x4C06 +#define XLOOP_SET_CAPACITY 0x4C07 +#define XLOOP_SET_DIRECT_IO 0x4C08 +#define XLOOP_SET_BLOCK_SIZE 0x4C09 +#define XLOOP_CONFIGURE 0x4C0A + +/* /dev/xloop-control interface */ +#define XLOOP_CTL_ADD 0x4C80 +#define XLOOP_CTL_REMOVE 0x4C81 +#define XLOOP_CTL_GET_FREE 0x4C82 +#endif /* _UAPI_LINUX_XLOOP_H */ diff --git a/kernel/xloop_file_fmt.c b/kernel/xloop_file_fmt.c new file mode 100644 index 0000000..18672f7 --- /dev/null +++ b/kernel/xloop_file_fmt.c @@ -0,0 +1,347 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt.c + * + * File format subsystem for the xloop device module. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#include +#include + +#include "xloop_file_fmt.h" + +/* storage for all registered file format drivers */ +static struct xloop_file_fmt_driver *xloop_file_fmt_drivers[MAX_XLO_FILE_FMT] = { + NULL +}; + +int xloop_file_fmt_register_driver(struct xloop_file_fmt_driver *drv) +{ + int ret = 0; + + if (drv == NULL) + return -EFAULT; + + if (drv->file_fmt_type > MAX_XLO_FILE_FMT) + return -EINVAL; + + if (xloop_file_fmt_drivers[drv->file_fmt_type] == NULL) { + xloop_file_fmt_drivers[drv->file_fmt_type] = drv; + printk(KERN_INFO "xloop_file_fmt: successfully registered file " + "format driver %s", drv->name); + } else { + printk(KERN_WARNING "xloop_file_fmt: driver for file format " + "already registered"); + ret = -EBUSY; + } + + return ret; +} +EXPORT_SYMBOL(xloop_file_fmt_register_driver); + +void xloop_file_fmt_unregister_driver(struct xloop_file_fmt_driver *drv) +{ + if (drv == NULL) + return; + + if (drv->file_fmt_type > MAX_XLO_FILE_FMT) + return; + + xloop_file_fmt_drivers[drv->file_fmt_type] = NULL; + printk(KERN_INFO "xloop_file_fmt: successfully unregistered file " + "format driver %s", drv->name); +} +EXPORT_SYMBOL(xloop_file_fmt_unregister_driver); + +struct xloop_file_fmt *xloop_file_fmt_alloc(void) +{ + return kzalloc(sizeof(struct xloop_file_fmt), GFP_KERNEL); +} + +void xloop_file_fmt_free(struct xloop_file_fmt *xlo_fmt) +{ + kfree(xlo_fmt); +} + +int xloop_file_fmt_set_xlo(struct xloop_file_fmt *xlo_fmt, struct xloop_device *xlo) +{ + if (xlo_fmt == NULL) + return -EINVAL; + + xlo_fmt->xlo = xlo; + + return 0; +} +EXPORT_SYMBOL(xloop_file_fmt_set_xlo); + +struct xloop_device *xloop_file_fmt_get_xlo(struct xloop_file_fmt *xlo_fmt) +{ + return xlo_fmt->xlo; +} +EXPORT_SYMBOL(xloop_file_fmt_get_xlo); + +int xloop_file_fmt_init(struct xloop_file_fmt *xlo_fmt, + u32 file_fmt_type) +{ + struct xloop_file_fmt_ops *ops; + struct module *drv; + int ret = 0; + + if (file_fmt_type > MAX_XLO_FILE_FMT) + return -EINVAL; + + xlo_fmt->file_fmt_type = file_fmt_type; + + if (xlo_fmt->file_fmt_state != file_fmt_uninitialized) { + printk(KERN_WARNING "xloop_file_fmt: file format is " + "initialized already"); + return -EINVAL; + } + + /* check if new file format driver is registered */ + if (xloop_file_fmt_drivers[xlo_fmt->file_fmt_type] == NULL) { + printk(KERN_ERR "xloop_file_fmt: file format driver is not " + "available"); + return -ENODEV; + } + + printk(KERN_INFO "xloop_file_fmt: use file format driver %s", + xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->name); + + drv = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->owner; + if (!try_module_get(drv)) { + printk(KERN_ERR "xloop_file_fmt: file format driver %s can not " + "be accessed", + xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->name); + return -ENODEV; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->init)) { + ret = ops->init(xlo_fmt); + if (ret < 0) + goto free_drv; + } + + /* after increasing the refcount of file format driver module and + * the successful initialization, the file format is initialized */ + xlo_fmt->file_fmt_state = file_fmt_initialized; + + return ret; + +free_drv: + module_put(drv); + xlo_fmt->file_fmt_state = file_fmt_uninitialized; + return ret; +} + +void xloop_file_fmt_exit(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_ops *ops; + struct module *drv; + + if (xlo_fmt->file_fmt_state != file_fmt_initialized) { + printk(KERN_WARNING "xloop_file_fmt: file format is " + "uninitialized already"); + return; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->exit)) + ops->exit(xlo_fmt); + + drv = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->owner; + module_put(drv); + + /* after decreasing the refcount of file format driver module, + * the file format is uninitialized */ + xlo_fmt->file_fmt_state = file_fmt_uninitialized; +} + +int xloop_file_fmt_read(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not read"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->read)) + return ops->read(xlo_fmt, rq); + else + return -EIO; +} + +int xloop_file_fmt_read_aio(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not read aio"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->read_aio)) + return ops->read_aio(xlo_fmt, rq); + else + return -EIO; +} + +int xloop_file_fmt_write(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not write"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->write)) + return ops->write(xlo_fmt, rq); + else + return -EIO; +} + +int xloop_file_fmt_write_aio(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not write aio"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->write_aio)) + return ops->write_aio(xlo_fmt, rq); + else + return -EIO; +} + +int xloop_file_fmt_write_zeros(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not write zeros"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->write_zeros)) + return ops->write_zeros(xlo_fmt, rq); + else + return -EIO; +} + +int xloop_file_fmt_discard(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not discard"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->discard)) + return ops->discard(xlo_fmt, rq); + else + return -EIO; +} + +int xloop_file_fmt_flush(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not flush"); + return -EINVAL; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->flush)) + return ops->flush(xlo_fmt); + + return 0; +} + +loff_t xloop_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, + struct file *file, loff_t offset, loff_t sizelimit) +{ + struct xloop_file_fmt_ops *ops; + + if (unlikely(xlo_fmt->file_fmt_state != file_fmt_initialized)) { + printk(KERN_ERR "xloop_file_fmt: file format is " + "not initialized, can not read sector size"); + return 0; + } + + ops = xloop_file_fmt_drivers[xlo_fmt->file_fmt_type]->ops; + if (likely(ops->sector_size)) + return ops->sector_size(xlo_fmt, file, offset, sizelimit); + else + return 0; +} + +int xloop_file_fmt_change(struct xloop_file_fmt *xlo_fmt, + u32 file_fmt_type_new) +{ + if (file_fmt_type_new > MAX_XLO_FILE_FMT) + return -EINVAL; + + /* Unload the old file format driver if the file format is + * initialized */ + if (xlo_fmt->file_fmt_state == file_fmt_initialized) + xloop_file_fmt_exit(xlo_fmt); + + /* Load the new file format driver because the file format is + * uninitialized now */ + return xloop_file_fmt_init(xlo_fmt, file_fmt_type_new); +} + +ssize_t xloop_file_fmt_print_type(u32 file_fmt_type, char *file_fmt_name) +{ + ssize_t len = 0; + + switch (file_fmt_type) { + case XLO_FILE_FMT_RAW: + len = sprintf(file_fmt_name, "%s", "RAW"); + break; + case XLO_FILE_FMT_QCOW: + len = sprintf(file_fmt_name, "%s", "QCOW"); + break; + case XLO_FILE_FMT_VDI: + len = sprintf(file_fmt_name, "%s", "VDI"); + break; + case XLO_FILE_FMT_VMDK: + len = sprintf(file_fmt_name, "%s", "VMDK"); + break; + default: + len = sprintf(file_fmt_name, "%s", "ERROR: Unsupported xloop " + "file format!"); + break; + } + + return len; +} +EXPORT_SYMBOL(xloop_file_fmt_print_type); diff --git a/kernel/xloop_file_fmt.h b/kernel/xloop_file_fmt.h new file mode 100644 index 0000000..a419f33 --- /dev/null +++ b/kernel/xloop_file_fmt.h @@ -0,0 +1,380 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt.h + * + * File format subsystem for the xloop device module. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#ifndef _LINUX_XLOOP_FILE_FMT_H +#define _LINUX_XLOOP_FILE_FMT_H + +#include "xloop_main.h" + +struct xloop_file_fmt; + +#define XLO_FILE_FMT_RAW 0 +#define XLO_FILE_FMT_QCOW 1 +#define XLO_FILE_FMT_VDI 2 +#define XLO_FILE_FMT_VMDK 3 +#define MAX_XLO_FILE_FMT (XLO_FILE_FMT_VMDK + 1) + +/** + * struct xloop_file_fmt_ops - File format subsystem operations + * + * Data structure representing the file format subsystem interface. + */ +struct xloop_file_fmt_ops { + /** + * @init: Initialization callback function + */ + int (*init) (struct xloop_file_fmt *xlo_fmt); + + /** + * @exit: Release callback function + */ + void (*exit) (struct xloop_file_fmt *xlo_fmt); + + /** + * @read: Read IO callback function + */ + int (*read) (struct xloop_file_fmt *xlo_fmt, + struct request *rq); + + /** + * @write: Write IO callback function + */ + int (*write) (struct xloop_file_fmt *xlo_fmt, + struct request *rq); + + /** + * @read_aio: Asynchronous read IO callback function + */ + int (*read_aio) (struct xloop_file_fmt *xlo_fmt, + struct request *rq); + + /** + * @write_aio: Asynchronous write IO callback function + */ + int (*write_aio) (struct xloop_file_fmt *xlo_fmt, + struct request *rq); + + /** + * @zero: Zero (discard) IO callback function + */ + int (*write_zeros) (struct xloop_file_fmt *xlo_fmt, + struct request *rq); + + /** + * @discard: Discard IO callback function + */ + int (*discard) (struct xloop_file_fmt *xlo_fmt, + struct request *rq); + + /** + * @flush: Flush callback function + */ + int (*flush) (struct xloop_file_fmt *xlo_fmt); + + /** + * @sector_size: Get sector size callback function + */ + loff_t (*sector_size) (struct xloop_file_fmt *xlo_fmt, + struct file *file, loff_t offset, loff_t sizelimit); +}; + +/** + * struct xloop_file_fmt_driver - File format subsystem driver + * + * Data structure to implement file format drivers for the file format + * subsystem. + */ +struct xloop_file_fmt_driver { + /** + * @name: Name of the file format driver + */ + const char *name; + + /** + * @file_fmt_type: xloop file format type of the file format driver + */ + const u32 file_fmt_type; + + /** + * @ops: Driver's implemented file format operations + */ + struct xloop_file_fmt_ops *ops; + + /** + * @ops: Owner of the file format driver + */ + struct module *owner; +}; + +/* + * states of the file format + * + * transitions: + * xloop_file_fmt_init(...) + * ---> uninitialized ------------------------------> initialized + * xloop_file_fmt_exit(...) + * initialized ------------------------------> uninitialized + * xloop_file_fmt_read(...) + * initialized ------------------------------> initialized + * xloop_file_fmt_read_aio(...) + * initialized ------------------------------> initialized + * xloop_file_fmt_write(...) + * initialized ------------------------------> initialized + * xloop_file_fmt_write_aio(...) + * initialized ------------------------------> initialized + * xloop_file_fmt_discard(...) + * initialized ------------------------------> initialized + * xloop_file_fmt_flush(...) + * initialized ------------------------------> initialized + * xloop_file_fmt_sector_size(...) + * initialized ------------------------------> initialized + * + * xloop_file_fmt_change(...) + * +-----------------------------------------------------------+ + * | exit(...) init(...) | + * | initialized -------> uninitialized -------> initialized | + * +-----------------------------------------------------------+ + */ +enum { + file_fmt_uninitialized = 0, + file_fmt_initialized +}; + +/** + * struct xloop_file_fmt - xloop file format + * + * Data structure to use with the file format the xloop file format subsystem. + */ +struct xloop_file_fmt { + /** + * @file_fmt_type: Current type of the xloop file format + */ + u32 file_fmt_type; + + /** + * @file_fmt_state: Current state of the xloop file format + */ + int file_fmt_state; + + /** + * @xlo: Link to a file format's xloop device + */ + struct xloop_device *xlo; + + /** + * @private_data: Optional link to a file format's driver specific data + */ + void *private_data; +}; + + +/* subsystem functions for the driver implementation */ + +/** + * xloop_file_fmt_register_driver - Register a xloop file format driver + * @drv: File format driver + * + * Registers the specified xloop file format driver @drv by the xloop file format + * subsystem. + */ +extern int xloop_file_fmt_register_driver(struct xloop_file_fmt_driver *drv); + +/** + * xloop_file_fmt_unregister_driver - Unregister a xloop file format driver + * @drv: File format driver + * + * Unregisters the specified xloop file format driver @drv from the xloop file + * format subsystem. + */ +extern void xloop_file_fmt_unregister_driver(struct xloop_file_fmt_driver *drv); + + +/* subsystem functions for subsystem usage */ + +/** + * xloop_file_fmt_alloc - Allocate a xloop file format + * + * Dynamically allocates a xloop file format and returns a pointer to the + * created xloop file format. + */ +extern struct xloop_file_fmt *xloop_file_fmt_alloc(void); + +/** + * xloop_file_fmt_free - Free an allocated xloop file format + * @xlo_fmt: xloop file format + * + * Frees the already allocated xloop file format @xlo_fmt. + */ +extern void xloop_file_fmt_free(struct xloop_file_fmt *xlo_fmt); + +/** + * xloop_file_fmt_set_xlo - Set the xloop file format's xloop device + * @xlo_fmt: xloop file format + * @xlo: xloop device + * + * The link to the xloop device @xlo is set in the xloop file format @xlo_fmt. + */ +extern int xloop_file_fmt_set_xlo(struct xloop_file_fmt *xlo_fmt, + struct xloop_device *xlo); + +/** + * xloop_file_fmt_get_xlo - Get the xloop file format's xloop device + * @xlo_fmt: xloop file format + * + * Returns a pointer to the xloop device of the xloop file format @xlo_fmt. + */ +extern struct xloop_device *xloop_file_fmt_get_xlo(struct xloop_file_fmt *xlo_fmt); + +/** + * xloop_file_fmt_init - Initialize a xloop file format + * @xlo_fmt: xloop file format + * @file_fmt_type: Type of the file format + * + * Initializes the specified xloop file format @xlo_fmt and sets up the correct + * file format type @file_fmt_type. Depending on @file_fmt_type, the correct + * xloop file format driver is loaded in the subsystems backend. If no xloop file + * format driver for the specified file format is available an error is + * returned. + */ +extern int xloop_file_fmt_init(struct xloop_file_fmt *xlo_fmt, + u32 file_fmt_type); + +/** + * xloop_file_fmt_exit - Release a xloop file format + * @xlo_fmt: xloop file format + * + * Releases the specified xloop file format @xlo_fmt and all its resources. + */ +extern void xloop_file_fmt_exit(struct xloop_file_fmt *xlo_fmt); + +/** + * xloop_file_fmt_read - Read IO from a xloop file format + * @xlo_fmt: xloop file format + * @rq: IO Request + * + * Reads IO from the file format's xloop device by sending the IO read request + * @rq to the xloop file format subsystem. The subsystem calls the registered + * callback function of the suitable xloop file format driver. + */ +extern int xloop_file_fmt_read(struct xloop_file_fmt *xlo_fmt, + struct request *rq); + +/** + * xloop_file_fmt_read_aio - Read IO from a xloop file format asynchronously + * @xlo_fmt: xloop file format + * @rq: IO Request + * + * Reads IO from the file format's xloop device asynchronously by sending the + * IO read aio request @rq to the xloop file format subsystem. The subsystem + * calls the registered callback function of the suitable xloop file format + * driver. + */ +extern int xloop_file_fmt_read_aio(struct xloop_file_fmt *xlo_fmt, + struct request *rq); + +/** + * xloop_file_fmt_write - Write IO to a xloop file format + * @xlo_fmt: xloop file format + * @rq: IO Request + * + * Write IO to the file format's xloop device by sending the IO write request + * @rq to the xloop file format subsystem. The subsystem calls the registered + * callback function of the suitable xloop file format driver. + */ +extern int xloop_file_fmt_write(struct xloop_file_fmt *xlo_fmt, + struct request *rq); + +/** + * xloop_file_fmt_write_aio - Write IO to a xloop file format asynchronously + * @xlo_fmt: xloop file format + * @rq: IO Request + * + * Write IO to the file format's xloop device asynchronously by sending the + * IO write aio request @rq to the xloop file format subsystem. The subsystem + * calls the registered callback function of the suitable xloop file format + * driver. + */ +extern int xloop_file_fmt_write_aio(struct xloop_file_fmt *xlo_fmt, + struct request *rq); + +/** + * xloop_file_fmt_write_zeros - Zero (discard) IO on a xloop file format + * @xlo_fmt: xloop file format + * @rq: IO Request + * + * Zero (discard) IO on the file format's xloop device by sending the IO write + * zeros request @rq to the xloop file format subsystem. The subsystem calls the + * registered callback function of the suitable xloop file format driver. + */ +extern int xloop_file_fmt_write_zeros(struct xloop_file_fmt *xlo_fmt, + struct request *rq); + +/** + * xloop_file_fmt_discard - Discard IO on a xloop file format + * @xlo_fmt: xloop file format + * @rq: IO Request + * + * Discard IO on the file format's xloop device by sending the IO discard + * request @rq to the xloop file format subsystem. The subsystem calls the + * registered callback function of the suitable xloop file format driver. + */ +extern int xloop_file_fmt_discard(struct xloop_file_fmt *xlo_fmt, + struct request *rq); + +/** + * xloop_file_fmt_flush - Flush a xloop file format + * @xlo_fmt: xloop file format + * + * Flush the file format's xloop device by calling the registered callback + * function of the suitable xloop file format driver. + */ +extern int xloop_file_fmt_flush(struct xloop_file_fmt *xlo_fmt); + +/** + * xloop_file_fmt_sector_size - Get sector size of a xloop file format + * @xlo_fmt: xloop file format + * @file: xloop file formats file for sector size calculation + * @offset: Offset within the file for sector size calculation + * @sizelimit: Sizelimit of the file for sector size calculation + * + * Returns the physical sector size of the given xloop file format's file. + * If the xloop file format implements a sparse disk image format, then this + * function returns the virtual sector size. + */ +extern loff_t xloop_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, + struct file *file, loff_t offset, loff_t sizelimit); + +/** + * xloop_file_fmt_change - Change the xloop file format's type + * @xlo_fmt: xloop file format + * @file_fmt_type_new: xloop file format type + * + * Changes the file format type of the already initialized xloop file format + * @xlo_fmt. Therefore, the function releases the old file format and frees all + * of its resources before the xloop file format @xlo_fmt is initialized and set + * up with the new file format @file_fmt_type_new. + */ +extern int xloop_file_fmt_change(struct xloop_file_fmt *xlo_fmt, + u32 file_fmt_type_new); + + +/* helper functions of the subsystem */ + +/** + * xloop_file_fmt_print_type - Convert file format type to string + * @file_fmt_type: xloop file format type + * @file_fmt_name: xloop file format type string + * + * Converts the specified numeric @file_fmt_type value into a human readable + * string stating the file format as string in @file_fmt_name. + */ +extern ssize_t xloop_file_fmt_print_type(u32 file_fmt_type, + char *file_fmt_name); + +#endif diff --git a/kernel/xloop_file_fmt_qcow_cache.c b/kernel/xloop_file_fmt_qcow_cache.c new file mode 100644 index 0000000..c0e19fb --- /dev/null +++ b/kernel/xloop_file_fmt_qcow_cache.c @@ -0,0 +1,218 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_qcow_cache.c + * + * QCOW file format driver for the xloop device module. + * + * Ported QCOW2 implementation of the QEMU project (GPL-2.0): + * L2/refcount table cache for the QCOW2 format. + * + * The copyright (C) 2010 of the original code is owned by + * Kevin Wolf + * + * Copyright (C) 2019 Manuel Bentele + */ + +#include +#include +#include +#include +#include +#include + +#include "xloop_file_fmt_qcow_main.h" +#include "xloop_file_fmt_qcow_cache.h" + +static inline void *__xloop_file_fmt_qcow_cache_get_table_addr( + struct xloop_file_fmt_qcow_cache *c, int table) +{ + return (u8 *) c->table_array + (size_t) table * c->table_size; +} + +static inline int __xloop_file_fmt_qcow_cache_get_table_idx( + struct xloop_file_fmt_qcow_cache *c, void *table) +{ + ptrdiff_t table_offset = (u8 *) table - (u8 *) c->table_array; + int idx = table_offset / c->table_size; + ASSERT(idx >= 0 && idx < c->size && table_offset % c->table_size == 0); + return idx; +} + +static inline const char *__xloop_file_fmt_qcow_cache_get_name( + struct xloop_file_fmt *xlo_fmt, struct xloop_file_fmt_qcow_cache *c) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + + if (c == qcow_data->refcount_block_cache) { + return "refcount block"; + } else if (c == qcow_data->l2_table_cache) { + return "L2 table"; + } else { + /* do not abort, because this is not critical */ + return "unknown"; + } +} + +struct xloop_file_fmt_qcow_cache *xloop_file_fmt_qcow_cache_create( + struct xloop_file_fmt *xlo_fmt, int num_tables, unsigned table_size) +{ +#ifdef CONFIG_DEBUG_DRIVER + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; +#endif + struct xloop_file_fmt_qcow_cache *c; + + ASSERT(num_tables > 0); + ASSERT(is_power_of_2(table_size)); + ASSERT(table_size >= (1 << QCOW_MIN_CLUSTER_BITS)); + ASSERT(table_size <= qcow_data->cluster_size); + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) { + return NULL; + } + + c->size = num_tables; + c->table_size = table_size; + c->entries = vzalloc(sizeof(struct xloop_file_fmt_qcow_cache_table) * + num_tables); + c->table_array = vzalloc(num_tables * c->table_size); + + if (!c->entries || !c->table_array) { + vfree(c->table_array); + vfree(c->entries); + kfree(c); + c = NULL; + } + + return c; +} + +void xloop_file_fmt_qcow_cache_destroy(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + struct xloop_file_fmt_qcow_cache *c = qcow_data->l2_table_cache; + int i; + + for (i = 0; i < c->size; i++) { + ASSERT(c->entries[i].ref == 0); + } + + vfree(c->table_array); + vfree(c->entries); + kfree(c); +} + +static int __xloop_file_fmt_qcow_cache_entry_flush( + struct xloop_file_fmt_qcow_cache *c, int i) +{ + if (!c->entries[i].dirty || !c->entries[i].offset) { + return 0; + } else { + printk(KERN_ERR "xloop_file_fmt_qcow: Flush dirty cache tables " + "is not supported yet\n"); + return -ENOSYS; + } +} + +static int __xloop_file_fmt_qcow_cache_do_get(struct xloop_file_fmt *xlo_fmt, + struct xloop_file_fmt_qcow_cache *c, u64 offset, void **table, + bool read_from_disk) +{ + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + int i; + int ret; + int lookup_index; + u64 min_lru_counter = U64_MAX; + int min_lru_index = -1; + u64 read_offset; + size_t len; + + ASSERT(offset != 0); + + if (!IS_ALIGNED(offset, c->table_size)) { + printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: Cannot get " + "entry from %s cache: offset %llx is unaligned\n", + __xloop_file_fmt_qcow_cache_get_name(xlo_fmt, c), + offset); + return -EIO; + } + + /* Check if the table is already cached */ + i = lookup_index = (offset / c->table_size * 4) % c->size; + do { + const struct xloop_file_fmt_qcow_cache_table *t = + &c->entries[i]; + if (t->offset == offset) { + goto found; + } + if (t->ref == 0 && t->lru_counter < min_lru_counter) { + min_lru_counter = t->lru_counter; + min_lru_index = i; + } + if (++i == c->size) { + i = 0; + } + } while (i != lookup_index); + + if (min_lru_index == -1) { + BUG(); + panic("Oops: This can't happen in current synchronous code, " + "but leave the check here as a reminder for whoever " + "starts using AIO with the QCOW cache"); + } + + /* Cache miss: write a table back and replace it */ + i = min_lru_index; + + ret = __xloop_file_fmt_qcow_cache_entry_flush(c, i); + if (ret < 0) { + return ret; + } + + c->entries[i].offset = 0; + if (read_from_disk) { + read_offset = offset; + len = kernel_read(xlo->xlo_backing_file, + __xloop_file_fmt_qcow_cache_get_table_addr(c, i), + c->table_size, &read_offset); + if (len < 0) { + len = ret; + return ret; + } + } + + c->entries[i].offset = offset; + + /* And return the right table */ +found: + c->entries[i].ref++; + *table = __xloop_file_fmt_qcow_cache_get_table_addr(c, i); + + return 0; +} + +int xloop_file_fmt_qcow_cache_get(struct xloop_file_fmt *xlo_fmt, u64 offset, + void **table) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + struct xloop_file_fmt_qcow_cache *c = qcow_data->l2_table_cache; + + return __xloop_file_fmt_qcow_cache_do_get(xlo_fmt, c, offset, table, + true); +} + +void xloop_file_fmt_qcow_cache_put(struct xloop_file_fmt *xlo_fmt, void **table) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + struct xloop_file_fmt_qcow_cache *c = qcow_data->l2_table_cache; + int i = __xloop_file_fmt_qcow_cache_get_table_idx(c, *table); + + c->entries[i].ref--; + *table = NULL; + + if (c->entries[i].ref == 0) { + c->entries[i].lru_counter = ++c->lru_counter; + } + + ASSERT(c->entries[i].ref >= 0); +} diff --git a/kernel/xloop_file_fmt_qcow_cache.h b/kernel/xloop_file_fmt_qcow_cache.h new file mode 100644 index 0000000..527d4ae --- /dev/null +++ b/kernel/xloop_file_fmt_qcow_cache.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_qcow_cache.h + * + * Ported QCOW2 implementation of the QEMU project (GPL-2.0): + * L2/refcount table cache for the QCOW2 format. + * + * The copyright (C) 2010 of the original code is owned by + * Kevin Wolf + * + * Copyright (C) 2019 Manuel Bentele + */ + +#ifndef _LINUX_XLOOP_FILE_FMT_QCOW_CACHE_H +#define _LINUX_XLOOP_FILE_FMT_QCOW_CACHE_H + +#include "xloop_file_fmt.h" + +struct xloop_file_fmt_qcow_cache_table { + s64 offset; + u64 lru_counter; + int ref; + bool dirty; +}; + +struct xloop_file_fmt_qcow_cache { + struct xloop_file_fmt_qcow_cache_table *entries; + struct xloop_file_fmt_qcow_cache *depends; + int size; + int table_size; + bool depends_on_flush; + void *table_array; + u64 lru_counter; + u64 cache_clean_lru_counter; +}; + +extern struct xloop_file_fmt_qcow_cache *xloop_file_fmt_qcow_cache_create( + struct xloop_file_fmt *xlo_fmt, + int num_tables, + unsigned table_size); + +extern void xloop_file_fmt_qcow_cache_destroy(struct xloop_file_fmt *xlo_fmt); + +extern int xloop_file_fmt_qcow_cache_get(struct xloop_file_fmt *xlo_fmt, + u64 offset, + void **table); + +extern void xloop_file_fmt_qcow_cache_put(struct xloop_file_fmt *xlo_fmt, + void **table); + +#endif diff --git a/kernel/xloop_file_fmt_qcow_cluster.c b/kernel/xloop_file_fmt_qcow_cluster.c new file mode 100644 index 0000000..82fbc4f --- /dev/null +++ b/kernel/xloop_file_fmt_qcow_cluster.c @@ -0,0 +1,270 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_qcow_cluster.c + * + * Ported QCOW2 implementation of the QEMU project (GPL-2.0): + * Cluster calculation and lookup for the QCOW2 format. + * + * The copyright (C) 2004-2006 of the original code is owned by Fabrice Bellard. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#include +#include + +#include "xloop_file_fmt.h" +#include "xloop_file_fmt_qcow_main.h" +#include "xloop_file_fmt_qcow_cache.h" +#include "xloop_file_fmt_qcow_cluster.h" + +/* + * Loads a L2 slice into memory (L2 slices are the parts of L2 tables + * that are loaded by the qcow2 cache). If the slice is in the cache, + * the cache is used; otherwise the L2 slice is loaded from the image + * file. + */ +static int __xloop_file_fmt_qcow_cluster_l2_load(struct xloop_file_fmt *xlo_fmt, + u64 offset, u64 l2_offset, u64 **l2_slice) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + + int start_of_slice = sizeof(u64) * ( + xloop_file_fmt_qcow_offset_to_l2_index(qcow_data, offset) - + xloop_file_fmt_qcow_offset_to_l2_slice_index(qcow_data, offset) + ); + + ASSERT(qcow_data->l2_table_cache != NULL); + return xloop_file_fmt_qcow_cache_get(xlo_fmt, l2_offset + start_of_slice, + (void **) l2_slice); +} + +/* + * Checks how many clusters in a given L2 slice are contiguous in the image + * file. As soon as one of the flags in the bitmask stop_flags changes compared + * to the first cluster, the search is stopped and the cluster is not counted + * as contiguous. (This allows it, for example, to stop at the first compressed + * cluster which may require a different handling) + */ +static int __xloop_file_fmt_qcow_cluster_count_contiguous( + struct xloop_file_fmt *xlo_fmt, int nb_clusters, int cluster_size, + u64 *l2_slice, u64 stop_flags) +{ + int i; + enum xloop_file_fmt_qcow_cluster_type first_cluster_type; + u64 mask = stop_flags | L2E_OFFSET_MASK | QCOW_OFLAG_COMPRESSED; + u64 first_entry = be64_to_cpu(l2_slice[0]); + u64 offset = first_entry & mask; + + first_cluster_type = xloop_file_fmt_qcow_get_cluster_type(xlo_fmt, + first_entry); + if (first_cluster_type == QCOW_CLUSTER_UNALLOCATED) { + return 0; + } + + /* must be allocated */ + ASSERT(first_cluster_type == QCOW_CLUSTER_NORMAL || + first_cluster_type == QCOW_CLUSTER_ZERO_ALLOC); + + for (i = 0; i < nb_clusters; i++) { + u64 l2_entry = be64_to_cpu(l2_slice[i]) & mask; + if (offset + (u64) i * cluster_size != l2_entry) { + break; + } + } + + return i; +} + +/* + * Checks how many consecutive unallocated clusters in a given L2 + * slice have the same cluster type. + */ +static int __xloop_file_fmt_qcow_cluster_count_contiguous_unallocated( + struct xloop_file_fmt *xlo_fmt, int nb_clusters, u64 *l2_slice, + enum xloop_file_fmt_qcow_cluster_type wanted_type) +{ + int i; + + ASSERT(wanted_type == QCOW_CLUSTER_ZERO_PLAIN || + wanted_type == QCOW_CLUSTER_UNALLOCATED); + + for (i = 0; i < nb_clusters; i++) { + u64 entry = be64_to_cpu(l2_slice[i]); + enum xloop_file_fmt_qcow_cluster_type type = + xloop_file_fmt_qcow_get_cluster_type(xlo_fmt, entry); + + if (type != wanted_type) { + break; + } + } + + return i; +} + +/* + * For a given offset of the virtual disk, find the cluster type and offset in + * the qcow2 file. The offset is stored in *cluster_offset. + * + * On entry, *bytes is the maximum number of contiguous bytes starting at + * offset that we are interested in. + * + * On exit, *bytes is the number of bytes starting at offset that have the same + * cluster type and (if applicable) are stored contiguously in the image file. + * Compressed clusters are always returned one by one. + * + * Returns the cluster type (QCOW2_CLUSTER_*) on success, -errno in error + * cases. + */ +int xloop_file_fmt_qcow_cluster_get_offset(struct xloop_file_fmt *xlo_fmt, + u64 offset, unsigned int *bytes, u64 *cluster_offset) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + unsigned int l2_index; + u64 l1_index, l2_offset, *l2_slice; + int c; + unsigned int offset_in_cluster; + u64 bytes_available, bytes_needed, nb_clusters; + enum xloop_file_fmt_qcow_cluster_type type; + int ret; + + offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster(qcow_data, + offset); + bytes_needed = (u64) *bytes + offset_in_cluster; + + /* compute how many bytes there are between the start of the cluster + * containing offset and the end of the l2 slice that contains + * the entry pointing to it */ + bytes_available = ((u64)( + qcow_data->l2_slice_size - + xloop_file_fmt_qcow_offset_to_l2_slice_index(qcow_data, offset)) + ) << qcow_data->cluster_bits; + + if (bytes_needed > bytes_available) { + bytes_needed = bytes_available; + } + + *cluster_offset = 0; + + /* seek to the l2 offset in the l1 table */ + l1_index = xloop_file_fmt_qcow_offset_to_l1_index(qcow_data, offset); + if (l1_index >= qcow_data->l1_size) { + type = QCOW_CLUSTER_UNALLOCATED; + goto out; + } + + l2_offset = qcow_data->l1_table[l1_index] & L1E_OFFSET_MASK; + if (!l2_offset) { + type = QCOW_CLUSTER_UNALLOCATED; + goto out; + } + + if (xloop_file_fmt_qcow_offset_into_cluster(qcow_data, l2_offset)) { + printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: L2 table " + "offset %llx unaligned (L1 index: %llx)", l2_offset, + l1_index); + return -EIO; + } + + /* load the l2 slice in memory */ + ret = __xloop_file_fmt_qcow_cluster_l2_load(xlo_fmt, offset, l2_offset, + &l2_slice); + if (ret < 0) { + return ret; + } + + /* find the cluster offset for the given disk offset */ + l2_index = xloop_file_fmt_qcow_offset_to_l2_slice_index(qcow_data, + offset); + *cluster_offset = be64_to_cpu(l2_slice[l2_index]); + + nb_clusters = xloop_file_fmt_qcow_size_to_clusters(qcow_data, + bytes_needed); + /* bytes_needed <= *bytes + offset_in_cluster, both of which are + * unsigned integers; the minimum cluster size is 512, so this + * assertion is always true */ + ASSERT(nb_clusters <= INT_MAX); + + type = xloop_file_fmt_qcow_get_cluster_type(xlo_fmt, *cluster_offset); + if (qcow_data->qcow_version < 3 && ( + type == QCOW_CLUSTER_ZERO_PLAIN || + type == QCOW_CLUSTER_ZERO_ALLOC)) { + printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: zero cluster " + "entry found in pre-v3 image (L2 offset: %llx, " + "L2 index: %x)\n", l2_offset, l2_index); + ret = -EIO; + goto fail; + } + switch (type) { + case QCOW_CLUSTER_COMPRESSED: + if (xloop_file_fmt_qcow_has_data_file(xlo_fmt)) { + printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: " + "compressed cluster entry found in image with " + "external data file (L2 offset: %llx, " + "L2 index: %x)", l2_offset, l2_index); + ret = -EIO; + goto fail; + } + /* Compressed clusters can only be processed one by one */ + c = 1; + *cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK; + break; + case QCOW_CLUSTER_ZERO_PLAIN: + case QCOW_CLUSTER_UNALLOCATED: + /* how many empty clusters ? */ + c = __xloop_file_fmt_qcow_cluster_count_contiguous_unallocated( + xlo_fmt, nb_clusters, &l2_slice[l2_index], type); + *cluster_offset = 0; + break; + case QCOW_CLUSTER_ZERO_ALLOC: + case QCOW_CLUSTER_NORMAL: + /* how many allocated clusters ? */ + c = __xloop_file_fmt_qcow_cluster_count_contiguous(xlo_fmt, + nb_clusters, qcow_data->cluster_size, + &l2_slice[l2_index], QCOW_OFLAG_ZERO); + *cluster_offset &= L2E_OFFSET_MASK; + if (xloop_file_fmt_qcow_offset_into_cluster(qcow_data, + *cluster_offset)) { + printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: " + "cluster allocation offset %llx unaligned " + "(L2 offset: %llx, L2 index: %x)\n", + *cluster_offset, l2_offset, l2_index); + ret = -EIO; + goto fail; + } + if (xloop_file_fmt_qcow_has_data_file(xlo_fmt) && + *cluster_offset != offset - offset_in_cluster) { + printk_ratelimited(KERN_ERR "xloop_file_fmt_qcow: " + "external data file host cluster offset %llx " + "does not match guest cluster offset: %llx, " + "L2 index: %x)", *cluster_offset, + offset - offset_in_cluster, l2_index); + ret = -EIO; + goto fail; + } + break; + default: + BUG(); + } + + xloop_file_fmt_qcow_cache_put(xlo_fmt, (void **) &l2_slice); + + bytes_available = (s64) c * qcow_data->cluster_size; + +out: + if (bytes_available > bytes_needed) { + bytes_available = bytes_needed; + } + + /* bytes_available <= bytes_needed <= *bytes + offset_in_cluster; + * subtracting offset_in_cluster will therefore definitely yield + * something not exceeding UINT_MAX */ + ASSERT(bytes_available - offset_in_cluster <= UINT_MAX); + *bytes = bytes_available - offset_in_cluster; + + return type; + +fail: + xloop_file_fmt_qcow_cache_put(xlo_fmt, (void **) &l2_slice); + return ret; +} diff --git a/kernel/xloop_file_fmt_qcow_cluster.h b/kernel/xloop_file_fmt_qcow_cluster.h new file mode 100644 index 0000000..ff3e0a1 --- /dev/null +++ b/kernel/xloop_file_fmt_qcow_cluster.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_qcow_cluster.h + * + * Ported QCOW2 implementation of the QEMU project (GPL-2.0): + * Cluster calculation and lookup for the QCOW2 format. + * + * The copyright (C) 2004-2006 of the original code is owned by Fabrice Bellard. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#ifndef _LINUX_XLOOP_FILE_FMT_QCOW_CLUSTER_H +#define _LINUX_XLOOP_FILE_FMT_QCOW_CLUSTER_H + +#include "xloop_file_fmt.h" + +extern int xloop_file_fmt_qcow_cluster_get_offset(struct xloop_file_fmt *xlo_fmt, + u64 offset, + unsigned int *bytes, + u64 *cluster_offset); + +#endif diff --git a/kernel/xloop_file_fmt_qcow_main.c b/kernel/xloop_file_fmt_qcow_main.c new file mode 100644 index 0000000..c1fe34c --- /dev/null +++ b/kernel/xloop_file_fmt_qcow_main.c @@ -0,0 +1,953 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_qcow.c + * + * QCOW file format driver for the xloop device module. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "xloop_file_fmt.h" +#include "xloop_file_fmt_qcow_main.h" +#include "xloop_file_fmt_qcow_cache.h" +#include "xloop_file_fmt_qcow_cluster.h" + +static int __qcow_file_fmt_header_read(struct file *file, + struct xloop_file_fmt_qcow_header *header) +{ + ssize_t len; + loff_t offset; + int ret = 0; + + /* read QCOW header */ + offset = 0; + len = kernel_read(file, header, sizeof(*header), &offset); + if (len < 0) { + printk(KERN_ERR "xloop_file_fmt_qcow: could not read QCOW " + "header"); + return len; + } + + header->magic = be32_to_cpu(header->magic); + header->version = be32_to_cpu(header->version); + header->backing_file_offset = be64_to_cpu(header->backing_file_offset); + header->backing_file_size = be32_to_cpu(header->backing_file_size); + header->cluster_bits = be32_to_cpu(header->cluster_bits); + header->size = be64_to_cpu(header->size); + header->crypt_method = be32_to_cpu(header->crypt_method); + header->l1_size = be32_to_cpu(header->l1_size); + header->l1_table_offset = be64_to_cpu(header->l1_table_offset); + header->refcount_table_offset = + be64_to_cpu(header->refcount_table_offset); + header->refcount_table_clusters = + be32_to_cpu(header->refcount_table_clusters); + header->nb_snapshots = be32_to_cpu(header->nb_snapshots); + header->snapshots_offset = be64_to_cpu(header->snapshots_offset); + + /* check QCOW file format and header version */ + if (header->magic != QCOW_MAGIC) { + printk(KERN_ERR "xloop_file_fmt_qcow: image is not in QCOW " + "format"); + return -EINVAL; + } + + if (header->version < 2 || header->version > 3) { + printk(KERN_ERR "xloop_file_fmt_qcow: unsupported QCOW version " + "%d", header->version); + return -ENOTSUPP; + } + + /* initialize version 3 header fields */ + if (header->version == 2) { + header->incompatible_features = 0; + header->compatible_features = 0; + header->autoclear_features = 0; + header->refcount_order = 4; + header->header_length = 72; + } else { + header->incompatible_features = + be64_to_cpu(header->incompatible_features); + header->compatible_features = + be64_to_cpu(header->compatible_features); + header->autoclear_features = + be64_to_cpu(header->autoclear_features); + header->refcount_order = be32_to_cpu(header->refcount_order); + header->header_length = be32_to_cpu(header->header_length); + + if (header->header_length < 104) { + printk(KERN_ERR "xloop_file_fmt_qcow: QCOW header too " + "short"); + return -EINVAL; + } + } + + return ret; +} + +static int __qcow_file_fmt_validate_table(struct xloop_file_fmt *xlo_fmt, + u64 offset, u64 entries, size_t entry_len, s64 max_size_bytes, + const char *table_name) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + + if (entries > max_size_bytes / entry_len) { + printk(KERN_INFO "xloop_file_fmt_qcow: %s too large", + table_name); + return -EFBIG; + } + + /* Use signed S64_MAX as the maximum even for u64 header fields, + * because values will be passed to qemu functions taking s64. */ + if ((S64_MAX - entries * entry_len < offset) || ( + xloop_file_fmt_qcow_offset_into_cluster(qcow_data, offset) != 0) + ) { + printk(KERN_INFO "xloop_file_fmt_qcow: %s offset invalid", + table_name); + return -EINVAL; + } + + return 0; +} + +static inline loff_t __qcow_file_fmt_rq_get_pos(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + return ((loff_t) blk_rq_pos(rq) << 9) + xlo->xlo_offset; +} + +static int __qcow_file_fmt_compression_init(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + int ret = 0; + + qcow_data->strm = kzalloc(sizeof(*qcow_data->strm), GFP_KERNEL); + if (!qcow_data->strm) { + ret = -ENOMEM; + goto out; + } + + qcow_data->strm->workspace = vzalloc(zlib_inflate_workspacesize()); + if (!qcow_data->strm->workspace) { + ret = -ENOMEM; + goto out_free_strm; + } + + qcow_data->cmp_last_coffset = ULLONG_MAX; + qcow_data->cmp_out_buf = vmalloc(qcow_data->cluster_size); + if (!qcow_data->cmp_out_buf) { + ret = -ENOMEM; + goto out_free_workspace; + } + + return ret; + +out_free_workspace: + vfree(qcow_data->strm->workspace); +out_free_strm: + kfree(qcow_data->strm); +out: + return ret; +} + +static void __qcow_file_fmt_compression_exit(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + + vfree(qcow_data->strm->workspace); + kfree(qcow_data->strm); + vfree(qcow_data->cmp_out_buf); +} + +#ifdef CONFIG_DEBUG_FS +static void __qcow_file_fmt_header_to_buf(struct xloop_file_fmt *xlo_fmt, + const struct xloop_file_fmt_qcow_header *header) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + char *header_buf = qcow_data->dbgfs_file_qcow_header_buf; + ssize_t len = 0; + + len += sprintf(header_buf + len, "magic: %d\n", + header->magic); + len += sprintf(header_buf + len, "version: %d\n", + header->version); + len += sprintf(header_buf + len, "backing_file_offset: %lld\n", + header->backing_file_offset); + len += sprintf(header_buf + len, "backing_file_size: %d\n", + header->backing_file_size); + len += sprintf(header_buf + len, "cluster_bits: %d\n", + header->cluster_bits); + len += sprintf(header_buf + len, "size: %lld\n", + header->size); + len += sprintf(header_buf + len, "crypt_method: %d\n", + header->crypt_method); + len += sprintf(header_buf + len, "l1_size: %d\n", + header->l1_size); + len += sprintf(header_buf + len, "l1_table_offset: %lld\n", + header->l1_table_offset); + len += sprintf(header_buf + len, "refcount_table_offset: %lld\n", + header->refcount_table_offset); + len += sprintf(header_buf + len, "refcount_table_clusters: %d\n", + header->refcount_table_clusters); + len += sprintf(header_buf + len, "nb_snapshots: %d\n", + header->nb_snapshots); + len += sprintf(header_buf + len, "snapshots_offset: %lld\n", + header->snapshots_offset); + + if (header->version == 3) { + len += sprintf(header_buf + len, + "incompatible_features: %lld\n", + header->incompatible_features); + len += sprintf(header_buf + len, + "compatible_features: %lld\n", + header->compatible_features); + len += sprintf(header_buf + len, + "autoclear_features: %lld\n", + header->autoclear_features); + len += sprintf(header_buf + len, + "refcount_order: %d\n", + header->refcount_order); + len += sprintf(header_buf + len, + "header_length: %d\n", + header->header_length); + } + + ASSERT(len < QCOW_HEADER_BUF_LEN); +} + +static ssize_t __qcow_file_fmt_dbgfs_hdr_read(struct file *file, + char __user *buf, size_t size, loff_t *ppos) +{ + struct xloop_file_fmt *xlo_fmt = file->private_data; + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + char *header_buf = qcow_data->dbgfs_file_qcow_header_buf; + + return simple_read_from_buffer(buf, size, ppos, header_buf, + strlen(header_buf)); +} + +static const struct file_operations qcow_file_fmt_dbgfs_hdr_fops = { + .open = simple_open, + .read = __qcow_file_fmt_dbgfs_hdr_read +}; + +static ssize_t __qcow_file_fmt_dbgfs_ofs_read(struct file *file, + char __user *buf, size_t size, loff_t *ppos) +{ + struct xloop_file_fmt *xlo_fmt = file->private_data; + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + unsigned int cur_bytes = 1; + u64 offset = 0; + u64 cluster_offset = 0; + s64 offset_in_cluster = 0; + ssize_t len = 0; + int ret = 0; + + /* read the share debugfs offset */ + ret = mutex_lock_interruptible(&qcow_data->dbgfs_qcow_offset_mutex); + if (ret) + return ret; + + offset = qcow_data->dbgfs_qcow_offset; + mutex_unlock(&qcow_data->dbgfs_qcow_offset_mutex); + + /* calculate and print the cluster offset */ + ret = xloop_file_fmt_qcow_cluster_get_offset(xlo_fmt, + offset, &cur_bytes, &cluster_offset); + if (ret < 0) + return -EINVAL; + + offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster(qcow_data, + offset); + + len = sprintf(qcow_data->dbgfs_file_qcow_cluster_buf, + "offset: %lld\ncluster_offset: %lld\noffset_in_cluster: %lld\n", + offset, cluster_offset, offset_in_cluster); + + ASSERT(len < QCOW_CLUSTER_BUF_LEN); + + return simple_read_from_buffer(buf, size, ppos, + qcow_data->dbgfs_file_qcow_cluster_buf, len); +} + +static ssize_t __qcow_file_fmt_dbgfs_ofs_write(struct file *file, + const char __user *buf, size_t size, loff_t *ppos) +{ + struct xloop_file_fmt *xlo_fmt = file->private_data; + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + ssize_t len = 0; + int ret = 0; + + if (*ppos > QCOW_OFFSET_BUF_LEN || size > QCOW_OFFSET_BUF_LEN) + return -EINVAL; + + len = simple_write_to_buffer(qcow_data->dbgfs_file_qcow_offset_buf, + QCOW_OFFSET_BUF_LEN, ppos, buf, size); + if (len < 0) + return len; + + qcow_data->dbgfs_file_qcow_offset_buf[len] = '\0'; + + ret = mutex_lock_interruptible(&qcow_data->dbgfs_qcow_offset_mutex); + if (ret) + return ret; + + ret = kstrtou64(qcow_data->dbgfs_file_qcow_offset_buf, 10, + &qcow_data->dbgfs_qcow_offset); + if (ret < 0) + goto out; + + ret = len; +out: + mutex_unlock(&qcow_data->dbgfs_qcow_offset_mutex); + return ret; +} + +static const struct file_operations qcow_file_fmt_dbgfs_ofs_fops = { + .open = simple_open, + .read = __qcow_file_fmt_dbgfs_ofs_read, + .write = __qcow_file_fmt_dbgfs_ofs_write +}; + +static int __qcow_file_fmt_dbgfs_init(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + int ret = 0; + + qcow_data->dbgfs_dir = debugfs_create_dir("QCOW", xlo->xlo_dbgfs_dir); + if (IS_ERR_OR_NULL(qcow_data->dbgfs_dir)) { + ret = -ENODEV; + goto out; + } + + qcow_data->dbgfs_file_qcow_header = debugfs_create_file("header", + S_IRUGO, qcow_data->dbgfs_dir, xlo_fmt, + &qcow_file_fmt_dbgfs_hdr_fops); + if (IS_ERR_OR_NULL(qcow_data->dbgfs_file_qcow_header)) { + ret = -ENODEV; + goto out_free_dbgfs_dir; + } + + qcow_data->dbgfs_file_qcow_offset = debugfs_create_file("offset", + S_IRUGO | S_IWUSR, qcow_data->dbgfs_dir, xlo_fmt, + &qcow_file_fmt_dbgfs_ofs_fops); + if (IS_ERR_OR_NULL(qcow_data->dbgfs_file_qcow_offset)) { + qcow_data->dbgfs_file_qcow_offset = NULL; + ret = -ENODEV; + goto out_free_dbgfs_hdr; + } + + qcow_data->dbgfs_qcow_offset = 0; + mutex_init(&qcow_data->dbgfs_qcow_offset_mutex); + + return ret; + +out_free_dbgfs_hdr: + debugfs_remove(qcow_data->dbgfs_file_qcow_header); + qcow_data->dbgfs_file_qcow_header = NULL; +out_free_dbgfs_dir: + debugfs_remove(qcow_data->dbgfs_dir); + qcow_data->dbgfs_dir = NULL; +out: + return ret; +} + +static void __qcow_file_fmt_dbgfs_exit(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + + if (qcow_data->dbgfs_file_qcow_offset) + debugfs_remove(qcow_data->dbgfs_file_qcow_offset); + + mutex_destroy(&qcow_data->dbgfs_qcow_offset_mutex); + + if (qcow_data->dbgfs_file_qcow_header) + debugfs_remove(qcow_data->dbgfs_file_qcow_header); + + if (qcow_data->dbgfs_dir) + debugfs_remove(qcow_data->dbgfs_dir); +} +#endif + +static int qcow_file_fmt_init(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data; + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + struct xloop_file_fmt_qcow_header header; + u64 l1_vm_state_index; + u64 l2_cache_size; + u64 l2_cache_entry_size; + ssize_t len; + unsigned int i; + int ret = 0; + + /* allocate memory for saving QCOW file format data */ + qcow_data = kzalloc(sizeof(*qcow_data), GFP_KERNEL); + if (!qcow_data) + return -ENOMEM; + + xlo_fmt->private_data = qcow_data; + + /* read the QCOW file header */ + ret = __qcow_file_fmt_header_read(xlo->xlo_backing_file, &header); + if (ret) + goto free_qcow_data; + + /* save information of the header fields in human readable format in + * a file buffer to access it with debugfs */ +#ifdef CONFIG_DEBUG_FS + __qcow_file_fmt_header_to_buf(xlo_fmt, &header); +#endif + + qcow_data->qcow_version = header.version; + + /* Initialise cluster size */ + if (header.cluster_bits < QCOW_MIN_CLUSTER_BITS + || header.cluster_bits > QCOW_MAX_CLUSTER_BITS) { + printk(KERN_ERR "xloop_file_fmt_qcow: unsupported cluster " + "size: 2^%d", header.cluster_bits); + ret = -EINVAL; + goto free_qcow_data; + } + + qcow_data->cluster_bits = header.cluster_bits; + qcow_data->cluster_size = 1 << qcow_data->cluster_bits; + qcow_data->cluster_sectors = 1 << + (qcow_data->cluster_bits - SECTOR_SHIFT); + + if (header.header_length > qcow_data->cluster_size) { + printk(KERN_ERR "xloop_file_fmt_qcow: QCOW header exceeds " + "cluster size"); + ret = -EINVAL; + goto free_qcow_data; + } + + if (header.backing_file_offset > qcow_data->cluster_size) { + printk(KERN_ERR "xloop_file_fmt_qcow: invalid backing file " + "offset"); + ret = -EINVAL; + goto free_qcow_data; + } + + if (header.backing_file_offset) { + printk(KERN_ERR "xloop_file_fmt_qcow: backing file support not " + "available"); + ret = -ENOTSUPP; + goto free_qcow_data; + } + + /* handle feature bits */ + qcow_data->incompatible_features = header.incompatible_features; + qcow_data->compatible_features = header.compatible_features; + qcow_data->autoclear_features = header.autoclear_features; + + if (qcow_data->incompatible_features & QCOW_INCOMPAT_DIRTY) { + printk(KERN_ERR "xloop_file_fmt_qcow: image contains " + "inconsistent refcounts"); + ret = -EACCES; + goto free_qcow_data; + } + + if (qcow_data->incompatible_features & QCOW_INCOMPAT_CORRUPT) { + printk(KERN_ERR "xloop_file_fmt_qcow: image is corrupt; cannot " + "be opened read/write"); + ret = -EACCES; + goto free_qcow_data; + } + + if (qcow_data->incompatible_features & QCOW_INCOMPAT_DATA_FILE) { + printk(KERN_ERR "xloop_file_fmt_qcow: clusters in the external " + "data file are not refcounted"); + ret = -EACCES; + goto free_qcow_data; + } + + /* Check support for various header values */ + if (header.refcount_order > 6) { + printk(KERN_ERR "xloop_file_fmt_qcow: reference count entry " + "width too large; may not exceed 64 bits"); + ret = -EINVAL; + goto free_qcow_data; + } + qcow_data->refcount_order = header.refcount_order; + qcow_data->refcount_bits = 1 << qcow_data->refcount_order; + qcow_data->refcount_max = U64_C(1) << (qcow_data->refcount_bits - 1); + qcow_data->refcount_max += qcow_data->refcount_max - 1; + + qcow_data->crypt_method_header = header.crypt_method; + if (qcow_data->crypt_method_header) { + printk(KERN_ERR "xloop_file_fmt_qcow: encryption support not " + "available"); + ret = -ENOTSUPP; + goto free_qcow_data; + } + + /* L2 is always one cluster */ + qcow_data->l2_bits = qcow_data->cluster_bits - 3; + qcow_data->l2_size = 1 << qcow_data->l2_bits; + /* 2^(qcow_data->refcount_order - 3) is the refcount width in bytes */ + qcow_data->refcount_block_bits = qcow_data->cluster_bits - + (qcow_data->refcount_order - 3); + qcow_data->refcount_block_size = 1 << qcow_data->refcount_block_bits; + qcow_data->size = header.size; + qcow_data->csize_shift = (62 - (qcow_data->cluster_bits - 8)); + qcow_data->csize_mask = (1 << (qcow_data->cluster_bits - 8)) - 1; + qcow_data->cluster_offset_mask = (1LL << qcow_data->csize_shift) - 1; + + qcow_data->refcount_table_offset = header.refcount_table_offset; + qcow_data->refcount_table_size = header.refcount_table_clusters << + (qcow_data->cluster_bits - 3); + + if (header.refcount_table_clusters == 0) { + printk(KERN_ERR "xloop_file_fmt_qcow: image does not contain a " + "reference count table"); + ret = -EINVAL; + goto free_qcow_data; + } + + ret = __qcow_file_fmt_validate_table(xlo_fmt, + qcow_data->refcount_table_offset, + header.refcount_table_clusters, qcow_data->cluster_size, + QCOW_MAX_REFTABLE_SIZE, "Reference count table"); + if (ret < 0) { + goto free_qcow_data; + } + + /* The total size in bytes of the snapshot table is checked in + * qcow2_read_snapshots() because the size of each snapshot is + * variable and we don't know it yet. + * Here we only check the offset and number of snapshots. */ + ret = __qcow_file_fmt_validate_table(xlo_fmt, header.snapshots_offset, + header.nb_snapshots, + sizeof(struct xloop_file_fmt_qcow_snapshot_header), + sizeof(struct xloop_file_fmt_qcow_snapshot_header) * + QCOW_MAX_SNAPSHOTS, "Snapshot table"); + if (ret < 0) { + goto free_qcow_data; + } + + /* read the level 1 table */ + ret = __qcow_file_fmt_validate_table(xlo_fmt, header.l1_table_offset, + header.l1_size, sizeof(u64), QCOW_MAX_L1_SIZE, + "Active L1 table"); + if (ret < 0) { + goto free_qcow_data; + } + qcow_data->l1_size = header.l1_size; + qcow_data->l1_table_offset = header.l1_table_offset; + + l1_vm_state_index = xloop_file_fmt_qcow_size_to_l1(qcow_data, + header.size); + if (l1_vm_state_index > INT_MAX) { + printk(KERN_ERR "xloop_file_fmt_qcow: image is too big"); + ret = -EFBIG; + goto free_qcow_data; + } + qcow_data->l1_vm_state_index = l1_vm_state_index; + + /* the L1 table must contain at least enough entries to put header.size + * bytes */ + if (qcow_data->l1_size < qcow_data->l1_vm_state_index) { + printk(KERN_ERR "xloop_file_fmt_qcow: L1 table is too small"); + ret = -EINVAL; + goto free_qcow_data; + } + + if (qcow_data->l1_size > 0) { + qcow_data->l1_table = vzalloc(round_up(qcow_data->l1_size * + sizeof(u64), 512)); + if (qcow_data->l1_table == NULL) { + printk(KERN_ERR "xloop_file_fmt_qcow: could not " + "allocate L1 table"); + ret = -ENOMEM; + goto free_qcow_data; + } + len = kernel_read(xlo->xlo_backing_file, qcow_data->l1_table, + qcow_data->l1_size * sizeof(u64), + &qcow_data->l1_table_offset); + if (len < 0) { + printk(KERN_ERR "xloop_file_fmt_qcow: could not read L1 " + "table"); + ret = len; + goto free_l1_table; + } + for (i = 0; i < qcow_data->l1_size; i++) { + qcow_data->l1_table[i] = + be64_to_cpu(qcow_data->l1_table[i]); + } + } + + /* Internal snapshots */ + qcow_data->snapshots_offset = header.snapshots_offset; + qcow_data->nb_snapshots = header.nb_snapshots; + + if (qcow_data->nb_snapshots > 0) { + printk(KERN_ERR "xloop_file_fmt_qcow: snapshots support not " + "available"); + ret = -ENOTSUPP; + goto free_l1_table; + } + + + /* create cache for L2 */ + l2_cache_size = qcow_data->size / (qcow_data->cluster_size / 8); + l2_cache_entry_size = min(qcow_data->cluster_size, (int)4096); + + /* limit the L2 size to maximum QCOW_DEFAULT_L2_CACHE_MAX_SIZE */ + l2_cache_size = min(l2_cache_size, (u64)QCOW_DEFAULT_L2_CACHE_MAX_SIZE); + + /* calculate the number of cache tables */ + l2_cache_size /= l2_cache_entry_size; + if (l2_cache_size < QCOW_MIN_L2_CACHE_SIZE) { + l2_cache_size = QCOW_MIN_L2_CACHE_SIZE; + } + + if (l2_cache_size > INT_MAX) { + printk(KERN_ERR "xloop_file_fmt_qcow: L2 cache size too big"); + ret = -EINVAL; + goto free_l1_table; + } + + qcow_data->l2_slice_size = l2_cache_entry_size / sizeof(u64); + + qcow_data->l2_table_cache = xloop_file_fmt_qcow_cache_create(xlo_fmt, + l2_cache_size, l2_cache_entry_size); + if (!qcow_data->l2_table_cache) { + ret = -ENOMEM; + goto free_l1_table; + } + + /* initialize compression support */ + ret = __qcow_file_fmt_compression_init(xlo_fmt); + if (ret < 0) + goto free_l2_cache; + + /* initialize debugfs entries */ +#ifdef CONFIG_DEBUG_FS + ret = __qcow_file_fmt_dbgfs_init(xlo_fmt); + if (ret < 0) + goto free_l2_cache; +#endif + + return ret; + +free_l2_cache: + xloop_file_fmt_qcow_cache_destroy(xlo_fmt); +free_l1_table: + vfree(qcow_data->l1_table); +free_qcow_data: + kfree(qcow_data); + xlo_fmt->private_data = NULL; + return ret; +} + +static void qcow_file_fmt_exit(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + +#ifdef CONFIG_DEBUG_FS + __qcow_file_fmt_dbgfs_exit(xlo_fmt); +#endif + + __qcow_file_fmt_compression_exit(xlo_fmt); + + if (qcow_data->l1_table) { + vfree(qcow_data->l1_table); + } + + if (qcow_data->l2_table_cache) { + xloop_file_fmt_qcow_cache_destroy(xlo_fmt); + } + + if (qcow_data) { + kfree(qcow_data); + xlo_fmt->private_data = NULL; + } +} + +static ssize_t __qcow_file_fmt_buffer_decompress(struct xloop_file_fmt *xlo_fmt, + void *dest, + size_t dest_size, + const void *src, + size_t src_size) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + int ret = 0; + + qcow_data->strm->avail_in = src_size; + qcow_data->strm->next_in = (void *) src; + qcow_data->strm->avail_out = dest_size; + qcow_data->strm->next_out = dest; + + ret = zlib_inflateInit2(qcow_data->strm, -12); + if (ret != Z_OK) { + return -1; + } + + ret = zlib_inflate(qcow_data->strm, Z_FINISH); + if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) + || qcow_data->strm->avail_out != 0) { + /* We approve Z_BUF_ERROR because we need @dest buffer to be + * filled, but @src buffer may be processed partly (because in + * qcow2 we know size of compressed data with precision of one + * sector) */ + ret = -1; + } else { + ret = 0; + } + return ret; +} + +static int __qcow_file_fmt_read_compressed(struct xloop_file_fmt *xlo_fmt, + struct bio_vec *bvec, + u64 file_cluster_offset, + u64 offset, + u64 bytes, + u64 bytes_done) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + int ret = 0, csize, nb_csectors; + u64 coffset; + u8 *in_buf = NULL; + ssize_t len; + void *data; + unsigned long irq_flags; + int offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster( + qcow_data, offset); + + coffset = file_cluster_offset & qcow_data->cluster_offset_mask; + nb_csectors = ((file_cluster_offset >> qcow_data->csize_shift) & + qcow_data->csize_mask) + 1; + csize = nb_csectors * QCOW_COMPRESSED_SECTOR_SIZE - + (coffset & ~QCOW_COMPRESSED_SECTOR_MASK); + + + if (qcow_data->cmp_last_coffset != coffset) { + in_buf = vmalloc(csize); + if (!in_buf) { + qcow_data->cmp_last_coffset = ULLONG_MAX; + return -ENOMEM; + } + qcow_data->cmp_last_coffset = coffset; + len = kernel_read(xlo->xlo_backing_file, in_buf, csize, &coffset); + if (len < 0) { + qcow_data->cmp_last_coffset = ULLONG_MAX; + ret = len; + goto out_free_in_buf; + } + + if (__qcow_file_fmt_buffer_decompress(xlo_fmt, qcow_data->cmp_out_buf, + qcow_data->cluster_size, in_buf, csize) < 0) { + qcow_data->cmp_last_coffset = ULLONG_MAX; + ret = -EIO; + goto out_free_in_buf; + } + } + + ASSERT(bytes <= bvec->bv_len); + data = bvec_kmap_irq(bvec, &irq_flags) + bytes_done; + memcpy(data, qcow_data->cmp_out_buf + offset_in_cluster, bytes); + flush_dcache_page(bvec->bv_page); + bvec_kunmap_irq(data, &irq_flags); + +out_free_in_buf: + vfree(in_buf); + + return ret; +} + +static int __qcow_file_fmt_read_bvec(struct xloop_file_fmt *xlo_fmt, + struct bio_vec *bvec, + loff_t *ppos) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + int offset_in_cluster; + int ret; + unsigned int cur_bytes; /* number of bytes in current iteration */ + u64 bytes; + u64 cluster_offset = 0; + u64 bytes_done = 0; + void *data; + unsigned long irq_flags; + ssize_t len; + loff_t pos_read; + + bytes = bvec->bv_len; + + while (bytes != 0) { + + /* prepare next request */ + cur_bytes = bytes; + + ret = xloop_file_fmt_qcow_cluster_get_offset(xlo_fmt, *ppos, + &cur_bytes, &cluster_offset); + if (ret < 0) { + goto fail; + } + + offset_in_cluster = xloop_file_fmt_qcow_offset_into_cluster( + qcow_data, *ppos); + + switch (ret) { + case QCOW_CLUSTER_UNALLOCATED: + case QCOW_CLUSTER_ZERO_PLAIN: + case QCOW_CLUSTER_ZERO_ALLOC: + data = bvec_kmap_irq(bvec, &irq_flags) + bytes_done; + memset(data, 0, cur_bytes); + flush_dcache_page(bvec->bv_page); + bvec_kunmap_irq(data, &irq_flags); + break; + + case QCOW_CLUSTER_COMPRESSED: + ret = __qcow_file_fmt_read_compressed(xlo_fmt, bvec, + cluster_offset, *ppos, cur_bytes, bytes_done); + if (ret < 0) { + goto fail; + } + + break; + + case QCOW_CLUSTER_NORMAL: + if ((cluster_offset & 511) != 0) { + ret = -EIO; + goto fail; + } + + pos_read = cluster_offset + offset_in_cluster; + + data = bvec_kmap_irq(bvec, &irq_flags) + bytes_done; + len = kernel_read(xlo->xlo_backing_file, data, cur_bytes, + &pos_read); + flush_dcache_page(bvec->bv_page); + bvec_kunmap_irq(data, &irq_flags); + + if (len < 0) + return len; + + break; + + default: + ret = -EIO; + goto fail; + } + + bytes -= cur_bytes; + *ppos += cur_bytes; + bytes_done += cur_bytes; + } + + ret = 0; + +fail: + return ret; +} + +static int qcow_file_fmt_read(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct bio_vec bvec; + struct req_iterator iter; + loff_t pos; + int ret = 0; + + pos = __qcow_file_fmt_rq_get_pos(xlo_fmt, rq); + + rq_for_each_segment(bvec, rq, iter) { + ret = __qcow_file_fmt_read_bvec(xlo_fmt, &bvec, &pos); + if (ret) + return ret; + + cond_resched(); + } + + return ret; +} + +static loff_t qcow_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, + struct file *file, loff_t offset, loff_t sizelimit) +{ + struct xloop_file_fmt_qcow_header header; + loff_t xloopsize; + int ret; + + /* temporary read the QCOW file header of other QCOW image file */ + ret = __qcow_file_fmt_header_read(file, &header); + if (ret) + return 0; + + /* compute xloopsize in bytes */ + xloopsize = header.size; + if (offset > 0) + xloopsize -= offset; + /* offset is beyond i_size, weird but possible */ + if (xloopsize < 0) + return 0; + + if (sizelimit > 0 && sizelimit < xloopsize) + xloopsize = sizelimit; + /* + * Unfortunately, if we want to do I/O on the device, + * the number of 512-byte sectors has to fit into a sector_t. + */ + return xloopsize >> 9; +} + +static struct xloop_file_fmt_ops qcow_file_fmt_ops = { + .init = qcow_file_fmt_init, + .exit = qcow_file_fmt_exit, + .read = qcow_file_fmt_read, + .write = NULL, + .read_aio = NULL, + .write_aio = NULL, + .write_zeros = NULL, + .discard = NULL, + .flush = NULL, + .sector_size = qcow_file_fmt_sector_size, +}; + +static struct xloop_file_fmt_driver qcow_file_fmt_driver = { + .name = "QCOW", + .file_fmt_type = XLO_FILE_FMT_QCOW, + .ops = &qcow_file_fmt_ops, + .owner = THIS_MODULE, +}; + +static int __init xloop_file_fmt_qcow_init(void) +{ + printk(KERN_INFO "xloop_file_fmt_qcow: init xloop device QCOW file " + "format driver"); + return xloop_file_fmt_register_driver(&qcow_file_fmt_driver); +} + +static void __exit xloop_file_fmt_qcow_exit(void) +{ + printk(KERN_INFO "xloop_file_fmt_qcow: exit xloop device QCOW file " + "format driver"); + xloop_file_fmt_unregister_driver(&qcow_file_fmt_driver); +} + +module_init(xloop_file_fmt_qcow_init); +module_exit(xloop_file_fmt_qcow_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Manuel Bentele "); +MODULE_DESCRIPTION("xloop device QCOW file format driver"); +MODULE_SOFTDEP("pre: xloop"); diff --git a/kernel/xloop_file_fmt_qcow_main.h b/kernel/xloop_file_fmt_qcow_main.h new file mode 100644 index 0000000..e6031be --- /dev/null +++ b/kernel/xloop_file_fmt_qcow_main.h @@ -0,0 +1,419 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_qcow.h + * + * QCOW file format driver for the xloop device module. + * + * Ported QCOW2 implementation of the QEMU project (GPL-2.0): + * Declarations for the QCOW2 file format. + * + * The copyright (C) 2004-2006 of the original code is owned by Fabrice Bellard. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#ifndef _LINUX_XLOOP_FILE_FMT_QCOW_H +#define _LINUX_XLOOP_FILE_FMT_QCOW_H + +#include +#include +#include +#include + +#ifdef CONFIG_DEBUG_FS +#include +#endif + +#include "xloop_file_fmt.h" + +#ifdef CONFIG_DEBUG_DRIVER +#define ASSERT(x) \ +do { \ + if (!(x)) { \ + printk(KERN_EMERG "assertion failed %s: %d: %s\n", \ + __FILE__, __LINE__, #x); \ + BUG(); \ + } \ +} while (0) +#else +#define ASSERT(x) do { } while (0) +#endif + +#define KiB (1024) +#define MiB (1024 * 1024) + +#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) + +#define QCOW_CRYPT_NONE 0 +#define QCOW_CRYPT_AES 1 +#define QCOW_CRYPT_LUKS 2 + +#define QCOW_MAX_CRYPT_CLUSTERS 32 +#define QCOW_MAX_SNAPSHOTS 65536 + +/* Field widths in QCOW mean normal cluster offsets cannot reach + * 64PB; depending on cluster size, compressed clusters can have a + * smaller limit (64PB for up to 16k clusters, then ramps down to + * 512TB for 2M clusters). */ +#define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) + +/* 8 MB refcount table is enough for 2 PB images at 64k cluster size + * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ +#define QCOW_MAX_REFTABLE_SIZE (8 * MiB) + +/* 32 MB L1 table is enough for 2 PB images at 64k cluster size + * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ +#define QCOW_MAX_L1_SIZE (32 * MiB) + +/* Allow for an average of 1k per snapshot table entry, should be plenty of + * space for snapshot names and IDs */ +#define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) + +/* Bitmap header extension constraints */ +#define QCOW_MAX_BITMAPS 65535 +#define QCOW_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW_MAX_BITMAPS) + +/* indicate that the refcount of the referenced cluster is exactly one. */ +#define QCOW_OFLAG_COPIED (1ULL << 63) +/* indicate that the cluster is compressed (they never have the copied flag) */ +#define QCOW_OFLAG_COMPRESSED (1ULL << 62) +/* The cluster reads as all zeros */ +#define QCOW_OFLAG_ZERO (1ULL << 0) + +#define QCOW_MIN_CLUSTER_BITS 9 +#define QCOW_MAX_CLUSTER_BITS 21 + +/* Defined in the qcow2 spec (compressed cluster descriptor) */ +#define QCOW_COMPRESSED_SECTOR_SIZE 512U +#define QCOW_COMPRESSED_SECTOR_MASK (~(QCOW_COMPRESSED_SECTOR_SIZE - 1)) + +/* Must be at least 2 to cover COW */ +#define QCOW_MIN_L2_CACHE_SIZE 2 /* cache entries */ + +/* Must be at least 4 to cover all cases of refcount table growth */ +#define QCOW_MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ + +#define QCOW_DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB) +#define QCOW_DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */ + +#define QCOW_DEFAULT_CLUSTER_SIZE 65536 + +/* Buffer size for debugfs file buffer to display QCOW header information */ +#define QCOW_HEADER_BUF_LEN 1024 + +/* Buffer size for debugfs file buffer to receive and display offset and + * cluster offset information */ +#define QCOW_OFFSET_BUF_LEN 32 +#define QCOW_CLUSTER_BUF_LEN 128 + +struct xloop_file_fmt_qcow_header { + u32 magic; + u32 version; + u64 backing_file_offset; + u32 backing_file_size; + u32 cluster_bits; + u64 size; /* in bytes */ + u32 crypt_method; + u32 l1_size; + u64 l1_table_offset; + u64 refcount_table_offset; + u32 refcount_table_clusters; + u32 nb_snapshots; + u64 snapshots_offset; + + /* The following fields are only valid for version >= 3 */ + u64 incompatible_features; + u64 compatible_features; + u64 autoclear_features; + + u32 refcount_order; + u32 header_length; +} __attribute__((packed)); + +struct xloop_file_fmt_qcow_snapshot_header { + /* header is 8 byte aligned */ + u64 l1_table_offset; + + u32 l1_size; + u16 id_str_size; + u16 name_size; + + u32 date_sec; + u32 date_nsec; + + u64 vm_clock_nsec; + + u32 vm_state_size; + /* for extension */ + u32 extra_data_size; + /* extra data follows */ + /* id_str follows */ + /* name follows */ +} __attribute__((packed)); + +enum { + QCOW_FEAT_TYPE_INCOMPATIBLE = 0, + QCOW_FEAT_TYPE_COMPATIBLE = 1, + QCOW_FEAT_TYPE_AUTOCLEAR = 2, +}; + +/* incompatible feature bits */ +enum { + QCOW_INCOMPAT_DIRTY_BITNR = 0, + QCOW_INCOMPAT_CORRUPT_BITNR = 1, + QCOW_INCOMPAT_DATA_FILE_BITNR = 2, + QCOW_INCOMPAT_DIRTY = 1 << QCOW_INCOMPAT_DIRTY_BITNR, + QCOW_INCOMPAT_CORRUPT = 1 << QCOW_INCOMPAT_CORRUPT_BITNR, + QCOW_INCOMPAT_DATA_FILE = 1 << QCOW_INCOMPAT_DATA_FILE_BITNR, + + QCOW_INCOMPAT_MASK = QCOW_INCOMPAT_DIRTY + | QCOW_INCOMPAT_CORRUPT + | QCOW_INCOMPAT_DATA_FILE, +}; + +/* compatible feature bits */ +enum { + QCOW_COMPAT_LAZY_REFCOUNTS_BITNR = 0, + QCOW_COMPAT_LAZY_REFCOUNTS = 1 << QCOW_COMPAT_LAZY_REFCOUNTS_BITNR, + + QCOW_COMPAT_FEAT_MASK = QCOW_COMPAT_LAZY_REFCOUNTS, +}; + +/* autoclear feature bits */ +enum { + QCOW_AUTOCLEAR_BITMAPS_BITNR = 0, + QCOW_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1, + QCOW_AUTOCLEAR_BITMAPS = 1 << QCOW_AUTOCLEAR_BITMAPS_BITNR, + QCOW_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW_AUTOCLEAR_DATA_FILE_RAW_BITNR, + + QCOW_AUTOCLEAR_MASK = QCOW_AUTOCLEAR_BITMAPS | + QCOW_AUTOCLEAR_DATA_FILE_RAW, +}; + +struct xloop_file_fmt_qcow_data { + u64 size; + int cluster_bits; + int cluster_size; + int cluster_sectors; + int l2_slice_size; + int l2_bits; + int l2_size; + int l1_size; + int l1_vm_state_index; + int refcount_block_bits; + int refcount_block_size; + int csize_shift; + int csize_mask; + u64 cluster_offset_mask; + u64 l1_table_offset; + u64 *l1_table; + + struct xloop_file_fmt_qcow_cache *l2_table_cache; + struct xloop_file_fmt_qcow_cache *refcount_block_cache; + + u64 *refcount_table; + u64 refcount_table_offset; + u32 refcount_table_size; + u32 max_refcount_table_index; /* Last used entry in refcount_table */ + u64 free_cluster_index; + u64 free_byte_offset; + + u32 crypt_method_header; + u64 snapshots_offset; + int snapshots_size; + unsigned int nb_snapshots; + + u32 nb_bitmaps; + u64 bitmap_directory_size; + u64 bitmap_directory_offset; + + int qcow_version; + bool use_lazy_refcounts; + int refcount_order; + int refcount_bits; + u64 refcount_max; + + u64 incompatible_features; + u64 compatible_features; + u64 autoclear_features; + + struct z_stream_s *strm; + u8 *cmp_out_buf; + u64 cmp_last_coffset; + + /* debugfs entries */ +#ifdef CONFIG_DEBUG_FS + struct dentry *dbgfs_dir; + struct dentry *dbgfs_file_qcow_header; + char dbgfs_file_qcow_header_buf[QCOW_HEADER_BUF_LEN]; + struct dentry *dbgfs_file_qcow_offset; + char dbgfs_file_qcow_offset_buf[QCOW_OFFSET_BUF_LEN]; + char dbgfs_file_qcow_cluster_buf[QCOW_CLUSTER_BUF_LEN]; + u64 dbgfs_qcow_offset; + struct mutex dbgfs_qcow_offset_mutex; +#endif +}; + +struct xloop_file_fmt_qcow_cow_region { + /** + * Offset of the COW region in bytes from the start of the first + * cluster touched by the request. + */ + unsigned offset; + + /** Number of bytes to copy */ + unsigned nb_bytes; +}; + +enum xloop_file_fmt_qcow_cluster_type { + QCOW_CLUSTER_UNALLOCATED, + QCOW_CLUSTER_ZERO_PLAIN, + QCOW_CLUSTER_ZERO_ALLOC, + QCOW_CLUSTER_NORMAL, + QCOW_CLUSTER_COMPRESSED, +}; + +enum xloop_file_fmt_qcow_metadata_overlap { + QCOW_OL_MAIN_HEADER_BITNR = 0, + QCOW_OL_ACTIVE_L1_BITNR = 1, + QCOW_OL_ACTIVE_L2_BITNR = 2, + QCOW_OL_REFCOUNT_TABLE_BITNR = 3, + QCOW_OL_REFCOUNT_BLOCK_BITNR = 4, + QCOW_OL_SNAPSHOT_TABLE_BITNR = 5, + QCOW_OL_INACTIVE_L1_BITNR = 6, + QCOW_OL_INACTIVE_L2_BITNR = 7, + QCOW_OL_BITMAP_DIRECTORY_BITNR = 8, + + QCOW_OL_MAX_BITNR = 9, + + QCOW_OL_NONE = 0, + QCOW_OL_MAIN_HEADER = (1 << QCOW_OL_MAIN_HEADER_BITNR), + QCOW_OL_ACTIVE_L1 = (1 << QCOW_OL_ACTIVE_L1_BITNR), + QCOW_OL_ACTIVE_L2 = (1 << QCOW_OL_ACTIVE_L2_BITNR), + QCOW_OL_REFCOUNT_TABLE = (1 << QCOW_OL_REFCOUNT_TABLE_BITNR), + QCOW_OL_REFCOUNT_BLOCK = (1 << QCOW_OL_REFCOUNT_BLOCK_BITNR), + QCOW_OL_SNAPSHOT_TABLE = (1 << QCOW_OL_SNAPSHOT_TABLE_BITNR), + QCOW_OL_INACTIVE_L1 = (1 << QCOW_OL_INACTIVE_L1_BITNR), + /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv + * reads. */ + QCOW_OL_INACTIVE_L2 = (1 << QCOW_OL_INACTIVE_L2_BITNR), + QCOW_OL_BITMAP_DIRECTORY = (1 << QCOW_OL_BITMAP_DIRECTORY_BITNR), +}; + +/* Perform all overlap checks which can be done in constant time */ +#define QCOW_OL_CONSTANT \ + (QCOW_OL_MAIN_HEADER | QCOW_OL_ACTIVE_L1 | QCOW_OL_REFCOUNT_TABLE | \ + QCOW_OL_SNAPSHOT_TABLE | QCOW_OL_BITMAP_DIRECTORY) + +/* Perform all overlap checks which don't require disk access */ +#define QCOW_OL_CACHED \ + (QCOW_OL_CONSTANT | QCOW_OL_ACTIVE_L2 | QCOW_OL_REFCOUNT_BLOCK | \ + QCOW_OL_INACTIVE_L1) + +/* Perform all overlap checks */ +#define QCOW_OL_ALL \ + (QCOW_OL_CACHED | QCOW_OL_INACTIVE_L2) + +#define L1E_OFFSET_MASK 0x00fffffffffffe00ULL +#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL +#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL + +#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL + +#define INV_OFFSET (-1ULL) + +static inline bool xloop_file_fmt_qcow_has_data_file( + struct xloop_file_fmt *xlo_fmt) +{ + /* At the moment, there is no support for copy on write! */ + return false; +} + +static inline bool xloop_file_fmt_qcow_data_file_is_raw( + struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_file_fmt_qcow_data *qcow_data = xlo_fmt->private_data; + return !!(qcow_data->autoclear_features & + QCOW_AUTOCLEAR_DATA_FILE_RAW); +} + +static inline s64 xloop_file_fmt_qcow_start_of_cluster( + struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) +{ + return offset & ~(qcow_data->cluster_size - 1); +} + +static inline s64 xloop_file_fmt_qcow_offset_into_cluster( + struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) +{ + return offset & (qcow_data->cluster_size - 1); +} + +static inline s64 xloop_file_fmt_qcow_size_to_clusters( + struct xloop_file_fmt_qcow_data *qcow_data, u64 size) +{ + return (size + (qcow_data->cluster_size - 1)) >> + qcow_data->cluster_bits; +} + +static inline s64 xloop_file_fmt_qcow_size_to_l1( + struct xloop_file_fmt_qcow_data *qcow_data, s64 size) +{ + int shift = qcow_data->cluster_bits + qcow_data->l2_bits; + return (size + (1ULL << shift) - 1) >> shift; +} + +static inline int xloop_file_fmt_qcow_offset_to_l1_index( + struct xloop_file_fmt_qcow_data *qcow_data, u64 offset) +{ + return offset >> (qcow_data->l2_bits + qcow_data->cluster_bits); +} + +static inline int xloop_file_fmt_qcow_offset_to_l2_index( + struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) +{ + return (offset >> qcow_data->cluster_bits) & (qcow_data->l2_size - 1); +} + +static inline int xloop_file_fmt_qcow_offset_to_l2_slice_index( + struct xloop_file_fmt_qcow_data *qcow_data, s64 offset) +{ + return (offset >> qcow_data->cluster_bits) & + (qcow_data->l2_slice_size - 1); +} + +static inline s64 xloop_file_fmt_qcow_vm_state_offset( + struct xloop_file_fmt_qcow_data *qcow_data) +{ + return (s64)qcow_data->l1_vm_state_index << + (qcow_data->cluster_bits + qcow_data->l2_bits); +} + +static inline enum xloop_file_fmt_qcow_cluster_type +xloop_file_fmt_qcow_get_cluster_type(struct xloop_file_fmt *xlo_fmt, u64 l2_entry) +{ + if (l2_entry & QCOW_OFLAG_COMPRESSED) { + return QCOW_CLUSTER_COMPRESSED; + } else if (l2_entry & QCOW_OFLAG_ZERO) { + if (l2_entry & L2E_OFFSET_MASK) { + return QCOW_CLUSTER_ZERO_ALLOC; + } + return QCOW_CLUSTER_ZERO_PLAIN; + } else if (!(l2_entry & L2E_OFFSET_MASK)) { + /* Offset 0 generally means unallocated, but it is ambiguous + * with external data files because 0 is a valid offset there. + * However, all clusters in external data files always have + * refcount 1, so we can rely on QCOW_OFLAG_COPIED to + * disambiguate. */ + if (xloop_file_fmt_qcow_has_data_file(xlo_fmt) && + (l2_entry & QCOW_OFLAG_COPIED)) { + return QCOW_CLUSTER_NORMAL; + } else { + return QCOW_CLUSTER_UNALLOCATED; + } + } else { + return QCOW_CLUSTER_NORMAL; + } +} + +#endif diff --git a/kernel/xloop_file_fmt_raw.c b/kernel/xloop_file_fmt_raw.c new file mode 100644 index 0000000..6c205ee --- /dev/null +++ b/kernel/xloop_file_fmt_raw.c @@ -0,0 +1,465 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * xloop_file_fmt_raw.c + * + * RAW file format driver for the xloop device module. + * + * Copyright (C) 2019 Manuel Bentele + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "xloop_file_fmt.h" + +static inline loff_t __raw_file_fmt_rq_get_pos(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + return ((loff_t) blk_rq_pos(rq) << 9) + xlo->xlo_offset; +} + +/* transfer function for DEPRECATED cryptoxloop support */ +static inline int __raw_file_fmt_do_transfer(struct xloop_device *xlo, int cmd, + struct page *rpage, unsigned roffs, + struct page *lpage, unsigned loffs, + int size, sector_t rblock) +{ + int ret; + + ret = xlo->transfer(xlo, cmd, rpage, roffs, lpage, loffs, size, rblock); + if (likely(!ret)) + return 0; + + printk_ratelimited(KERN_ERR + "xloop_file_fmt_raw: Transfer error at byte offset %llu, length %i.\n", + (unsigned long long)rblock << 9, size); + return ret; +} + +static int __raw_file_fmt_read_transfer(struct xloop_device *xlo, + struct request *rq, loff_t pos) +{ + struct bio_vec bvec, b; + struct req_iterator iter; + struct iov_iter i; + struct page *page; + ssize_t len; + int ret = 0; + + page = alloc_page(GFP_NOIO); + if (unlikely(!page)) + return -ENOMEM; + + rq_for_each_segment(bvec, rq, iter) { + loff_t offset = pos; + + b.bv_page = page; + b.bv_offset = 0; + b.bv_len = bvec.bv_len; + + iov_iter_bvec(&i, READ, &b, 1, b.bv_len); + len = vfs_iter_read(xlo->xlo_backing_file, &i, &pos, 0); + if (len < 0) { + ret = len; + goto out_free_page; + } + + ret = __raw_file_fmt_do_transfer(xlo, READ, page, 0, bvec.bv_page, + bvec.bv_offset, len, offset >> 9); + if (ret) + goto out_free_page; + + flush_dcache_page(bvec.bv_page); + + if (len != bvec.bv_len) { + struct bio *bio; + + __rq_for_each_bio(bio, rq) + zero_fill_bio(bio); + break; + } + } + + ret = 0; +out_free_page: + __free_page(page); + return ret; +} + +static int raw_file_fmt_read(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct bio_vec bvec; + struct req_iterator iter; + struct iov_iter i; + ssize_t len; + struct xloop_device *xlo; + loff_t pos; + + xlo = xloop_file_fmt_get_xlo(xlo_fmt); + pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); + + if (xlo->transfer) + return __raw_file_fmt_read_transfer(xlo, rq, pos); + + rq_for_each_segment(bvec, rq, iter) { + iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len); + len = vfs_iter_read(xlo->xlo_backing_file, &i, &pos, 0); + if (len < 0) + return len; + + flush_dcache_page(bvec.bv_page); + + if (len != bvec.bv_len) { + struct bio *bio; + + __rq_for_each_bio(bio, rq) + zero_fill_bio(bio); + break; + } + cond_resched(); + } + + return 0; +} + +static void __raw_file_fmt_rw_aio_do_completion(struct xloop_cmd *cmd) +{ + struct request *rq = blk_mq_rq_from_pdu(cmd); + + if (!atomic_dec_and_test(&cmd->ref)) + return; + kfree(cmd->bvec); + cmd->bvec = NULL; +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) + if (likely(!blk_should_fake_timeout(rq->q))) + blk_mq_complete_request(rq); +#else + blk_mq_complete_request(rq); +#endif +} + +static void __raw_file_fmt_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) +{ + struct xloop_cmd *cmd = container_of(iocb, struct xloop_cmd, iocb); + + if (cmd->css) + css_put(cmd->css); + cmd->ret = ret; + __raw_file_fmt_rw_aio_do_completion(cmd); +} + +static int __raw_file_fmt_rw_aio(struct xloop_device *xlo, + struct xloop_cmd *cmd, loff_t pos, bool rw) +{ + struct iov_iter iter; + struct req_iterator rq_iter; + struct bio_vec *bvec; + struct request *rq = blk_mq_rq_from_pdu(cmd); + struct bio *bio = rq->bio; + struct file *file = xlo->xlo_backing_file; + struct bio_vec tmp; + unsigned int offset; + int nr_bvec = 0; + int ret; + + rq_for_each_bvec(tmp, rq, rq_iter) + nr_bvec++; + + if (rq->bio != rq->biotail) { + + bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), + GFP_NOIO); + if (!bvec) + return -EIO; + cmd->bvec = bvec; + + /* + * The bios of the request may be started from the middle of + * the 'bvec' because of bio splitting, so we can't directly + * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec + * API will take care of all details for us. + */ + rq_for_each_bvec(tmp, rq, rq_iter) { + *bvec = tmp; + bvec++; + } + bvec = cmd->bvec; + offset = 0; + } else { + /* + * Same here, this bio may be started from the middle of the + * 'bvec' because of bio splitting, so offset from the bvec + * must be passed to iov iterator + */ + offset = bio->bi_iter.bi_bvec_done; + bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); + } + atomic_set(&cmd->ref, 2); + + iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq)); + iter.iov_offset = offset; + + cmd->iocb.ki_pos = pos; + cmd->iocb.ki_filp = file; + cmd->iocb.ki_complete = __raw_file_fmt_rw_aio_complete; + cmd->iocb.ki_flags = IOCB_DIRECT; + cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); + if (cmd->css) + kthread_associate_blkcg(cmd->css); + + if (rw == WRITE) + ret = call_write_iter(file, &cmd->iocb, &iter); + else + ret = call_read_iter(file, &cmd->iocb, &iter); + + __raw_file_fmt_rw_aio_do_completion(cmd); + kthread_associate_blkcg(NULL); + + if (ret != -EIOCBQUEUED) + cmd->iocb.ki_complete(&cmd->iocb, ret, 0); + return 0; +} + +static int raw_file_fmt_read_aio(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); + + return __raw_file_fmt_rw_aio(xlo, cmd, pos, READ); +} + +static int __raw_file_fmt_write_bvec(struct file *file, + struct bio_vec *bvec, + loff_t *ppos) +{ + struct iov_iter i; + ssize_t bw; + + iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len); + + file_start_write(file); + bw = vfs_iter_write(file, &i, ppos, 0); + file_end_write(file); + + if (likely(bw == bvec->bv_len)) + return 0; + + printk_ratelimited(KERN_ERR + "xloop_file_fmt_raw: Write error at byte offset %llu, length " + "%i.\n", (unsigned long long)*ppos, bvec->bv_len); + if (bw >= 0) + bw = -EIO; + return bw; +} + +/* + * This is the slow, transforming version that needs to double buffer the + * data as it cannot do the transformations in place without having direct + * access to the destination pages of the backing file. + */ +static int __raw_file_fmt_write_transfer(struct xloop_device *xlo, + struct request *rq, loff_t pos) +{ +struct bio_vec bvec, b; + struct req_iterator iter; + struct page *page; + int ret = 0; + + page = alloc_page(GFP_NOIO); + if (unlikely(!page)) + return -ENOMEM; + + rq_for_each_segment(bvec, rq, iter) { + ret = __raw_file_fmt_do_transfer(xlo, WRITE, page, 0, bvec.bv_page, + bvec.bv_offset, bvec.bv_len, pos >> 9); + if (unlikely(ret)) + break; + + b.bv_page = page; + b.bv_offset = 0; + b.bv_len = bvec.bv_len; + ret = __raw_file_fmt_write_bvec(xlo->xlo_backing_file, &b, &pos); + if (ret < 0) + break; + } + + __free_page(page); + return ret; +} + +static int raw_file_fmt_write(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct bio_vec bvec; + struct req_iterator iter; + int ret = 0; + struct xloop_device *xlo; + loff_t pos; + + xlo = xloop_file_fmt_get_xlo(xlo_fmt); + pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); + + if (xlo->transfer) + return __raw_file_fmt_write_transfer(xlo, rq, pos); + + rq_for_each_segment(bvec, rq, iter) { + ret = __raw_file_fmt_write_bvec(xlo->xlo_backing_file, &bvec, &pos); + if (ret < 0) + break; + cond_resched(); + } + + return ret; +} + +static int raw_file_fmt_write_aio(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); + + return __raw_file_fmt_rw_aio(xlo, cmd, pos, WRITE); +} + +static int __raw_file_fmt_fallocate(struct xloop_device *xlo, + struct request *rq, loff_t pos, int mode) +{ + /* + * We use fallocate to manipulate the space mappings used by the image + * a.k.a. discard/zerorange. However we do not support this if + * encryption is enabled, because it may give an attacker useful + * information. + */ + struct file *file = xlo->xlo_backing_file; + struct request_queue *q = xlo->xlo_queue; + int ret; + + mode |= FALLOC_FL_KEEP_SIZE; + + if (!blk_queue_discard(q)) { + ret = -EOPNOTSUPP; + goto out; + } + + ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); + if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) + ret = -EIO; +out: + return ret; +} + +static int raw_file_fmt_write_zeros(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + + /* + * If the caller doesn't want deallocation, call zeroout to + * write zeroes the range. Otherwise, punch them out. + */ + return __raw_file_fmt_fallocate(xlo, rq, pos, + (rq->cmd_flags & REQ_NOUNMAP) ? + FALLOC_FL_ZERO_RANGE : + FALLOC_FL_PUNCH_HOLE); +} + +static int raw_file_fmt_discard(struct xloop_file_fmt *xlo_fmt, + struct request *rq) +{ + loff_t pos = __raw_file_fmt_rq_get_pos(xlo_fmt, rq); + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + + return __raw_file_fmt_fallocate(xlo, rq, pos, FALLOC_FL_PUNCH_HOLE); +} + +static int raw_file_fmt_flush(struct xloop_file_fmt *xlo_fmt) +{ + struct xloop_device *xlo = xloop_file_fmt_get_xlo(xlo_fmt); + struct file *file = xlo->xlo_backing_file; + int ret = vfs_fsync(file, 0); + if (unlikely(ret && ret != -EINVAL)) + ret = -EIO; + + return ret; +} + +static loff_t raw_file_fmt_sector_size(struct xloop_file_fmt *xlo_fmt, + struct file *file, loff_t offset, loff_t sizelimit) +{ + loff_t xloopsize; + + /* Compute xloopsize in bytes */ + xloopsize = i_size_read(file->f_mapping->host); + if (offset > 0) + xloopsize -= offset; + /* offset is beyond i_size, weird but possible */ + if (xloopsize < 0) + return 0; + + if (sizelimit > 0 && sizelimit < xloopsize) + xloopsize = sizelimit; + /* + * Unfortunately, if we want to do I/O on the device, + * the number of 512-byte sectors has to fit into a sector_t. + */ + return xloopsize >> 9; +} + +static struct xloop_file_fmt_ops raw_file_fmt_ops = { + .init = NULL, + .exit = NULL, + .read = raw_file_fmt_read, + .write = raw_file_fmt_write, + .read_aio = raw_file_fmt_read_aio, + .write_aio = raw_file_fmt_write_aio, + .write_zeros = raw_file_fmt_write_zeros, + .discard = raw_file_fmt_discard, + .flush = raw_file_fmt_flush, + .sector_size = raw_file_fmt_sector_size, +}; + +static struct xloop_file_fmt_driver raw_file_fmt_driver = { + .name = "RAW", + .file_fmt_type = XLO_FILE_FMT_RAW, + .ops = &raw_file_fmt_ops, + .owner = THIS_MODULE, +}; + +static int __init xloop_file_fmt_raw_init(void) +{ + printk(KERN_INFO "xloop_file_fmt_raw: init xloop device RAW file format " + "driver"); + return xloop_file_fmt_register_driver(&raw_file_fmt_driver); +} + +static void __exit xloop_file_fmt_raw_exit(void) +{ + printk(KERN_INFO "xloop_file_fmt_raw: exit xloop device RAW file format " + "driver"); + xloop_file_fmt_unregister_driver(&raw_file_fmt_driver); +} + +module_init(xloop_file_fmt_raw_init); +module_exit(xloop_file_fmt_raw_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Manuel Bentele "); +MODULE_DESCRIPTION("xloop device RAW file format driver"); +MODULE_SOFTDEP("pre: xloop"); diff --git a/kernel/xloop_main.c b/kernel/xloop_main.c new file mode 100644 index 0000000..a29b644 --- /dev/null +++ b/kernel/xloop_main.c @@ -0,0 +1,2221 @@ +/* + * xloop_main.c + * + * Written by Theodore Ts'o, 3/29/93 + * + * Copyright 1993 by Theodore Ts'o. Redistribution of this file is + * permitted under the GNU General Public License. + * + * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 + * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 + * + * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 + * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 + * + * Fixed do_xloop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 + * + * Added devfs support - Richard Gooch 16-Jan-1998 + * + * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 + * + * Loadable modules and other fixes by AK, 1998 + * + * Make real block number available to downstream transfer functions, enables + * CBC (and relatives) mode encryption requiring unique IVs per data block. + * Reed H. Petty, rhp@draper.net + * + * Maximum number of xloop devices now dynamic via max_xloop module parameter. + * Russell Kroll 19990701 + * + * Maximum number of xloop devices when compiled-in now selectable by passing + * max_xloop=<1-255> to the kernel on boot. + * Erik I. Bolsø, , Oct 31, 1999 + * + * Completely rewrite request handling to be make_request_fn style and + * non blocking, pushing work to a helper thread. Lots of fixes from + * Al Viro too. + * Jens Axboe , Nov 2000 + * + * Support up to 256 xloop devices + * Heinz Mauelshagen , Feb 2002 + * + * Support for falling back on the write file operation when the address space + * operations write_begin is not available on the backing filesystem. + * Anton Altaparmakov, 16 Feb 2005 + * + * Support for using file formats. + * Manuel Bentele , 2019 + * + * Still To Fix: + * - Advisory locking is ignored here. + * - Should use an own CAP_* category instead of CAP_SYS_ADMIN + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_DEBUG_FS +#include +#endif + +#include "xloop_file_fmt.h" +#include "xloop_main.h" + +#include + +static DEFINE_IDR(xloop_index_idr); +static DEFINE_MUTEX(xloop_ctl_mutex); + +static int max_part; +static int part_shift; + +static int transfer_xor(struct xloop_device *xlo, int cmd, + struct page *raw_page, unsigned raw_off, + struct page *xloop_page, unsigned xloop_off, + int size, sector_t real_block) +{ + char *raw_buf = kmap_atomic(raw_page) + raw_off; + char *xloop_buf = kmap_atomic(xloop_page) + xloop_off; + char *in, *out, *key; + int i, keysize; + + if (cmd == READ) { + in = raw_buf; + out = xloop_buf; + } else { + in = xloop_buf; + out = raw_buf; + } + + key = xlo->xlo_encrypt_key; + keysize = xlo->xlo_encrypt_key_size; + for (i = 0; i < size; i++) + *out++ = *in++ ^ key[(i & 511) % keysize]; + + kunmap_atomic(xloop_buf); + kunmap_atomic(raw_buf); + cond_resched(); + return 0; +} + +static int xor_init(struct xloop_device *xlo, const struct xloop_info64 *info) +{ + if (unlikely(info->xlo_encrypt_key_size <= 0)) + return -EINVAL; + return 0; +} + +static struct xloop_func_table none_funcs = { + .number = XLO_CRYPT_NONE, +}; + +static struct xloop_func_table xor_funcs = { + .number = XLO_CRYPT_XOR, + .transfer = transfer_xor, + .init = xor_init +}; + +/* xfer_funcs[0] is special - its release function is never called */ +static struct xloop_func_table *xfer_funcs[MAX_XLO_CRYPT] = { + &none_funcs, + &xor_funcs +}; + +static loff_t get_xloop_size(struct xloop_device *xlo, struct file *file) +{ + return xloop_file_fmt_sector_size(xlo->xlo_fmt, file, xlo->xlo_offset, + xlo->xlo_sizelimit); +} + +static void __xloop_update_dio(struct xloop_device *xlo, bool dio) +{ + struct file *file = xlo->xlo_backing_file; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + unsigned short sb_bsize = 0; + unsigned dio_align = 0; + bool use_dio; + + if (inode->i_sb->s_bdev) { + sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); + dio_align = sb_bsize - 1; + } + + /* + * We support direct I/O only if xlo_offset is aligned with the + * logical I/O size of backing device, and the logical block + * size of xloop is bigger than the backing device's and the xloop + * needn't transform transfer. + * + * TODO: the above condition may be loosed in the future, and + * direct I/O may be switched runtime at that time because most + * of requests in sane applications should be PAGE_SIZE aligned + */ + if (dio) { + if (queue_logical_block_size(xlo->xlo_queue) >= sb_bsize && + !(xlo->xlo_offset & dio_align) && + mapping->a_ops->direct_IO && + !xlo->transfer) + use_dio = true; + else + use_dio = false; + } else { + use_dio = false; + } + + if (xlo->use_dio == use_dio) + return; + + /* flush dirty pages before changing direct IO */ + xloop_file_fmt_flush(xlo->xlo_fmt); + + /* + * The flag of XLO_FLAGS_DIRECT_IO is handled similarly with + * XLO_FLAGS_READ_ONLY, both are set from kernel, and losetup + * will get updated by ioctl(XLOOP_GET_STATUS) + */ + if (xlo->xlo_state == Xlo_bound) + blk_mq_freeze_queue(xlo->xlo_queue); + xlo->use_dio = use_dio; + if (use_dio) { + blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); + xlo->xlo_flags |= XLO_FLAGS_DIRECT_IO; + } else { + blk_queue_flag_set(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); + xlo->xlo_flags &= ~XLO_FLAGS_DIRECT_IO; + } + if (xlo->xlo_state == Xlo_bound) + blk_mq_unfreeze_queue(xlo->xlo_queue); +} + +/** + * xloop_validate_block_size() - validates the passed in block size + * @bsize: size to validate + */ +static int +xloop_validate_block_size(unsigned short bsize) +{ + if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize)) + return -EINVAL; + + return 0; +} + +/** + * xloop_set_size() - sets device size and notifies userspace + * @xlo: struct xloop_device to set the size for + * @size: new size of the xloop device + * + * Callers must validate that the size passed into this function fits into + * a sector_t, eg using xloop_validate_size() + */ +static void xloop_set_size(struct xloop_device *xlo, loff_t size) +{ + struct block_device *bdev = xlo->xlo_device; +#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 7, 0) + sector_t capacity; +#endif + + bd_set_size(bdev, size << SECTOR_SHIFT); + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 7, 0) + set_capacity_revalidate_and_notify(xlo->xlo_disk, size, false); +#else + capacity = get_capacity(xlo->xlo_disk); + set_capacity(xlo->xlo_disk, size); + if (capacity != size && capacity != 0 && size != 0) { + char *envp[] = { "RESIZE=1", NULL }; + kobject_uevent_env(&disk_to_dev(xlo->xlo_disk)->kobj, KOBJ_CHANGE, + envp); + } +#endif +} + +static void xlo_complete_rq(struct request *rq) +{ + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + blk_status_t ret = BLK_STS_OK; + + if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || + req_op(rq) != REQ_OP_READ) { + if (cmd->ret < 0) + ret = errno_to_blk_status(cmd->ret); + goto end_io; + } + + /* + * Short READ - if we got some data, advance our request and + * retry it. If we got no data, end the rest with EIO. + */ + if (cmd->ret) { + blk_update_request(rq, BLK_STS_OK, cmd->ret); + cmd->ret = 0; + blk_mq_requeue_request(rq, true); + } else { + if (cmd->use_aio) { + struct bio *bio = rq->bio; + + while (bio) { + zero_fill_bio(bio); + bio = bio->bi_next; + } + } + ret = BLK_STS_IOERR; +end_io: + blk_mq_end_request(rq, ret); + } +} + +static int do_req_filebacked(struct xloop_device *xlo, struct request *rq) +{ + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + + /* + * xlo_write_simple and xlo_read_simple should have been covered + * by io submit style function like xlo_rw_aio(), one blocker + * is that xlo_read_simple() need to call flush_dcache_page after + * the page is written from kernel, and it isn't easy to handle + * this in io submit style function which submits all segments + * of the req at one time. And direct read IO doesn't need to + * run flush_dcache_page(). + */ + switch (req_op(rq)) { + case REQ_OP_FLUSH: + return xloop_file_fmt_flush(xlo->xlo_fmt); + case REQ_OP_WRITE_ZEROES: + return xloop_file_fmt_write_zeros(xlo->xlo_fmt, rq); + case REQ_OP_DISCARD: + return xloop_file_fmt_discard(xlo->xlo_fmt, rq); + case REQ_OP_WRITE: + if (cmd->use_aio) + return xloop_file_fmt_write_aio(xlo->xlo_fmt, rq); + else + return xloop_file_fmt_write(xlo->xlo_fmt, rq); + case REQ_OP_READ: + if (cmd->use_aio) + return xloop_file_fmt_read_aio(xlo->xlo_fmt, rq); + else + return xloop_file_fmt_read(xlo->xlo_fmt, rq); + default: + WARN_ON_ONCE(1); + return -EIO; + } +} + +static inline void xloop_update_dio(struct xloop_device *xlo) +{ + __xloop_update_dio(xlo, (xlo->xlo_backing_file->f_flags & O_DIRECT) | + xlo->use_dio); +} + +static void xloop_reread_partitions(struct xloop_device *xlo, + struct block_device *bdev) +{ + int rc; + + mutex_lock(&bdev->bd_mutex); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0) + rc = bdev_disk_changed(bdev, false); +#else + rc = blkdev_reread_part(bdev); +#endif + mutex_unlock(&bdev->bd_mutex); + if (rc) + pr_warn("%s: partition scan of xloop%d (%s) failed (rc=%d)\n", + __func__, xlo->xlo_number, xlo->xlo_file_name, rc); +} + +static inline int is_xloop_device(struct file *file) +{ + struct inode *i = file->f_mapping->host; + + return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == XLOOP_MAJOR; +} + +static int xloop_validate_file(struct file *file, struct block_device *bdev) +{ + struct inode *inode = file->f_mapping->host; + struct file *f = file; + + /* Avoid recursion */ + while (is_xloop_device(f)) { + struct xloop_device *l; + + if (f->f_mapping->host->i_bdev == bdev) + return -EBADF; + + l = f->f_mapping->host->i_bdev->bd_disk->private_data; + if (l->xlo_state != Xlo_bound) { + return -EINVAL; + } + f = l->xlo_backing_file; + } + if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) + return -EINVAL; + return 0; +} + +/* + * xloop_change_fd switched the backing store of a xloopback device to + * a new file. This is useful for operating system installers to free up + * the original file and in High Availability environments to switch to + * an alternative location for the content in case of server meltdown. + * This can only work if the xloop device is used read-only, and if the + * new backing store is the same size and type as the old backing store. + */ +static int xloop_change_fd(struct xloop_device *xlo, struct block_device *bdev, + unsigned int arg) +{ + struct file *file = NULL, *old_file; + int error; + bool partscan; + + error = mutex_lock_killable(&xloop_ctl_mutex); + if (error) + return error; + error = -ENXIO; + if (xlo->xlo_state != Xlo_bound) + goto out_err; + + /* the xloop device has to be read-only */ + error = -EINVAL; + if (!(xlo->xlo_flags & XLO_FLAGS_READ_ONLY)) + goto out_err; + + error = -EBADF; + file = fget(arg); + if (!file) + goto out_err; + + error = xloop_validate_file(file, bdev); + if (error) + goto out_err; + + old_file = xlo->xlo_backing_file; + + error = -EINVAL; + + /* size of the new backing store needs to be the same */ + if (get_xloop_size(xlo, file) != get_xloop_size(xlo, old_file)) + goto out_err; + + /* and ... switch */ + blk_mq_freeze_queue(xlo->xlo_queue); + mapping_set_gfp_mask(old_file->f_mapping, xlo->old_gfp_mask); + xlo->xlo_backing_file = file; + xlo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); + mapping_set_gfp_mask(file->f_mapping, + xlo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); + xloop_update_dio(xlo); + blk_mq_unfreeze_queue(xlo->xlo_queue); + partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN; + mutex_unlock(&xloop_ctl_mutex); + /* + * We must drop file reference outside of xloop_ctl_mutex as dropping + * the file ref can take bd_mutex which creates circular locking + * dependency. + */ + fput(old_file); + if (partscan) + xloop_reread_partitions(xlo, bdev); + return 0; + +out_err: + mutex_unlock(&xloop_ctl_mutex); + if (file) + fput(file); + return error; +} + +/* xloop sysfs attributes */ + +static ssize_t xloop_attr_show(struct device *dev, char *page, + ssize_t (*callback)(struct xloop_device *, char *)) +{ + struct gendisk *disk = dev_to_disk(dev); + struct xloop_device *xlo = disk->private_data; + + return callback(xlo, page); +} + +#define XLOOP_ATTR_RO(_name) \ +static ssize_t xloop_attr_##_name##_show(struct xloop_device *, char *); \ +static ssize_t xloop_attr_do_show_##_name(struct device *d, \ + struct device_attribute *attr, char *b) \ +{ \ + return xloop_attr_show(d, b, xloop_attr_##_name##_show); \ +} \ +static struct device_attribute xloop_attr_##_name = \ + __ATTR(_name, 0444, xloop_attr_do_show_##_name, NULL); + +static ssize_t xloop_attr_backing_file_show(struct xloop_device *xlo, char *buf) +{ + ssize_t ret; + char *p = NULL; + + spin_lock_irq(&xlo->xlo_lock); + if (xlo->xlo_backing_file) + p = file_path(xlo->xlo_backing_file, buf, PAGE_SIZE - 1); + spin_unlock_irq(&xlo->xlo_lock); + + if (IS_ERR_OR_NULL(p)) + ret = PTR_ERR(p); + else { + ret = strlen(p); + memmove(buf, p, ret); + buf[ret++] = '\n'; + buf[ret] = 0; + } + + return ret; +} + +static ssize_t xloop_attr_file_fmt_type_show(struct xloop_device *xlo, + char *buf) +{ + ssize_t len = 0; + + len = xloop_file_fmt_print_type(xlo->xlo_fmt->file_fmt_type, buf); + len += sprintf(buf + len, "\n"); + + return len; +} + +static ssize_t xloop_attr_offset_show(struct xloop_device *xlo, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)xlo->xlo_offset); +} + +static ssize_t xloop_attr_sizelimit_show(struct xloop_device *xlo, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)xlo->xlo_sizelimit); +} + +static ssize_t xloop_attr_autoclear_show(struct xloop_device *xlo, char *buf) +{ + int autoclear = (xlo->xlo_flags & XLO_FLAGS_AUTOCLEAR); + + return sprintf(buf, "%s\n", autoclear ? "1" : "0"); +} + +static ssize_t xloop_attr_partscan_show(struct xloop_device *xlo, char *buf) +{ + int partscan = (xlo->xlo_flags & XLO_FLAGS_PARTSCAN); + + return sprintf(buf, "%s\n", partscan ? "1" : "0"); +} + +static ssize_t xloop_attr_dio_show(struct xloop_device *xlo, char *buf) +{ + int dio = (xlo->xlo_flags & XLO_FLAGS_DIRECT_IO); + + return sprintf(buf, "%s\n", dio ? "1" : "0"); +} + +XLOOP_ATTR_RO(backing_file); +XLOOP_ATTR_RO(file_fmt_type); +XLOOP_ATTR_RO(offset); +XLOOP_ATTR_RO(sizelimit); +XLOOP_ATTR_RO(autoclear); +XLOOP_ATTR_RO(partscan); +XLOOP_ATTR_RO(dio); + +static struct attribute *xloop_attrs[] = { + &xloop_attr_backing_file.attr, + &xloop_attr_file_fmt_type.attr, + &xloop_attr_offset.attr, + &xloop_attr_sizelimit.attr, + &xloop_attr_autoclear.attr, + &xloop_attr_partscan.attr, + &xloop_attr_dio.attr, + NULL, +}; + +static struct attribute_group xloop_attribute_group = { + .name = "xloop", + .attrs= xloop_attrs, +}; + +static void xloop_sysfs_init(struct xloop_device *xlo) +{ + xlo->sysfs_inited = !sysfs_create_group(&disk_to_dev(xlo->xlo_disk)->kobj, + &xloop_attribute_group); +} + +static void xloop_sysfs_exit(struct xloop_device *xlo) +{ + if (xlo->sysfs_inited) + sysfs_remove_group(&disk_to_dev(xlo->xlo_disk)->kobj, + &xloop_attribute_group); +} + +static void xloop_config_discard(struct xloop_device *xlo) +{ + struct file *file = xlo->xlo_backing_file; + struct inode *inode = file->f_mapping->host; + struct request_queue *q = xlo->xlo_queue; + u32 granularity, max_discard_sectors; + + /* + * If the backing device is a block device, mirror its zeroing + * capability. Set the discard sectors to the block device's zeroing + * capabilities because xloop discards result in blkdev_issue_zeroout(), + * not blkdev_issue_discard(). This maintains consistent behavior with + * file-backed xloop devices: discarded regions read back as zero. + */ + if (S_ISBLK(inode->i_mode) && !xlo->xlo_encrypt_key_size) { + struct request_queue *backingq; + + backingq = bdev_get_queue(inode->i_bdev); + + max_discard_sectors = backingq->limits.max_write_zeroes_sectors; + granularity = backingq->limits.discard_granularity ?: + queue_physical_block_size(backingq); + + /* + * We use punch hole to reclaim the free space used by the + * image a.k.a. discard. However we do not support discard if + * encryption is enabled, because it may give an attacker + * useful information. + */ + } else if (!file->f_op->fallocate || xlo->xlo_encrypt_key_size) { + max_discard_sectors = 0; + granularity = 0; + + } else { + max_discard_sectors = UINT_MAX >> 9; + granularity = inode->i_sb->s_blocksize; + } + + if (max_discard_sectors) { + q->limits.discard_granularity = granularity; + blk_queue_max_discard_sectors(q, max_discard_sectors); + blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); + blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); + } else { + q->limits.discard_granularity = 0; + blk_queue_max_discard_sectors(q, 0); + blk_queue_max_write_zeroes_sectors(q, 0); + blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); + } + q->limits.discard_alignment = 0; +} + +static void xloop_unprepare_queue(struct xloop_device *xlo) +{ + kthread_flush_worker(&xlo->worker); + kthread_stop(xlo->worker_task); +} + +static int xloop_kthread_worker_fn(void *worker_ptr) +{ +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0) + current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; +#else + current->flags |= PF_LESS_THROTTLE | PF_MEMALLOC_NOIO; +#endif + return kthread_worker_fn(worker_ptr); +} + +static int xloop_prepare_queue(struct xloop_device *xlo) +{ + kthread_init_worker(&xlo->worker); + xlo->worker_task = kthread_run(xloop_kthread_worker_fn, + &xlo->worker, "xloop%d", xlo->xlo_number); + if (IS_ERR(xlo->worker_task)) + return -ENOMEM; + set_user_nice(xlo->worker_task, MIN_NICE); + return 0; +} + +static void xloop_update_rotational(struct xloop_device *xlo) +{ + struct file *file = xlo->xlo_backing_file; + struct inode *file_inode = file->f_mapping->host; + struct block_device *file_bdev = file_inode->i_sb->s_bdev; + struct request_queue *q = xlo->xlo_queue; + bool nonrot = true; + + /* not all filesystems (e.g. tmpfs) have a sb->s_bdev */ + if (file_bdev) + nonrot = blk_queue_nonrot(bdev_get_queue(file_bdev)); + + if (nonrot) + blk_queue_flag_set(QUEUE_FLAG_NONROT, q); + else + blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); +} + +static int +xloop_release_xfer(struct xloop_device *xlo) +{ + int err = 0; + struct xloop_func_table *xfer = xlo->xlo_encryption; + + if (xfer) { + if (xfer->release) + err = xfer->release(xlo); + xlo->transfer = NULL; + xlo->xlo_encryption = NULL; + module_put(xfer->owner); + } + return err; +} + +static int +xloop_init_xfer(struct xloop_device *xlo, struct xloop_func_table *xfer, + const struct xloop_info64 *i) +{ + int err = 0; + + if (xfer) { + struct module *owner = xfer->owner; + + if (!try_module_get(owner)) + return -EINVAL; + if (xfer->init) + err = xfer->init(xlo, i); + if (err) + module_put(owner); + else + xlo->xlo_encryption = xfer; + } + return err; +} + +/** + * xloop_set_status_from_info - configure device from xloop_info + * @xlo: struct xloop_device to configure + * @info: struct xloop_info64 to configure the device with + * + * Configures the xloop device parameters according to the passed + * in xloop_info64 configuration. + */ +static int +xloop_set_status_from_info(struct xloop_device *xlo, + const struct xloop_info64 *info) +{ + int err; + struct xloop_func_table *xfer; + kuid_t uid = current_uid(); + + if ((unsigned int) info->xlo_encrypt_key_size > XLO_KEY_SIZE) + return -EINVAL; + + err = xloop_release_xfer(xlo); + if (err) + return err; + + if (info->xlo_encrypt_type) { + unsigned int type = info->xlo_encrypt_type; + + if (type >= MAX_XLO_CRYPT) + return -EINVAL; + xfer = xfer_funcs[type]; + if (xfer == NULL) + return -EINVAL; + } else + xfer = NULL; + + err = xloop_init_xfer(xlo, xfer, info); + if (err) + return err; + + xlo->xlo_offset = info->xlo_offset; + xlo->xlo_sizelimit = info->xlo_sizelimit; + memcpy(xlo->xlo_file_name, info->xlo_file_name, XLO_NAME_SIZE); + memcpy(xlo->xlo_crypt_name, info->xlo_crypt_name, XLO_NAME_SIZE); + xlo->xlo_file_name[XLO_NAME_SIZE-1] = 0; + xlo->xlo_crypt_name[XLO_NAME_SIZE-1] = 0; + + if (!xfer) + xfer = &none_funcs; + xlo->transfer = xfer->transfer; + xlo->ioctl = xfer->ioctl; + + xlo->xlo_flags = info->xlo_flags; + + xlo->xlo_encrypt_key_size = info->xlo_encrypt_key_size; + xlo->xlo_init[0] = info->xlo_init[0]; + xlo->xlo_init[1] = info->xlo_init[1]; + if (info->xlo_encrypt_key_size) { + memcpy(xlo->xlo_encrypt_key, info->xlo_encrypt_key, + info->xlo_encrypt_key_size); + xlo->xlo_key_owner = uid; + } + + return 0; +} + +static int xloop_configure(struct xloop_device *xlo, fmode_t mode, + struct block_device *bdev, + const struct xloop_config *config) +{ + struct file *file; + struct inode *inode; + struct address_space *mapping; + struct block_device *claimed_bdev = NULL; + int error; + loff_t size; + bool partscan; + unsigned short bsize; + + /* This is safe, since we have a reference from open(). */ + __module_get(THIS_MODULE); + + error = -EBADF; + file = fget(config->fd); + if (!file) + goto out; + + /* + * If we don't hold exclusive handle for the device, upgrade to it + * here to avoid changing device under exclusive owner. + */ + if (!(mode & FMODE_EXCL)) { +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) + claimed_bdev = bdev->bd_contains; + error = bd_prepare_to_claim(bdev, claimed_bdev, xloop_configure); + if (error) + goto out_putf; +#else + claimed_bdev = bd_start_claiming(bdev, xloop_configure); + if (IS_ERR(claimed_bdev)) { + error = PTR_ERR(claimed_bdev); + goto out_putf; + } +#endif + } + + error = mutex_lock_killable(&xloop_ctl_mutex); + if (error) + goto out_bdev; + + error = -EBUSY; + if (xlo->xlo_state != Xlo_unbound) + goto out_unlock; + + error = xloop_validate_file(file, bdev); + if (error) + goto out_unlock; + + mapping = file->f_mapping; + inode = mapping->host; + + if ((config->info.xlo_flags & ~XLOOP_CONFIGURE_SETTABLE_FLAGS) != 0) { + error = -EINVAL; + goto out_unlock; + } + + if (config->block_size) { + error = xloop_validate_block_size(config->block_size); + if (error) + goto out_unlock; + } + + error = xloop_set_status_from_info(xlo, &config->info); + if (error) + goto out_unlock; + + if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || + !file->f_op->write_iter) + xlo->xlo_flags |= XLO_FLAGS_READ_ONLY; + + error = xloop_prepare_queue(xlo); + if (error) + goto out_unlock; + + error = xloop_file_fmt_init(xlo->xlo_fmt, + config->info.xlo_file_fmt_type); + if (error) + goto out_unlock; + + set_device_ro(bdev, (xlo->xlo_flags & XLO_FLAGS_READ_ONLY) != 0); + + xlo->use_dio = xlo->xlo_flags & XLO_FLAGS_DIRECT_IO; + xlo->xlo_device = bdev; + xlo->xlo_backing_file = file; + xlo->old_gfp_mask = mapping_gfp_mask(mapping); + mapping_set_gfp_mask(mapping, xlo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); + + if (!(xlo->xlo_flags & XLO_FLAGS_READ_ONLY) && file->f_op->fsync) + blk_queue_write_cache(xlo->xlo_queue, true, false); + + if (config->block_size) + bsize = config->block_size; + else if ((xlo->xlo_backing_file->f_flags & O_DIRECT) && inode->i_sb->s_bdev) + /* In case of direct I/O, match underlying block size */ + bsize = bdev_logical_block_size(inode->i_sb->s_bdev); + else + bsize = 512; + + blk_queue_logical_block_size(xlo->xlo_queue, bsize); + blk_queue_physical_block_size(xlo->xlo_queue, bsize); + blk_queue_io_min(xlo->xlo_queue, bsize); + + xloop_update_rotational(xlo); + xloop_update_dio(xlo); + xloop_sysfs_init(xlo); + + size = get_xloop_size(xlo, file); + xloop_set_size(xlo, size); + + set_blocksize(bdev, S_ISBLK(inode->i_mode) ? + block_size(inode->i_bdev) : PAGE_SIZE); + + xlo->xlo_state = Xlo_bound; + if (part_shift) + xlo->xlo_flags |= XLO_FLAGS_PARTSCAN; + partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN; + if (partscan) + xlo->xlo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; + + /* Grab the block_device to prevent its destruction after we + * put /dev/xloopXX inode. Later in __xloop_clr_fd() we bdput(bdev). + */ + bdgrab(bdev); + mutex_unlock(&xloop_ctl_mutex); + if (partscan) + xloop_reread_partitions(xlo, bdev); + if (claimed_bdev) + bd_abort_claiming(bdev, claimed_bdev, xloop_configure); + return 0; + +out_unlock: + mutex_unlock(&xloop_ctl_mutex); +out_bdev: + if (claimed_bdev) + bd_abort_claiming(bdev, claimed_bdev, xloop_configure); +out_putf: + fput(file); +out: + /* This is safe: open() is still holding a reference. */ + module_put(THIS_MODULE); + return error; +} + +static int __xloop_clr_fd(struct xloop_device *xlo, bool release) +{ + struct file *filp = NULL; + gfp_t gfp = xlo->old_gfp_mask; + struct block_device *bdev = xlo->xlo_device; + int err = 0; + bool partscan = false; + int xlo_number; + + mutex_lock(&xloop_ctl_mutex); + if (WARN_ON_ONCE(xlo->xlo_state != Xlo_rundown)) { + err = -ENXIO; + goto out_unlock; + } + + filp = xlo->xlo_backing_file; + if (filp == NULL) { + err = -EINVAL; + goto out_unlock; + } + + /* freeze request queue during the transition */ + blk_mq_freeze_queue(xlo->xlo_queue); + + xloop_file_fmt_exit(xlo->xlo_fmt); + + spin_lock_irq(&xlo->xlo_lock); + xlo->xlo_backing_file = NULL; + spin_unlock_irq(&xlo->xlo_lock); + + xloop_release_xfer(xlo); + xlo->transfer = NULL; + xlo->ioctl = NULL; + xlo->xlo_device = NULL; + xlo->xlo_encryption = NULL; + xlo->xlo_offset = 0; + xlo->xlo_sizelimit = 0; + xlo->xlo_encrypt_key_size = 0; + memset(xlo->xlo_encrypt_key, 0, XLO_KEY_SIZE); + memset(xlo->xlo_crypt_name, 0, XLO_NAME_SIZE); + memset(xlo->xlo_file_name, 0, XLO_NAME_SIZE); + blk_queue_logical_block_size(xlo->xlo_queue, 512); + blk_queue_physical_block_size(xlo->xlo_queue, 512); + blk_queue_io_min(xlo->xlo_queue, 512); + if (bdev) { + bdput(bdev); + invalidate_bdev(bdev); + bdev->bd_inode->i_mapping->wb_err = 0; + } + set_capacity(xlo->xlo_disk, 0); + xloop_sysfs_exit(xlo); + if (bdev) { + bd_set_size(bdev, 0); + /* let user-space know about this change */ + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); + } + mapping_set_gfp_mask(filp->f_mapping, gfp); + /* This is safe: open() is still holding a reference. */ + module_put(THIS_MODULE); + blk_mq_unfreeze_queue(xlo->xlo_queue); + + partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN && bdev; + xlo_number = xlo->xlo_number; + xloop_unprepare_queue(xlo); +out_unlock: + mutex_unlock(&xloop_ctl_mutex); + if (partscan) { + /* + * bd_mutex has been held already in release path, so don't + * acquire it if this function is called in such case. + * + * If the reread partition isn't from release path, xlo_refcnt + * must be at least one and it can only become zero when the + * current holder is released. + */ + if (!release) + mutex_lock(&bdev->bd_mutex); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0) + err = bdev_disk_changed(bdev, false); +#else + err = blkdev_reread_part(bdev); +#endif + if (!release) + mutex_unlock(&bdev->bd_mutex); + if (err) + pr_warn("%s: partition scan of xloop%d failed (rc=%d)\n", + __func__, xlo_number, err); + /* Device is gone, no point in returning error */ + err = 0; + } + + /* + * xlo->xlo_state is set to Xlo_unbound here after above partscan has + * finished. + * + * There cannot be anybody else entering __xloop_clr_fd() as + * xlo->xlo_backing_file is already cleared and Xlo_rundown state + * protects us from all the other places trying to change the 'xlo' + * device. + */ + mutex_lock(&xloop_ctl_mutex); + xlo->xlo_flags = 0; + if (!part_shift) + xlo->xlo_disk->flags |= GENHD_FL_NO_PART_SCAN; + xlo->xlo_state = Xlo_unbound; + mutex_unlock(&xloop_ctl_mutex); + + /* + * Need not hold xloop_ctl_mutex to fput backing file. + * Calling fput holding xloop_ctl_mutex triggers a circular + * lock dependency possibility warning as fput can take + * bd_mutex which is usually taken before xloop_ctl_mutex. + */ + if (filp) + fput(filp); + return err; +} + +static int xloop_clr_fd(struct xloop_device *xlo) +{ + int err; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + if (xlo->xlo_state != Xlo_bound) { + mutex_unlock(&xloop_ctl_mutex); + return -ENXIO; + } + /* + * If we've explicitly asked to tear down the xloop device, + * and it has an elevated reference count, set it for auto-teardown when + * the last reference goes away. This stops $!~#$@ udev from + * preventing teardown because it decided that it needs to run blkid on + * the xloopback device whenever they appear. xfstests is notorious for + * failing tests because blkid via udev races with a losetup + * /do something like mkfs/losetup -d causing the losetup -d + * command to fail with EBUSY. + */ + if (atomic_read(&xlo->xlo_refcnt) > 1) { + xlo->xlo_flags |= XLO_FLAGS_AUTOCLEAR; + mutex_unlock(&xloop_ctl_mutex); + return 0; + } + xlo->xlo_state = Xlo_rundown; + mutex_unlock(&xloop_ctl_mutex); + + return __xloop_clr_fd(xlo, false); +} + +static int +xloop_set_status(struct xloop_device *xlo, const struct xloop_info64 *info) +{ + int err; + struct block_device *bdev; + kuid_t uid = current_uid(); + int prev_xlo_flags; + bool partscan = false; + bool size_changed = false; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + if (xlo->xlo_encrypt_key_size && + !uid_eq(xlo->xlo_key_owner, uid) && + !capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto out_unlock; + } + if (xlo->xlo_state != Xlo_bound) { + err = -ENXIO; + goto out_unlock; + } + + if (xlo->xlo_offset != info->xlo_offset || + xlo->xlo_sizelimit != info->xlo_sizelimit) { + size_changed = true; + sync_blockdev(xlo->xlo_device); + invalidate_bdev(xlo->xlo_device); + } + + /* I/O need to be drained during transfer transition */ + blk_mq_freeze_queue(xlo->xlo_queue); + + if (size_changed && xlo->xlo_device->bd_inode->i_mapping->nrpages) { + /* If any pages were dirtied after invalidate_bdev(), try again */ + err = -EAGAIN; + pr_warn("%s: xloop%d (%s) has still dirty pages (nrpages=%lu)\n", + __func__, xlo->xlo_number, xlo->xlo_file_name, + xlo->xlo_device->bd_inode->i_mapping->nrpages); + goto out_unfreeze; + } + + prev_xlo_flags = xlo->xlo_flags; + + err = xloop_set_status_from_info(xlo, info); + if (err) + goto out_unfreeze; + + /* Mask out flags that can't be set using XLOOP_SET_STATUS. */ + xlo->xlo_flags &= XLOOP_SET_STATUS_SETTABLE_FLAGS; + /* For those flags, use the previous values instead */ + xlo->xlo_flags |= prev_xlo_flags & ~XLOOP_SET_STATUS_SETTABLE_FLAGS; + /* For flags that can't be cleared, use previous values too */ + xlo->xlo_flags |= prev_xlo_flags & ~XLOOP_SET_STATUS_CLEARABLE_FLAGS; + + if (xlo->xlo_fmt->file_fmt_type != info->xlo_file_fmt_type) { + /* xloop file format has changed, so change file format driver */ + err = xloop_file_fmt_change(xlo->xlo_fmt, info->xlo_file_fmt_type); + if (err) + goto out_unfreeze; + + /* After change of the file format, recalculate the capacity of + * the loop device. */ + size_changed = true; + } + + if (size_changed) { + loff_t new_size = get_xloop_size(xlo, xlo->xlo_backing_file); + xloop_set_size(xlo, new_size); + } + + xloop_config_discard(xlo); + + /* update dio if xlo_offset or transfer is changed */ + __xloop_update_dio(xlo, xlo->use_dio); + +out_unfreeze: + blk_mq_unfreeze_queue(xlo->xlo_queue); + + if (!err && (xlo->xlo_flags & XLO_FLAGS_PARTSCAN) && + !(prev_xlo_flags & XLO_FLAGS_PARTSCAN)) { + xlo->xlo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; + bdev = xlo->xlo_device; + partscan = true; + } +out_unlock: + mutex_unlock(&xloop_ctl_mutex); + if (partscan) + xloop_reread_partitions(xlo, bdev); + + return err; +} + +static int +xloop_get_status(struct xloop_device *xlo, struct xloop_info64 *info) +{ + struct path path; + struct kstat stat; + int ret; + + ret = mutex_lock_killable(&xloop_ctl_mutex); + if (ret) + return ret; + if (xlo->xlo_state != Xlo_bound) { + mutex_unlock(&xloop_ctl_mutex); + return -ENXIO; + } + + memset(info, 0, sizeof(*info)); + info->xlo_number = xlo->xlo_number; + info->xlo_offset = xlo->xlo_offset; + info->xlo_sizelimit = xlo->xlo_sizelimit; + info->xlo_flags = xlo->xlo_flags; + memcpy(info->xlo_file_name, xlo->xlo_file_name, XLO_NAME_SIZE); + memcpy(info->xlo_crypt_name, xlo->xlo_crypt_name, XLO_NAME_SIZE); + info->xlo_encrypt_type = + xlo->xlo_encryption ? xlo->xlo_encryption->number : 0; + if (xlo->xlo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { + info->xlo_encrypt_key_size = xlo->xlo_encrypt_key_size; + memcpy(info->xlo_encrypt_key, xlo->xlo_encrypt_key, + xlo->xlo_encrypt_key_size); + } + + /* Drop xloop_ctl_mutex while we call into the filesystem. */ + path = xlo->xlo_backing_file->f_path; + path_get(&path); + mutex_unlock(&xloop_ctl_mutex); + ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT); + if (!ret) { + info->xlo_device = huge_encode_dev(stat.dev); + info->xlo_inode = stat.ino; + info->xlo_rdevice = huge_encode_dev(stat.rdev); + } + path_put(&path); + return ret; +} + +static void +xloop_info64_from_old(const struct xloop_info *info, struct xloop_info64 *info64) +{ + memset(info64, 0, sizeof(*info64)); + info64->xlo_number = info->xlo_number; + info64->xlo_device = info->xlo_device; + info64->xlo_inode = info->xlo_inode; + info64->xlo_rdevice = info->xlo_rdevice; + info64->xlo_offset = info->xlo_offset; + info64->xlo_sizelimit = 0; + info64->xlo_encrypt_type = info->xlo_encrypt_type; + info64->xlo_encrypt_key_size = info->xlo_encrypt_key_size; + info64->xlo_flags = info->xlo_flags; + info64->xlo_init[0] = info->xlo_init[0]; + info64->xlo_init[1] = info->xlo_init[1]; + info64->xlo_file_fmt_type = info->xlo_file_fmt_type; + if (info->xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info64->xlo_crypt_name, info->xlo_name, XLO_NAME_SIZE); + else + memcpy(info64->xlo_file_name, info->xlo_name, XLO_NAME_SIZE); + memcpy(info64->xlo_encrypt_key, info->xlo_encrypt_key, XLO_KEY_SIZE); +} + +static int +xloop_info64_to_old(const struct xloop_info64 *info64, struct xloop_info *info) +{ + memset(info, 0, sizeof(*info)); + info->xlo_number = info64->xlo_number; + info->xlo_device = info64->xlo_device; + info->xlo_inode = info64->xlo_inode; + info->xlo_rdevice = info64->xlo_rdevice; + info->xlo_offset = info64->xlo_offset; + info->xlo_encrypt_type = info64->xlo_encrypt_type; + info->xlo_encrypt_key_size = info64->xlo_encrypt_key_size; + info->xlo_flags = info64->xlo_flags; + info->xlo_init[0] = info64->xlo_init[0]; + info->xlo_init[1] = info64->xlo_init[1]; + info->xlo_file_fmt_type = info64->xlo_file_fmt_type; + if (info->xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info->xlo_name, info64->xlo_crypt_name, XLO_NAME_SIZE); + else + memcpy(info->xlo_name, info64->xlo_file_name, XLO_NAME_SIZE); + memcpy(info->xlo_encrypt_key, info64->xlo_encrypt_key, XLO_KEY_SIZE); + + /* error in case values were truncated */ + if (info->xlo_device != info64->xlo_device || + info->xlo_rdevice != info64->xlo_rdevice || + info->xlo_inode != info64->xlo_inode || + info->xlo_offset != info64->xlo_offset) + return -EOVERFLOW; + + return 0; +} + +static int +xloop_set_status_old(struct xloop_device *xlo, const struct xloop_info __user *arg) +{ + struct xloop_info info; + struct xloop_info64 info64; + + if (copy_from_user(&info, arg, sizeof (struct xloop_info))) + return -EFAULT; + xloop_info64_from_old(&info, &info64); + return xloop_set_status(xlo, &info64); +} + +static int +xloop_set_status64(struct xloop_device *xlo, const struct xloop_info64 __user *arg) +{ + struct xloop_info64 info64; + + if (copy_from_user(&info64, arg, sizeof (struct xloop_info64))) + return -EFAULT; + return xloop_set_status(xlo, &info64); +} + +static int +xloop_get_status_old(struct xloop_device *xlo, struct xloop_info __user *arg) { + struct xloop_info info; + struct xloop_info64 info64; + int err; + + if (!arg) + return -EINVAL; + err = xloop_get_status(xlo, &info64); + if (!err) + err = xloop_info64_to_old(&info64, &info); + if (!err && copy_to_user(arg, &info, sizeof(info))) + err = -EFAULT; + + return err; +} + +static int +xloop_get_status64(struct xloop_device *xlo, struct xloop_info64 __user *arg) { + struct xloop_info64 info64; + int err; + + if (!arg) + return -EINVAL; + err = xloop_get_status(xlo, &info64); + if (!err && copy_to_user(arg, &info64, sizeof(info64))) + err = -EFAULT; + + return err; +} + +static int xloop_set_capacity(struct xloop_device *xlo) +{ + loff_t size; + + if (unlikely(xlo->xlo_state != Xlo_bound)) + return -ENXIO; + + size = get_xloop_size(xlo, xlo->xlo_backing_file); + xloop_set_size(xlo, size); + + return 0; +} + +static int xloop_set_dio(struct xloop_device *xlo, unsigned long arg) +{ + int error = -ENXIO; + if (xlo->xlo_state != Xlo_bound) + goto out; + + __xloop_update_dio(xlo, !!arg); + if (xlo->use_dio == !!arg) + return 0; + error = -EINVAL; + out: + return error; +} + +static int xloop_set_block_size(struct xloop_device *xlo, unsigned long arg) +{ + int err = 0; + + if (xlo->xlo_state != Xlo_bound) + return -ENXIO; + + err = xloop_validate_block_size(arg); + if (err) + return err; + + if (xlo->xlo_queue->limits.logical_block_size == arg) + return 0; + + sync_blockdev(xlo->xlo_device); + invalidate_bdev(xlo->xlo_device); + + blk_mq_freeze_queue(xlo->xlo_queue); + + /* invalidate_bdev should have truncated all the pages */ + if (xlo->xlo_device->bd_inode->i_mapping->nrpages) { + err = -EAGAIN; + pr_warn("%s: xloop%d (%s) has still dirty pages (nrpages=%lu)\n", + __func__, xlo->xlo_number, xlo->xlo_file_name, + xlo->xlo_device->bd_inode->i_mapping->nrpages); + goto out_unfreeze; + } + + blk_queue_logical_block_size(xlo->xlo_queue, arg); + blk_queue_physical_block_size(xlo->xlo_queue, arg); + blk_queue_io_min(xlo->xlo_queue, arg); + xloop_update_dio(xlo); +out_unfreeze: + blk_mq_unfreeze_queue(xlo->xlo_queue); + + return err; +} + +static int xlo_simple_ioctl(struct xloop_device *xlo, unsigned int cmd, + unsigned long arg) +{ + int err; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + switch (cmd) { + case XLOOP_SET_CAPACITY: + err = xloop_set_capacity(xlo); + break; + case XLOOP_SET_DIRECT_IO: + err = xloop_set_dio(xlo, arg); + break; + case XLOOP_SET_BLOCK_SIZE: + err = xloop_set_block_size(xlo, arg); + break; + default: + err = xlo->ioctl ? xlo->ioctl(xlo, cmd, arg) : -EINVAL; + } + mutex_unlock(&xloop_ctl_mutex); + return err; +} + +static int xlo_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct xloop_device *xlo = bdev->bd_disk->private_data; + void __user *argp = (void __user *) arg; + int err; + + switch (cmd) { + case XLOOP_SET_FD: { + /* + * Legacy case - pass in a zeroed out struct xloop_config with + * only the file descriptor set , which corresponds with the + * default parameters we'd have used otherwise. + */ + struct xloop_config config; + + memset(&config, 0, sizeof(config)); + config.fd = arg; + + return xloop_configure(xlo, mode, bdev, &config); + } + case XLOOP_CONFIGURE: { + struct xloop_config config; + + if (copy_from_user(&config, argp, sizeof(config))) + return -EFAULT; + + return xloop_configure(xlo, mode, bdev, &config); + } + case XLOOP_CHANGE_FD: + return xloop_change_fd(xlo, bdev, arg); + case XLOOP_CLR_FD: + return xloop_clr_fd(xlo); + case XLOOP_SET_STATUS: + err = -EPERM; + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { + err = xloop_set_status_old(xlo, argp); + } + break; + case XLOOP_GET_STATUS: + return xloop_get_status_old(xlo, argp); + case XLOOP_SET_STATUS64: + err = -EPERM; + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { + err = xloop_set_status64(xlo, argp); + } + break; + case XLOOP_GET_STATUS64: + return xloop_get_status64(xlo, argp); + case XLOOP_SET_CAPACITY: + case XLOOP_SET_DIRECT_IO: + case XLOOP_SET_BLOCK_SIZE: + if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN)) + return -EPERM; + fallthrough; + default: + err = xlo_simple_ioctl(xlo, cmd, arg); + break; + } + + return err; +} + +#ifdef CONFIG_COMPAT +struct compat_xloop_info { + compat_int_t xlo_number; /* ioctl r/o */ + compat_dev_t xlo_device; /* ioctl r/o */ + compat_ulong_t xlo_inode; /* ioctl r/o */ + compat_dev_t xlo_rdevice; /* ioctl r/o */ + compat_int_t xlo_offset; + compat_int_t xlo_encrypt_type; + compat_int_t xlo_encrypt_key_size; /* ioctl w/o */ + compat_int_t xlo_flags; /* ioctl r/o */ + char xlo_name[XLO_NAME_SIZE]; + unsigned char xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ + compat_ulong_t xlo_init[2]; + char reserved[4]; + compat_int_t xlo_file_fmt_type; +}; + +/* + * Transfer 32-bit compatibility structure in userspace to 64-bit xloop info + * - noinlined to reduce stack space usage in main part of driver + */ +static noinline int +xloop_info64_from_compat(const struct compat_xloop_info __user *arg, + struct xloop_info64 *info64) +{ + struct compat_xloop_info info; + + if (copy_from_user(&info, arg, sizeof(info))) + return -EFAULT; + + memset(info64, 0, sizeof(*info64)); + info64->xlo_number = info.xlo_number; + info64->xlo_device = info.xlo_device; + info64->xlo_inode = info.xlo_inode; + info64->xlo_rdevice = info.xlo_rdevice; + info64->xlo_offset = info.xlo_offset; + info64->xlo_sizelimit = 0; + info64->xlo_encrypt_type = info.xlo_encrypt_type; + info64->xlo_encrypt_key_size = info.xlo_encrypt_key_size; + info64->xlo_flags = info.xlo_flags; + info64->xlo_init[0] = info.xlo_init[0]; + info64->xlo_init[1] = info.xlo_init[1]; + info64->xlo_file_fmt_type = info.xlo_file_fmt_type; + if (info.xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info64->xlo_crypt_name, info.xlo_name, XLO_NAME_SIZE); + else + memcpy(info64->xlo_file_name, info.xlo_name, XLO_NAME_SIZE); + memcpy(info64->xlo_encrypt_key, info.xlo_encrypt_key, XLO_KEY_SIZE); + return 0; +} + +/* + * Transfer 64-bit xloop info to 32-bit compatibility structure in userspace + * - noinlined to reduce stack space usage in main part of driver + */ +static noinline int +xloop_info64_to_compat(const struct xloop_info64 *info64, + struct compat_xloop_info __user *arg) +{ + struct compat_xloop_info info; + + memset(&info, 0, sizeof(info)); + info.xlo_number = info64->xlo_number; + info.xlo_device = info64->xlo_device; + info.xlo_inode = info64->xlo_inode; + info.xlo_rdevice = info64->xlo_rdevice; + info.xlo_offset = info64->xlo_offset; + info.xlo_encrypt_type = info64->xlo_encrypt_type; + info.xlo_encrypt_key_size = info64->xlo_encrypt_key_size; + info.xlo_flags = info64->xlo_flags; + info.xlo_init[0] = info64->xlo_init[0]; + info.xlo_init[1] = info64->xlo_init[1]; + if (info.xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info.xlo_name, info64->xlo_crypt_name, XLO_NAME_SIZE); + else + memcpy(info.xlo_name, info64->xlo_file_name, XLO_NAME_SIZE); + memcpy(info.xlo_encrypt_key, info64->xlo_encrypt_key, XLO_KEY_SIZE); + + /* error in case values were truncated */ + if (info.xlo_device != info64->xlo_device || + info.xlo_rdevice != info64->xlo_rdevice || + info.xlo_inode != info64->xlo_inode || + info.xlo_offset != info64->xlo_offset || + info.xlo_init[0] != info64->xlo_init[0] || + info.xlo_init[1] != info64->xlo_init[1]) + return -EOVERFLOW; + + if (copy_to_user(arg, &info, sizeof(info))) + return -EFAULT; + return 0; +} + +static int +xloop_set_status_compat(struct xloop_device *xlo, + const struct compat_xloop_info __user *arg) +{ + struct xloop_info64 info64; + int ret; + + ret = xloop_info64_from_compat(arg, &info64); + if (ret < 0) + return ret; + return xloop_set_status(xlo, &info64); +} + +static int +xloop_get_status_compat(struct xloop_device *xlo, + struct compat_xloop_info __user *arg) +{ + struct xloop_info64 info64; + int err; + + if (!arg) + return -EINVAL; + err = xloop_get_status(xlo, &info64); + if (!err) + err = xloop_info64_to_compat(&info64, arg); + return err; +} + +static int xlo_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct xloop_device *xlo = bdev->bd_disk->private_data; + int err; + + switch(cmd) { + case XLOOP_SET_STATUS: + err = xloop_set_status_compat(xlo, + (const struct compat_xloop_info __user *)arg); + break; + case XLOOP_GET_STATUS: + err = xloop_get_status_compat(xlo, + (struct compat_xloop_info __user *)arg); + break; + case XLOOP_SET_CAPACITY: + case XLOOP_CLR_FD: + case XLOOP_GET_STATUS64: + case XLOOP_SET_STATUS64: + case XLOOP_CONFIGURE: + arg = (unsigned long) compat_ptr(arg); + fallthrough; + case XLOOP_SET_FD: + case XLOOP_CHANGE_FD: + case XLOOP_SET_BLOCK_SIZE: + case XLOOP_SET_DIRECT_IO: + err = xlo_ioctl(bdev, mode, cmd, arg); + break; + default: + err = -ENOIOCTLCMD; + break; + } + return err; +} +#endif + +static int xlo_open(struct block_device *bdev, fmode_t mode) +{ + struct xloop_device *xlo; + int err; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + xlo = bdev->bd_disk->private_data; + if (!xlo) { + err = -ENXIO; + goto out; + } + + atomic_inc(&xlo->xlo_refcnt); +out: + mutex_unlock(&xloop_ctl_mutex); + return err; +} + +static void xlo_release(struct gendisk *disk, fmode_t mode) +{ + struct xloop_device *xlo; + + mutex_lock(&xloop_ctl_mutex); + xlo = disk->private_data; + if (atomic_dec_return(&xlo->xlo_refcnt)) + goto out_unlock; + + if (xlo->xlo_flags & XLO_FLAGS_AUTOCLEAR) { + if (xlo->xlo_state != Xlo_bound) + goto out_unlock; + xlo->xlo_state = Xlo_rundown; + mutex_unlock(&xloop_ctl_mutex); + /* + * In autoclear mode, stop the xloop thread + * and remove configuration after last close. + */ + __xloop_clr_fd(xlo, true); + return; + } else if (xlo->xlo_state == Xlo_bound) { + /* + * Otherwise keep thread (if running) and config, + * but flush possible ongoing bios in thread. + */ + blk_mq_freeze_queue(xlo->xlo_queue); + blk_mq_unfreeze_queue(xlo->xlo_queue); + } + +out_unlock: + mutex_unlock(&xloop_ctl_mutex); +} + +static const struct block_device_operations xlo_fops = { + .owner = THIS_MODULE, + .open = xlo_open, + .release = xlo_release, + .ioctl = xlo_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = xlo_compat_ioctl, +#endif +}; + +/* + * And now the modules code and kernel interface. + */ +static int max_xloop; +module_param(max_xloop, int, 0444); +MODULE_PARM_DESC(max_xloop, "Maximum number of xloop devices"); +module_param(max_part, int, 0444); +MODULE_PARM_DESC(max_part, "Maximum number of partitions per xloop device"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_BLOCKDEV_MAJOR(XLOOP_MAJOR); + +int xloop_register_transfer(struct xloop_func_table *funcs) +{ + unsigned int n = funcs->number; + + if (n >= MAX_XLO_CRYPT || xfer_funcs[n]) + return -EINVAL; + xfer_funcs[n] = funcs; + return 0; +} + +static int unregister_transfer_cb(int id, void *ptr, void *data) +{ + struct xloop_device *xlo = ptr; + struct xloop_func_table *xfer = data; + + mutex_lock(&xloop_ctl_mutex); + if (xlo->xlo_encryption == xfer) + xloop_release_xfer(xlo); + mutex_unlock(&xloop_ctl_mutex); + return 0; +} + +int xloop_unregister_transfer(int number) +{ + unsigned int n = number; + struct xloop_func_table *xfer; + + if (n == 0 || n >= MAX_XLO_CRYPT || (xfer = xfer_funcs[n]) == NULL) + return -EINVAL; + + xfer_funcs[n] = NULL; + idr_for_each(&xloop_index_idr, &unregister_transfer_cb, xfer); + return 0; +} + +EXPORT_SYMBOL(xloop_register_transfer); +EXPORT_SYMBOL(xloop_unregister_transfer); + +static blk_status_t xloop_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct request *rq = bd->rq; + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + struct xloop_device *xlo = rq->q->queuedata; + + blk_mq_start_request(rq); + + if (xlo->xlo_state != Xlo_bound) + return BLK_STS_IOERR; + + switch (req_op(rq)) { + case REQ_OP_FLUSH: + case REQ_OP_DISCARD: + case REQ_OP_WRITE_ZEROES: + cmd->use_aio = false; + break; + default: + cmd->use_aio = xlo->use_dio; + break; + } + + /* always use the first bio's css */ +#ifdef CONFIG_BLK_CGROUP + if (cmd->use_aio && rq->bio && rq->bio->bi_blkg) { + cmd->css = &bio_blkcg(rq->bio)->css; + css_get(cmd->css); + } else +#endif + cmd->css = NULL; + kthread_queue_work(&xlo->worker, &cmd->work); + + return BLK_STS_OK; +} + +static void xloop_handle_cmd(struct xloop_cmd *cmd) +{ + struct request *rq = blk_mq_rq_from_pdu(cmd); + const bool write = op_is_write(req_op(rq)); + struct xloop_device *xlo = rq->q->queuedata; + int ret = 0; + + if (write && (xlo->xlo_flags & XLO_FLAGS_READ_ONLY)) { + ret = -EIO; + goto failed; + } + + ret = do_req_filebacked(xlo, rq); + failed: + /* complete non-aio request */ + if (!cmd->use_aio || ret) { + if (ret == -EOPNOTSUPP) + cmd->ret = ret; + else + cmd->ret = ret ? -EIO : 0; +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) + if (likely(!blk_should_fake_timeout(rq->q))) + blk_mq_complete_request(rq); +#else + blk_mq_complete_request(rq); +#endif + } +} + +static void xloop_queue_work(struct kthread_work *work) +{ + struct xloop_cmd *cmd = + container_of(work, struct xloop_cmd, work); + + xloop_handle_cmd(cmd); +} + +static int xloop_init_request(struct blk_mq_tag_set *set, struct request *rq, + unsigned int hctx_idx, unsigned int numa_node) +{ + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + + kthread_init_work(&cmd->work, xloop_queue_work); + return 0; +} + +static const struct blk_mq_ops xloop_mq_ops = { + .queue_rq = xloop_queue_rq, + .init_request = xloop_init_request, + .complete = xlo_complete_rq, +}; + +static struct dentry *xloop_dbgfs_dir; + +static int xloop_add(struct xloop_device **l, int i) +{ + struct xloop_device *xlo; + struct gendisk *disk; + int err; + + err = -ENOMEM; + xlo = kzalloc(sizeof(*xlo), GFP_KERNEL); + if (!xlo) + goto out; + + xlo->xlo_state = Xlo_unbound; + + /* allocate id, if @id >= 0, we're requesting that specific id */ + if (i >= 0) { + err = idr_alloc(&xloop_index_idr, xlo, i, i + 1, GFP_KERNEL); + if (err == -ENOSPC) + err = -EEXIST; + } else { + err = idr_alloc(&xloop_index_idr, xlo, 0, 0, GFP_KERNEL); + } + if (err < 0) + goto out_free_dev; + i = err; + + err = -ENOMEM; + xlo->tag_set.ops = &xloop_mq_ops; + xlo->tag_set.nr_hw_queues = 1; + xlo->tag_set.queue_depth = 128; + xlo->tag_set.numa_node = NUMA_NO_NODE; + xlo->tag_set.cmd_size = sizeof(struct xloop_cmd); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0) + xlo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING; +#else + xlo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; +#endif + xlo->tag_set.driver_data = xlo; + + err = blk_mq_alloc_tag_set(&xlo->tag_set); + if (err) + goto out_free_idr; + + xlo->xlo_queue = blk_mq_init_queue(&xlo->tag_set); + if (IS_ERR(xlo->xlo_queue)) { + err = PTR_ERR(xlo->xlo_queue); + goto out_cleanup_tags; + } + xlo->xlo_queue->queuedata = xlo; + + blk_queue_max_hw_sectors(xlo->xlo_queue, BLK_DEF_MAX_SECTORS); + + /* + * By default, we do buffer IO, so it doesn't make sense to enable + * merge because the I/O submitted to backing file is handled page by + * page. For directio mode, merge does help to dispatch bigger request + * to underlayer disk. We will enable merge once directio is enabled. + */ + blk_queue_flag_set(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); + + err = -ENOMEM; + xlo->xlo_fmt = xloop_file_fmt_alloc(); + if (!xlo->xlo_fmt) + goto out_free_queue; + + xloop_file_fmt_set_xlo(xlo->xlo_fmt, xlo); + + err = -ENOMEM; + disk = xlo->xlo_disk = alloc_disk(1 << part_shift); + if (!disk) + goto out_free_file_fmt; + + /* + * Disable partition scanning by default. The in-kernel partition + * scanning can be requested individually per-device during its + * setup. Userspace can always add and remove partitions from all + * devices. The needed partition minors are allocated from the + * extended minor space, the main xloop device numbers will continue + * to match the xloop minors, regardless of the number of partitions + * used. + * + * If max_part is given, partition scanning is globally enabled for + * all xloop devices. The minors for the main xloop devices will be + * multiples of max_part. + * + * Note: Global-for-all-devices, set-only-at-init, read-only module + * parameteters like 'max_xloop' and 'max_part' make things needlessly + * complicated, are too static, inflexible and may surprise + * userspace tools. Parameters like this in general should be avoided. + */ + if (!part_shift) + disk->flags |= GENHD_FL_NO_PART_SCAN; + disk->flags |= GENHD_FL_EXT_DEVT; + atomic_set(&xlo->xlo_refcnt, 0); + xlo->xlo_number = i; + spin_lock_init(&xlo->xlo_lock); + disk->major = XLOOP_MAJOR; + disk->first_minor = i << part_shift; + disk->fops = &xlo_fops; + disk->private_data = xlo; + disk->queue = xlo->xlo_queue; + sprintf(disk->disk_name, "xloop%d", i); + add_disk(disk); + *l = xlo; + + /* initialize debugfs entries */ + /* create for each loop device a debugfs directory under 'loop' if + * the 'block' directory exists, otherwise create the loop directory in + * the root directory */ +#ifdef CONFIG_DEBUG_FS + xlo->xlo_dbgfs_dir = debugfs_create_dir(disk->disk_name, xloop_dbgfs_dir); + + if (IS_ERR_OR_NULL(xlo->xlo_dbgfs_dir)) { + err = -ENODEV; + xlo->xlo_dbgfs_dir = NULL; + goto out_free_file_fmt; + } +#endif + + return xlo->xlo_number; + +out_free_file_fmt: + xloop_file_fmt_free(xlo->xlo_fmt); +out_free_queue: + blk_cleanup_queue(xlo->xlo_queue); +out_cleanup_tags: + blk_mq_free_tag_set(&xlo->tag_set); +out_free_idr: + idr_remove(&xloop_index_idr, i); +out_free_dev: + kfree(xlo); +out: + return err; +} + +static void xloop_remove(struct xloop_device *xlo) +{ + xloop_file_fmt_free(xlo->xlo_fmt); + debugfs_remove(xlo->xlo_dbgfs_dir); + del_gendisk(xlo->xlo_disk); + blk_cleanup_queue(xlo->xlo_queue); + blk_mq_free_tag_set(&xlo->tag_set); + put_disk(xlo->xlo_disk); + kfree(xlo); +} + +static int find_free_cb(int id, void *ptr, void *data) +{ + struct xloop_device *xlo = ptr; + struct xloop_device **l = data; + + if (xlo->xlo_state == Xlo_unbound) { + *l = xlo; + return 1; + } + return 0; +} + +static int xloop_lookup(struct xloop_device **l, int i) +{ + struct xloop_device *xlo; + int ret = -ENODEV; + + if (i < 0) { + int err; + + err = idr_for_each(&xloop_index_idr, &find_free_cb, &xlo); + if (err == 1) { + *l = xlo; + ret = xlo->xlo_number; + } + goto out; + } + + /* lookup and return a specific i */ + xlo = idr_find(&xloop_index_idr, i); + if (xlo) { + *l = xlo; + ret = xlo->xlo_number; + } +out: + return ret; +} + +static struct kobject *xloop_probe(dev_t dev, int *part, void *data) +{ + struct xloop_device *xlo; + struct kobject *kobj; + int err; + + mutex_lock(&xloop_ctl_mutex); + err = xloop_lookup(&xlo, MINOR(dev) >> part_shift); + if (err < 0) + err = xloop_add(&xlo, MINOR(dev) >> part_shift); + if (err < 0) + kobj = NULL; + else + kobj = get_disk_and_module(xlo->xlo_disk); + mutex_unlock(&xloop_ctl_mutex); + + *part = 0; + return kobj; +} + +static long xloop_control_ioctl(struct file *file, unsigned int cmd, + unsigned long parm) +{ + struct xloop_device *xlo; + int ret; + + ret = mutex_lock_killable(&xloop_ctl_mutex); + if (ret) + return ret; + + ret = -ENOSYS; + switch (cmd) { + case XLOOP_CTL_ADD: + ret = xloop_lookup(&xlo, parm); + if (ret >= 0) { + ret = -EEXIST; + break; + } + ret = xloop_add(&xlo, parm); + break; + case XLOOP_CTL_REMOVE: + ret = xloop_lookup(&xlo, parm); + if (ret < 0) + break; + if (xlo->xlo_state != Xlo_unbound) { + ret = -EBUSY; + break; + } + if (atomic_read(&xlo->xlo_refcnt) > 0) { + ret = -EBUSY; + break; + } + xlo->xlo_disk->private_data = NULL; + idr_remove(&xloop_index_idr, xlo->xlo_number); + xloop_remove(xlo); + break; + case XLOOP_CTL_GET_FREE: + ret = xloop_lookup(&xlo, -1); + if (ret >= 0) + break; + ret = xloop_add(&xlo, -1); + } + mutex_unlock(&xloop_ctl_mutex); + + return ret; +} + +static const struct file_operations xloop_ctl_fops = { + .open = nonseekable_open, + .unlocked_ioctl = xloop_control_ioctl, + .compat_ioctl = xloop_control_ioctl, + .owner = THIS_MODULE, + .llseek = noop_llseek, +}; + +static struct miscdevice xloop_misc = { + .minor = XLOOP_CTRL_MINOR, + .name = "xloop-control", + .fops = &xloop_ctl_fops, +}; + +MODULE_ALIAS_MISCDEV(XLOOP_CTRL_MINOR); +MODULE_ALIAS("devname:xloop-control"); + +static int __init xloop_init(void) +{ + int i, nr; + unsigned long range; + struct xloop_device *xlo; + int err; + + part_shift = 0; + if (max_part > 0) { + part_shift = fls(max_part); + + /* + * Adjust max_part according to part_shift as it is exported + * to user space so that user can decide correct minor number + * if [s]he want to create more devices. + * + * Note that -1 is required because partition 0 is reserved + * for the whole disk. + */ + max_part = (1UL << part_shift) - 1; + } + + if ((1UL << part_shift) > DISK_MAX_PARTS) { + err = -EINVAL; + goto err_out; + } + + if (max_xloop > 1UL << (MINORBITS - part_shift)) { + err = -EINVAL; + goto err_out; + } + + /* + * If max_xloop is specified, create that many devices upfront. + * This also becomes a hard limit. If max_xloop is not specified, + * create CONFIG_BLK_DEV_XLOOP_MIN_COUNT xloop devices at module + * init time. xloop devices can be requested on-demand with the + * /dev/xloop-control interface, or be instantiated by accessing + * a 'dead' device node. + */ + if (max_xloop) { + nr = CONFIG_BLK_DEV_XLOOP_MIN_COUNT; + range = 1UL << MINORBITS; + } + + err = misc_register(&xloop_misc); + if (err < 0) + goto err_out; + + + if (register_blkdev(XLOOP_MAJOR, "xloop")) { + err = -EIO; + goto misc_out; + } + +#ifdef CONFIG_DEBUG_FS + xloop_dbgfs_dir = debugfs_create_dir("xloop", NULL); + if (IS_ERR_OR_NULL(xloop_dbgfs_dir)) { + err = -ENODEV; + goto misc_out; + } +#endif + + blk_register_region(MKDEV(XLOOP_MAJOR, 0), range, + THIS_MODULE, xloop_probe, NULL, NULL); + + /* pre-create number of devices given by config or max_xloop */ + mutex_lock(&xloop_ctl_mutex); + for (i = 0; i < nr; i++) + xloop_add(&xlo, i); + mutex_unlock(&xloop_ctl_mutex); + + printk(KERN_INFO "xloop: module loaded\n"); + return 0; + +misc_out: + misc_deregister(&xloop_misc); +err_out: + return err; +} + +static int xloop_exit_cb(int id, void *ptr, void *data) +{ + struct xloop_device *xlo = ptr; + + xloop_remove(xlo); + return 0; +} + +static void __exit xloop_exit(void) +{ + unsigned long range; + + range = max_xloop ? max_xloop << part_shift : 1UL << MINORBITS; + + mutex_lock(&xloop_ctl_mutex); + + idr_for_each(&xloop_index_idr, &xloop_exit_cb, NULL); + idr_destroy(&xloop_index_idr); + + blk_unregister_region(MKDEV(XLOOP_MAJOR, 0), range); + unregister_blkdev(XLOOP_MAJOR, "xloop"); + +#ifdef CONFIG_DEBUG_FS + debugfs_remove(xloop_dbgfs_dir); +#endif + + misc_deregister(&xloop_misc); + + mutex_unlock(&xloop_ctl_mutex); +} + +module_init(xloop_init); +module_exit(xloop_exit); + +#ifndef MODULE +static int __init max_xloop_setup(char *str) +{ + max_xloop = simple_strtol(str, NULL, 0); + return 1; +} + +__setup("max_xloop=", max_xloop_setup); +#endif diff --git a/kernel/xloop_main.h b/kernel/xloop_main.h new file mode 100644 index 0000000..b9d0405 --- /dev/null +++ b/kernel/xloop_main.h @@ -0,0 +1,105 @@ +/* + * loop_main.h + * + * Written by Theodore Ts'o, 3/29/93. + * + * Copyright 1993 by Theodore Ts'o. Redistribution of this file is + * permitted under the GNU General Public License. + */ +#ifndef _LINUX_XLOOP_H +#define _LINUX_XLOOP_H + +#include +#include +#include +#include +#include +#include +#include "uapi/linux/xloop.h" +#ifdef CONFIG_DEBUG_FS +#include +#endif + +#include "xloop_file_fmt.h" + +/* Possible states of device */ +enum { + Xlo_unbound, + Xlo_bound, + Xlo_rundown, +}; + +struct xloop_func_table; + +struct xloop_device { + int xlo_number; + atomic_t xlo_refcnt; + loff_t xlo_offset; + loff_t xlo_sizelimit; + int xlo_flags; + int (*transfer)(struct xloop_device *, int cmd, + struct page *raw_page, unsigned raw_off, + struct page *xloop_page, unsigned xloop_off, + int size, sector_t real_block); + char xlo_file_name[XLO_NAME_SIZE]; + char xlo_crypt_name[XLO_NAME_SIZE]; + char xlo_encrypt_key[XLO_KEY_SIZE]; + int xlo_encrypt_key_size; + struct xloop_func_table *xlo_encryption; + __u32 xlo_init[2]; + kuid_t xlo_key_owner; /* Who set the key */ + int (*ioctl)(struct xloop_device *, int cmd, + unsigned long arg); + + struct xloop_file_fmt *xlo_fmt; + + struct file * xlo_backing_file; + struct block_device *xlo_device; + void *key_data; + + gfp_t old_gfp_mask; + + spinlock_t xlo_lock; + int xlo_state; + struct kthread_worker worker; + struct task_struct *worker_task; + bool use_dio; + bool sysfs_inited; + + struct request_queue *xlo_queue; + struct blk_mq_tag_set tag_set; + struct gendisk *xlo_disk; + +#ifdef CONFIG_DEBUG_FS + struct dentry *xlo_dbgfs_dir; +#endif +}; + +struct xloop_cmd { + struct kthread_work work; + bool use_aio; /* use AIO interface to handle I/O */ + atomic_t ref; /* only for aio */ + long ret; + struct kiocb iocb; + struct bio_vec *bvec; + struct cgroup_subsys_state *css; +}; + +/* Support for loadable transfer modules */ +struct xloop_func_table { + int number; /* filter type */ + int (*transfer)(struct xloop_device *xlo, int cmd, + struct page *raw_page, unsigned raw_off, + struct page *xloop_page, unsigned xloop_off, + int size, sector_t real_block); + int (*init)(struct xloop_device *, const struct xloop_info64 *); + /* release is called from xloop_unregister_transfer or clr_fd */ + int (*release)(struct xloop_device *); + int (*ioctl)(struct xloop_device *, int cmd, unsigned long arg); + struct module *owner; +}; + +int xloop_register_transfer(struct xloop_func_table *funcs); +int xloop_unregister_transfer(int number); + +#endif diff --git a/utils/CMakeLists.txt b/utils/CMakeLists.txt index 93fc41c..7669fd9 100644 --- a/utils/CMakeLists.txt +++ b/utils/CMakeLists.txt @@ -14,6 +14,6 @@ add_subdirectory(lib) add_subdirectory(libsmartcols) add_subdirectory(sys-utils) -install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/bash-completion/losetup +install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/bash-completion/xlosetup DESTINATION /usr/share/bash-completion/completions PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ) \ No newline at end of file diff --git a/utils/bash-completion/losetup b/utils/bash-completion/losetup deleted file mode 100644 index e085abe..0000000 --- a/utils/bash-completion/losetup +++ /dev/null @@ -1,85 +0,0 @@ -_losetup_module() -{ - local cur prev OPTS ARG - COMPREPLY=() - cur="${COMP_WORDS[COMP_CWORD]}" - prev="${COMP_WORDS[COMP_CWORD-1]}" - case $prev in - '-d'|'--detach') - ARG="$($1 --output NAME | awk '{if (1 < NR) {print}}')" - COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) - return 0 - ;; - '-j'|'--associated') - ARG="$($1 --output BACK-FILE | awk '{if (1 < NR) {print}}')" - COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) - return 0 - ;; - '-c'|'--set-capacity') - ARG="$(for I in /dev/loop[0-9]*; do if [ -e $I ]; then echo $I; fi; done)" - COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) - return 0 - ;; - '-o'|'--offset'|'--sizelimit') - COMPREPLY=( $(compgen -W "number" -- $cur) ) - return 0 - ;; - '-t'|'--type') - ARG="RAW QCOW VDI VMDK" - COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) - return 0 - ;; - '-O'|'--output') - local prefix realcur OUTPUT_ALL OUTPUT - realcur="${cur##*,}" - prefix="${cur%$realcur}" - OUTPUT_ALL="NAME AUTOCLEAR BACK-FILE BACK-INO - BACK-MAJ:MIN FILE-FORMAT MAJ:MIN OFFSET PARTSCAN RO - SIZELIMIT DIO" - for WORD in $OUTPUT_ALL; do - if ! [[ $prefix == *"$WORD"* ]]; then - OUTPUT="$WORD ${OUTPUT:-""}" - fi - done - compopt -o nospace - COMPREPLY=( $(compgen -P "$prefix" -W "$OUTPUT" -S ',' -- $realcur) ) - return 0 - ;; - '-h'|'--help'|'-V'|'--version') - return 0 - ;; - esac - case $cur in - -*) - OPTS="--all - --detach - --detach-all - --find - --set-capacity - --associated - --nooverlap - --offset - --sizelimit - --partscan - --read-only - --show - --type - --verbose - --json - --list - --noheadings - --output - --output-all - --raw - --help - --version" - COMPREPLY=( $(compgen -W "${OPTS[*]}" -- $cur) ) - return 0 - ;; - esac - local IFS=$'\n' - compopt -o filenames - COMPREPLY=( $(compgen -f -- $cur) ) - return 0 -} -complete -F _losetup_module losetup diff --git a/utils/bash-completion/xlosetup b/utils/bash-completion/xlosetup new file mode 100644 index 0000000..cdf75f1 --- /dev/null +++ b/utils/bash-completion/xlosetup @@ -0,0 +1,85 @@ +_xlosetup_module() +{ + local cur prev OPTS ARG + COMPREPLY=() + cur="${COMP_WORDS[COMP_CWORD]}" + prev="${COMP_WORDS[COMP_CWORD-1]}" + case $prev in + '-d'|'--detach') + ARG="$($1 --output NAME | awk '{if (1 < NR) {print}}')" + COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) + return 0 + ;; + '-j'|'--associated') + ARG="$($1 --output BACK-FILE | awk '{if (1 < NR) {print}}')" + COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) + return 0 + ;; + '-c'|'--set-capacity') + ARG="$(for I in /dev/xloop[0-9]*; do if [ -e $I ]; then echo $I; fi; done)" + COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) + return 0 + ;; + '-o'|'--offset'|'--sizelimit') + COMPREPLY=( $(compgen -W "number" -- $cur) ) + return 0 + ;; + '-t'|'--type') + ARG="RAW QCOW VDI VMDK" + COMPREPLY=( $(compgen -W "$ARG" -- $cur) ) + return 0 + ;; + '-O'|'--output') + local prefix realcur OUTPUT_ALL OUTPUT + realcur="${cur##*,}" + prefix="${cur%$realcur}" + OUTPUT_ALL="NAME AUTOCLEAR BACK-FILE BACK-INO + BACK-MAJ:MIN FILE-FORMAT MAJ:MIN OFFSET PARTSCAN RO + SIZELIMIT DIO" + for WORD in $OUTPUT_ALL; do + if ! [[ $prefix == *"$WORD"* ]]; then + OUTPUT="$WORD ${OUTPUT:-""}" + fi + done + compopt -o nospace + COMPREPLY=( $(compgen -P "$prefix" -W "$OUTPUT" -S ',' -- $realcur) ) + return 0 + ;; + '-h'|'--help'|'-V'|'--version') + return 0 + ;; + esac + case $cur in + -*) + OPTS="--all + --detach + --detach-all + --find + --set-capacity + --associated + --nooverlap + --offset + --sizelimit + --partscan + --read-only + --show + --type + --verbose + --json + --list + --noheadings + --output + --output-all + --raw + --help + --version" + COMPREPLY=( $(compgen -W "${OPTS[*]}" -- $cur) ) + return 0 + ;; + esac + local IFS=$'\n' + compopt -o filenames + COMPREPLY=( $(compgen -f -- $cur) ) + return 0 +} +complete -F _xlosetup_module xlosetup diff --git a/utils/lib/loopdev.c b/utils/lib/loopdev.c index 686be53..57129bd 100644 --- a/utils/lib/loopdev.c +++ b/utils/lib/loopdev.c @@ -13,7 +13,7 @@ * - reads info from /sys/block/loop/loop/ (new kernels) * - reads info by ioctl * - supports *unlimited* number of loop devices - * - supports /dev/loop as well as /dev/loop/ + * - supports /dev/xloop as well as /dev/xloop/ * - minimize overhead (fd, loopinfo, ... are shared for all operations) * - setup (associate device and backing file) * - delete (dis-associate file) @@ -77,9 +77,9 @@ static void loopdev_init_debug(void) * @lc: context * @device: device name, absolute device path or NULL to reset the current setting * - * Sets device, absolute paths (e.g. "/dev/loop") are unchanged, device - * names ("loop") are converted to the path (/dev/loop or to - * /dev/loop/) + * Sets device, absolute paths (e.g. "/dev/xloop") are unchanged, device + * names ("xloop") are converted to the path (/dev/xloop or to + * /dev/xloop/) * * This sets the device name, but does not check if the device exists! * @@ -107,9 +107,9 @@ int loopcxt_set_device(struct loopdev_cxt *lc, const char *device) if (*device != '/') { const char *dir = _PATH_DEV; - /* compose device name for /dev/loop or /dev/loop/ */ + /* compose device name for /dev/xloop or /dev/xloop/ */ if (lc->flags & LOOPDEV_FL_DEVSUBDIR) { - if (strlen(device) < 5) + if (strlen(device) < 6) return -1; device += 4; dir = _PATH_DEV_LOOP "/"; /* _PATH_DEV uses tailing slash */ @@ -324,7 +324,7 @@ int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags) if (!lc->extra_check) { /* - * Check for /dev/loop/ subdirectory + * Check for /dev/xloop/ subdirectory */ if (!(lc->flags & LOOPDEV_FL_DEVSUBDIR) && stat(_PATH_DEV_LOOP, &st) == 0 && S_ISDIR(st.st_mode)) @@ -438,11 +438,11 @@ static int loop_scandir(const char *dirname, int **ary, int hasprefix) continue; if (hasprefix) { - /* /dev/loop */ - if (sscanf(d->d_name, "loop%u", &n) != 1) + /* /dev/xloop */ + if (sscanf(d->d_name, "xloop%u", &n) != 1) continue; } else { - /* /dev/loop/ */ + /* /dev/xloop/ */ char *end = NULL; errno = 0; @@ -451,7 +451,7 @@ static int loop_scandir(const char *dirname, int **ary, int hasprefix) continue; } if (n < LOOPDEV_DEFAULT_NNODES) - continue; /* ignore loop<0..7> */ + continue; /* ignore xloop<0..7> */ if (count + 1 > arylen) { int *tmp; @@ -542,10 +542,10 @@ static int loopcxt_next_from_sysfs(struct loopdev_cxt *lc) if (strcmp(d->d_name, ".") == 0 || strcmp(d->d_name, "..") == 0 - || strncmp(d->d_name, "loop", 4) != 0) + || strncmp(d->d_name, "xloop", 4) != 0) continue; - snprintf(name, sizeof(name), "%s/loop/backing_file", d->d_name); + snprintf(name, sizeof(name), "%s/xloop/backing_file", d->d_name); if (fstatat(fd, name, &st, 0) != 0) continue; @@ -599,7 +599,7 @@ int loopcxt_next(struct loopdev_cxt *lc) for (++iter->ncur; iter->ncur < LOOPDEV_DEFAULT_NNODES; iter->ncur++) { char name[16]; - snprintf(name, sizeof(name), "loop%d", iter->ncur); + snprintf(name, sizeof(name), "xloop%d", iter->ncur); if (loopiter_set_device(lc, name) == 0) return 0; @@ -607,7 +607,7 @@ int loopcxt_next(struct loopdev_cxt *lc) iter->default_check = 0; } - /* C) the worst possibility, scan whole /dev or /dev/loop/ + /* C) the worst possibility, scan whole /dev or /dev/xloop/ */ if (!iter->minors) { DBG(ITER, ul_debugobj(iter, "next: scanning /dev")); @@ -618,7 +618,7 @@ int loopcxt_next(struct loopdev_cxt *lc) } for (++iter->ncur; iter->ncur < iter->nminors; iter->ncur++) { char name[16]; - snprintf(name, sizeof(name), "loop%d", iter->minors[iter->ncur]); + snprintf(name, sizeof(name), "xloop%d", iter->minors[iter->ncur]); if (loopiter_set_device(lc, name) == 0) return 0; @@ -694,7 +694,7 @@ char *loopcxt_get_backing_file(struct loopdev_cxt *lc) * This is always preferred, the loop_info64 * has too small buffer for the filename. */ - ul_path_read_string(sysfs, &res, "loop/backing_file"); + ul_path_read_string(sysfs, &res, "xloop/backing_file"); if (!res && loopcxt_ioctl_enabled(lc)) { struct loop_info64 *lo = loopcxt_get_info(lc); @@ -722,7 +722,7 @@ int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset) int rc = -EINVAL; if (sysfs) - rc = ul_path_read_u64(sysfs, offset, "loop/offset"); + rc = ul_path_read_u64(sysfs, offset, "xloop/offset"); if (rc && loopcxt_ioctl_enabled(lc)) { struct loop_info64 *lo = loopcxt_get_info(lc); @@ -782,7 +782,7 @@ int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size) int rc = -EINVAL; if (sysfs) - rc = ul_path_read_u64(sysfs, size, "loop/sizelimit"); + rc = ul_path_read_u64(sysfs, size, "xloop/sizelimit"); if (rc && loopcxt_ioctl_enabled(lc)) { struct loop_info64 *lo = loopcxt_get_info(lc); @@ -861,7 +861,7 @@ int loopcxt_get_file_fmt_type(struct loopdev_cxt *lc, uint32_t* file_fmt_type) if (sysfs) { /* check if file_fmt_type is accessible and supported by the kernel module */ char* file_fmt_str = NULL; - if (ul_path_read_string(sysfs, &file_fmt_str, "loop/file_fmt_type") == 0) + if (ul_path_read_string(sysfs, &file_fmt_str, "xloop/file_fmt_type") == 0) rc = parse_file_fmt_type(file_fmt_str, file_fmt_type); } else rc = -errno; @@ -886,9 +886,9 @@ char *loopcxt_get_file_fmt_type_string(struct loopdev_cxt *lc) char *res = NULL; if (sysfs) - ul_path_read_string(sysfs, &res, "loop/file_fmt_type"); + ul_path_read_string(sysfs, &res, "xloop/file_fmt_type"); - DBG(CXT, ul_debugobj(lc, "loopcxt_get_file_fmt_type_string [%s]", res)); + DBG(CXT, ul_debugobj(lc, "xloopcxt_get_file_fmt_type_string [%s]", res)); return res; } @@ -1001,7 +1001,7 @@ int loopcxt_is_partscan(struct loopdev_cxt *lc) if (sysfs) { /* kernel >= 3.2 */ int fl; - if (ul_path_read_s32(sysfs, &fl, "loop/partscan") == 0) + if (ul_path_read_s32(sysfs, &fl, "xloop/partscan") == 0) return fl; } @@ -1020,7 +1020,7 @@ int loopcxt_is_autoclear(struct loopdev_cxt *lc) if (sysfs) { int fl; - if (ul_path_read_s32(sysfs, &fl, "loop/autoclear") == 0) + if (ul_path_read_s32(sysfs, &fl, "xloop/autoclear") == 0) return fl; } @@ -1066,7 +1066,7 @@ int loopcxt_is_dio(struct loopdev_cxt *lc) if (sysfs) { int fl; - if (ul_path_read_s32(sysfs, &fl, "loop/dio") == 0) + if (ul_path_read_s32(sysfs, &fl, "xloop/dio") == 0) return fl; } if (loopcxt_ioctl_enabled(lc)) { @@ -1407,8 +1407,8 @@ int loopcxt_setup_device(struct loopdev_cxt *lc) break; if (errno != EACCES && errno != ENOENT) break; - /* We have permissions to open /dev/loop-control, but open - * /dev/loopN failed with EACCES, it's probably because udevd + /* We have permissions to open /dev/xloop-control, but open + * /dev/xloopN failed with EACCES, it's probably because udevd * does not applied chown yet. Let's wait a moment. */ xusleep(25000); } while (cnt++ < 16); @@ -1643,7 +1643,7 @@ int loopcxt_find_unused(struct loopdev_cxt *lc) rc = ioctl(ctl, LOOP_CTL_GET_FREE); if (rc >= 0) { char name[16]; - snprintf(name, sizeof(name), "loop%d", rc); + snprintf(name, sizeof(name), "xloop%d", rc); rc = loopiter_set_device(lc, name); } diff --git a/utils/sys-utils/CMakeLists.txt b/utils/sys-utils/CMakeLists.txt index a36e88c..8f3ee47 100644 --- a/utils/sys-utils/CMakeLists.txt +++ b/utils/sys-utils/CMakeLists.txt @@ -4,11 +4,11 @@ cmake_minimum_required(VERSION 3.10) project(xloop-utils-sys-utils) # add xlosetup executable -add_executable(xlosetup ${CMAKE_CURRENT_SOURCE_DIR}/losetup.c) +add_executable(xlosetup ${CMAKE_CURRENT_SOURCE_DIR}/xlosetup.c) target_link_libraries(xlosetup LINK_PUBLIC libcommon libsmartcols) target_include_directories(xlosetup PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/../lib ${CMAKE_CURRENT_SOURCE_DIR}/../libsmartcols) install(TARGETS xlosetup DESTINATION bin) -install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/losetup.8 +install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/xlosetup.8 DESTINATION /usr/share/man/man8 PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ) \ No newline at end of file diff --git a/utils/sys-utils/losetup.8 b/utils/sys-utils/losetup.8 deleted file mode 100644 index 92aff3e..0000000 --- a/utils/sys-utils/losetup.8 +++ /dev/null @@ -1,215 +0,0 @@ -.TH LOSETUP 8 "November 2015" "util-linux" "System Administration" -.SH NAME -losetup \- set up and control loop devices -.SH SYNOPSIS -.ad l -Get info: -.sp -.in +5 -.B losetup -[\fIloopdev\fP] -.sp -.B losetup \-l -.RB [ \-a ] -.sp -.B losetup \-j -.I file -.RB [ \-o -.IR offset ] -.sp -.in -5 -Detach a loop device: -.sp -.in +5 -.B "losetup \-d" -.IR loopdev ... -.sp -.in -5 -Detach all associated loop devices: -.sp -.in +5 -.B "losetup \-D" -.sp -.in -5 -Set up a loop device: -.sp -.in +5 -.B losetup -.RB [ \-o -.IR offset ] -.RB [ \-\-sizelimit -.IR size ] -.RB [ \-\-sector\-size -.IR size ] -.in +8 -.RB [ \-Pr ] -.RB [ \-\-show ] " \-f" | \fIloopdev\fP -.I file -.sp -.in -13 -Resize a loop device: -.sp -.in +5 -.B "losetup \-c" -.I loopdev -.in -5 -.ad b -.SH DESCRIPTION -.B losetup -is used to associate loop devices with regular files or block devices, -to detach loop devices, and to query the status of a loop device. If only the -\fIloopdev\fP argument is given, the status of the corresponding loop -device is shown. If no option is given, all loop devices are shown. -.sp -Note that the old output format (i.e., \fBlosetup \-a\fR) with comma-delimited -strings is deprecated in favour of the \fB\-\-list\fR output format. -.sp -It's possible to create more independent loop devices for the same backing -file. -.B This setup may be dangerous, can cause data loss, corruption and overwrites. -Use \fB\-\-nooverlap\fR with \fB\-\-find\fR during setup to avoid this problem. - -.SH OPTIONS -The \fIsize\fR and \fIoffset\fR -arguments may be followed by the multiplicative suffixes KiB (=1024), -MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is -optional, e.g., "K" has the same meaning as "KiB") or the suffixes -KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB. - -.TP -.BR \-a , " \-\-all" -Show the status of all loop devices. Note that not all information is accessible -for non-root users. See also \fB\-\-list\fR. The old output format (as printed -without \fB\-\-list)\fR is deprecated. -.TP -.BR \-d , " \-\-detach " \fIloopdev\fR... -Detach the file or device associated with the specified loop device(s). Note -that since Linux v3.7 kernel uses "lazy device destruction". The detach -operation does not return EBUSY error anymore if device is actively used by -system, but it is marked by autoclear flag and destroyed later. -.TP -.BR \-D , " \-\-detach\-all" -Detach all associated loop devices. -.TP -.BR \-f , " \-\-find " "\fR[\fIfile\fR]" -Find the first unused loop device. If a \fIfile\fR argument is present, use -the found device as loop device. Otherwise, just print its name. -.IP "\fB\-\-show\fP" -Display the name of the assigned loop device if the \fB\-f\fP option and a -\fIfile\fP argument are present. -.TP -.BR \-L , " \-\-nooverlap" -Check for conflicts between loop devices to avoid situation when the same -backing file is shared between more loop devices. If the file is already used -by another device then re-use the device rather than a new one. The option -makes sense only with \fB\-\-find\fP. -.TP -.BR \-j , " \-\-associated " \fIfile\fR " \fR[\fB\-o \fIoffset\fR]" -Show the status of all loop devices associated with the given \fIfile\fR. -.TP -.BR \-o , " \-\-offset " \fIoffset -The data start is moved \fIoffset\fP bytes into the specified file or device. The \fIoffset\fP -may be followed by the multiplicative suffixes; see above. -.IP "\fB\-\-sizelimit \fIsize\fP" -The data end is set to no more than \fIsize\fP bytes after the data start. The \fIsize\fP -may be followed by the multiplicative suffixes; see above. -.TP -.BR \-b , " \-\-sector-size " \fIsize -Set the logical sector size of the loop device in bytes (since Linux 4.14). The -option may be used when create a new loop device as well as stand-alone command -to modify sector size of the already existing loop device. -.TP -.BR \-c , " \-\-set\-capacity " \fIloopdev -Force the loop driver to reread the size of the file associated with the -specified loop device. -.TP -.BR \-P , " \-\-partscan" -Force the kernel to scan the partition table on a newly created loop device. Note that the -partition table parsing depends on sector sizes. The default is sector size is 512 bytes, -otherwise you need to use the option \fB\-\-sector\-size\fR together with \fB\-\-partscan\fR. -.TP -.BR \-r , " \-\-read\-only" -Set up a read-only loop device. -.TP -.BR \-\-direct\-io [ =on | off ] -Enable or disable direct I/O for the backing file. The optional argument -can be either \fBon\fR or \fBoff\fR. If the argument is omitted, it defaults -to \fBoff\fR. -.TP -.BR \-t , " \-\-type \fIformat\fR" -Set the file format type of the loop device. If no file format type is specified, -the RAW file format is used by default. Valid file formats are: \fBRAW\fR, -\fBQCOW\fR, \fBVDI\fR, \fBVMDK\fR. -.TP -.BR \-v , " \-\-verbose" -Verbose mode. -.TP -.BR \-l , " \-\-list" -If a loop device or the \fB\-a\fR option is specified, print the default columns -for either the specified loop device or all loop devices; the default is to -print info about all devices. See also \fB\-\-output\fP, \fB\-\-noheadings\fP, -\fB\-\-raw\fP, and \fB\-\-json\fP. -.TP -.BR \-O , " \-\-output " \fIcolumn\fR[,\fIcolumn\fR]... -Specify the columns that are to be printed for the \fB\-\-list\fP output. -Use \fB\-\-help\fR to get a list of all supported columns. -.TP -.B \-\-output\-all -Output all available columns. -.TP -.BR \-n , " \-\-noheadings" -Don't print headings for \fB\-\-list\fP output format. -.IP "\fB\-\-raw\fP" -Use the raw \fB\-\-list\fP output format. -.TP -.BR \-J , " \-\-json" -Use JSON format for \fB\-\-list\fP output. -.TP -.BR \-V , " \-\-version" -Display version information and exit. -.TP -.BR \-h , " \-\-help" -Display help text and exit. - -.SH ENCRYPTION -.B Cryptoloop is no longer supported in favor of dm-crypt. -.B For more details see cryptsetup(8). - -.SH EXIT STATUS -.B losetup -returns 0 on success, nonzero on failure. When -.B losetup -displays the status of a loop device, it returns 1 if the device -is not configured and 2 if an error occurred which prevented -determining the status of the device. - -.SH ENVIRONMENT -.IP LOOPDEV_DEBUG=all -enables debug output. - -.SH FILES -.TP -.I /dev/loop[0..N] -loop block devices -.TP -.I /dev/loop-control -loop control device -.SH EXAMPLE -The following commands can be used as an example of using the loop device. -.nf -.IP -# dd if=/dev/zero of=~/file.img bs=1024k count=10 -# losetup \-\-find \-\-show ~/file.img -/dev/loop0 -# mkfs \-t ext2 /dev/loop0 -# mount /dev/loop0 /mnt - ... -# umount /dev/loop0 -# losetup \-\-detach /dev/loop0 -.fi -.SH AUTHORS -Karel Zak , based on the original version from -Theodore Ts'o -.SH AVAILABILITY -The losetup command is part of the util-linux package and is available from -https://www.kernel.org/pub/linux/utils/util-linux/. diff --git a/utils/sys-utils/losetup.c b/utils/sys-utils/losetup.c deleted file mode 100644 index 5e5ce9e..0000000 --- a/utils/sys-utils/losetup.c +++ /dev/null @@ -1,955 +0,0 @@ -/* - * Copyright (C) 2011 Karel Zak - * Originally from Ted's losetup.c - * - * losetup.c - setup and control loop devices - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include - -#include "c.h" -#include "nls.h" -#include "strutils.h" -#include "loopdev.h" -#include "closestream.h" -#include "optutils.h" -#include "xalloc.h" -#include "canonicalize.h" -#include "pathnames.h" - -enum { - A_CREATE = 1, /* setup a new device */ - A_DELETE, /* delete given device(s) */ - A_DELETE_ALL, /* delete all devices */ - A_SHOW, /* list devices */ - A_SHOW_ONE, /* print info about one device */ - A_FIND_FREE, /* find first unused */ - A_SET_CAPACITY, /* set device capacity */ - A_SET_DIRECT_IO, /* set accessing backing file by direct io */ - A_SET_BLOCKSIZE, /* set logical block size of the loop device */ -}; - -enum { - COL_NAME = 0, - COL_AUTOCLR, - COL_BACK_FILE, - COL_FILE_FMT_TYPE, - COL_BACK_INO, - COL_BACK_MAJMIN, - COL_MAJMIN, - COL_OFFSET, - COL_PARTSCAN, - COL_RO, - COL_SIZELIMIT, - COL_DIO, - COL_LOGSEC, -}; - -/* basic output flags */ -static int no_headings; -static int raw; -static int json; - -struct colinfo { - const char *name; - double whint; - int flags; - const char *help; - - int json_type; /* default is string */ -}; - -static struct colinfo infos[] = { - [COL_AUTOCLR] = { "AUTOCLEAR", 1, SCOLS_FL_RIGHT, N_("autoclear flag set"), SCOLS_JSON_BOOLEAN}, - [COL_BACK_FILE] = { "BACK-FILE", 0.3, 0, N_("device backing file")}, - [COL_FILE_FMT_TYPE] = { "FILE-FORMAT", 1, 0, N_("backing file format")}, - [COL_BACK_INO] = { "BACK-INO", 4, SCOLS_FL_RIGHT, N_("backing file inode number"), SCOLS_JSON_NUMBER}, - [COL_BACK_MAJMIN] = { "BACK-MAJ:MIN", 6, 0, N_("backing file major:minor device number")}, - [COL_NAME] = { "NAME", 0.25, 0, N_("loop device name")}, - [COL_OFFSET] = { "OFFSET", 5, SCOLS_FL_RIGHT, N_("offset from the beginning"), SCOLS_JSON_NUMBER}, - [COL_PARTSCAN] = { "PARTSCAN", 1, SCOLS_FL_RIGHT, N_("partscan flag set"), SCOLS_JSON_BOOLEAN}, - [COL_RO] = { "RO", 1, SCOLS_FL_RIGHT, N_("read-only device"), SCOLS_JSON_BOOLEAN}, - [COL_SIZELIMIT] = { "SIZELIMIT", 5, SCOLS_FL_RIGHT, N_("size limit of the file in bytes"), SCOLS_JSON_NUMBER}, - [COL_MAJMIN] = { "MAJ:MIN", 3, 0, N_("loop device major:minor number")}, - [COL_DIO] = { "DIO", 1, SCOLS_FL_RIGHT, N_("access backing file with direct-io"), SCOLS_JSON_BOOLEAN}, - [COL_LOGSEC] = { "LOG-SEC", 4, SCOLS_FL_RIGHT, N_("logical sector size in bytes"), SCOLS_JSON_NUMBER}, -}; - -static int columns[ARRAY_SIZE(infos) * 2] = {-1}; -static size_t ncolumns; - -static int get_column_id(int num) -{ - assert(num >= 0); - assert((size_t) num < ncolumns); - assert(columns[num] < (int) ARRAY_SIZE(infos)); - return columns[num]; -} - -static struct colinfo *get_column_info(int num) -{ - return &infos[ get_column_id(num) ]; -} - -static int column_name_to_id(const char *name, size_t namesz) -{ - size_t i; - - for (i = 0; i < ARRAY_SIZE(infos); i++) { - const char *cn = infos[i].name; - - if (!strncasecmp(name, cn, namesz) && !*(cn + namesz)) - return i; - } - warnx(_("unknown column: %s"), name); - return -1; -} - -static int printf_loopdev(struct loopdev_cxt *lc) -{ - uint64_t x; - dev_t dev = 0; - ino_t ino = 0; - char *fname; - uint32_t type; - char *file_fmt_str; - - fname = loopcxt_get_backing_file(lc); - if (!fname) - return -EINVAL; - - file_fmt_str = loopcxt_get_file_fmt_type_string(lc); - if (!file_fmt_str) - return -EINVAL; - - if (loopcxt_get_backing_devno(lc, &dev) == 0) - loopcxt_get_backing_inode(lc, &ino); - - if (!dev && !ino) { - /* - * Probably non-root user (no permissions to - * call LOOP_GET_STATUS ioctls). - */ - printf("%s: []: (%s)", - loopcxt_get_device(lc), fname); - - if (loopcxt_get_offset(lc, &x) == 0 && x) - printf(_(", offset %ju"), x); - - if (loopcxt_get_sizelimit(lc, &x) == 0 && x) - printf(_(", sizelimit %ju"), x); - - printf(_(", file-format %s"), file_fmt_str); - - goto done; - } - - printf("%s: [%04d]:%" PRIu64 " (%s)", - loopcxt_get_device(lc), (int) dev, ino, fname); - - if (loopcxt_get_offset(lc, &x) == 0 && x) - printf(_(", offset %ju"), x); - - if (loopcxt_get_sizelimit(lc, &x) == 0 && x) - printf(_(", sizelimit %ju"), x); - - if (loopcxt_get_encrypt_type(lc, &type) == 0) { - const char *e = loopcxt_get_crypt_name(lc); - - if ((!e || !*e) && type == 1) - e = "XOR"; - if (e && *e) - printf(_(", encryption %s (type %u)"), e, type); - } - - printf(_(", file-format %s"), file_fmt_str); - -done: - free(fname); - printf("\n"); - return 0; -} - -static int show_all_loops(struct loopdev_cxt *lc, const char *file, - uint64_t offset, int flags) -{ - struct stat sbuf, *st = &sbuf; - char *cn_file = NULL; - - if (loopcxt_init_iterator(lc, LOOPITER_FL_USED)) - return -1; - - if (!file || stat(file, st)) - st = NULL; - - while (loopcxt_next(lc) == 0) { - if (file) { - int used; - const char *bf = cn_file ? cn_file : file; - - used = loopcxt_is_used(lc, st, bf, offset, 0, flags); - if (!used && !cn_file) { - bf = cn_file = canonicalize_path(file); - used = loopcxt_is_used(lc, st, bf, offset, 0, flags); - } - if (!used) - continue; - } - printf_loopdev(lc); - } - loopcxt_deinit_iterator(lc); - free(cn_file); - return 0; -} - -static int delete_loop(struct loopdev_cxt *lc) -{ - if (loopcxt_delete_device(lc)) - warn(_("%s: detach failed"), loopcxt_get_device(lc)); - else - return 0; - - return -1; -} - -static int delete_all_loops(struct loopdev_cxt *lc) -{ - int res = 0; - - if (loopcxt_init_iterator(lc, LOOPITER_FL_USED)) - return -1; - - while (loopcxt_next(lc) == 0) - res += delete_loop(lc); - - loopcxt_deinit_iterator(lc); - return res; -} - -static int set_scols_data(struct loopdev_cxt *lc, struct libscols_line *ln) -{ - size_t i; - - for (i = 0; i < ncolumns; i++) { - const char *p = NULL; /* external data */ - char *np = NULL; /* allocated here */ - uint64_t x = 0; - int rc = 0; - - switch(get_column_id(i)) { - case COL_NAME: - p = loopcxt_get_device(lc); - break; - case COL_BACK_FILE: - p = loopcxt_get_backing_file(lc); - break; - case COL_FILE_FMT_TYPE: - p = loopcxt_get_file_fmt_type_string(lc); - break; - case COL_OFFSET: - if (loopcxt_get_offset(lc, &x) == 0) - xasprintf(&np, "%jd", x); - break; - case COL_SIZELIMIT: - if (loopcxt_get_sizelimit(lc, &x) == 0) - xasprintf(&np, "%jd", x); - break; - case COL_BACK_MAJMIN: - { - dev_t dev = 0; - if (loopcxt_get_backing_devno(lc, &dev) == 0 && dev) - xasprintf(&np, "%8u:%-3u", major(dev), minor(dev)); - break; - } - case COL_MAJMIN: - { - struct stat st; - - if (loopcxt_get_device(lc) - && stat(loopcxt_get_device(lc), &st) == 0 - && S_ISBLK(st.st_mode) - && major(st.st_rdev) == LOOPDEV_MAJOR) - xasprintf(&np, "%3u:%-3u", major(st.st_rdev), - minor(st.st_rdev)); - break; - } - case COL_BACK_INO: - { - ino_t ino = 0; - if (loopcxt_get_backing_inode(lc, &ino) == 0 && ino) - xasprintf(&np, "%ju", ino); - break; - } - case COL_AUTOCLR: - p = loopcxt_is_autoclear(lc) ? "1" : "0"; - break; - case COL_RO: - p = loopcxt_is_readonly(lc) ? "1" : "0"; - break; - case COL_DIO: - p = loopcxt_is_dio(lc) ? "1" : "0"; - break; - case COL_PARTSCAN: - p = loopcxt_is_partscan(lc) ? "1" : "0"; - break; - case COL_LOGSEC: - if (loopcxt_get_blocksize(lc, &x) == 0) - xasprintf(&np, "%jd", x); - break; - default: - return -EINVAL; - } - - - if (p) - rc = scols_line_set_data(ln, i, p); /* calls strdup() */ - else if (np) - rc = scols_line_refer_data(ln, i, np); /* only refers */ - - if (rc) - err(EXIT_FAILURE, _("failed to add output data")); - } - - return 0; -} - -static int show_table(struct loopdev_cxt *lc, - const char *file, - uint64_t offset, - int flags) -{ - struct stat sbuf, *st = &sbuf; - struct libscols_table *tb; - struct libscols_line *ln; - int rc = 0; - size_t i; - - scols_init_debug(0); - - if (!(tb = scols_new_table())) - err(EXIT_FAILURE, _("failed to allocate output table")); - scols_table_enable_raw(tb, raw); - scols_table_enable_json(tb, json); - scols_table_enable_noheadings(tb, no_headings); - - if (json) - scols_table_set_name(tb, "loopdevices"); - - for (i = 0; i < ncolumns; i++) { - struct colinfo *ci = get_column_info(i); - struct libscols_column *cl; - - cl = scols_table_new_column(tb, ci->name, ci->whint, ci->flags); - if (!cl) - err(EXIT_FAILURE, _("failed to allocate output column")); - if (json) - scols_column_set_json_type(cl, ci->json_type); - } - - /* only one loopdev requested (already assigned to loopdev_cxt) */ - if (loopcxt_get_device(lc)) { - ln = scols_table_new_line(tb, NULL); - if (!ln) - err(EXIT_FAILURE, _("failed to allocate output line")); - rc = set_scols_data(lc, ln); - - /* list all loopdevs */ - } else { - char *cn_file = NULL; - - rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED); - if (rc) - goto done; - if (!file || stat(file, st)) - st = NULL; - - while (loopcxt_next(lc) == 0) { - if (file) { - int used; - const char *bf = cn_file ? cn_file : file; - - used = loopcxt_is_used(lc, st, bf, offset, 0, flags); - if (!used && !cn_file) { - bf = cn_file = canonicalize_path(file); - used = loopcxt_is_used(lc, st, bf, offset, 0, flags); - } - if (!used) - continue; - } - - ln = scols_table_new_line(tb, NULL); - if (!ln) - err(EXIT_FAILURE, _("failed to allocate output line")); - rc = set_scols_data(lc, ln); - if (rc) - break; - } - - loopcxt_deinit_iterator(lc); - free(cn_file); - } -done: - if (rc == 0) - rc = scols_print_table(tb); - scols_unref_table(tb); - return rc; -} - -static void __attribute__((__noreturn__)) usage(void) -{ - FILE *out = stdout; - size_t i; - - fputs(USAGE_HEADER, out); - - fprintf(out, - _(" %1$s [options] []\n" - " %1$s [options] -f | \n"), - program_invocation_short_name); - - fputs(USAGE_SEPARATOR, out); - fputs(_("Set up and control loop devices.\n"), out); - - /* commands */ - fputs(USAGE_OPTIONS, out); - fputs(_(" -a, --all list all used devices\n"), out); - fputs(_(" -d, --detach ... detach one or more devices\n"), out); - fputs(_(" -D, --detach-all detach all used devices\n"), out); - fputs(_(" -f, --find find first unused device\n"), out); - fputs(_(" -c, --set-capacity resize the device\n"), out); - fputs(_(" -j, --associated list all devices associated with \n"), out); - fputs(_(" -L, --nooverlap avoid possible conflict between devices\n"), out); - - /* commands options */ - fputs(USAGE_SEPARATOR, out); - fputs(_(" -o, --offset start at offset into file\n"), out); - fputs(_(" --sizelimit device is limited to bytes of the file\n"), out); - fputs(_(" -b, --sector-size set the logical sector size to \n"), out); - fputs(_(" -P, --partscan create a partitioned loop device\n"), out); - fputs(_(" -r, --read-only set up a read-only loop device\n"), out); - fputs(_(" --direct-io[=] open backing file with O_DIRECT\n"), out); - fputs(_(" --show print device name after setup (with -f)\n"), out); - fputs(_(" -t, --type set file format type of the loop device\n"), out); - fputs(_(" -v, --verbose verbose mode\n"), out); - - /* output options */ - fputs(USAGE_SEPARATOR, out); - fputs(_(" -J, --json use JSON --list output format\n"), out); - fputs(_(" -l, --list list info about all or specified (default)\n"), out); - fputs(_(" -n, --noheadings don't print headings for --list output\n"), out); - fputs(_(" -O, --output specify columns to output for --list\n"), out); - fputs(_(" --output-all output all columns\n"), out); - fputs(_(" --raw use raw --list output format\n"), out); - - fputs(USAGE_SEPARATOR, out); - printf(USAGE_HELP_OPTIONS(31)); - - fputs(USAGE_COLUMNS, out); - for (i = 0; i < ARRAY_SIZE(infos); i++) - fprintf(out, " %12s %s\n", infos[i].name, _(infos[i].help)); - - printf(USAGE_MAN_TAIL("losetup(8)")); - - exit(EXIT_SUCCESS); -} - -static void warn_size(const char *filename, uint64_t size, uint64_t offset, int flags) -{ - struct stat st; - - if (!size) { - if (stat(filename, &st) || S_ISBLK(st.st_mode)) - return; - size = st.st_size; - - if (flags & LOOPDEV_FL_OFFSET) - size -= offset; - } - - if (size < 512) - warnx(_("%s: Warning: file is smaller than 512 bytes; the loop device " - "may be useless or invisible for system tools."), - filename); - else if (size % 512) - warnx(_("%s: Warning: file does not fit into a 512-byte sector; " - "the end of the file will be ignored."), - filename); -} - -static int create_loop(struct loopdev_cxt *lc, - int nooverlap, int lo_flags, int flags, - const char *file, uint64_t offset, uint64_t sizelimit, - uint64_t blocksize, uint32_t file_fmt_type) -{ - int hasdev = loopcxt_has_device(lc); - int rc = 0; - - /* losetup --find --noverlap file.img */ - if (!hasdev && nooverlap) { - rc = loopcxt_find_overlap(lc, file, offset, sizelimit); - switch (rc) { - case 0: /* not found */ - break; - - case 1: /* overlap */ - loopcxt_deinit(lc); - errx(EXIT_FAILURE, _("%s: overlapping loop device exists"), file); - - case 2: /* overlap -- full size and offset match (reuse) */ - { - uint32_t lc_encrypt_type; - - /* Once a loop is initialized RO, there is no - * way to change its parameters. */ - if (loopcxt_is_readonly(lc) - && !(lo_flags & LO_FLAGS_READ_ONLY)) { - loopcxt_deinit(lc); - errx(EXIT_FAILURE, _("%s: overlapping read-only loop device exists"), file); - } - - /* This is no more supported, but check to be safe. */ - if (loopcxt_get_encrypt_type(lc, &lc_encrypt_type) == 0 - && lc_encrypt_type != LO_CRYPT_NONE) { - loopcxt_deinit(lc); - errx(EXIT_FAILURE, _("%s: overlapping encrypted loop device exists"), file); - } - - lc->info.lo_flags &= ~LO_FLAGS_AUTOCLEAR; - if (loopcxt_ioctl_status(lc)) { - loopcxt_deinit(lc); - errx(EXIT_FAILURE, _("%s: failed to re-use loop device"), file); - } - return 0; /* success, re-use */ - } - default: /* error */ - loopcxt_deinit(lc); - errx(EXIT_FAILURE, _("failed to inspect loop devices")); - return -errno; - } - } - - if (hasdev && !is_loopdev(loopcxt_get_device(lc))) - loopcxt_add_device(lc); - - /* losetup --noverlap /dev/loopN file.img */ - if (hasdev && nooverlap) { - struct loopdev_cxt lc2; - - if (loopcxt_init(&lc2, 0)) { - loopcxt_deinit(lc); - err(EXIT_FAILURE, _("failed to initialize loopcxt")); - } - rc = loopcxt_find_overlap(&lc2, file, offset, sizelimit); - loopcxt_deinit(&lc2); - - if (rc) { - loopcxt_deinit(lc); - if (rc > 0) - errx(EXIT_FAILURE, _("%s: overlapping loop device exists"), file); - err(EXIT_FAILURE, _("%s: failed to check for conflicting loop devices"), file); - } - } - - /* Create a new device */ - do { - const char *errpre; - - /* Note that loopcxt_{find_unused,set_device}() resets - * loopcxt struct. - */ - if (!hasdev && (rc = loopcxt_find_unused(lc))) { - warnx(_("cannot find an unused loop device")); - break; - } - if (flags & LOOPDEV_FL_OFFSET) - loopcxt_set_offset(lc, offset); - if (flags & LOOPDEV_FL_SIZELIMIT) - loopcxt_set_sizelimit(lc, sizelimit); - if (lo_flags) - loopcxt_set_flags(lc, lo_flags); - if (blocksize > 0) - loopcxt_set_blocksize(lc, blocksize); - - if ((rc = loopcxt_set_backing_file(lc, file))) { - warn(_("%s: failed to use backing file"), file); - break; - } - - if ((rc = loopcxt_set_file_fmt_type(lc, file_fmt_type))) { - warn(_("failed to use backing file format type")); - break; - } - - errno = 0; - rc = loopcxt_setup_device(lc); - if (rc == 0) - break; /* success */ - if (errno == EBUSY && !hasdev) - continue; - - /* errors */ - errpre = hasdev && loopcxt_get_fd(lc) < 0 ? - loopcxt_get_device(lc) : file; - warn(_("%s: failed to set up loop device"), errpre); - break; - } while (hasdev == 0); - - return rc; -} - -int main(int argc, char **argv) -{ - struct loopdev_cxt lc; - int act = 0, flags = 0, no_overlap = 0, c; - char *file = NULL; - uint64_t offset = 0, sizelimit = 0, blocksize = 0; - int res = 0, showdev = 0, lo_flags = 0; - char *outarg = NULL; - int list = 0; - unsigned long use_dio = 0, set_dio = 0, set_blocksize = 0; - int use_file_fmt_type = 0; - uint32_t file_fmt_type = 0; - - enum { - OPT_SIZELIMIT = CHAR_MAX + 1, - OPT_SHOW, - OPT_RAW, - OPT_DIO, - OPT_OUTPUT_ALL - }; - static const struct option longopts[] = { - { "all", no_argument, NULL, 'a' }, - { "set-capacity", required_argument, NULL, 'c' }, - { "detach", required_argument, NULL, 'd' }, - { "detach-all", no_argument, NULL, 'D' }, - { "find", no_argument, NULL, 'f' }, - { "nooverlap", no_argument, NULL, 'L' }, - { "help", no_argument, NULL, 'h' }, - { "associated", required_argument, NULL, 'j' }, - { "json", no_argument, NULL, 'J' }, - { "list", no_argument, NULL, 'l' }, - { "sector-size", required_argument, NULL, 'b' }, - { "noheadings", no_argument, NULL, 'n' }, - { "offset", required_argument, NULL, 'o' }, - { "output", required_argument, NULL, 'O' }, - { "output-all", no_argument, NULL, OPT_OUTPUT_ALL }, - { "sizelimit", required_argument, NULL, OPT_SIZELIMIT }, - { "partscan", no_argument, NULL, 'P' }, - { "read-only", no_argument, NULL, 'r' }, - { "direct-io", optional_argument, NULL, OPT_DIO }, - { "raw", no_argument, NULL, OPT_RAW }, - { "show", no_argument, NULL, OPT_SHOW }, - { "type", required_argument, NULL, 't' }, - { "verbose", no_argument, NULL, 'v' }, - { "version", no_argument, NULL, 'V' }, - { NULL, 0, NULL, 0 } - }; - - static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ - { 'D','a','c','d','f','j' }, - { 'D','c','d','f','l' }, - { 'D','c','d','f','O' }, - { 'J',OPT_RAW }, - { 0 } - }; - int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; - - setlocale(LC_ALL, ""); - bindtextdomain(PACKAGE, LOCALEDIR); - textdomain(PACKAGE); - close_stdout_atexit(); - - if (loopcxt_init(&lc, 0)) - err(EXIT_FAILURE, _("failed to initialize loopcxt")); - - while ((c = getopt_long(argc, argv, "ab:c:d:Dfhj:JlLno:O:Prt:vV", - longopts, NULL)) != -1) { - - err_exclusive_options(c, longopts, excl, excl_st); - - switch (c) { - case 'a': - act = A_SHOW; - break; - case 'b': - set_blocksize = 1; - blocksize = strtosize_or_err(optarg, _("failed to parse logical block size")); - break; - case 'c': - act = A_SET_CAPACITY; - if (!is_loopdev(optarg) || - loopcxt_set_device(&lc, optarg)) - err(EXIT_FAILURE, _("%s: failed to use device"), - optarg); - break; - case 'r': - lo_flags |= LO_FLAGS_READ_ONLY; - break; - case 'd': - act = A_DELETE; - if (!is_loopdev(optarg) || - loopcxt_set_device(&lc, optarg)) - err(EXIT_FAILURE, _("%s: failed to use device"), - optarg); - break; - case 'D': - act = A_DELETE_ALL; - break; - case 'f': - act = A_FIND_FREE; - break; - case 'J': - json = 1; - break; - case 'j': - act = A_SHOW; - file = optarg; - break; - case 'l': - list = 1; - break; - case 'L': - no_overlap = 1; - break; - case 'n': - no_headings = 1; - break; - case OPT_RAW: - raw = 1; - break; - case 'o': - offset = strtosize_or_err(optarg, _("failed to parse offset")); - flags |= LOOPDEV_FL_OFFSET; - break; - case 'O': - outarg = optarg; - list = 1; - break; - case OPT_OUTPUT_ALL: - for (ncolumns = 0; ncolumns < ARRAY_SIZE(infos); ncolumns++) - columns[ncolumns] = ncolumns; - break; - case 'P': - lo_flags |= LO_FLAGS_PARTSCAN; - break; - case OPT_SHOW: - showdev = 1; - break; - case OPT_DIO: - use_dio = set_dio = 1; - if (optarg) - use_dio = parse_switch(optarg, _("argument error"), "on", "off", NULL); - break; - case 't': - if (optarg) { - if (parse_file_fmt_type(optarg, &file_fmt_type) == 0) - use_file_fmt_type = 1; - else - errx(EXIT_FAILURE, _("failed to parse file format type")); - } - break; - case 'v': - break; - case OPT_SIZELIMIT: /* --sizelimit */ - sizelimit = strtosize_or_err(optarg, _("failed to parse size")); - flags |= LOOPDEV_FL_SIZELIMIT; - break; - - case 'h': - usage(); - case 'V': - print_version(EXIT_SUCCESS); - default: - errtryhelp(EXIT_FAILURE); - } - } - - ul_path_init_debug(); - ul_sysfs_init_debug(); - - /* default is --list --all */ - if (argc == 1) { - act = A_SHOW; - list = 1; - } - - if (!act && argc == 2 && (raw || json)) { - act = A_SHOW; - list = 1; - } - - /* default --list output columns */ - if (list && !ncolumns) { - columns[ncolumns++] = COL_NAME; - columns[ncolumns++] = COL_SIZELIMIT; - columns[ncolumns++] = COL_OFFSET; - columns[ncolumns++] = COL_AUTOCLR; - columns[ncolumns++] = COL_RO; - columns[ncolumns++] = COL_BACK_FILE; - columns[ncolumns++] = COL_FILE_FMT_TYPE; - columns[ncolumns++] = COL_DIO; - columns[ncolumns++] = COL_LOGSEC; - } - - if (act == A_FIND_FREE && optind < argc) { - /* - * losetup -f - */ - act = A_CREATE; - file = argv[optind++]; - - if (optind < argc) - errx(EXIT_FAILURE, _("unexpected arguments")); - } - - if (list && !act && optind == argc) - /* - * losetup --list defaults to --all - */ - act = A_SHOW; - - if (!act && optind + 1 == argc) { - /* - * losetup [--list] - * OR - * losetup {--direct-io[=off]|--logical-blocksize=size}... - */ - if (!(set_dio || set_blocksize)) - act = A_SHOW_ONE; - if (set_dio) - act = A_SET_DIRECT_IO; - if (set_blocksize) - act = A_SET_BLOCKSIZE; - if (!is_loopdev(argv[optind]) || - loopcxt_set_device(&lc, argv[optind])) - err(EXIT_FAILURE, _("%s: failed to use device"), - argv[optind]); - optind++; - } - if (!act) { - /* - * losetup - */ - act = A_CREATE; - - if (optind >= argc) - errx(EXIT_FAILURE, _("no loop device specified")); - /* don't use is_loopdev() here, the device does not have exist yet */ - if (loopcxt_set_device(&lc, argv[optind])) - err(EXIT_FAILURE, _("%s: failed to use device"), - argv[optind]); - optind++; - - if (optind >= argc) - errx(EXIT_FAILURE, _("no file specified")); - file = argv[optind++]; - } - - if (act != A_CREATE && - (sizelimit || lo_flags || showdev || use_file_fmt_type)) - errx(EXIT_FAILURE, - _("the options %s are allowed during loop device setup only"), - "--{sizelimit,partscan,read-only,show,type}"); - - if ((flags & LOOPDEV_FL_OFFSET) && - act != A_CREATE && (act != A_SHOW || !file)) - errx(EXIT_FAILURE, _("the option --offset is not allowed in this context")); - - if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns), - &ncolumns, column_name_to_id) < 0) - return EXIT_FAILURE; - - switch (act) { - case A_CREATE: - res = create_loop(&lc, no_overlap, lo_flags, flags, file, - offset, sizelimit, blocksize, file_fmt_type); - if (res == 0) { - if (showdev) - printf("%s\n", loopcxt_get_device(&lc)); - warn_size(file, sizelimit, offset, flags); - if (set_dio) - goto lo_set_dio; - } - break; - case A_DELETE: - res = delete_loop(&lc); - while (optind < argc) { - if (!is_loopdev(argv[optind]) || - loopcxt_set_device(&lc, argv[optind])) - warn(_("%s: failed to use device"), - argv[optind]); - optind++; - res += delete_loop(&lc); - } - break; - case A_DELETE_ALL: - res = delete_all_loops(&lc); - break; - case A_FIND_FREE: - res = loopcxt_find_unused(&lc); - if (res) { - int errsv = errno; - - if (access(_PATH_DEV_LOOPCTL, F_OK) == 0 && - access(_PATH_DEV_LOOPCTL, W_OK) != 0) - ; - else - errno = errsv; - - warn(_("cannot find an unused loop device")); - } else - printf("%s\n", loopcxt_get_device(&lc)); - break; - case A_SHOW: - if (list) - res = show_table(&lc, file, offset, flags); - else - res = show_all_loops(&lc, file, offset, flags); - break; - case A_SHOW_ONE: - if (list) - res = show_table(&lc, NULL, 0, 0); - else - res = printf_loopdev(&lc); - if (res) - warn("%s", loopcxt_get_device(&lc)); - break; - case A_SET_CAPACITY: - res = loopcxt_ioctl_capacity(&lc); - if (res) - warn(_("%s: set capacity failed"), - loopcxt_get_device(&lc)); - break; - case A_SET_DIRECT_IO: -lo_set_dio: - res = loopcxt_ioctl_dio(&lc, use_dio); - if (res) - warn(_("%s: set direct io failed"), - loopcxt_get_device(&lc)); - break; - case A_SET_BLOCKSIZE: - res = loopcxt_ioctl_blocksize(&lc, blocksize); - if (res) - warn(_("%s: set logical block size failed"), - loopcxt_get_device(&lc)); - break; - default: - warnx(_("bad usage")); - errtryhelp(EXIT_FAILURE); - break; - } - - loopcxt_deinit(&lc); - return res ? EXIT_FAILURE : EXIT_SUCCESS; -} - diff --git a/utils/sys-utils/xlosetup.8 b/utils/sys-utils/xlosetup.8 new file mode 100644 index 0000000..92aff3e --- /dev/null +++ b/utils/sys-utils/xlosetup.8 @@ -0,0 +1,215 @@ +.TH LOSETUP 8 "November 2015" "util-linux" "System Administration" +.SH NAME +losetup \- set up and control loop devices +.SH SYNOPSIS +.ad l +Get info: +.sp +.in +5 +.B losetup +[\fIloopdev\fP] +.sp +.B losetup \-l +.RB [ \-a ] +.sp +.B losetup \-j +.I file +.RB [ \-o +.IR offset ] +.sp +.in -5 +Detach a loop device: +.sp +.in +5 +.B "losetup \-d" +.IR loopdev ... +.sp +.in -5 +Detach all associated loop devices: +.sp +.in +5 +.B "losetup \-D" +.sp +.in -5 +Set up a loop device: +.sp +.in +5 +.B losetup +.RB [ \-o +.IR offset ] +.RB [ \-\-sizelimit +.IR size ] +.RB [ \-\-sector\-size +.IR size ] +.in +8 +.RB [ \-Pr ] +.RB [ \-\-show ] " \-f" | \fIloopdev\fP +.I file +.sp +.in -13 +Resize a loop device: +.sp +.in +5 +.B "losetup \-c" +.I loopdev +.in -5 +.ad b +.SH DESCRIPTION +.B losetup +is used to associate loop devices with regular files or block devices, +to detach loop devices, and to query the status of a loop device. If only the +\fIloopdev\fP argument is given, the status of the corresponding loop +device is shown. If no option is given, all loop devices are shown. +.sp +Note that the old output format (i.e., \fBlosetup \-a\fR) with comma-delimited +strings is deprecated in favour of the \fB\-\-list\fR output format. +.sp +It's possible to create more independent loop devices for the same backing +file. +.B This setup may be dangerous, can cause data loss, corruption and overwrites. +Use \fB\-\-nooverlap\fR with \fB\-\-find\fR during setup to avoid this problem. + +.SH OPTIONS +The \fIsize\fR and \fIoffset\fR +arguments may be followed by the multiplicative suffixes KiB (=1024), +MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is +optional, e.g., "K" has the same meaning as "KiB") or the suffixes +KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB. + +.TP +.BR \-a , " \-\-all" +Show the status of all loop devices. Note that not all information is accessible +for non-root users. See also \fB\-\-list\fR. The old output format (as printed +without \fB\-\-list)\fR is deprecated. +.TP +.BR \-d , " \-\-detach " \fIloopdev\fR... +Detach the file or device associated with the specified loop device(s). Note +that since Linux v3.7 kernel uses "lazy device destruction". The detach +operation does not return EBUSY error anymore if device is actively used by +system, but it is marked by autoclear flag and destroyed later. +.TP +.BR \-D , " \-\-detach\-all" +Detach all associated loop devices. +.TP +.BR \-f , " \-\-find " "\fR[\fIfile\fR]" +Find the first unused loop device. If a \fIfile\fR argument is present, use +the found device as loop device. Otherwise, just print its name. +.IP "\fB\-\-show\fP" +Display the name of the assigned loop device if the \fB\-f\fP option and a +\fIfile\fP argument are present. +.TP +.BR \-L , " \-\-nooverlap" +Check for conflicts between loop devices to avoid situation when the same +backing file is shared between more loop devices. If the file is already used +by another device then re-use the device rather than a new one. The option +makes sense only with \fB\-\-find\fP. +.TP +.BR \-j , " \-\-associated " \fIfile\fR " \fR[\fB\-o \fIoffset\fR]" +Show the status of all loop devices associated with the given \fIfile\fR. +.TP +.BR \-o , " \-\-offset " \fIoffset +The data start is moved \fIoffset\fP bytes into the specified file or device. The \fIoffset\fP +may be followed by the multiplicative suffixes; see above. +.IP "\fB\-\-sizelimit \fIsize\fP" +The data end is set to no more than \fIsize\fP bytes after the data start. The \fIsize\fP +may be followed by the multiplicative suffixes; see above. +.TP +.BR \-b , " \-\-sector-size " \fIsize +Set the logical sector size of the loop device in bytes (since Linux 4.14). The +option may be used when create a new loop device as well as stand-alone command +to modify sector size of the already existing loop device. +.TP +.BR \-c , " \-\-set\-capacity " \fIloopdev +Force the loop driver to reread the size of the file associated with the +specified loop device. +.TP +.BR \-P , " \-\-partscan" +Force the kernel to scan the partition table on a newly created loop device. Note that the +partition table parsing depends on sector sizes. The default is sector size is 512 bytes, +otherwise you need to use the option \fB\-\-sector\-size\fR together with \fB\-\-partscan\fR. +.TP +.BR \-r , " \-\-read\-only" +Set up a read-only loop device. +.TP +.BR \-\-direct\-io [ =on | off ] +Enable or disable direct I/O for the backing file. The optional argument +can be either \fBon\fR or \fBoff\fR. If the argument is omitted, it defaults +to \fBoff\fR. +.TP +.BR \-t , " \-\-type \fIformat\fR" +Set the file format type of the loop device. If no file format type is specified, +the RAW file format is used by default. Valid file formats are: \fBRAW\fR, +\fBQCOW\fR, \fBVDI\fR, \fBVMDK\fR. +.TP +.BR \-v , " \-\-verbose" +Verbose mode. +.TP +.BR \-l , " \-\-list" +If a loop device or the \fB\-a\fR option is specified, print the default columns +for either the specified loop device or all loop devices; the default is to +print info about all devices. See also \fB\-\-output\fP, \fB\-\-noheadings\fP, +\fB\-\-raw\fP, and \fB\-\-json\fP. +.TP +.BR \-O , " \-\-output " \fIcolumn\fR[,\fIcolumn\fR]... +Specify the columns that are to be printed for the \fB\-\-list\fP output. +Use \fB\-\-help\fR to get a list of all supported columns. +.TP +.B \-\-output\-all +Output all available columns. +.TP +.BR \-n , " \-\-noheadings" +Don't print headings for \fB\-\-list\fP output format. +.IP "\fB\-\-raw\fP" +Use the raw \fB\-\-list\fP output format. +.TP +.BR \-J , " \-\-json" +Use JSON format for \fB\-\-list\fP output. +.TP +.BR \-V , " \-\-version" +Display version information and exit. +.TP +.BR \-h , " \-\-help" +Display help text and exit. + +.SH ENCRYPTION +.B Cryptoloop is no longer supported in favor of dm-crypt. +.B For more details see cryptsetup(8). + +.SH EXIT STATUS +.B losetup +returns 0 on success, nonzero on failure. When +.B losetup +displays the status of a loop device, it returns 1 if the device +is not configured and 2 if an error occurred which prevented +determining the status of the device. + +.SH ENVIRONMENT +.IP LOOPDEV_DEBUG=all +enables debug output. + +.SH FILES +.TP +.I /dev/loop[0..N] +loop block devices +.TP +.I /dev/loop-control +loop control device +.SH EXAMPLE +The following commands can be used as an example of using the loop device. +.nf +.IP +# dd if=/dev/zero of=~/file.img bs=1024k count=10 +# losetup \-\-find \-\-show ~/file.img +/dev/loop0 +# mkfs \-t ext2 /dev/loop0 +# mount /dev/loop0 /mnt + ... +# umount /dev/loop0 +# losetup \-\-detach /dev/loop0 +.fi +.SH AUTHORS +Karel Zak , based on the original version from +Theodore Ts'o +.SH AVAILABILITY +The losetup command is part of the util-linux package and is available from +https://www.kernel.org/pub/linux/utils/util-linux/. diff --git a/utils/sys-utils/xlosetup.c b/utils/sys-utils/xlosetup.c new file mode 100644 index 0000000..cab1037 --- /dev/null +++ b/utils/sys-utils/xlosetup.c @@ -0,0 +1,955 @@ +/* + * Copyright (C) 2011 Karel Zak + * Originally from Ted's losetup.c + * + * xlosetup.c - setup and control loop devices + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "c.h" +#include "nls.h" +#include "strutils.h" +#include "loopdev.h" +#include "closestream.h" +#include "optutils.h" +#include "xalloc.h" +#include "canonicalize.h" +#include "pathnames.h" + +enum { + A_CREATE = 1, /* setup a new device */ + A_DELETE, /* delete given device(s) */ + A_DELETE_ALL, /* delete all devices */ + A_SHOW, /* list devices */ + A_SHOW_ONE, /* print info about one device */ + A_FIND_FREE, /* find first unused */ + A_SET_CAPACITY, /* set device capacity */ + A_SET_DIRECT_IO, /* set accessing backing file by direct io */ + A_SET_BLOCKSIZE, /* set logical block size of the loop device */ +}; + +enum { + COL_NAME = 0, + COL_AUTOCLR, + COL_BACK_FILE, + COL_FILE_FMT_TYPE, + COL_BACK_INO, + COL_BACK_MAJMIN, + COL_MAJMIN, + COL_OFFSET, + COL_PARTSCAN, + COL_RO, + COL_SIZELIMIT, + COL_DIO, + COL_LOGSEC, +}; + +/* basic output flags */ +static int no_headings; +static int raw; +static int json; + +struct colinfo { + const char *name; + double whint; + int flags; + const char *help; + + int json_type; /* default is string */ +}; + +static struct colinfo infos[] = { + [COL_AUTOCLR] = { "AUTOCLEAR", 1, SCOLS_FL_RIGHT, N_("autoclear flag set"), SCOLS_JSON_BOOLEAN}, + [COL_BACK_FILE] = { "BACK-FILE", 0.3, 0, N_("device backing file")}, + [COL_FILE_FMT_TYPE] = { "FILE-FORMAT", 1, 0, N_("backing file format")}, + [COL_BACK_INO] = { "BACK-INO", 4, SCOLS_FL_RIGHT, N_("backing file inode number"), SCOLS_JSON_NUMBER}, + [COL_BACK_MAJMIN] = { "BACK-MAJ:MIN", 6, 0, N_("backing file major:minor device number")}, + [COL_NAME] = { "NAME", 0.25, 0, N_("loop device name")}, + [COL_OFFSET] = { "OFFSET", 5, SCOLS_FL_RIGHT, N_("offset from the beginning"), SCOLS_JSON_NUMBER}, + [COL_PARTSCAN] = { "PARTSCAN", 1, SCOLS_FL_RIGHT, N_("partscan flag set"), SCOLS_JSON_BOOLEAN}, + [COL_RO] = { "RO", 1, SCOLS_FL_RIGHT, N_("read-only device"), SCOLS_JSON_BOOLEAN}, + [COL_SIZELIMIT] = { "SIZELIMIT", 5, SCOLS_FL_RIGHT, N_("size limit of the file in bytes"), SCOLS_JSON_NUMBER}, + [COL_MAJMIN] = { "MAJ:MIN", 3, 0, N_("loop device major:minor number")}, + [COL_DIO] = { "DIO", 1, SCOLS_FL_RIGHT, N_("access backing file with direct-io"), SCOLS_JSON_BOOLEAN}, + [COL_LOGSEC] = { "LOG-SEC", 4, SCOLS_FL_RIGHT, N_("logical sector size in bytes"), SCOLS_JSON_NUMBER}, +}; + +static int columns[ARRAY_SIZE(infos) * 2] = {-1}; +static size_t ncolumns; + +static int get_column_id(int num) +{ + assert(num >= 0); + assert((size_t) num < ncolumns); + assert(columns[num] < (int) ARRAY_SIZE(infos)); + return columns[num]; +} + +static struct colinfo *get_column_info(int num) +{ + return &infos[ get_column_id(num) ]; +} + +static int column_name_to_id(const char *name, size_t namesz) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(infos); i++) { + const char *cn = infos[i].name; + + if (!strncasecmp(name, cn, namesz) && !*(cn + namesz)) + return i; + } + warnx(_("unknown column: %s"), name); + return -1; +} + +static int printf_loopdev(struct loopdev_cxt *lc) +{ + uint64_t x; + dev_t dev = 0; + ino_t ino = 0; + char *fname; + uint32_t type; + char *file_fmt_str; + + fname = loopcxt_get_backing_file(lc); + if (!fname) + return -EINVAL; + + file_fmt_str = loopcxt_get_file_fmt_type_string(lc); + if (!file_fmt_str) + return -EINVAL; + + if (loopcxt_get_backing_devno(lc, &dev) == 0) + loopcxt_get_backing_inode(lc, &ino); + + if (!dev && !ino) { + /* + * Probably non-root user (no permissions to + * call LOOP_GET_STATUS ioctls). + */ + printf("%s: []: (%s)", + loopcxt_get_device(lc), fname); + + if (loopcxt_get_offset(lc, &x) == 0 && x) + printf(_(", offset %ju"), x); + + if (loopcxt_get_sizelimit(lc, &x) == 0 && x) + printf(_(", sizelimit %ju"), x); + + printf(_(", file-format %s"), file_fmt_str); + + goto done; + } + + printf("%s: [%04d]:%" PRIu64 " (%s)", + loopcxt_get_device(lc), (int) dev, ino, fname); + + if (loopcxt_get_offset(lc, &x) == 0 && x) + printf(_(", offset %ju"), x); + + if (loopcxt_get_sizelimit(lc, &x) == 0 && x) + printf(_(", sizelimit %ju"), x); + + if (loopcxt_get_encrypt_type(lc, &type) == 0) { + const char *e = loopcxt_get_crypt_name(lc); + + if ((!e || !*e) && type == 1) + e = "XOR"; + if (e && *e) + printf(_(", encryption %s (type %u)"), e, type); + } + + printf(_(", file-format %s"), file_fmt_str); + +done: + free(fname); + printf("\n"); + return 0; +} + +static int show_all_loops(struct loopdev_cxt *lc, const char *file, + uint64_t offset, int flags) +{ + struct stat sbuf, *st = &sbuf; + char *cn_file = NULL; + + if (loopcxt_init_iterator(lc, LOOPITER_FL_USED)) + return -1; + + if (!file || stat(file, st)) + st = NULL; + + while (loopcxt_next(lc) == 0) { + if (file) { + int used; + const char *bf = cn_file ? cn_file : file; + + used = loopcxt_is_used(lc, st, bf, offset, 0, flags); + if (!used && !cn_file) { + bf = cn_file = canonicalize_path(file); + used = loopcxt_is_used(lc, st, bf, offset, 0, flags); + } + if (!used) + continue; + } + printf_loopdev(lc); + } + loopcxt_deinit_iterator(lc); + free(cn_file); + return 0; +} + +static int delete_loop(struct loopdev_cxt *lc) +{ + if (loopcxt_delete_device(lc)) + warn(_("%s: detach failed"), loopcxt_get_device(lc)); + else + return 0; + + return -1; +} + +static int delete_all_loops(struct loopdev_cxt *lc) +{ + int res = 0; + + if (loopcxt_init_iterator(lc, LOOPITER_FL_USED)) + return -1; + + while (loopcxt_next(lc) == 0) + res += delete_loop(lc); + + loopcxt_deinit_iterator(lc); + return res; +} + +static int set_scols_data(struct loopdev_cxt *lc, struct libscols_line *ln) +{ + size_t i; + + for (i = 0; i < ncolumns; i++) { + const char *p = NULL; /* external data */ + char *np = NULL; /* allocated here */ + uint64_t x = 0; + int rc = 0; + + switch(get_column_id(i)) { + case COL_NAME: + p = loopcxt_get_device(lc); + break; + case COL_BACK_FILE: + p = loopcxt_get_backing_file(lc); + break; + case COL_FILE_FMT_TYPE: + p = loopcxt_get_file_fmt_type_string(lc); + break; + case COL_OFFSET: + if (loopcxt_get_offset(lc, &x) == 0) + xasprintf(&np, "%jd", x); + break; + case COL_SIZELIMIT: + if (loopcxt_get_sizelimit(lc, &x) == 0) + xasprintf(&np, "%jd", x); + break; + case COL_BACK_MAJMIN: + { + dev_t dev = 0; + if (loopcxt_get_backing_devno(lc, &dev) == 0 && dev) + xasprintf(&np, "%8u:%-3u", major(dev), minor(dev)); + break; + } + case COL_MAJMIN: + { + struct stat st; + + if (loopcxt_get_device(lc) + && stat(loopcxt_get_device(lc), &st) == 0 + && S_ISBLK(st.st_mode) + && major(st.st_rdev) == LOOPDEV_MAJOR) + xasprintf(&np, "%3u:%-3u", major(st.st_rdev), + minor(st.st_rdev)); + break; + } + case COL_BACK_INO: + { + ino_t ino = 0; + if (loopcxt_get_backing_inode(lc, &ino) == 0 && ino) + xasprintf(&np, "%ju", ino); + break; + } + case COL_AUTOCLR: + p = loopcxt_is_autoclear(lc) ? "1" : "0"; + break; + case COL_RO: + p = loopcxt_is_readonly(lc) ? "1" : "0"; + break; + case COL_DIO: + p = loopcxt_is_dio(lc) ? "1" : "0"; + break; + case COL_PARTSCAN: + p = loopcxt_is_partscan(lc) ? "1" : "0"; + break; + case COL_LOGSEC: + if (loopcxt_get_blocksize(lc, &x) == 0) + xasprintf(&np, "%jd", x); + break; + default: + return -EINVAL; + } + + + if (p) + rc = scols_line_set_data(ln, i, p); /* calls strdup() */ + else if (np) + rc = scols_line_refer_data(ln, i, np); /* only refers */ + + if (rc) + err(EXIT_FAILURE, _("failed to add output data")); + } + + return 0; +} + +static int show_table(struct loopdev_cxt *lc, + const char *file, + uint64_t offset, + int flags) +{ + struct stat sbuf, *st = &sbuf; + struct libscols_table *tb; + struct libscols_line *ln; + int rc = 0; + size_t i; + + scols_init_debug(0); + + if (!(tb = scols_new_table())) + err(EXIT_FAILURE, _("failed to allocate output table")); + scols_table_enable_raw(tb, raw); + scols_table_enable_json(tb, json); + scols_table_enable_noheadings(tb, no_headings); + + if (json) + scols_table_set_name(tb, "loopdevices"); + + for (i = 0; i < ncolumns; i++) { + struct colinfo *ci = get_column_info(i); + struct libscols_column *cl; + + cl = scols_table_new_column(tb, ci->name, ci->whint, ci->flags); + if (!cl) + err(EXIT_FAILURE, _("failed to allocate output column")); + if (json) + scols_column_set_json_type(cl, ci->json_type); + } + + /* only one loopdev requested (already assigned to loopdev_cxt) */ + if (loopcxt_get_device(lc)) { + ln = scols_table_new_line(tb, NULL); + if (!ln) + err(EXIT_FAILURE, _("failed to allocate output line")); + rc = set_scols_data(lc, ln); + + /* list all loopdevs */ + } else { + char *cn_file = NULL; + + rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED); + if (rc) + goto done; + if (!file || stat(file, st)) + st = NULL; + + while (loopcxt_next(lc) == 0) { + if (file) { + int used; + const char *bf = cn_file ? cn_file : file; + + used = loopcxt_is_used(lc, st, bf, offset, 0, flags); + if (!used && !cn_file) { + bf = cn_file = canonicalize_path(file); + used = loopcxt_is_used(lc, st, bf, offset, 0, flags); + } + if (!used) + continue; + } + + ln = scols_table_new_line(tb, NULL); + if (!ln) + err(EXIT_FAILURE, _("failed to allocate output line")); + rc = set_scols_data(lc, ln); + if (rc) + break; + } + + loopcxt_deinit_iterator(lc); + free(cn_file); + } +done: + if (rc == 0) + rc = scols_print_table(tb); + scols_unref_table(tb); + return rc; +} + +static void __attribute__((__noreturn__)) usage(void) +{ + FILE *out = stdout; + size_t i; + + fputs(USAGE_HEADER, out); + + fprintf(out, + _(" %1$s [options] []\n" + " %1$s [options] -f | \n"), + program_invocation_short_name); + + fputs(USAGE_SEPARATOR, out); + fputs(_("Set up and control loop devices.\n"), out); + + /* commands */ + fputs(USAGE_OPTIONS, out); + fputs(_(" -a, --all list all used devices\n"), out); + fputs(_(" -d, --detach ... detach one or more devices\n"), out); + fputs(_(" -D, --detach-all detach all used devices\n"), out); + fputs(_(" -f, --find find first unused device\n"), out); + fputs(_(" -c, --set-capacity resize the device\n"), out); + fputs(_(" -j, --associated list all devices associated with \n"), out); + fputs(_(" -L, --nooverlap avoid possible conflict between devices\n"), out); + + /* commands options */ + fputs(USAGE_SEPARATOR, out); + fputs(_(" -o, --offset start at offset into file\n"), out); + fputs(_(" --sizelimit device is limited to bytes of the file\n"), out); + fputs(_(" -b, --sector-size set the logical sector size to \n"), out); + fputs(_(" -P, --partscan create a partitioned loop device\n"), out); + fputs(_(" -r, --read-only set up a read-only loop device\n"), out); + fputs(_(" --direct-io[=] open backing file with O_DIRECT\n"), out); + fputs(_(" --show print device name after setup (with -f)\n"), out); + fputs(_(" -t, --type set file format type of the loop device\n"), out); + fputs(_(" -v, --verbose verbose mode\n"), out); + + /* output options */ + fputs(USAGE_SEPARATOR, out); + fputs(_(" -J, --json use JSON --list output format\n"), out); + fputs(_(" -l, --list list info about all or specified (default)\n"), out); + fputs(_(" -n, --noheadings don't print headings for --list output\n"), out); + fputs(_(" -O, --output specify columns to output for --list\n"), out); + fputs(_(" --output-all output all columns\n"), out); + fputs(_(" --raw use raw --list output format\n"), out); + + fputs(USAGE_SEPARATOR, out); + printf(USAGE_HELP_OPTIONS(31)); + + fputs(USAGE_COLUMNS, out); + for (i = 0; i < ARRAY_SIZE(infos); i++) + fprintf(out, " %12s %s\n", infos[i].name, _(infos[i].help)); + + printf(USAGE_MAN_TAIL("xlosetup(8)")); + + exit(EXIT_SUCCESS); +} + +static void warn_size(const char *filename, uint64_t size, uint64_t offset, int flags) +{ + struct stat st; + + if (!size) { + if (stat(filename, &st) || S_ISBLK(st.st_mode)) + return; + size = st.st_size; + + if (flags & LOOPDEV_FL_OFFSET) + size -= offset; + } + + if (size < 512) + warnx(_("%s: Warning: file is smaller than 512 bytes; the loop device " + "may be useless or invisible for system tools."), + filename); + else if (size % 512) + warnx(_("%s: Warning: file does not fit into a 512-byte sector; " + "the end of the file will be ignored."), + filename); +} + +static int create_loop(struct loopdev_cxt *lc, + int nooverlap, int lo_flags, int flags, + const char *file, uint64_t offset, uint64_t sizelimit, + uint64_t blocksize, uint32_t file_fmt_type) +{ + int hasdev = loopcxt_has_device(lc); + int rc = 0; + + /* xlosetup --find --noverlap file.img */ + if (!hasdev && nooverlap) { + rc = loopcxt_find_overlap(lc, file, offset, sizelimit); + switch (rc) { + case 0: /* not found */ + break; + + case 1: /* overlap */ + loopcxt_deinit(lc); + errx(EXIT_FAILURE, _("%s: overlapping loop device exists"), file); + + case 2: /* overlap -- full size and offset match (reuse) */ + { + uint32_t lc_encrypt_type; + + /* Once a loop is initialized RO, there is no + * way to change its parameters. */ + if (loopcxt_is_readonly(lc) + && !(lo_flags & LO_FLAGS_READ_ONLY)) { + loopcxt_deinit(lc); + errx(EXIT_FAILURE, _("%s: overlapping read-only loop device exists"), file); + } + + /* This is no more supported, but check to be safe. */ + if (loopcxt_get_encrypt_type(lc, &lc_encrypt_type) == 0 + && lc_encrypt_type != LO_CRYPT_NONE) { + loopcxt_deinit(lc); + errx(EXIT_FAILURE, _("%s: overlapping encrypted loop device exists"), file); + } + + lc->info.lo_flags &= ~LO_FLAGS_AUTOCLEAR; + if (loopcxt_ioctl_status(lc)) { + loopcxt_deinit(lc); + errx(EXIT_FAILURE, _("%s: failed to re-use loop device"), file); + } + return 0; /* success, re-use */ + } + default: /* error */ + loopcxt_deinit(lc); + errx(EXIT_FAILURE, _("failed to inspect loop devices")); + return -errno; + } + } + + if (hasdev && !is_loopdev(loopcxt_get_device(lc))) + loopcxt_add_device(lc); + + /* xlosetup --noverlap /dev/loopN file.img */ + if (hasdev && nooverlap) { + struct loopdev_cxt lc2; + + if (loopcxt_init(&lc2, 0)) { + loopcxt_deinit(lc); + err(EXIT_FAILURE, _("failed to initialize loopcxt")); + } + rc = loopcxt_find_overlap(&lc2, file, offset, sizelimit); + loopcxt_deinit(&lc2); + + if (rc) { + loopcxt_deinit(lc); + if (rc > 0) + errx(EXIT_FAILURE, _("%s: overlapping loop device exists"), file); + err(EXIT_FAILURE, _("%s: failed to check for conflicting loop devices"), file); + } + } + + /* Create a new device */ + do { + const char *errpre; + + /* Note that loopcxt_{find_unused,set_device}() resets + * loopcxt struct. + */ + if (!hasdev && (rc = loopcxt_find_unused(lc))) { + warnx(_("cannot find an unused loop device")); + break; + } + if (flags & LOOPDEV_FL_OFFSET) + loopcxt_set_offset(lc, offset); + if (flags & LOOPDEV_FL_SIZELIMIT) + loopcxt_set_sizelimit(lc, sizelimit); + if (lo_flags) + loopcxt_set_flags(lc, lo_flags); + if (blocksize > 0) + loopcxt_set_blocksize(lc, blocksize); + + if ((rc = loopcxt_set_backing_file(lc, file))) { + warn(_("%s: failed to use backing file"), file); + break; + } + + if ((rc = loopcxt_set_file_fmt_type(lc, file_fmt_type))) { + warn(_("failed to use backing file format type")); + break; + } + + errno = 0; + rc = loopcxt_setup_device(lc); + if (rc == 0) + break; /* success */ + if (errno == EBUSY && !hasdev) + continue; + + /* errors */ + errpre = hasdev && loopcxt_get_fd(lc) < 0 ? + loopcxt_get_device(lc) : file; + warn(_("%s: failed to set up loop device"), errpre); + break; + } while (hasdev == 0); + + return rc; +} + +int main(int argc, char **argv) +{ + struct loopdev_cxt lc; + int act = 0, flags = 0, no_overlap = 0, c; + char *file = NULL; + uint64_t offset = 0, sizelimit = 0, blocksize = 0; + int res = 0, showdev = 0, lo_flags = 0; + char *outarg = NULL; + int list = 0; + unsigned long use_dio = 0, set_dio = 0, set_blocksize = 0; + int use_file_fmt_type = 0; + uint32_t file_fmt_type = 0; + + enum { + OPT_SIZELIMIT = CHAR_MAX + 1, + OPT_SHOW, + OPT_RAW, + OPT_DIO, + OPT_OUTPUT_ALL + }; + static const struct option longopts[] = { + { "all", no_argument, NULL, 'a' }, + { "set-capacity", required_argument, NULL, 'c' }, + { "detach", required_argument, NULL, 'd' }, + { "detach-all", no_argument, NULL, 'D' }, + { "find", no_argument, NULL, 'f' }, + { "nooverlap", no_argument, NULL, 'L' }, + { "help", no_argument, NULL, 'h' }, + { "associated", required_argument, NULL, 'j' }, + { "json", no_argument, NULL, 'J' }, + { "list", no_argument, NULL, 'l' }, + { "sector-size", required_argument, NULL, 'b' }, + { "noheadings", no_argument, NULL, 'n' }, + { "offset", required_argument, NULL, 'o' }, + { "output", required_argument, NULL, 'O' }, + { "output-all", no_argument, NULL, OPT_OUTPUT_ALL }, + { "sizelimit", required_argument, NULL, OPT_SIZELIMIT }, + { "partscan", no_argument, NULL, 'P' }, + { "read-only", no_argument, NULL, 'r' }, + { "direct-io", optional_argument, NULL, OPT_DIO }, + { "raw", no_argument, NULL, OPT_RAW }, + { "show", no_argument, NULL, OPT_SHOW }, + { "type", required_argument, NULL, 't' }, + { "verbose", no_argument, NULL, 'v' }, + { "version", no_argument, NULL, 'V' }, + { NULL, 0, NULL, 0 } + }; + + static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ + { 'D','a','c','d','f','j' }, + { 'D','c','d','f','l' }, + { 'D','c','d','f','O' }, + { 'J',OPT_RAW }, + { 0 } + }; + int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + close_stdout_atexit(); + + if (loopcxt_init(&lc, 0)) + err(EXIT_FAILURE, _("failed to initialize loopcxt")); + + while ((c = getopt_long(argc, argv, "ab:c:d:Dfhj:JlLno:O:Prt:vV", + longopts, NULL)) != -1) { + + err_exclusive_options(c, longopts, excl, excl_st); + + switch (c) { + case 'a': + act = A_SHOW; + break; + case 'b': + set_blocksize = 1; + blocksize = strtosize_or_err(optarg, _("failed to parse logical block size")); + break; + case 'c': + act = A_SET_CAPACITY; + if (!is_loopdev(optarg) || + loopcxt_set_device(&lc, optarg)) + err(EXIT_FAILURE, _("%s: failed to use device"), + optarg); + break; + case 'r': + lo_flags |= LO_FLAGS_READ_ONLY; + break; + case 'd': + act = A_DELETE; + if (!is_loopdev(optarg) || + loopcxt_set_device(&lc, optarg)) + err(EXIT_FAILURE, _("%s: failed to use device"), + optarg); + break; + case 'D': + act = A_DELETE_ALL; + break; + case 'f': + act = A_FIND_FREE; + break; + case 'J': + json = 1; + break; + case 'j': + act = A_SHOW; + file = optarg; + break; + case 'l': + list = 1; + break; + case 'L': + no_overlap = 1; + break; + case 'n': + no_headings = 1; + break; + case OPT_RAW: + raw = 1; + break; + case 'o': + offset = strtosize_or_err(optarg, _("failed to parse offset")); + flags |= LOOPDEV_FL_OFFSET; + break; + case 'O': + outarg = optarg; + list = 1; + break; + case OPT_OUTPUT_ALL: + for (ncolumns = 0; ncolumns < ARRAY_SIZE(infos); ncolumns++) + columns[ncolumns] = ncolumns; + break; + case 'P': + lo_flags |= LO_FLAGS_PARTSCAN; + break; + case OPT_SHOW: + showdev = 1; + break; + case OPT_DIO: + use_dio = set_dio = 1; + if (optarg) + use_dio = parse_switch(optarg, _("argument error"), "on", "off", NULL); + break; + case 't': + if (optarg) { + if (parse_file_fmt_type(optarg, &file_fmt_type) == 0) + use_file_fmt_type = 1; + else + errx(EXIT_FAILURE, _("failed to parse file format type")); + } + break; + case 'v': + break; + case OPT_SIZELIMIT: /* --sizelimit */ + sizelimit = strtosize_or_err(optarg, _("failed to parse size")); + flags |= LOOPDEV_FL_SIZELIMIT; + break; + + case 'h': + usage(); + case 'V': + print_version(EXIT_SUCCESS); + default: + errtryhelp(EXIT_FAILURE); + } + } + + ul_path_init_debug(); + ul_sysfs_init_debug(); + + /* default is --list --all */ + if (argc == 1) { + act = A_SHOW; + list = 1; + } + + if (!act && argc == 2 && (raw || json)) { + act = A_SHOW; + list = 1; + } + + /* default --list output columns */ + if (list && !ncolumns) { + columns[ncolumns++] = COL_NAME; + columns[ncolumns++] = COL_SIZELIMIT; + columns[ncolumns++] = COL_OFFSET; + columns[ncolumns++] = COL_AUTOCLR; + columns[ncolumns++] = COL_RO; + columns[ncolumns++] = COL_BACK_FILE; + columns[ncolumns++] = COL_FILE_FMT_TYPE; + columns[ncolumns++] = COL_DIO; + columns[ncolumns++] = COL_LOGSEC; + } + + if (act == A_FIND_FREE && optind < argc) { + /* + * xlosetup -f + */ + act = A_CREATE; + file = argv[optind++]; + + if (optind < argc) + errx(EXIT_FAILURE, _("unexpected arguments")); + } + + if (list && !act && optind == argc) + /* + * xlosetup --list defaults to --all + */ + act = A_SHOW; + + if (!act && optind + 1 == argc) { + /* + * xlosetup [--list] + * OR + * xlosetup {--direct-io[=off]|--logical-blocksize=size}... + */ + if (!(set_dio || set_blocksize)) + act = A_SHOW_ONE; + if (set_dio) + act = A_SET_DIRECT_IO; + if (set_blocksize) + act = A_SET_BLOCKSIZE; + if (!is_loopdev(argv[optind]) || + loopcxt_set_device(&lc, argv[optind])) + err(EXIT_FAILURE, _("%s: failed to use device"), + argv[optind]); + optind++; + } + if (!act) { + /* + * xlosetup + */ + act = A_CREATE; + + if (optind >= argc) + errx(EXIT_FAILURE, _("no loop device specified")); + /* don't use is_loopdev() here, the device does not have exist yet */ + if (loopcxt_set_device(&lc, argv[optind])) + err(EXIT_FAILURE, _("%s: failed to use device"), + argv[optind]); + optind++; + + if (optind >= argc) + errx(EXIT_FAILURE, _("no file specified")); + file = argv[optind++]; + } + + if (act != A_CREATE && + (sizelimit || lo_flags || showdev || use_file_fmt_type)) + errx(EXIT_FAILURE, + _("the options %s are allowed during loop device setup only"), + "--{sizelimit,partscan,read-only,show,type}"); + + if ((flags & LOOPDEV_FL_OFFSET) && + act != A_CREATE && (act != A_SHOW || !file)) + errx(EXIT_FAILURE, _("the option --offset is not allowed in this context")); + + if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns), + &ncolumns, column_name_to_id) < 0) + return EXIT_FAILURE; + + switch (act) { + case A_CREATE: + res = create_loop(&lc, no_overlap, lo_flags, flags, file, + offset, sizelimit, blocksize, file_fmt_type); + if (res == 0) { + if (showdev) + printf("%s\n", loopcxt_get_device(&lc)); + warn_size(file, sizelimit, offset, flags); + if (set_dio) + goto lo_set_dio; + } + break; + case A_DELETE: + res = delete_loop(&lc); + while (optind < argc) { + if (!is_loopdev(argv[optind]) || + loopcxt_set_device(&lc, argv[optind])) + warn(_("%s: failed to use device"), + argv[optind]); + optind++; + res += delete_loop(&lc); + } + break; + case A_DELETE_ALL: + res = delete_all_loops(&lc); + break; + case A_FIND_FREE: + res = loopcxt_find_unused(&lc); + if (res) { + int errsv = errno; + + if (access(_PATH_DEV_LOOPCTL, F_OK) == 0 && + access(_PATH_DEV_LOOPCTL, W_OK) != 0) + ; + else + errno = errsv; + + warn(_("cannot find an unused loop device")); + } else + printf("%s\n", loopcxt_get_device(&lc)); + break; + case A_SHOW: + if (list) + res = show_table(&lc, file, offset, flags); + else + res = show_all_loops(&lc, file, offset, flags); + break; + case A_SHOW_ONE: + if (list) + res = show_table(&lc, NULL, 0, 0); + else + res = printf_loopdev(&lc); + if (res) + warn("%s", loopcxt_get_device(&lc)); + break; + case A_SET_CAPACITY: + res = loopcxt_ioctl_capacity(&lc); + if (res) + warn(_("%s: set capacity failed"), + loopcxt_get_device(&lc)); + break; + case A_SET_DIRECT_IO: +lo_set_dio: + res = loopcxt_ioctl_dio(&lc, use_dio); + if (res) + warn(_("%s: set direct io failed"), + loopcxt_get_device(&lc)); + break; + case A_SET_BLOCKSIZE: + res = loopcxt_ioctl_blocksize(&lc, blocksize); + if (res) + warn(_("%s: set logical block size failed"), + loopcxt_get_device(&lc)); + break; + default: + warnx(_("bad usage")); + errtryhelp(EXIT_FAILURE); + break; + } + + loopcxt_deinit(&lc); + return res ? EXIT_FAILURE : EXIT_SUCCESS; +} + -- cgit v1.2.3-55-g7522