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authorSimon Rettberg2022-03-04 11:58:03 +0100
committerSimon Rettberg2022-03-04 12:05:59 +0100
commit46a0f97d263ecc750a1b107940c6b379d221e661 (patch)
tree2469c3acbc029889285b99e300512167ee78c62e /src
parentSplit xloop_main into separate files for pre-5.15 and 5.15+ (diff)
downloadxloop-46a0f97d263ecc750a1b107940c6b379d221e661.tar.gz
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Add support for RHEL 8.5
Diffstat (limited to 'src')
-rw-r--r--src/kernel/xloop_main.c8
-rw-r--r--src/kernel/xloop_main.h11
-rw-r--r--src/kernel/xloop_main_4.18.c9
-rw-r--r--src/kernel/xloop_main_5.15.c2
-rw-r--r--src/kernel/xloop_main_rhel_8.5.c2111
-rw-r--r--src/kernel/xloop_main_rhel_8.5.h104
6 files changed, 2231 insertions, 14 deletions
diff --git a/src/kernel/xloop_main.c b/src/kernel/xloop_main.c
index b3f7963..cd1a767 100644
--- a/src/kernel/xloop_main.c
+++ b/src/kernel/xloop_main.c
@@ -1,6 +1,10 @@
-#include <linux/version.h>
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
+#include "xloop_main.h"
+
+#if RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 5))
+#include "xloop_main_rhel_8.5.c"
+#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
#include "xloop_main_4.18.c"
#else
#include "xloop_main_5.15.c"
diff --git a/src/kernel/xloop_main.h b/src/kernel/xloop_main.h
index c1cc919..3649039 100644
--- a/src/kernel/xloop_main.h
+++ b/src/kernel/xloop_main.h
@@ -1,6 +1,15 @@
#include <linux/version.h>
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
+/* define RHEL_CHECK_VERSION macro to check CentOS version */
+#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION)
+#define RHEL_CHECK_VERSION(CONDITION) (CONDITION)
+#else
+#define RHEL_CHECK_VERSION(CONDITION) (0)
+#endif
+
+#if RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 5))
+#include "xloop_main_rhel_8.5.h"
+#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
#include "xloop_main_4.18.h"
#else
#include "xloop_main_5.15.h"
diff --git a/src/kernel/xloop_main_4.18.c b/src/kernel/xloop_main_4.18.c
index 9fe0c70..dde0ad0 100644
--- a/src/kernel/xloop_main_4.18.c
+++ b/src/kernel/xloop_main_4.18.c
@@ -53,8 +53,6 @@
*
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
@@ -96,13 +94,6 @@
#include <linux/uaccess.h>
-/* define RHEL_CHECK_VERSION macro to check CentOS version */
-#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION)
-#define RHEL_CHECK_VERSION(CONDITION) (CONDITION)
-#else
-#define RHEL_CHECK_VERSION(CONDITION) (0)
-#endif
-
static DEFINE_IDR(xloop_index_idr);
static DEFINE_MUTEX(xloop_ctl_mutex);
diff --git a/src/kernel/xloop_main_5.15.c b/src/kernel/xloop_main_5.15.c
index d133709..9866c2b 100644
--- a/src/kernel/xloop_main_5.15.c
+++ b/src/kernel/xloop_main_5.15.c
@@ -53,8 +53,6 @@
*
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
diff --git a/src/kernel/xloop_main_rhel_8.5.c b/src/kernel/xloop_main_rhel_8.5.c
new file mode 100644
index 0000000..eb1538e
--- /dev/null
+++ b/src/kernel/xloop_main_rhel_8.5.c
@@ -0,0 +1,2111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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 <rgooch@atnf.csiro.au> 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 <rkroll@exploits.org> 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, <eriki@himolde.no>, 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 <axboe@suse.de>, Nov 2000
+ *
+ * Support up to 256 xloop devices
+ * Heinz Mauelshagen <mge@sistina.com>, 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 <development@manuel-bentele.de>, 2019
+ *
+ * Still To Fix:
+ * - Advisory locking is ignored here.
+ * - Should use an own CAP_* category instead of CAP_SYS_ADMIN
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/major.h>
+#include <linux/wait.h>
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/init.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <linux/compat.h>
+#include <linux/suspend.h>
+#include <linux/freezer.h>
+#include <linux/mutex.h>
+#include <linux/writeback.h>
+#include <linux/completion.h>
+#include <linux/highmem.h>
+#include <linux/kthread.h>
+#include <linux/splice.h>
+#include <linux/sysfs.h>
+#include <linux/miscdevice.h>
+#include <linux/falloc.h>
+#include <linux/uio.h>
+#include <linux/ioprio.h>
+#include <linux/blk-cgroup.h>
+#include <linux/version.h>
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#endif
+
+#include <xloop/version.h>
+
+#include "xloop_file_fmt.h"
+#include "xloop_main.h"
+
+#include <linux/uaccess.h>
+
+static DEFINE_IDR(xloop_index_idr);
+static DEFINE_MUTEX(xloop_ctl_mutex);
+
+static int max_part;
+static int part_shift;
+
+struct device *xloop_device_to_dev(struct xloop_device *xlo)
+{
+ return disk_to_dev(xlo->xlo_disk);
+}
+EXPORT_SYMBOL(xloop_device_to_dev);
+
+static int transfer_xor(struct xloop_device *xlo, int cmd, struct page *raw_page, unsigned int raw_off,
+ struct page *xloop_page, unsigned int 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 int 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;
+
+ bd_set_nr_sectors(bdev, size);
+
+ if (!set_capacity_revalidate_and_notify(xlo->xlo_disk, size, false))
+ kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
+}
+
+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);
+ rc = bdev_disk_changed(bdev, false);
+ mutex_unlock(&bdev->bd_mutex);
+ if (rc)
+ dev_warn(xloop_device_to_dev(xlo), "partition scan failed (rc=%d)\n", 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)
+{
+ current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO;
+ 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)) {
+ claimed_bdev = bdev->bd_contains;
+ error = bd_prepare_to_claim(bdev, claimed_bdev, xloop_configure);
+ if (error)
+ goto out_putf;
+ }
+
+ 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;
+
+ 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));
+
+ error = xloop_file_fmt_init(xlo->xlo_fmt, config->info.xlo_file_fmt_type);
+ if (error)
+ goto out_unlock;
+
+ 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_nr_sectors(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);
+ err = bdev_disk_changed(bdev, false);
+ if (!release)
+ mutex_unlock(&bdev->bd_mutex);
+ if (err)
+ dev_warn(xloop_device_to_dev(xlo), "partition scan failed (rc=%d)\n", 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
+ * <dev>/do something like mkfs/losetup -d <dev> 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;
+ dev_warn(xloop_device_to_dev(xlo),
+ "xloop device has still dirty pages (nrpages=%lu)\n",
+ 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 xloop 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;
+ dev_warn(xloop_device_to_dev(xlo),
+ "xloop device has still dirty pages (nrpages=%lu)\n",
+ 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];
+ 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 ||
+ 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)
+ 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_AUTHOR("Manuel Bentele <development@manuel-bentele.de>");
+MODULE_VERSION(XLOOP_VERSION);
+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;
+}
+EXPORT_SYMBOL(xloop_register_transfer);
+
+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;
+
+ xfer = xfer_funcs[n];
+
+ if (n == 0 || n >= MAX_XLO_CRYPT || xfer == NULL)
+ return -EINVAL;
+
+ xfer_funcs[n] = NULL;
+ idr_for_each(&xloop_index_idr, &unregister_transfer_cb, xfer);
+ return 0;
+}
+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 (likely(!blk_should_fake_timeout(rq->q)))
+ blk_mq_complete_request(rq);
+ }
+}
+
+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);
+ xlo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING;
+ 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 void xloop_probe(dev_t dev)
+{
+ struct xloop_device *xlo;
+ 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);
+ mutex_unlock(&xloop_ctl_mutex);
+}
+
+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 = -EINVAL;
+ 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
+
+ if (__register_blkdev(XLOOP_MAJOR, "xloop", xloop_probe)) {
+ err = -EIO;
+ goto misc_out;
+ }
+
+ /* 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);
+
+ pr_info("module in version %s loaded\n", XLOOP_VERSION);
+ return 0;
+
+misc_out:
+ misc_deregister(&xloop_misc);
+err_out:
+ return err;
+}
+
+static void __exit xloop_exit(void)
+{
+ struct xloop_device *xlo;
+ int id;
+
+ unregister_blkdev(XLOOP_MAJOR, "xloop");
+ misc_deregister(&xloop_misc);
+
+ /*
+ * There is no need to use xloop_ctl_mutex here, for nobody else can
+ * access xloop_index_idr when this module is unloading (unless forced
+ * module unloading is requested). If this is not a clean unloading,
+ * we have no means to avoid kernel crash.
+ */
+ idr_for_each_entry(&xloop_index_idr, xlo, id)
+ xloop_remove(xlo);
+
+ idr_destroy(&xloop_index_idr);
+
+#ifdef CONFIG_DEBUG_FS
+ debugfs_remove(xloop_dbgfs_dir);
+#endif
+
+ pr_info("exit module\n");
+}
+
+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/src/kernel/xloop_main_rhel_8.5.h b/src/kernel/xloop_main_rhel_8.5.h
new file mode 100644
index 0000000..97c2654
--- /dev/null
+++ b/src/kernel/xloop_main_rhel_8.5.h
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * 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 <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/kthread.h>
+#include "uapi_xloop.h"
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#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 *xlo, int cmd, struct page *raw_page,
+ unsigned int raw_off, struct page *xloop_page, unsigned int 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 *xlo, 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 int raw_off,
+ struct page *xloop_page, unsigned int xloop_off, int size, sector_t real_block);
+ int (*init)(struct xloop_device *xlo, const struct xloop_info64 *info);
+ /* release is called from xloop_unregister_transfer or clr_fd */
+ int (*release)(struct xloop_device *xlo);
+ int (*ioctl)(struct xloop_device *xlo, int cmd, unsigned long arg);
+ struct module *owner;
+};
+
+extern inline struct device *xloop_device_to_dev(struct xloop_device *xlo);
+
+int xloop_register_transfer(struct xloop_func_table *funcs);
+int xloop_unregister_transfer(int number);
+
+#endif