From 8760366cdbbddc574860294a443041982b90e2f5 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:47 +0200 Subject: nbd: Remove unused nbd_export_get_blockdev() Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Eric Blake Message-Id: <20200924152717.287415-2-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- include/block/nbd.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include') diff --git a/include/block/nbd.h b/include/block/nbd.h index 9bc3bfaeec..0451683d03 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -338,8 +338,6 @@ void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); void nbd_export_get(NBDExport *exp); void nbd_export_put(NBDExport *exp); -BlockBackend *nbd_export_get_blockdev(NBDExport *exp); - AioContext *nbd_export_aio_context(NBDExport *exp); NBDExport *nbd_export_find(const char *name); void nbd_export_close_all(void); -- cgit v1.2.3-55-g7522 From 5daa6bfd8eec913872d6438bc679a92f92a7a0c4 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:48 +0200 Subject: qapi: Create block-export module Move all block export related types and commands from block-core to the new QAPI module block-export. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Eric Blake Message-Id: <20200924152717.287415-3-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/monitor/block-hmp-cmds.c | 1 + blockdev-nbd.c | 2 +- include/block/nbd.h | 2 +- qapi/block-core.json | 166 --------------------------------- qapi/block-export.json | 174 +++++++++++++++++++++++++++++++++++ qapi/meson.build | 4 +- qapi/qapi-schema.json | 1 + storage-daemon/qapi/qapi-schema.json | 1 + storage-daemon/qemu-storage-daemon.c | 2 +- 9 files changed, 183 insertions(+), 170 deletions(-) create mode 100644 qapi/block-export.json (limited to 'include') diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index 4d3db5ed3c..6ce0f8f87c 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -40,6 +40,7 @@ #include "sysemu/block-backend.h" #include "sysemu/blockdev.h" #include "qapi/qapi-commands-block.h" +#include "qapi/qapi-commands-block-export.h" #include "qapi/qmp/qdict.h" #include "qapi/error.h" #include "qapi/qmp/qerror.h" diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 1a95d89f00..0f6b80c58f 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -14,7 +14,7 @@ #include "sysemu/block-backend.h" #include "hw/block/block.h" #include "qapi/error.h" -#include "qapi/qapi-commands-block.h" +#include "qapi/qapi-commands-block-export.h" #include "block/nbd.h" #include "io/channel-socket.h" #include "io/net-listener.h" diff --git a/include/block/nbd.h b/include/block/nbd.h index 0451683d03..262f6da2ce 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -20,7 +20,7 @@ #ifndef NBD_H #define NBD_H -#include "qapi/qapi-types-block.h" +#include "qapi/qapi-types-block-export.h" #include "io/channel-socket.h" #include "crypto/tlscreds.h" #include "qapi/error.h" diff --git a/qapi/block-core.json b/qapi/block-core.json index 86ed72ef9f..12a24772b5 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -5194,172 +5194,6 @@ 'iothread': 'StrOrNull', '*force': 'bool' } } -## -# @NbdServerOptions: -# -# @addr: Address on which to listen. -# @tls-creds: ID of the TLS credentials object (since 2.6). -# @tls-authz: ID of the QAuthZ authorization object used to validate -# the client's x509 distinguished name. This object is -# is only resolved at time of use, so can be deleted and -# recreated on the fly while the NBD server is active. -# If missing, it will default to denying access (since 4.0). -# -# Keep this type consistent with the nbd-server-start arguments. The only -# intended difference is using SocketAddress instead of SocketAddressLegacy. -# -# Since: 4.2 -## -{ 'struct': 'NbdServerOptions', - 'data': { 'addr': 'SocketAddress', - '*tls-creds': 'str', - '*tls-authz': 'str'} } - -## -# @nbd-server-start: -# -# Start an NBD server listening on the given host and port. Block -# devices can then be exported using @nbd-server-add. The NBD -# server will present them as named exports; for example, another -# QEMU instance could refer to them as "nbd:HOST:PORT:exportname=NAME". -# -# Keep this type consistent with the NbdServerOptions type. The only intended -# difference is using SocketAddressLegacy instead of SocketAddress. -# -# @addr: Address on which to listen. -# @tls-creds: ID of the TLS credentials object (since 2.6). -# @tls-authz: ID of the QAuthZ authorization object used to validate -# the client's x509 distinguished name. This object is -# is only resolved at time of use, so can be deleted and -# recreated on the fly while the NBD server is active. -# If missing, it will default to denying access (since 4.0). -# -# Returns: error if the server is already running. -# -# Since: 1.3.0 -## -{ 'command': 'nbd-server-start', - 'data': { 'addr': 'SocketAddressLegacy', - '*tls-creds': 'str', - '*tls-authz': 'str'} } - -## -# @BlockExportNbd: -# -# An NBD block export. -# -# @device: The device name or node name of the node to be exported -# -# @name: Export name. If unspecified, the @device parameter is used as the -# export name. (Since 2.12) -# -# @description: Free-form description of the export, up to 4096 bytes. -# (Since 5.0) -# -# @writable: Whether clients should be able to write to the device via the -# NBD connection (default false). -# -# @bitmap: Also export the dirty bitmap reachable from @device, so the -# NBD client can use NBD_OPT_SET_META_CONTEXT with -# "qemu:dirty-bitmap:NAME" to inspect the bitmap. (since 4.0) -# -# Since: 5.0 -## -{ 'struct': 'BlockExportNbd', - 'data': {'device': 'str', '*name': 'str', '*description': 'str', - '*writable': 'bool', '*bitmap': 'str' } } - -## -# @nbd-server-add: -# -# Export a block node to QEMU's embedded NBD server. -# -# Returns: error if the server is not running, or export with the same name -# already exists. -# -# Since: 1.3.0 -## -{ 'command': 'nbd-server-add', - 'data': 'BlockExportNbd', 'boxed': true } - -## -# @NbdServerRemoveMode: -# -# Mode for removing an NBD export. -# -# @safe: Remove export if there are no existing connections, fail otherwise. -# -# @hard: Drop all connections immediately and remove export. -# -# Potential additional modes to be added in the future: -# -# hide: Just hide export from new clients, leave existing connections as is. -# Remove export after all clients are disconnected. -# -# soft: Hide export from new clients, answer with ESHUTDOWN for all further -# requests from existing clients. -# -# Since: 2.12 -## -{'enum': 'NbdServerRemoveMode', 'data': ['safe', 'hard']} - -## -# @nbd-server-remove: -# -# Remove NBD export by name. -# -# @name: Export name. -# -# @mode: Mode of command operation. See @NbdServerRemoveMode description. -# Default is 'safe'. -# -# Returns: error if -# - the server is not running -# - export is not found -# - mode is 'safe' and there are existing connections -# -# Since: 2.12 -## -{ 'command': 'nbd-server-remove', - 'data': {'name': 'str', '*mode': 'NbdServerRemoveMode'} } - -## -# @nbd-server-stop: -# -# Stop QEMU's embedded NBD server, and unregister all devices previously -# added via @nbd-server-add. -# -# Since: 1.3.0 -## -{ 'command': 'nbd-server-stop' } - -## -# @BlockExportType: -# -# An enumeration of block export types -# -# @nbd: NBD export -# -# Since: 4.2 -## -{ 'enum': 'BlockExportType', - 'data': [ 'nbd' ] } - -## -# @BlockExport: -# -# Describes a block export, i.e. how single node should be exported on an -# external interface. -# -# Since: 4.2 -## -{ 'union': 'BlockExport', - 'base': { 'type': 'BlockExportType' }, - 'discriminator': 'type', - 'data': { - 'nbd': 'BlockExportNbd' - } } - ## # @QuorumOpType: # diff --git a/qapi/block-export.json b/qapi/block-export.json new file mode 100644 index 0000000000..b21b8e3f4d --- /dev/null +++ b/qapi/block-export.json @@ -0,0 +1,174 @@ +# -*- Mode: Python -*- +# vim: filetype=python + +## +# == Block device exports +## + +{ 'include': 'sockets.json' } + +## +# @NbdServerOptions: +# +# Keep this type consistent with the nbd-server-start arguments. The only +# intended difference is using SocketAddress instead of SocketAddressLegacy. +# +# @addr: Address on which to listen. +# @tls-creds: ID of the TLS credentials object (since 2.6). +# @tls-authz: ID of the QAuthZ authorization object used to validate +# the client's x509 distinguished name. This object is +# is only resolved at time of use, so can be deleted and +# recreated on the fly while the NBD server is active. +# If missing, it will default to denying access (since 4.0). +# +# Since: 4.2 +## +{ 'struct': 'NbdServerOptions', + 'data': { 'addr': 'SocketAddress', + '*tls-creds': 'str', + '*tls-authz': 'str'} } + +## +# @nbd-server-start: +# +# Start an NBD server listening on the given host and port. Block +# devices can then be exported using @nbd-server-add. The NBD +# server will present them as named exports; for example, another +# QEMU instance could refer to them as "nbd:HOST:PORT:exportname=NAME". +# +# Keep this type consistent with the NbdServerOptions type. The only intended +# difference is using SocketAddressLegacy instead of SocketAddress. +# +# @addr: Address on which to listen. +# @tls-creds: ID of the TLS credentials object (since 2.6). +# @tls-authz: ID of the QAuthZ authorization object used to validate +# the client's x509 distinguished name. This object is +# is only resolved at time of use, so can be deleted and +# recreated on the fly while the NBD server is active. +# If missing, it will default to denying access (since 4.0). +# +# Returns: error if the server is already running. +# +# Since: 1.3.0 +## +{ 'command': 'nbd-server-start', + 'data': { 'addr': 'SocketAddressLegacy', + '*tls-creds': 'str', + '*tls-authz': 'str'} } + +## +# @BlockExportNbd: +# +# An NBD block export. +# +# @device: The device name or node name of the node to be exported +# +# @name: Export name. If unspecified, the @device parameter is used as the +# export name. (Since 2.12) +# +# @description: Free-form description of the export, up to 4096 bytes. +# (Since 5.0) +# +# @writable: Whether clients should be able to write to the device via the +# NBD connection (default false). +# +# @bitmap: Also export the dirty bitmap reachable from @device, so the +# NBD client can use NBD_OPT_SET_META_CONTEXT with +# "qemu:dirty-bitmap:NAME" to inspect the bitmap. (since 4.0) +# +# Since: 5.0 +## +{ 'struct': 'BlockExportNbd', + 'data': {'device': 'str', '*name': 'str', '*description': 'str', + '*writable': 'bool', '*bitmap': 'str' } } + +## +# @nbd-server-add: +# +# Export a block node to QEMU's embedded NBD server. +# +# Returns: error if the server is not running, or export with the same name +# already exists. +# +# Since: 1.3.0 +## +{ 'command': 'nbd-server-add', + 'data': 'BlockExportNbd', 'boxed': true } + +## +# @NbdServerRemoveMode: +# +# Mode for removing an NBD export. +# +# @safe: Remove export if there are no existing connections, fail otherwise. +# +# @hard: Drop all connections immediately and remove export. +# +# Potential additional modes to be added in the future: +# +# hide: Just hide export from new clients, leave existing connections as is. +# Remove export after all clients are disconnected. +# +# soft: Hide export from new clients, answer with ESHUTDOWN for all further +# requests from existing clients. +# +# Since: 2.12 +## +{'enum': 'NbdServerRemoveMode', 'data': ['safe', 'hard']} + +## +# @nbd-server-remove: +# +# Remove NBD export by name. +# +# @name: Export name. +# +# @mode: Mode of command operation. See @NbdServerRemoveMode description. +# Default is 'safe'. +# +# Returns: error if +# - the server is not running +# - export is not found +# - mode is 'safe' and there are existing connections +# +# Since: 2.12 +## +{ 'command': 'nbd-server-remove', + 'data': {'name': 'str', '*mode': 'NbdServerRemoveMode'} } + +## +# @nbd-server-stop: +# +# Stop QEMU's embedded NBD server, and unregister all devices previously +# added via @nbd-server-add. +# +# Since: 1.3.0 +## +{ 'command': 'nbd-server-stop' } + +## +# @BlockExportType: +# +# An enumeration of block export types +# +# @nbd: NBD export +# +# Since: 4.2 +## +{ 'enum': 'BlockExportType', + 'data': [ 'nbd' ] } + +## +# @BlockExport: +# +# Describes a block export, i.e. how single node should be exported on an +# external interface. +# +# Since: 4.2 +## +{ 'union': 'BlockExport', + 'base': { 'type': 'BlockExportType' }, + 'discriminator': 'type', + 'data': { + 'nbd': 'BlockExportNbd' + } } diff --git a/qapi/meson.build b/qapi/meson.build index 7c4a89a882..ea359a0148 100644 --- a/qapi/meson.build +++ b/qapi/meson.build @@ -17,8 +17,9 @@ qapi_all_modules = [ 'acpi', 'audio', 'authz', - 'block-core', 'block', + 'block-core', + 'block-export', 'char', 'common', 'control', @@ -49,6 +50,7 @@ qapi_all_modules = [ qapi_storage_daemon_modules = [ 'block-core', + 'block-export', 'char', 'common', 'control', diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json index 0c6ca5c000..8d567e1386 100644 --- a/qapi/qapi-schema.json +++ b/qapi/qapi-schema.json @@ -66,6 +66,7 @@ { 'include': 'run-state.json' } { 'include': 'crypto.json' } { 'include': 'block.json' } +{ 'include': 'block-export.json' } { 'include': 'char.json' } { 'include': 'dump.json' } { 'include': 'job.json' } diff --git a/storage-daemon/qapi/qapi-schema.json b/storage-daemon/qapi/qapi-schema.json index 6100d1f0c9..c6ad5ae1e3 100644 --- a/storage-daemon/qapi/qapi-schema.json +++ b/storage-daemon/qapi/qapi-schema.json @@ -16,6 +16,7 @@ { 'include': '../../qapi/pragma.json' } { 'include': '../../qapi/block-core.json' } +{ 'include': '../../qapi/block-export.json' } { 'include': '../../qapi/char.json' } { 'include': '../../qapi/common.json' } { 'include': '../../qapi/control.json' } diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c index 7e9b0e0d3f..ed9d2afcf3 100644 --- a/storage-daemon/qemu-storage-daemon.c +++ b/storage-daemon/qemu-storage-daemon.c @@ -35,8 +35,8 @@ #include "monitor/monitor-internal.h" #include "qapi/error.h" -#include "qapi/qapi-visit-block.h" #include "qapi/qapi-visit-block-core.h" +#include "qapi/qapi-visit-block-export.h" #include "qapi/qapi-visit-control.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp/qstring.h" -- cgit v1.2.3-55-g7522 From 56ee86261e0ffa151e82b383d9628cf5660be355 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:50 +0200 Subject: block/export: Add BlockExport infrastructure and block-export-add We want to have a common set of commands for all types of block exports. Currently, this is only NBD, but we're going to add more types. This patch adds the basic BlockExport and BlockExportDriver structs and a QMP command block-export-add that creates a new export based on the given BlockExportOptions. qmp_nbd_server_add() becomes a wrapper around qmp_block_export_add(). Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-5-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block/export/export.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ block/export/meson.build | 1 + block/meson.build | 2 ++ blockdev-nbd.c | 28 +++++++++++++++++++++------- include/block/export.h | 33 +++++++++++++++++++++++++++++++++ include/block/nbd.h | 5 ++++- meson.build | 2 +- nbd/server.c | 15 ++++++++++++++- qapi/block-export.json | 10 ++++++++++ 9 files changed, 134 insertions(+), 10 deletions(-) create mode 100644 block/export/export.c create mode 100644 block/export/meson.build create mode 100644 include/block/export.h (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c new file mode 100644 index 0000000000..fd65541963 --- /dev/null +++ b/block/export/export.c @@ -0,0 +1,48 @@ +/* + * Common block export infrastructure + * + * Copyright (c) 2012, 2020 Red Hat, Inc. + * + * Authors: + * Paolo Bonzini + * Kevin Wolf + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" + +#include "block/export.h" +#include "block/nbd.h" +#include "qapi/error.h" +#include "qapi/qapi-commands-block-export.h" + +static const BlockExportDriver *blk_exp_drivers[] = { + &blk_exp_nbd, +}; + +static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(blk_exp_drivers); i++) { + if (blk_exp_drivers[i]->type == type) { + return blk_exp_drivers[i]; + } + } + return NULL; +} + +void qmp_block_export_add(BlockExportOptions *export, Error **errp) +{ + const BlockExportDriver *drv; + + drv = blk_exp_find_driver(export->type); + if (!drv) { + error_setg(errp, "No driver found for the requested export type"); + return; + } + + drv->create(export, errp); +} diff --git a/block/export/meson.build b/block/export/meson.build new file mode 100644 index 0000000000..558ef35d38 --- /dev/null +++ b/block/export/meson.build @@ -0,0 +1 @@ +block_ss.add(files('export.c')) diff --git a/block/meson.build b/block/meson.build index a3e56b7cd1..0b38dc36f7 100644 --- a/block/meson.build +++ b/block/meson.build @@ -110,6 +110,8 @@ block_ss.add(module_block_h) block_ss.add(files('stream.c')) softmmu_ss.add(files('qapi-sysemu.c')) + +subdir('export') subdir('monitor') modules += {'block': block_modules} diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 98ee1b6170..47b04f166a 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -148,17 +148,20 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr, qapi_free_SocketAddress(addr_flat); } -void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) +BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) { + BlockExportOptionsNbd *arg = &exp_args->u.nbd; BlockDriverState *bs = NULL; BlockBackend *on_eject_blk; - NBDExport *exp; + NBDExport *exp = NULL; int64_t len; AioContext *aio_context; + assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); + if (!nbd_server) { error_setg(errp, "NBD server not running"); - return; + return NULL; } if (!arg->has_name) { @@ -167,24 +170,24 @@ void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) if (strlen(arg->name) > NBD_MAX_STRING_SIZE) { error_setg(errp, "export name '%s' too long", arg->name); - return; + return NULL; } if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { error_setg(errp, "description '%s' too long", arg->description); - return; + return NULL; } if (nbd_export_find(arg->name)) { error_setg(errp, "NBD server already has export named '%s'", arg->name); - return; + return NULL; } on_eject_blk = blk_by_name(arg->device); bs = bdrv_lookup_bs(arg->device, arg->device, errp); if (!bs) { - return; + return NULL; } aio_context = bdrv_get_aio_context(bs); @@ -217,6 +220,17 @@ void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) out: aio_context_release(aio_context); + /* TODO Remove the cast: nbd_export_new() will return a BlockExport. */ + return (BlockExport*) exp; +} + +void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) +{ + BlockExportOptions export = { + .type = BLOCK_EXPORT_TYPE_NBD, + .u.nbd = *arg, + }; + qmp_block_export_add(&export, errp); } void qmp_nbd_server_remove(const char *name, diff --git a/include/block/export.h b/include/block/export.h new file mode 100644 index 0000000000..42e3c055fc --- /dev/null +++ b/include/block/export.h @@ -0,0 +1,33 @@ +/* + * Declarations for block exports + * + * Copyright (c) 2012, 2020 Red Hat, Inc. + * + * Authors: + * Paolo Bonzini + * Kevin Wolf + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#ifndef BLOCK_EXPORT_H +#define BLOCK_EXPORT_H + +#include "qapi/qapi-types-block-export.h" + +typedef struct BlockExport BlockExport; + +typedef struct BlockExportDriver { + /* The export type that this driver services */ + BlockExportType type; + + /* Creates and starts a new block export */ + BlockExport *(*create)(BlockExportOptions *, Error **); +} BlockExportDriver; + +struct BlockExport { + const BlockExportDriver *drv; +}; + +#endif diff --git a/include/block/nbd.h b/include/block/nbd.h index 262f6da2ce..7698453fb2 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -20,11 +20,13 @@ #ifndef NBD_H #define NBD_H -#include "qapi/qapi-types-block-export.h" +#include "block/export.h" #include "io/channel-socket.h" #include "crypto/tlscreds.h" #include "qapi/error.h" +extern const BlockExportDriver blk_exp_nbd; + /* Handshake phase structs - this struct is passed on the wire */ struct NBDOption { @@ -328,6 +330,7 @@ int nbd_errno_to_system_errno(int err); typedef struct NBDExport NBDExport; typedef struct NBDClient NBDClient; +BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp); NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, uint64_t size, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, diff --git a/meson.build b/meson.build index 3161c1f037..0f0cc21d16 100644 --- a/meson.build +++ b/meson.build @@ -970,6 +970,7 @@ subdir('dump') block_ss.add(files( 'block.c', + 'blockdev-nbd.c', 'blockjob.c', 'job.c', 'qemu-io-cmds.c', @@ -982,7 +983,6 @@ subdir('block') blockdev_ss.add(files( 'blockdev.c', - 'blockdev-nbd.c', 'iothread.c', 'job-qmp.c', )) diff --git a/nbd/server.c b/nbd/server.c index bd53f7baea..f5af93c253 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -18,6 +18,8 @@ */ #include "qemu/osdep.h" + +#include "block/export.h" #include "qapi/error.h" #include "qemu/queue.h" #include "trace.h" @@ -80,6 +82,7 @@ struct NBDRequestData { }; struct NBDExport { + BlockExport common; int refcount; void (*close)(NBDExport *exp); @@ -1512,10 +1515,15 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, { AioContext *ctx; BlockBackend *blk; - NBDExport *exp = g_new0(NBDExport, 1); + NBDExport *exp; uint64_t perm; int ret; + exp = g_new0(NBDExport, 1); + exp->common = (BlockExport) { + .drv = &blk_exp_nbd, + }; + /* * NBD exports are used for non-shared storage migration. Make sure * that BDRV_O_INACTIVE is cleared and the image is ready for write @@ -1731,6 +1739,11 @@ void nbd_export_put(NBDExport *exp) } } +const BlockExportDriver blk_exp_nbd = { + .type = BLOCK_EXPORT_TYPE_NBD, + .create = nbd_export_create, +}; + void nbd_export_close_all(void) { NBDExport *exp, *next; diff --git a/qapi/block-export.json b/qapi/block-export.json index 6ac3a63123..5890a94219 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -172,3 +172,13 @@ 'data': { 'nbd': 'BlockExportOptionsNbd' } } + +## +# @block-export-add: +# +# Creates a new block export. +# +# Since: 5.2 +## +{ 'command': 'block-export-add', + 'data': 'BlockExportOptions', 'boxed': true } -- cgit v1.2.3-55-g7522 From b57e4de079d90caca05fed5b45aeb642c6c29aa0 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:52 +0200 Subject: qemu-nbd: Use raw block driver for --offset Instead of implementing qemu-nbd --offset in the NBD code, just put a raw block node with the requested offset on top of the user image and rely on that doing the job. This does not only simplify the nbd_export_new() interface and bring it closer to the set of options that the nbd-server-add QMP command offers, but in fact it also eliminates a potential source for bugs in the NBD code which previously had to add the offset manually in all relevant places. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Eric Blake Message-Id: <20200924152717.287415-7-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- blockdev-nbd.c | 9 +-------- include/block/nbd.h | 4 ++-- nbd/server.c | 33 ++++++++++++++++----------------- qemu-nbd.c | 27 ++++++++++++--------------- 4 files changed, 31 insertions(+), 42 deletions(-) (limited to 'include') diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 47b04f166a..96cb0100e9 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -154,7 +154,6 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) BlockDriverState *bs = NULL; BlockBackend *on_eject_blk; NBDExport *exp = NULL; - int64_t len; AioContext *aio_context; assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); @@ -192,12 +191,6 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); - len = bdrv_getlength(bs); - if (len < 0) { - error_setg_errno(errp, -len, - "Failed to determine the NBD export's length"); - goto out; - } if (!arg->has_writable) { arg->writable = false; @@ -206,7 +199,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) arg->writable = false; } - exp = nbd_export_new(bs, 0, len, arg->name, arg->description, arg->bitmap, + exp = nbd_export_new(bs, arg->name, arg->description, arg->bitmap, !arg->writable, !arg->writable, NULL, false, on_eject_blk, errp); if (!exp) { diff --git a/include/block/nbd.h b/include/block/nbd.h index 7698453fb2..451f399b0a 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -331,8 +331,8 @@ typedef struct NBDExport NBDExport; typedef struct NBDClient NBDClient; BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp); -NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, - uint64_t size, const char *name, const char *desc, +NBDExport *nbd_export_new(BlockDriverState *bs, + const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, void (*close)(NBDExport *), bool writethrough, BlockBackend *on_eject_blk, Error **errp); diff --git a/nbd/server.c b/nbd/server.c index f5af93c253..33aaca918c 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -89,7 +89,6 @@ struct NBDExport { BlockBackend *blk; char *name; char *description; - uint64_t dev_offset; uint64_t size; uint16_t nbdflags; QTAILQ_HEAD(, NBDClient) clients; @@ -1507,8 +1506,8 @@ static void nbd_eject_notifier(Notifier *n, void *data) aio_context_release(aio_context); } -NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, - uint64_t size, const char *name, const char *desc, +NBDExport *nbd_export_new(BlockDriverState *bs, + const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, void (*close)(NBDExport *), bool writethrough, BlockBackend *on_eject_blk, Error **errp) @@ -1516,9 +1515,17 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, AioContext *ctx; BlockBackend *blk; NBDExport *exp; + int64_t size; uint64_t perm; int ret; + size = bdrv_getlength(bs); + if (size < 0) { + error_setg_errno(errp, -size, + "Failed to determine the NBD export's length"); + return NULL; + } + exp = g_new0(NBDExport, 1); exp->common = (BlockExport) { .drv = &blk_exp_nbd, @@ -1553,8 +1560,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, exp->refcount = 1; QTAILQ_INIT(&exp->clients); exp->blk = blk; - assert(dev_offset <= INT64_MAX); - exp->dev_offset = dev_offset; exp->name = g_strdup(name); assert(!desc || strlen(desc) <= NBD_MAX_STRING_SIZE); exp->description = g_strdup(desc); @@ -1569,7 +1574,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES | NBD_FLAG_SEND_FAST_ZERO); } - assert(size <= INT64_MAX - dev_offset); exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); if (bitmap) { @@ -1928,8 +1932,7 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, stl_be_p(&chunk.length, pnum); ret = nbd_co_send_iov(client, iov, 1, errp); } else { - ret = blk_pread(exp->blk, offset + progress + exp->dev_offset, - data + progress, pnum); + ret = blk_pread(exp->blk, offset + progress, data + progress, pnum); if (ret < 0) { error_setg_errno(errp, -ret, "reading from file failed"); break; @@ -2303,8 +2306,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, data, request->len, errp); } - ret = blk_pread(exp->blk, request->from + exp->dev_offset, data, - request->len); + ret = blk_pread(exp->blk, request->from, data, request->len); if (ret < 0) { return nbd_send_generic_reply(client, request->handle, ret, "reading from file failed", errp); @@ -2339,7 +2341,7 @@ static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request, assert(request->type == NBD_CMD_CACHE); - ret = blk_co_preadv(exp->blk, request->from + exp->dev_offset, request->len, + ret = blk_co_preadv(exp->blk, request->from, request->len, NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); return nbd_send_generic_reply(client, request->handle, ret, @@ -2370,8 +2372,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, if (request->flags & NBD_CMD_FLAG_FUA) { flags |= BDRV_REQ_FUA; } - ret = blk_pwrite(exp->blk, request->from + exp->dev_offset, - data, request->len, flags); + ret = blk_pwrite(exp->blk, request->from, data, request->len, flags); return nbd_send_generic_reply(client, request->handle, ret, "writing to file failed", errp); @@ -2392,8 +2393,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, int align = client->check_align ?: 1; int len = MIN(request->len, QEMU_ALIGN_DOWN(BDRV_REQUEST_MAX_BYTES, align)); - ret = blk_pwrite_zeroes(exp->blk, request->from + exp->dev_offset, - len, flags); + ret = blk_pwrite_zeroes(exp->blk, request->from, len, flags); request->len -= len; request->from += len; } @@ -2416,8 +2416,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, int align = client->check_align ?: 1; int len = MIN(request->len, QEMU_ALIGN_DOWN(BDRV_REQUEST_MAX_BYTES, align)); - ret = blk_co_pdiscard(exp->blk, request->from + exp->dev_offset, - len); + ret = blk_co_pdiscard(exp->blk, request->from, len); request->len -= len; request->from += len; } diff --git a/qemu-nbd.c b/qemu-nbd.c index e39d3b23c1..16473d809c 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -524,7 +524,6 @@ int main(int argc, char **argv) const char *port = NULL; char *sockpath = NULL; char *device = NULL; - int64_t fd_size; QemuOpts *sn_opts = NULL; const char *sn_id_or_name = NULL; const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:B:L"; @@ -1037,6 +1036,17 @@ int main(int argc, char **argv) } bs = blk_bs(blk); + if (dev_offset) { + QDict *raw_opts = qdict_new(); + qdict_put_str(raw_opts, "driver", "raw"); + qdict_put_str(raw_opts, "file", bs->node_name); + qdict_put_int(raw_opts, "offset", dev_offset); + bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal); + blk_remove_bs(blk); + blk_insert_bs(blk, bs, &error_fatal); + bdrv_unref(bs); + } + blk_set_enable_write_cache(blk, !writethrough); if (sn_opts) { @@ -1054,21 +1064,8 @@ int main(int argc, char **argv) } bs->detect_zeroes = detect_zeroes; - fd_size = blk_getlength(blk); - if (fd_size < 0) { - error_report("Failed to determine the image length: %s", - strerror(-fd_size)); - exit(EXIT_FAILURE); - } - - if (dev_offset >= fd_size) { - error_report("Offset (%" PRIu64 ") has to be smaller than the image " - "size (%" PRId64 ")", dev_offset, fd_size); - exit(EXIT_FAILURE); - } - fd_size -= dev_offset; - export = nbd_export_new(bs, dev_offset, fd_size, export_name, + export = nbd_export_new(bs, export_name, export_description, bitmap, readonly, shared > 1, nbd_export_closed, writethrough, NULL, &error_fatal); -- cgit v1.2.3-55-g7522 From 9b562c646bc0ad5fca3cfa00720e431c7e72769a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:53 +0200 Subject: block/export: Remove magic from block-export-add nbd-server-add tries to be convenient and adds two questionable features that we don't want to share in block-export-add, even for NBD exports: 1. When requesting a writable export of a read-only device, the export is silently downgraded to read-only. This should be an error in the context of block-export-add. 2. When using a BlockBackend name, unplugging the device from the guest will automatically stop the NBD server, too. This may sometimes be what you want, but it could also be very surprising. Let's keep things explicit with block-export-add. If the user wants to stop the export, they should tell us so. Move these things into the nbd-server-add QMP command handler so that they apply only there. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-8-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 13 ++++++++++--- blockdev-nbd.c | 47 +++++++++++++++++++++++++++++++++++++++-------- include/block/export.h | 2 ++ include/block/nbd.h | 3 ++- nbd/server.c | 20 +++++++++++++------- qemu-nbd.c | 3 +-- 6 files changed, 67 insertions(+), 21 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index fd65541963..05bc5e3744 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -13,6 +13,8 @@ #include "qemu/osdep.h" +#include "block/block.h" +#include "sysemu/block-backend.h" #include "block/export.h" #include "block/nbd.h" #include "qapi/error.h" @@ -34,15 +36,20 @@ static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) return NULL; } -void qmp_block_export_add(BlockExportOptions *export, Error **errp) +BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) { const BlockExportDriver *drv; drv = blk_exp_find_driver(export->type); if (!drv) { error_setg(errp, "No driver found for the requested export type"); - return; + return NULL; } - drv->create(export, errp); + return drv->create(export, errp); +} + +void qmp_block_export_add(BlockExportOptions *export, Error **errp) +{ + blk_exp_add(export, errp); } diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 96cb0100e9..7bcca105f9 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -152,7 +152,6 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) { BlockExportOptionsNbd *arg = &exp_args->u.nbd; BlockDriverState *bs = NULL; - BlockBackend *on_eject_blk; NBDExport *exp = NULL; AioContext *aio_context; @@ -182,8 +181,6 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) return NULL; } - on_eject_blk = blk_by_name(arg->device); - bs = bdrv_lookup_bs(arg->device, arg->device, errp); if (!bs) { return NULL; @@ -195,13 +192,14 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) if (!arg->has_writable) { arg->writable = false; } - if (bdrv_is_read_only(bs)) { - arg->writable = false; + if (bdrv_is_read_only(bs) && arg->writable) { + error_setg(errp, "Cannot export read-only node as writable"); + goto out; } exp = nbd_export_new(bs, arg->name, arg->description, arg->bitmap, !arg->writable, !arg->writable, - NULL, false, on_eject_blk, errp); + NULL, false, errp); if (!exp) { goto out; } @@ -219,11 +217,44 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) void qmp_nbd_server_add(BlockExportOptionsNbd *arg, Error **errp) { - BlockExportOptions export = { + BlockExport *export; + BlockDriverState *bs; + BlockBackend *on_eject_blk; + BlockExportOptions export_opts; + + bs = bdrv_lookup_bs(arg->device, arg->device, errp); + if (!bs) { + return; + } + + export_opts = (BlockExportOptions) { .type = BLOCK_EXPORT_TYPE_NBD, .u.nbd = *arg, }; - qmp_block_export_add(&export, errp); + + /* + * nbd-server-add doesn't complain when a read-only device should be + * exported as writable, but simply downgrades it. This is an error with + * block-export-add. + */ + if (bdrv_is_read_only(bs)) { + export_opts.u.nbd.has_writable = true; + export_opts.u.nbd.writable = false; + } + + export = blk_exp_add(&export_opts, errp); + if (!export) { + return; + } + + /* + * nbd-server-add removes the export when the named BlockBackend used for + * @device goes away. + */ + on_eject_blk = blk_by_name(arg->device); + if (on_eject_blk) { + nbd_export_set_on_eject_blk(export, on_eject_blk); + } } void qmp_nbd_server_remove(const char *name, diff --git a/include/block/export.h b/include/block/export.h index 42e3c055fc..e7af2c7687 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -30,4 +30,6 @@ struct BlockExport { const BlockExportDriver *drv; }; +BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp); + #endif diff --git a/include/block/nbd.h b/include/block/nbd.h index 451f399b0a..f55f5b710b 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -335,7 +335,8 @@ NBDExport *nbd_export_new(BlockDriverState *bs, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, void (*close)(NBDExport *), bool writethrough, - BlockBackend *on_eject_blk, Error **errp); + Error **errp); +void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); void nbd_export_close(NBDExport *exp); void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); void nbd_export_get(NBDExport *exp); diff --git a/nbd/server.c b/nbd/server.c index 33aaca918c..23d9a53094 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1506,11 +1506,23 @@ static void nbd_eject_notifier(Notifier *n, void *data) aio_context_release(aio_context); } +void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) +{ + NBDExport *nbd_exp = container_of(exp, NBDExport, common); + assert(exp->drv == &blk_exp_nbd); + assert(nbd_exp->eject_notifier_blk == NULL); + + blk_ref(blk); + nbd_exp->eject_notifier_blk = blk; + nbd_exp->eject_notifier.notify = nbd_eject_notifier; + blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); +} + NBDExport *nbd_export_new(BlockDriverState *bs, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, void (*close)(NBDExport *), bool writethrough, - BlockBackend *on_eject_blk, Error **errp) + Error **errp) { AioContext *ctx; BlockBackend *blk; @@ -1617,12 +1629,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, exp->ctx = ctx; blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); - if (on_eject_blk) { - blk_ref(on_eject_blk); - exp->eject_notifier_blk = on_eject_blk; - exp->eject_notifier.notify = nbd_eject_notifier; - blk_add_remove_bs_notifier(on_eject_blk, &exp->eject_notifier); - } QTAILQ_INSERT_TAIL(&exports, exp, next); nbd_export_get(exp); return exp; diff --git a/qemu-nbd.c b/qemu-nbd.c index 16473d809c..b2a0ea6c5e 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -1067,8 +1067,7 @@ int main(int argc, char **argv) export = nbd_export_new(bs, export_name, export_description, bitmap, readonly, shared > 1, - nbd_export_closed, writethrough, NULL, - &error_fatal); + nbd_export_closed, writethrough, &error_fatal); if (device) { #if HAVE_NBD_DEVICE -- cgit v1.2.3-55-g7522 From 1c8222b014484145d66740d0597ae86b4a989b73 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:54 +0200 Subject: nbd: Add max-connections to nbd-server-start This is a QMP equivalent of qemu-nbd's --shared option, limiting the maximum number of clients that can attach at the same time. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Eric Blake Message-Id: <20200924152717.287415-9-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/monitor/block-hmp-cmds.c | 2 +- blockdev-nbd.c | 33 ++++++++++++++++++++++++++------- include/block/nbd.h | 3 ++- qapi/block-export.json | 10 ++++++++-- storage-daemon/qemu-storage-daemon.c | 4 ++-- 5 files changed, 39 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index fb632b1189..662b7f7d00 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -411,7 +411,7 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict) goto exit; } - nbd_server_start(addr, NULL, NULL, &local_err); + nbd_server_start(addr, NULL, NULL, 0, &local_err); qapi_free_SocketAddress(addr); if (local_err != NULL) { goto exit; diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 7bcca105f9..41d5542987 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -23,23 +23,41 @@ typedef struct NBDServerData { QIONetListener *listener; QCryptoTLSCreds *tlscreds; char *tlsauthz; + uint32_t max_connections; + uint32_t connections; } NBDServerData; static NBDServerData *nbd_server; +static void nbd_update_server_watch(NBDServerData *s); + static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) { nbd_client_put(client); + assert(nbd_server->connections > 0); + nbd_server->connections--; + nbd_update_server_watch(nbd_server); } static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, gpointer opaque) { + nbd_server->connections++; + nbd_update_server_watch(nbd_server); + qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server"); nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz, nbd_blockdev_client_closed); } +static void nbd_update_server_watch(NBDServerData *s) +{ + if (!s->max_connections || s->connections < s->max_connections) { + qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL); + } else { + qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL); + } +} static void nbd_server_free(NBDServerData *server) { @@ -88,7 +106,8 @@ static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp) + const char *tls_authz, uint32_t max_connections, + Error **errp) { if (nbd_server) { error_setg(errp, "NBD server already running"); @@ -96,6 +115,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, } nbd_server = g_new0(NBDServerData, 1); + nbd_server->max_connections = max_connections; nbd_server->listener = qio_net_listener_new(); qio_net_listener_set_name(nbd_server->listener, @@ -120,10 +140,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, nbd_server->tlsauthz = g_strdup(tls_authz); - qio_net_listener_set_client_func(nbd_server->listener, - nbd_accept, - NULL, - NULL); + nbd_update_server_watch(nbd_server); return; @@ -134,17 +151,19 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, void nbd_server_start_options(NbdServerOptions *arg, Error **errp) { - nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, errp); + nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, + arg->max_connections, errp); } void qmp_nbd_server_start(SocketAddressLegacy *addr, bool has_tls_creds, const char *tls_creds, bool has_tls_authz, const char *tls_authz, + bool has_max_connections, uint32_t max_connections, Error **errp) { SocketAddress *addr_flat = socket_address_flatten(addr); - nbd_server_start(addr_flat, tls_creds, tls_authz, errp); + nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp); qapi_free_SocketAddress(addr_flat); } diff --git a/include/block/nbd.h b/include/block/nbd.h index f55f5b710b..acccdb3180 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -354,7 +354,8 @@ void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp); + const char *tls_authz, uint32_t max_connections, + Error **errp); void nbd_server_start_options(NbdServerOptions *arg, Error **errp); /* nbd_read diff --git a/qapi/block-export.json b/qapi/block-export.json index 5890a94219..8aa8a01fa6 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -20,13 +20,16 @@ # is only resolved at time of use, so can be deleted and # recreated on the fly while the NBD server is active. # If missing, it will default to denying access (since 4.0). +# @max-connections: The maximum number of connections to allow at the same +# time, 0 for unlimited. (since 5.2; default: 0) # # Since: 4.2 ## { 'struct': 'NbdServerOptions', 'data': { 'addr': 'SocketAddress', '*tls-creds': 'str', - '*tls-authz': 'str'} } + '*tls-authz': 'str', + '*max-connections': 'uint32' } } ## # @nbd-server-start: @@ -46,6 +49,8 @@ # is only resolved at time of use, so can be deleted and # recreated on the fly while the NBD server is active. # If missing, it will default to denying access (since 4.0). +# @max-connections: The maximum number of connections to allow at the same +# time, 0 for unlimited. (since 5.2; default: 0) # # Returns: error if the server is already running. # @@ -54,7 +59,8 @@ { 'command': 'nbd-server-start', 'data': { 'addr': 'SocketAddressLegacy', '*tls-creds': 'str', - '*tls-authz': 'str'} } + '*tls-authz': 'str', + '*max-connections': 'uint32' } } ## # @BlockExportOptionsNbd: diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c index b6f678d3ab..0fcab6ed2d 100644 --- a/storage-daemon/qemu-storage-daemon.c +++ b/storage-daemon/qemu-storage-daemon.c @@ -101,9 +101,9 @@ static void help(void) " configure a QMP monitor\n" "\n" " --nbd-server addr.type=inet,addr.host=,addr.port=\n" -" [,tls-creds=][,tls-authz=]\n" +" [,tls-creds=][,tls-authz=][,max-connections=]\n" " --nbd-server addr.type=unix,addr.path=\n" -" [,tls-creds=][,tls-authz=]\n" +" [,tls-creds=][,tls-authz=][,max-connections=]\n" " start an NBD server for exporting block nodes\n" "\n" " --object help list object types that can be added\n" -- cgit v1.2.3-55-g7522 From d794f7f3728df0845be978a3c9aecead9d48c81d Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:56 +0200 Subject: nbd: Remove NBDExport.close callback The export close callback is unused by the built-in NBD server. qemu-nbd uses it only during shutdown to wait for the unrefed export to actually go away. It can just use nbd_export_close_all() instead and do without the callback. This removes the close callback from nbd_export_new() and makes both callers of it more similar. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Eric Blake Message-Id: <20200924152717.287415-11-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- blockdev-nbd.c | 2 +- include/block/nbd.h | 3 +-- nbd/server.c | 9 +-------- qemu-nbd.c | 14 ++++---------- 4 files changed, 7 insertions(+), 21 deletions(-) (limited to 'include') diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 09247a8ded..3a51b3e792 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -222,7 +222,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) exp = nbd_export_new(bs, arg->name, arg->description, arg->bitmap, !arg->writable, !arg->writable, - NULL, exp_args->writethrough, errp); + exp_args->writethrough, errp); if (!exp) { goto out; } diff --git a/include/block/nbd.h b/include/block/nbd.h index acccdb3180..9449b3dac4 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -334,8 +334,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp); NBDExport *nbd_export_new(BlockDriverState *bs, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, - void (*close)(NBDExport *), bool writethrough, - Error **errp); + bool writethrough, Error **errp); void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); void nbd_export_close(NBDExport *exp); void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); diff --git a/nbd/server.c b/nbd/server.c index 23d9a53094..1cc915f01d 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -84,7 +84,6 @@ struct NBDRequestData { struct NBDExport { BlockExport common; int refcount; - void (*close)(NBDExport *exp); BlockBackend *blk; char *name; @@ -1521,8 +1520,7 @@ void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) NBDExport *nbd_export_new(BlockDriverState *bs, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, - void (*close)(NBDExport *), bool writethrough, - Error **errp) + bool writethrough, Error **errp) { AioContext *ctx; BlockBackend *blk; @@ -1625,7 +1623,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, assert(strlen(exp->export_bitmap_context) < NBD_MAX_STRING_SIZE); } - exp->close = close; exp->ctx = ctx; blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); @@ -1723,10 +1720,6 @@ void nbd_export_put(NBDExport *exp) assert(exp->name == NULL); assert(exp->description == NULL); - if (exp->close) { - exp->close(exp); - } - if (exp->blk) { if (exp->eject_notifier_blk) { notifier_remove(&exp->eject_notifier); diff --git a/qemu-nbd.c b/qemu-nbd.c index b2a0ea6c5e..abbed8f87e 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -70,7 +70,7 @@ static int verbose; static char *srcpath; static SocketAddress *saddr; static int persistent = 0; -static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; +static enum { RUNNING, TERMINATE, TERMINATED } state; static int shared = 1; static int nb_fds; static QIONetListener *server; @@ -332,12 +332,6 @@ static int nbd_can_accept(void) return state == RUNNING && nb_fds < shared; } -static void nbd_export_closed(NBDExport *export) -{ - assert(state == TERMINATING); - state = TERMINATED; -} - static void nbd_update_server_watch(void); static void nbd_client_closed(NBDClient *client, bool negotiated) @@ -1067,7 +1061,7 @@ int main(int argc, char **argv) export = nbd_export_new(bs, export_name, export_description, bitmap, readonly, shared > 1, - nbd_export_closed, writethrough, &error_fatal); + writethrough, &error_fatal); if (device) { #if HAVE_NBD_DEVICE @@ -1107,10 +1101,10 @@ int main(int argc, char **argv) do { main_loop_wait(false); if (state == TERMINATE) { - state = TERMINATING; - nbd_export_close(export); nbd_export_put(export); + nbd_export_close_all(); export = NULL; + state = TERMINATED; } } while (state != TERMINATED); -- cgit v1.2.3-55-g7522 From 00917172a688892003605836454312364864e89d Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:57 +0200 Subject: qemu-nbd: Use blk_exp_add() to create the export With this change, NBD exports are now only created through the BlockExport interface. This allows us finally to move things from the NBD layer to the BlockExport layer if they make sense for other export types, too. blk_exp_add() returns only a weak reference, so the explicit nbd_export_put() goes away. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-12-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- blockdev-nbd.c | 8 +++++++- include/block/nbd.h | 1 + qemu-nbd.c | 28 ++++++++++++++++++++++------ 3 files changed, 30 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 3a51b3e792..7bb0b09697 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -28,9 +28,15 @@ typedef struct NBDServerData { } NBDServerData; static NBDServerData *nbd_server; +static bool is_qemu_nbd; static void nbd_update_server_watch(NBDServerData *s); +void nbd_server_is_qemu_nbd(bool value) +{ + is_qemu_nbd = value; +} + static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) { nbd_client_put(client); @@ -176,7 +182,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); - if (!nbd_server) { + if (!nbd_server && !is_qemu_nbd) { error_setg(errp, "NBD server not running"); return NULL; } diff --git a/include/block/nbd.h b/include/block/nbd.h index 9449b3dac4..1dafe70615 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -352,6 +352,7 @@ void nbd_client_new(QIOChannelSocket *sioc, void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); +void nbd_server_is_qemu_nbd(bool value); void nbd_server_start(SocketAddress *addr, const char *tls_creds, const char *tls_authz, uint32_t max_connections, Error **errp); diff --git a/qemu-nbd.c b/qemu-nbd.c index abbed8f87e..fc6e68a797 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -65,7 +65,6 @@ #define MBR_SIZE 512 -static NBDExport *export; static int verbose; static char *srcpath; static SocketAddress *saddr; @@ -580,6 +579,7 @@ int main(int argc, char **argv) int old_stderr = -1; unsigned socket_activation; const char *pid_file_name = NULL; + BlockExportOptions *export_opts; #if HAVE_NBD_DEVICE /* The client thread uses SIGTERM to interrupt the server. A signal @@ -1059,9 +1059,27 @@ int main(int argc, char **argv) bs->detect_zeroes = detect_zeroes; - export = nbd_export_new(bs, export_name, - export_description, bitmap, readonly, shared > 1, - writethrough, &error_fatal); + nbd_server_is_qemu_nbd(true); + + export_opts = g_new(BlockExportOptions, 1); + *export_opts = (BlockExportOptions) { + .type = BLOCK_EXPORT_TYPE_NBD, + .has_writethrough = true, + .writethrough = writethrough, + .u.nbd = { + .device = g_strdup(bdrv_get_node_name(bs)), + .has_name = true, + .name = g_strdup(export_name), + .has_description = !!export_description, + .description = g_strdup(export_description), + .has_writable = true, + .writable = !readonly, + .has_bitmap = !!bitmap, + .bitmap = g_strdup(bitmap), + }, + }; + blk_exp_add(export_opts, &error_fatal); + qapi_free_BlockExportOptions(export_opts); if (device) { #if HAVE_NBD_DEVICE @@ -1101,9 +1119,7 @@ int main(int argc, char **argv) do { main_loop_wait(false); if (state == TERMINATE) { - nbd_export_put(export); nbd_export_close_all(); - export = NULL; state = TERMINATED; } } while (state != TERMINATED); -- cgit v1.2.3-55-g7522 From c69de1bef59ba0d824cd9d5e9da602cb23c29e4b Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:26:59 +0200 Subject: block/export: Move refcount from NBDExport to BlockExport Having a refcount makes sense for all types of block exports. It is also a prerequisite for keeping a list of all exports at the BlockExport level. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-14-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 14 ++++++++++ blockdev-nbd.c | 2 +- include/block/export.h | 15 +++++++++++ include/block/nbd.h | 2 -- nbd/server.c | 72 +++++++++++++++++++++++--------------------------- 5 files changed, 63 insertions(+), 42 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index 05bc5e3744..baba4e94ff 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -49,6 +49,20 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return drv->create(export, errp); } +void blk_exp_ref(BlockExport *exp) +{ + assert(exp->refcount > 0); + exp->refcount++; +} + +void blk_exp_unref(BlockExport *exp) +{ + assert(exp->refcount > 0); + if (--exp->refcount == 0) { + exp->drv->delete(exp); + } +} + void qmp_block_export_add(BlockExportOptions *export, Error **errp) { blk_exp_add(export, errp); diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 7bb0b09697..e208324d42 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -236,7 +236,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) /* The list of named exports has a strong reference to this export now and * our only way of accessing it is through nbd_export_find(), so we can drop * the strong reference that is @exp. */ - nbd_export_put(exp); + blk_exp_unref((BlockExport*) exp); out: aio_context_release(aio_context); diff --git a/include/block/export.h b/include/block/export.h index e7af2c7687..5236a35e12 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -24,12 +24,27 @@ typedef struct BlockExportDriver { /* Creates and starts a new block export */ BlockExport *(*create)(BlockExportOptions *, Error **); + + /* + * Frees a removed block export. This function is only called after all + * references have been dropped. + */ + void (*delete)(BlockExport *); } BlockExportDriver; struct BlockExport { const BlockExportDriver *drv; + + /* + * Reference count for this block export. This includes strong references + * both from the owner (qemu-nbd or the monitor) and clients connected to + * the export. + */ + int refcount; }; BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp); +void blk_exp_ref(BlockExport *exp); +void blk_exp_unref(BlockExport *exp); #endif diff --git a/include/block/nbd.h b/include/block/nbd.h index 1dafe70615..e3bd112227 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -338,8 +338,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); void nbd_export_close(NBDExport *exp); void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); -void nbd_export_get(NBDExport *exp); -void nbd_export_put(NBDExport *exp); AioContext *nbd_export_aio_context(NBDExport *exp); NBDExport *nbd_export_find(const char *name); diff --git a/nbd/server.c b/nbd/server.c index fb70374df5..7be81c7bda 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -83,7 +83,6 @@ struct NBDRequestData { struct NBDExport { BlockExport common; - int refcount; BlockBackend *blk; char *name; @@ -499,7 +498,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes, } QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); - nbd_export_get(client->exp); + blk_exp_ref(&client->exp->common); nbd_check_meta_export(client); return 0; @@ -707,7 +706,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, Error **errp) client->exp = exp; client->check_align = check_align; QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); - nbd_export_get(client->exp); + blk_exp_ref(&client->exp->common); nbd_check_meta_export(client); rc = 1; } @@ -1406,7 +1405,7 @@ void nbd_client_put(NBDClient *client) g_free(client->tlsauthz); if (client->exp) { QTAILQ_REMOVE(&client->exp->clients, client, next); - nbd_export_put(client->exp); + blk_exp_unref(&client->exp->common); } g_free(client); } @@ -1538,7 +1537,8 @@ NBDExport *nbd_export_new(BlockDriverState *bs, exp = g_new0(NBDExport, 1); exp->common = (BlockExport) { - .drv = &blk_exp_nbd, + .drv = &blk_exp_nbd, + .refcount = 1, }; /* @@ -1567,7 +1567,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, blk_set_enable_write_cache(blk, !writethrough); blk_set_allow_aio_context_change(blk, true); - exp->refcount = 1; QTAILQ_INIT(&exp->clients); exp->blk = blk; exp->name = g_strdup(name); @@ -1626,8 +1625,9 @@ NBDExport *nbd_export_new(BlockDriverState *bs, exp->ctx = ctx; blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); + blk_exp_ref(&exp->common); QTAILQ_INSERT_TAIL(&exports, exp, next); - nbd_export_get(exp); + return exp; fail: @@ -1660,7 +1660,7 @@ void nbd_export_close(NBDExport *exp) { NBDClient *client, *next; - nbd_export_get(exp); + blk_exp_ref(&exp->common); /* * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a * close mode that stops advertising the export to new clients but @@ -1672,13 +1672,13 @@ void nbd_export_close(NBDExport *exp) client_close(client, true); } if (exp->name) { - nbd_export_put(exp); + blk_exp_unref(&exp->common); g_free(exp->name); exp->name = NULL; QTAILQ_REMOVE(&exports, exp, next); QTAILQ_INSERT_TAIL(&closed_exports, exp, next); } - nbd_export_put(exp); + blk_exp_unref(&exp->common); } void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp) @@ -1695,47 +1695,41 @@ void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp) error_append_hint(errp, "Use mode='hard' to force client disconnect\n"); } -void nbd_export_get(NBDExport *exp) -{ - assert(exp->refcount > 0); - exp->refcount++; -} - -void nbd_export_put(NBDExport *exp) +static void nbd_export_delete(BlockExport *blk_exp) { - assert(exp->refcount > 0); - if (--exp->refcount == 0) { - assert(exp->name == NULL); - assert(QTAILQ_EMPTY(&exp->clients)); + NBDExport *exp = container_of(blk_exp, NBDExport, common); - g_free(exp->description); - exp->description = NULL; + assert(exp->name == NULL); + assert(QTAILQ_EMPTY(&exp->clients)); - if (exp->blk) { - if (exp->eject_notifier_blk) { - notifier_remove(&exp->eject_notifier); - blk_unref(exp->eject_notifier_blk); - } - blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, - blk_aio_detach, exp); - blk_unref(exp->blk); - exp->blk = NULL; - } + g_free(exp->description); + exp->description = NULL; - if (exp->export_bitmap) { - bdrv_dirty_bitmap_set_busy(exp->export_bitmap, false); - g_free(exp->export_bitmap_context); + if (exp->blk) { + if (exp->eject_notifier_blk) { + notifier_remove(&exp->eject_notifier); + blk_unref(exp->eject_notifier_blk); } + blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, + blk_aio_detach, exp); + blk_unref(exp->blk); + exp->blk = NULL; + } - QTAILQ_REMOVE(&closed_exports, exp, next); - g_free(exp); - aio_wait_kick(); + if (exp->export_bitmap) { + bdrv_dirty_bitmap_set_busy(exp->export_bitmap, false); + g_free(exp->export_bitmap_context); } + + QTAILQ_REMOVE(&closed_exports, exp, next); + g_free(exp); + aio_wait_kick(); } const BlockExportDriver blk_exp_nbd = { .type = BLOCK_EXPORT_TYPE_NBD, .create = nbd_export_create, + .delete = nbd_export_delete, }; void nbd_export_close_all(void) -- cgit v1.2.3-55-g7522 From 8612c6867341e52416e63fce8b19ede8501c159a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:00 +0200 Subject: block/export: Move AioContext from NBDExport to BlockExport Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-15-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 2 ++ include/block/export.h | 3 +++ nbd/server.c | 26 +++++++++++++------------- 3 files changed, 18 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index baba4e94ff..8635318ef1 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -49,12 +49,14 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return drv->create(export, errp); } +/* Callers must hold exp->ctx lock */ void blk_exp_ref(BlockExport *exp) { assert(exp->refcount > 0); exp->refcount++; } +/* Callers must hold exp->ctx lock */ void blk_exp_unref(BlockExport *exp) { assert(exp->refcount > 0); diff --git a/include/block/export.h b/include/block/export.h index 5236a35e12..e6f96f4e1e 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -41,6 +41,9 @@ struct BlockExport { * the export. */ int refcount; + + /* The AioContext whose lock protects this BlockExport object. */ + AioContext *ctx; }; BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp); diff --git a/nbd/server.c b/nbd/server.c index 7be81c7bda..7cf81646fc 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -92,8 +92,6 @@ struct NBDExport { QTAILQ_HEAD(, NBDClient) clients; QTAILQ_ENTRY(NBDExport) next; - AioContext *ctx; - BlockBackend *eject_notifier_blk; Notifier eject_notifier; @@ -1333,8 +1331,8 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) } /* Attach the channel to the same AioContext as the export */ - if (client->exp && client->exp->ctx) { - qio_channel_attach_aio_context(client->ioc, client->exp->ctx); + if (client->exp && client->exp->common.ctx) { + qio_channel_attach_aio_context(client->ioc, client->exp->common.ctx); } assert(!client->optlen); @@ -1466,7 +1464,7 @@ static void blk_aio_attached(AioContext *ctx, void *opaque) trace_nbd_blk_aio_attached(exp->name, ctx); - exp->ctx = ctx; + exp->common.ctx = ctx; QTAILQ_FOREACH(client, &exp->clients, next) { qio_channel_attach_aio_context(client->ioc, ctx); @@ -1484,13 +1482,13 @@ static void blk_aio_detach(void *opaque) NBDExport *exp = opaque; NBDClient *client; - trace_nbd_blk_aio_detach(exp->name, exp->ctx); + trace_nbd_blk_aio_detach(exp->name, exp->common.ctx); QTAILQ_FOREACH(client, &exp->clients, next) { qio_channel_detach_aio_context(client->ioc); } - exp->ctx = NULL; + exp->common.ctx = NULL; } static void nbd_eject_notifier(Notifier *n, void *data) @@ -1498,7 +1496,7 @@ static void nbd_eject_notifier(Notifier *n, void *data) NBDExport *exp = container_of(n, NBDExport, eject_notifier); AioContext *aio_context; - aio_context = exp->ctx; + aio_context = exp->common.ctx; aio_context_acquire(aio_context); nbd_export_close(exp); aio_context_release(aio_context); @@ -1535,10 +1533,13 @@ NBDExport *nbd_export_new(BlockDriverState *bs, return NULL; } + ctx = bdrv_get_aio_context(bs); + exp = g_new0(NBDExport, 1); exp->common = (BlockExport) { .drv = &blk_exp_nbd, .refcount = 1, + .ctx = ctx, }; /* @@ -1548,7 +1549,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, * ctx was acquired in the caller. */ assert(name && strlen(name) <= NBD_MAX_STRING_SIZE); - ctx = bdrv_get_aio_context(bs); + bdrv_invalidate_cache(bs, NULL); /* Don't allow resize while the NBD server is running, otherwise we don't @@ -1622,7 +1623,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, assert(strlen(exp->export_bitmap_context) < NBD_MAX_STRING_SIZE); } - exp->ctx = ctx; blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); blk_exp_ref(&exp->common); @@ -1653,7 +1653,7 @@ NBDExport *nbd_export_find(const char *name) AioContext * nbd_export_aio_context(NBDExport *exp) { - return exp->ctx; + return exp->common.ctx; } void nbd_export_close(NBDExport *exp) @@ -1738,7 +1738,7 @@ void nbd_export_close_all(void) AioContext *aio_context; QTAILQ_FOREACH_SAFE(exp, &exports, next, next) { - aio_context = exp->ctx; + aio_context = exp->common.ctx; aio_context_acquire(aio_context); nbd_export_close(exp); aio_context_release(aio_context); @@ -2537,7 +2537,7 @@ static void nbd_client_receive_next_request(NBDClient *client) if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS) { nbd_client_get(client); client->recv_coroutine = qemu_coroutine_create(nbd_trip, client); - aio_co_schedule(client->exp->ctx, client->recv_coroutine); + aio_co_schedule(client->exp->common.ctx, client->recv_coroutine); } } -- cgit v1.2.3-55-g7522 From a6ff7989662d659aed0888670e77e68cb8c9bd81 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:02 +0200 Subject: block/export: Allocate BlockExport in blk_exp_add() Instead of letting the driver allocate and return the BlockExport object, allocate it already in blk_exp_add() and pass it. This allows us to initialise the generic part before calling into the driver so that the driver can just use these values instead of having to parse the options a second time. For symmetry, move freeing the BlockExport to blk_exp_unref(). Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-17-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 18 +++++++++++++++++- blockdev-nbd.c | 26 ++++++++++++++------------ include/block/export.h | 8 +++++++- include/block/nbd.h | 11 ++++++----- nbd/server.c | 30 +++++++++++++----------------- 5 files changed, 57 insertions(+), 36 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index 8635318ef1..6b2b29078b 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -39,6 +39,8 @@ static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) { const BlockExportDriver *drv; + BlockExport *exp; + int ret; drv = blk_exp_find_driver(export->type); if (!drv) { @@ -46,7 +48,20 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return NULL; } - return drv->create(export, errp); + assert(drv->instance_size >= sizeof(BlockExport)); + exp = g_malloc0(drv->instance_size); + *exp = (BlockExport) { + .drv = drv, + .refcount = 1, + }; + + ret = drv->create(exp, export, errp); + if (ret < 0) { + g_free(exp); + return NULL; + } + + return exp; } /* Callers must hold exp->ctx lock */ @@ -62,6 +77,7 @@ void blk_exp_unref(BlockExport *exp) assert(exp->refcount > 0); if (--exp->refcount == 0) { exp->drv->delete(exp); + g_free(exp); } } diff --git a/blockdev-nbd.c b/blockdev-nbd.c index ef14303b25..b34f159888 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -173,18 +173,19 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr, qapi_free_SocketAddress(addr_flat); } -BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) +int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, + Error **errp) { BlockExportOptionsNbd *arg = &exp_args->u.nbd; BlockDriverState *bs = NULL; - NBDExport *exp = NULL; AioContext *aio_context; + int ret; assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); if (!nbd_server && !is_qemu_nbd) { error_setg(errp, "NBD server not running"); - return NULL; + return -EINVAL; } if (!arg->has_name) { @@ -193,22 +194,22 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) if (strlen(arg->name) > NBD_MAX_STRING_SIZE) { error_setg(errp, "export name '%s' too long", arg->name); - return NULL; + return -EINVAL; } if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { error_setg(errp, "description '%s' too long", arg->description); - return NULL; + return -EINVAL; } if (nbd_export_find(arg->name)) { error_setg(errp, "NBD server already has export named '%s'", arg->name); - return NULL; + return -EEXIST; } bs = bdrv_lookup_bs(NULL, exp_args->node_name, errp); if (!bs) { - return NULL; + return -ENOENT; } aio_context = bdrv_get_aio_context(bs); @@ -218,6 +219,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) arg->writable = false; } if (bdrv_is_read_only(bs) && arg->writable) { + ret = -EINVAL; error_setg(errp, "Cannot export read-only node as writable"); goto out; } @@ -226,22 +228,22 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp) exp_args->writethrough = false; } - exp = nbd_export_new(bs, arg->name, arg->description, arg->bitmap, + ret = nbd_export_new(exp, bs, arg->name, arg->description, arg->bitmap, !arg->writable, !arg->writable, exp_args->writethrough, errp); - if (!exp) { + if (ret < 0) { goto out; } /* The list of named exports has a strong reference to this export now and * our only way of accessing it is through nbd_export_find(), so we can drop * the strong reference that is @exp. */ - blk_exp_unref((BlockExport*) exp); + blk_exp_unref(exp); + ret = 0; out: aio_context_release(aio_context); - /* TODO Remove the cast: nbd_export_new() will return a BlockExport. */ - return (BlockExport*) exp; + return ret; } void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) diff --git a/include/block/export.h b/include/block/export.h index e6f96f4e1e..cf9b1c9dad 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -22,8 +22,14 @@ typedef struct BlockExportDriver { /* The export type that this driver services */ BlockExportType type; + /* + * The size of the driver-specific state that contains BlockExport as its + * first field. + */ + size_t instance_size; + /* Creates and starts a new block export */ - BlockExport *(*create)(BlockExportOptions *, Error **); + int (*create)(BlockExport *, BlockExportOptions *, Error **); /* * Frees a removed block export. This function is only called after all diff --git a/include/block/nbd.h b/include/block/nbd.h index e3bd112227..fc2c153d5b 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -330,11 +330,12 @@ int nbd_errno_to_system_errno(int err); typedef struct NBDExport NBDExport; typedef struct NBDClient NBDClient; -BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp); -NBDExport *nbd_export_new(BlockDriverState *bs, - const char *name, const char *desc, - const char *bitmap, bool readonly, bool shared, - bool writethrough, Error **errp); +int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, + Error **errp); +int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, + const char *name, const char *desc, + const char *bitmap, bool readonly, bool shared, + bool writethrough, Error **errp); void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); void nbd_export_close(NBDExport *exp); void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); diff --git a/nbd/server.c b/nbd/server.c index 7cf81646fc..f31d8bbb60 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1514,14 +1514,14 @@ void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); } -NBDExport *nbd_export_new(BlockDriverState *bs, - const char *name, const char *desc, - const char *bitmap, bool readonly, bool shared, - bool writethrough, Error **errp) +int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, + const char *name, const char *desc, + const char *bitmap, bool readonly, bool shared, + bool writethrough, Error **errp) { + NBDExport *exp = container_of(blk_exp, NBDExport, common); AioContext *ctx; BlockBackend *blk; - NBDExport *exp; int64_t size; uint64_t perm; int ret; @@ -1530,17 +1530,11 @@ NBDExport *nbd_export_new(BlockDriverState *bs, if (size < 0) { error_setg_errno(errp, -size, "Failed to determine the NBD export's length"); - return NULL; + return size; } ctx = bdrv_get_aio_context(bs); - - exp = g_new0(NBDExport, 1); - exp->common = (BlockExport) { - .drv = &blk_exp_nbd, - .refcount = 1, - .ctx = ctx, - }; + blk_exp->ctx = ctx; /* * NBD exports are used for non-shared storage migration. Make sure @@ -1599,16 +1593,19 @@ NBDExport *nbd_export_new(BlockDriverState *bs, } if (bm == NULL) { + ret = -ENOENT; error_setg(errp, "Bitmap '%s' is not found", bitmap); goto fail; } if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) { + ret = -EINVAL; goto fail; } if (readonly && bdrv_is_writable(bs) && bdrv_dirty_bitmap_enabled(bm)) { + ret = -EINVAL; error_setg(errp, "Enabled bitmap '%s' incompatible with readonly export", bitmap); @@ -1628,14 +1625,13 @@ NBDExport *nbd_export_new(BlockDriverState *bs, blk_exp_ref(&exp->common); QTAILQ_INSERT_TAIL(&exports, exp, next); - return exp; + return 0; fail: blk_unref(blk); g_free(exp->name); g_free(exp->description); - g_free(exp); - return NULL; + return ret; } NBDExport *nbd_export_find(const char *name) @@ -1722,12 +1718,12 @@ static void nbd_export_delete(BlockExport *blk_exp) } QTAILQ_REMOVE(&closed_exports, exp, next); - g_free(exp); aio_wait_kick(); } const BlockExportDriver blk_exp_nbd = { .type = BLOCK_EXPORT_TYPE_NBD, + .instance_size = sizeof(NBDExport), .create = nbd_export_create, .delete = nbd_export_delete, }; -- cgit v1.2.3-55-g7522 From bc4ee65b8c309ed6a726e3ea1b73f7fa31b4bb95 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:03 +0200 Subject: block/export: Add blk_exp_close_all(_type) This adds a function to shut down all block exports, and another one to shut down the block exports of a single type. The latter is used for now when stopping the NBD server. As soon as we implement support for multiple NBD servers, we'll need a per-server list of exports and it will be replaced by a function using that. As a side effect, the BlockExport layer has a list tracking all existing exports now. closed_exports loses its only user and can go away. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-18-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block.c | 2 +- block/export/export.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++-- blockdev-nbd.c | 2 +- include/block/export.h | 15 +++++++++ include/block/nbd.h | 2 -- nbd/server.c | 34 +++----------------- qemu-nbd.c | 2 +- 7 files changed, 107 insertions(+), 36 deletions(-) (limited to 'include') diff --git a/block.c b/block.c index f72a2e26e8..f4b6dd5d3d 100644 --- a/block.c +++ b/block.c @@ -4462,7 +4462,7 @@ static void bdrv_close(BlockDriverState *bs) void bdrv_close_all(void) { assert(job_next(NULL) == NULL); - nbd_export_close_all(); + blk_exp_close_all(); /* Drop references from requests still in flight, such as canceled block * jobs whose AIO context has not been polled yet */ diff --git a/block/export/export.c b/block/export/export.c index 6b2b29078b..e94a68c183 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -24,6 +24,10 @@ static const BlockExportDriver *blk_exp_drivers[] = { &blk_exp_nbd, }; +/* Only accessed from the main thread */ +static QLIST_HEAD(, BlockExport) block_exports = + QLIST_HEAD_INITIALIZER(block_exports); + static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) { int i; @@ -61,6 +65,7 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return NULL; } + QLIST_INSERT_HEAD(&block_exports, exp, next); return exp; } @@ -71,14 +76,91 @@ void blk_exp_ref(BlockExport *exp) exp->refcount++; } +/* Runs in the main thread */ +static void blk_exp_delete_bh(void *opaque) +{ + BlockExport *exp = opaque; + AioContext *aio_context = exp->ctx; + + aio_context_acquire(aio_context); + + assert(exp->refcount == 0); + QLIST_REMOVE(exp, next); + exp->drv->delete(exp); + g_free(exp); + + aio_context_release(aio_context); +} + /* Callers must hold exp->ctx lock */ void blk_exp_unref(BlockExport *exp) { assert(exp->refcount > 0); if (--exp->refcount == 0) { - exp->drv->delete(exp); - g_free(exp); + /* Touch the block_exports list only in the main thread */ + aio_bh_schedule_oneshot(qemu_get_aio_context(), blk_exp_delete_bh, + exp); + } +} + +/* + * Drops the user reference to the export and requests that all client + * connections and other internally held references start to shut down. When + * the function returns, there may still be active references while the export + * is in the process of shutting down. + * + * Acquires exp->ctx internally. Callers must *not* hold the lock. + */ +void blk_exp_request_shutdown(BlockExport *exp) +{ + AioContext *aio_context = exp->ctx; + + aio_context_acquire(aio_context); + exp->drv->request_shutdown(exp); + aio_context_release(aio_context); +} + +/* + * Returns whether a block export of the given type exists. + * type == BLOCK_EXPORT_TYPE__MAX checks for an export of any type. + */ +static bool blk_exp_has_type(BlockExportType type) +{ + BlockExport *exp; + + if (type == BLOCK_EXPORT_TYPE__MAX) { + return !QLIST_EMPTY(&block_exports); + } + + QLIST_FOREACH(exp, &block_exports, next) { + if (exp->drv->type == type) { + return true; + } } + + return false; +} + +/* type == BLOCK_EXPORT_TYPE__MAX for all types */ +void blk_exp_close_all_type(BlockExportType type) +{ + BlockExport *exp, *next; + + assert(in_aio_context_home_thread(qemu_get_aio_context())); + + QLIST_FOREACH_SAFE(exp, &block_exports, next, next) { + if (type != BLOCK_EXPORT_TYPE__MAX && exp->drv->type != type) { + continue; + } + blk_exp_request_shutdown(exp); + } + + AIO_WAIT_WHILE(NULL, blk_exp_has_type(type)); +} + +void blk_exp_close_all(void) +{ + blk_exp_close_all_type(BLOCK_EXPORT_TYPE__MAX); } void qmp_block_export_add(BlockExportOptions *export, Error **errp) diff --git a/blockdev-nbd.c b/blockdev-nbd.c index b34f159888..f927264777 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -345,7 +345,7 @@ void qmp_nbd_server_stop(Error **errp) return; } - nbd_export_close_all(); + blk_exp_close_all_type(BLOCK_EXPORT_TYPE_NBD); nbd_server_free(nbd_server); nbd_server = NULL; diff --git a/include/block/export.h b/include/block/export.h index cf9b1c9dad..6fffcb5651 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -15,6 +15,7 @@ #define BLOCK_EXPORT_H #include "qapi/qapi-types-block-export.h" +#include "qemu/queue.h" typedef struct BlockExport BlockExport; @@ -36,6 +37,14 @@ typedef struct BlockExportDriver { * references have been dropped. */ void (*delete)(BlockExport *); + + /* + * Start to disconnect all clients and drop other references held + * internally by the export driver. When the function returns, there may + * still be active references while the export is in the process of + * shutting down. + */ + void (*request_shutdown)(BlockExport *); } BlockExportDriver; struct BlockExport { @@ -50,10 +59,16 @@ struct BlockExport { /* The AioContext whose lock protects this BlockExport object. */ AioContext *ctx; + + /* List entry for block_exports */ + QLIST_ENTRY(BlockExport) next; }; BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp); void blk_exp_ref(BlockExport *exp); void blk_exp_unref(BlockExport *exp); +void blk_exp_request_shutdown(BlockExport *exp); +void blk_exp_close_all(void); +void blk_exp_close_all_type(BlockExportType type); #endif diff --git a/include/block/nbd.h b/include/block/nbd.h index fc2c153d5b..0b9f3e5d4e 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -337,12 +337,10 @@ int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, const char *bitmap, bool readonly, bool shared, bool writethrough, Error **errp); void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); -void nbd_export_close(NBDExport *exp); void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); AioContext *nbd_export_aio_context(NBDExport *exp); NBDExport *nbd_export_find(const char *name); -void nbd_export_close_all(void); void nbd_client_new(QIOChannelSocket *sioc, QCryptoTLSCreds *tlscreds, diff --git a/nbd/server.c b/nbd/server.c index f31d8bbb60..32147e4871 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -100,8 +100,6 @@ struct NBDExport { }; static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports); -static QTAILQ_HEAD(, NBDExport) closed_exports = - QTAILQ_HEAD_INITIALIZER(closed_exports); /* NBDExportMetaContexts represents a list of contexts to be exported, * as selected by NBD_OPT_SET_META_CONTEXT. Also used for @@ -1494,12 +1492,8 @@ static void blk_aio_detach(void *opaque) static void nbd_eject_notifier(Notifier *n, void *data) { NBDExport *exp = container_of(n, NBDExport, eject_notifier); - AioContext *aio_context; - aio_context = exp->common.ctx; - aio_context_acquire(aio_context); - nbd_export_close(exp); - aio_context_release(aio_context); + blk_exp_request_shutdown(&exp->common); } void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) @@ -1652,8 +1646,9 @@ nbd_export_aio_context(NBDExport *exp) return exp->common.ctx; } -void nbd_export_close(NBDExport *exp) +static void nbd_export_request_shutdown(BlockExport *blk_exp) { + NBDExport *exp = container_of(blk_exp, NBDExport, common); NBDClient *client, *next; blk_exp_ref(&exp->common); @@ -1672,7 +1667,6 @@ void nbd_export_close(NBDExport *exp) g_free(exp->name); exp->name = NULL; QTAILQ_REMOVE(&exports, exp, next); - QTAILQ_INSERT_TAIL(&closed_exports, exp, next); } blk_exp_unref(&exp->common); } @@ -1681,7 +1675,7 @@ void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp) { ERRP_GUARD(); if (mode == NBD_SERVER_REMOVE_MODE_HARD || QTAILQ_EMPTY(&exp->clients)) { - nbd_export_close(exp); + nbd_export_request_shutdown(&exp->common); return; } @@ -1716,9 +1710,6 @@ static void nbd_export_delete(BlockExport *blk_exp) bdrv_dirty_bitmap_set_busy(exp->export_bitmap, false); g_free(exp->export_bitmap_context); } - - QTAILQ_REMOVE(&closed_exports, exp, next); - aio_wait_kick(); } const BlockExportDriver blk_exp_nbd = { @@ -1726,24 +1717,9 @@ const BlockExportDriver blk_exp_nbd = { .instance_size = sizeof(NBDExport), .create = nbd_export_create, .delete = nbd_export_delete, + .request_shutdown = nbd_export_request_shutdown, }; -void nbd_export_close_all(void) -{ - NBDExport *exp, *next; - AioContext *aio_context; - - QTAILQ_FOREACH_SAFE(exp, &exports, next, next) { - aio_context = exp->common.ctx; - aio_context_acquire(aio_context); - nbd_export_close(exp); - aio_context_release(aio_context); - } - - AIO_WAIT_WHILE(NULL, !(QTAILQ_EMPTY(&exports) && - QTAILQ_EMPTY(&closed_exports))); -} - static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov, unsigned niov, Error **errp) { diff --git a/qemu-nbd.c b/qemu-nbd.c index fe0d1928c3..cfa5b78b1a 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -1119,7 +1119,7 @@ int main(int argc, char **argv) do { main_loop_wait(false); if (state == TERMINATE) { - nbd_export_close_all(); + blk_exp_close_all(); state = TERMINATED; } } while (state != TERMINATED); -- cgit v1.2.3-55-g7522 From d53be9ce55a38e430b88985f637f696bf99cbf0b Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:04 +0200 Subject: block/export: Add 'id' option to block-export-add We'll need an id to identify block exports in monitor commands. This adds one. Note that this is different from the 'name' option in the NBD server, which is the externally visible export name. While block export ids need to be unique in the whole process, export names must be unique only for the same server. Different export types or (potentially in the future) multiple NBD servers can have the same export name externally, but still need different block export ids internally. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-19-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 26 ++++++++++++++++++++++++++ blockdev-nbd.c | 1 + include/block/export.h | 3 +++ qapi/block-export.json | 5 +++++ qemu-nbd.c | 1 + storage-daemon/qemu-storage-daemon.c | 2 +- tests/qemu-iotests/223.out | 4 ++-- 7 files changed, 39 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index e94a68c183..7a4a78449a 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -19,6 +19,7 @@ #include "block/nbd.h" #include "qapi/error.h" #include "qapi/qapi-commands-block-export.h" +#include "qemu/id.h" static const BlockExportDriver *blk_exp_drivers[] = { &blk_exp_nbd, @@ -28,6 +29,19 @@ static const BlockExportDriver *blk_exp_drivers[] = { static QLIST_HEAD(, BlockExport) block_exports = QLIST_HEAD_INITIALIZER(block_exports); +static BlockExport *blk_exp_find(const char *id) +{ + BlockExport *exp; + + QLIST_FOREACH(exp, &block_exports, next) { + if (strcmp(id, exp->id) == 0) { + return exp; + } + } + + return NULL; +} + static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) { int i; @@ -46,6 +60,15 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) BlockExport *exp; int ret; + if (!id_wellformed(export->id)) { + error_setg(errp, "Invalid block export id"); + return NULL; + } + if (blk_exp_find(export->id)) { + error_setg(errp, "Block export id '%s' is already in use", export->id); + return NULL; + } + drv = blk_exp_find_driver(export->type); if (!drv) { error_setg(errp, "No driver found for the requested export type"); @@ -57,10 +80,12 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) *exp = (BlockExport) { .drv = drv, .refcount = 1, + .id = g_strdup(export->id), }; ret = drv->create(exp, export, errp); if (ret < 0) { + g_free(exp->id); g_free(exp); return NULL; } @@ -87,6 +112,7 @@ static void blk_exp_delete_bh(void *opaque) assert(exp->refcount == 0); QLIST_REMOVE(exp, next); exp->drv->delete(exp); + g_free(exp->id); g_free(exp); aio_context_release(aio_context); diff --git a/blockdev-nbd.c b/blockdev-nbd.c index f927264777..814554dd90 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -269,6 +269,7 @@ void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) export_opts = g_new(BlockExportOptions, 1); *export_opts = (BlockExportOptions) { .type = BLOCK_EXPORT_TYPE_NBD, + .id = g_strdup(arg->name), .node_name = g_strdup(bdrv_get_node_name(bs)), .u.nbd = { .has_name = true, diff --git a/include/block/export.h b/include/block/export.h index 6fffcb5651..cdc6e161ea 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -50,6 +50,9 @@ typedef struct BlockExportDriver { struct BlockExport { const BlockExportDriver *drv; + /* Unique identifier for the export */ + char *id; + /* * Reference count for this block export. This includes strong references * both from the owner (qemu-nbd or the monitor) and clients connected to diff --git a/qapi/block-export.json b/qapi/block-export.json index 1091c97f6f..658bdf05e1 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -105,6 +105,8 @@ # # Export a block node to QEMU's embedded NBD server. # +# The export name will be used as the id for the resulting block export. +# # Returns: error if the server is not running, or export with the same name # already exists. # @@ -182,6 +184,8 @@ # Describes a block export, i.e. how single node should be exported on an # external interface. # +# @id: A unique identifier for the block export (across all export types) +# # @node-name: The node name of the block node to be exported (since: 5.2) # # @writethrough: If true, caches are flushed after every write request to the @@ -192,6 +196,7 @@ ## { 'union': 'BlockExportOptions', 'base': { 'type': 'BlockExportType', + 'id': 'str', 'node-name': 'str', '*writethrough': 'bool' }, 'discriminator': 'type', diff --git a/qemu-nbd.c b/qemu-nbd.c index cfa5b78b1a..66cb8f91b1 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -1064,6 +1064,7 @@ int main(int argc, char **argv) export_opts = g_new(BlockExportOptions, 1); *export_opts = (BlockExportOptions) { .type = BLOCK_EXPORT_TYPE_NBD, + .id = g_strdup("qemu-nbd-export"), .node_name = g_strdup(bdrv_get_node_name(bs)), .has_writethrough = true, .writethrough = writethrough, diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c index 0fcab6ed2d..e6157ff518 100644 --- a/storage-daemon/qemu-storage-daemon.c +++ b/storage-daemon/qemu-storage-daemon.c @@ -92,7 +92,7 @@ static void help(void) " --chardev configure a character device backend\n" " (see the qemu(1) man page for possible options)\n" "\n" -" --export [type=]nbd,device=[,name=]\n" +" --export [type=]nbd,device=,id=,[,name=]\n" " [,writable=on|off][,bitmap=]\n" " export the specified block node over NBD\n" " (requires --nbd-server)\n" diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out index e1eaaedb55..31ce9e6fe0 100644 --- a/tests/qemu-iotests/223.out +++ b/tests/qemu-iotests/223.out @@ -45,7 +45,7 @@ exports available: 0 {"execute":"nbd-server-add", "arguments":{"device":"nosuch"}} {"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}} {"execute":"nbd-server-add", "arguments":{"device":"n"}} -{"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}} +{"error": {"class": "GenericError", "desc": "Block export id 'n' is already in use"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b2"}} {"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b3"}} @@ -126,7 +126,7 @@ exports available: 0 {"execute":"nbd-server-add", "arguments":{"device":"nosuch"}} {"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}} {"execute":"nbd-server-add", "arguments":{"device":"n"}} -{"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}} +{"error": {"class": "GenericError", "desc": "Block export id 'n' is already in use"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b2"}} {"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b3"}} -- cgit v1.2.3-55-g7522 From 3859ad36f0bdf45a6610d93296b52c9604b6d6f7 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:05 +0200 Subject: block/export: Move strong user reference to block_exports The reference owned by the user/monitor that is created when adding the export and dropped when removing it was tied to the 'exports' list in nbd/server.c. Every block export will have a user reference, so move it to the block export level and tie it to the 'block_exports' list in block/export/export.c instead. This is necessary for introducing a QMP command for removing exports. Note that exports are present in block_exports even after the user has requested shutdown. This is different from NBD's exports where exports are immediately removed on a shutdown request, even if they are still in the process of shutting down. In order to avoid that the user still interacts with an export that is shutting down (and possibly removes it a second time), we need to remember if the user actually still owns it. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-20-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 6 ++++++ blockdev-nbd.c | 5 ----- include/block/export.h | 8 ++++++++ nbd/server.c | 2 -- 4 files changed, 14 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index 7a4a78449a..62699dfa05 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -80,6 +80,7 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) *exp = (BlockExport) { .drv = drv, .refcount = 1, + .user_owned = true, .id = g_strdup(export->id), }; @@ -143,6 +144,11 @@ void blk_exp_request_shutdown(BlockExport *exp) aio_context_acquire(aio_context); exp->drv->request_shutdown(exp); + + assert(exp->user_owned); + exp->user_owned = false; + blk_exp_unref(exp); + aio_context_release(aio_context); } diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 814554dd90..9efbaef8f7 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -235,11 +235,6 @@ int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, goto out; } - /* The list of named exports has a strong reference to this export now and - * our only way of accessing it is through nbd_export_find(), so we can drop - * the strong reference that is @exp. */ - blk_exp_unref(exp); - ret = 0; out: aio_context_release(aio_context); diff --git a/include/block/export.h b/include/block/export.h index cdc6e161ea..4833947e89 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -60,6 +60,14 @@ struct BlockExport { */ int refcount; + /* + * True if one of the references in refcount belongs to the user. After the + * user has dropped their reference, they may not e.g. remove the same + * export a second time (which would decrease the refcount without having + * it incremented first). + */ + bool user_owned; + /* The AioContext whose lock protects this BlockExport object. */ AioContext *ctx; diff --git a/nbd/server.c b/nbd/server.c index 32147e4871..22a1d66168 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1616,7 +1616,6 @@ int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); - blk_exp_ref(&exp->common); QTAILQ_INSERT_TAIL(&exports, exp, next); return 0; @@ -1663,7 +1662,6 @@ static void nbd_export_request_shutdown(BlockExport *blk_exp) client_close(client, true); } if (exp->name) { - blk_exp_unref(&exp->common); g_free(exp->name); exp->name = NULL; QTAILQ_REMOVE(&exports, exp, next); -- cgit v1.2.3-55-g7522 From 3c3bc462adeb561f5dfdcbb84ae691c95ccef916 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:06 +0200 Subject: block/export: Add block-export-del Implement a new QMP command block-export-del and make nbd-server-remove a wrapper around it. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-21-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 43 +++++++++++++++++++++++++++++++++++++++++- block/monitor/block-hmp-cmds.c | 4 ++-- blockdev-nbd.c | 25 ++++++------------------ include/block/export.h | 1 + include/block/nbd.h | 1 - nbd/server.c | 14 -------------- qapi/block-export.json | 32 +++++++++++++++++++++++++------ 7 files changed, 77 insertions(+), 43 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index 62699dfa05..d186beffe9 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -29,7 +29,7 @@ static const BlockExportDriver *blk_exp_drivers[] = { static QLIST_HEAD(, BlockExport) block_exports = QLIST_HEAD_INITIALIZER(block_exports); -static BlockExport *blk_exp_find(const char *id) +BlockExport *blk_exp_find(const char *id) { BlockExport *exp; @@ -143,12 +143,23 @@ void blk_exp_request_shutdown(BlockExport *exp) AioContext *aio_context = exp->ctx; aio_context_acquire(aio_context); + + /* + * If the user doesn't own the export any more, it is already shutting + * down. We must not call .request_shutdown and decrease the refcount a + * second time. + */ + if (!exp->user_owned) { + goto out; + } + exp->drv->request_shutdown(exp); assert(exp->user_owned); exp->user_owned = false; blk_exp_unref(exp); +out: aio_context_release(aio_context); } @@ -199,3 +210,33 @@ void qmp_block_export_add(BlockExportOptions *export, Error **errp) { blk_exp_add(export, errp); } + +void qmp_block_export_del(const char *id, + bool has_mode, BlockExportRemoveMode mode, + Error **errp) +{ + ERRP_GUARD(); + BlockExport *exp; + + exp = blk_exp_find(id); + if (exp == NULL) { + error_setg(errp, "Export '%s' is not found", id); + return; + } + if (!exp->user_owned) { + error_setg(errp, "Export '%s' is already shutting down", id); + return; + } + + if (!has_mode) { + mode = BLOCK_EXPORT_REMOVE_MODE_SAFE; + } + if (mode == BLOCK_EXPORT_REMOVE_MODE_SAFE && exp->refcount > 1) { + error_setg(errp, "export '%s' still in use", exp->id); + error_append_hint(errp, "Use mode='hard' to force client " + "disconnect\n"); + return; + } + + blk_exp_request_shutdown(exp); +} diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index db357cafcb..d15a2be827 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -476,8 +476,8 @@ void hmp_nbd_server_remove(Monitor *mon, const QDict *qdict) bool force = qdict_get_try_bool(qdict, "force", false); Error *err = NULL; - /* Rely on NBD_SERVER_REMOVE_MODE_SAFE being the default */ - qmp_nbd_server_remove(name, force, NBD_SERVER_REMOVE_MODE_HARD, &err); + /* Rely on BLOCK_EXPORT_REMOVE_MODE_SAFE being the default */ + qmp_nbd_server_remove(name, force, BLOCK_EXPORT_REMOVE_MODE_HARD, &err); hmp_handle_error(mon, err); } diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 9efbaef8f7..4a9a1be571 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -307,31 +307,18 @@ fail: } void qmp_nbd_server_remove(const char *name, - bool has_mode, NbdServerRemoveMode mode, + bool has_mode, BlockExportRemoveMode mode, Error **errp) { - NBDExport *exp; - AioContext *aio_context; - - if (!nbd_server) { - error_setg(errp, "NBD server not running"); - return; - } + BlockExport *exp; - exp = nbd_export_find(name); - if (exp == NULL) { - error_setg(errp, "Export '%s' is not found", name); + exp = blk_exp_find(name); + if (exp && exp->drv->type != BLOCK_EXPORT_TYPE_NBD) { + error_setg(errp, "Block export '%s' is not an NBD export", name); return; } - if (!has_mode) { - mode = NBD_SERVER_REMOVE_MODE_SAFE; - } - - aio_context = nbd_export_aio_context(exp); - aio_context_acquire(aio_context); - nbd_export_remove(exp, mode, errp); - aio_context_release(aio_context); + qmp_block_export_del(name, has_mode, mode, errp); } void qmp_nbd_server_stop(Error **errp) diff --git a/include/block/export.h b/include/block/export.h index 4833947e89..ff54d35872 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -76,6 +76,7 @@ struct BlockExport { }; BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp); +BlockExport *blk_exp_find(const char *id); void blk_exp_ref(BlockExport *exp); void blk_exp_unref(BlockExport *exp); void blk_exp_request_shutdown(BlockExport *exp); diff --git a/include/block/nbd.h b/include/block/nbd.h index 0b9f3e5d4e..a4dc1f9e54 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -337,7 +337,6 @@ int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, const char *bitmap, bool readonly, bool shared, bool writethrough, Error **errp); void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); -void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp); AioContext *nbd_export_aio_context(NBDExport *exp); NBDExport *nbd_export_find(const char *name); diff --git a/nbd/server.c b/nbd/server.c index 22a1d66168..1a0e1db401 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1669,20 +1669,6 @@ static void nbd_export_request_shutdown(BlockExport *blk_exp) blk_exp_unref(&exp->common); } -void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp) -{ - ERRP_GUARD(); - if (mode == NBD_SERVER_REMOVE_MODE_HARD || QTAILQ_EMPTY(&exp->clients)) { - nbd_export_request_shutdown(&exp->common); - return; - } - - assert(mode == NBD_SERVER_REMOVE_MODE_SAFE); - - error_setg(errp, "export '%s' still in use", exp->name); - error_append_hint(errp, "Use mode='hard' to force client disconnect\n"); -} - static void nbd_export_delete(BlockExport *blk_exp) { NBDExport *exp = container_of(blk_exp, NBDExport, common); diff --git a/qapi/block-export.json b/qapi/block-export.json index 658bdf05e1..3d22527c84 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -116,9 +116,9 @@ 'data': 'NbdServerAddOptions', 'boxed': true } ## -# @NbdServerRemoveMode: +# @BlockExportRemoveMode: # -# Mode for removing an NBD export. +# Mode for removing a block export. # # @safe: Remove export if there are no existing connections, fail otherwise. # @@ -134,16 +134,16 @@ # # Since: 2.12 ## -{'enum': 'NbdServerRemoveMode', 'data': ['safe', 'hard']} +{'enum': 'BlockExportRemoveMode', 'data': ['safe', 'hard']} ## # @nbd-server-remove: # # Remove NBD export by name. # -# @name: Export name. +# @name: Block export id. # -# @mode: Mode of command operation. See @NbdServerRemoveMode description. +# @mode: Mode of command operation. See @BlockExportRemoveMode description. # Default is 'safe'. # # Returns: error if @@ -154,7 +154,7 @@ # Since: 2.12 ## { 'command': 'nbd-server-remove', - 'data': {'name': 'str', '*mode': 'NbdServerRemoveMode'} } + 'data': {'name': 'str', '*mode': 'BlockExportRemoveMode'} } ## # @nbd-server-stop: @@ -213,3 +213,23 @@ ## { 'command': 'block-export-add', 'data': 'BlockExportOptions', 'boxed': true } + +## +# @block-export-del: +# +# Request to remove a block export. This drops the user's reference to the +# export, but the export may still stay around after this command returns until +# the shutdown of the export has completed. +# +# @id: Block export id. +# +# @mode: Mode of command operation. See @BlockExportRemoveMode description. +# Default is 'safe'. +# +# Returns: Error if the export is not found or @mode is 'safe' and the export +# is still in use (e.g. by existing client connections) +# +# Since: 5.2 +## +{ 'command': 'block-export-del', + 'data': { 'id': 'str', '*mode': 'BlockExportRemoveMode' } } -- cgit v1.2.3-55-g7522 From 37a4f70cea72a38fe981cbff517c222cefa46f21 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:08 +0200 Subject: block/export: Move blk to BlockExport Every block export has a BlockBackend representing the disk that is exported. It should live in BlockExport therefore. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-23-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 3 +++ include/block/export.h | 3 +++ nbd/server.c | 43 ++++++++++++++++++++++--------------------- 3 files changed, 28 insertions(+), 21 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index 87940d5c40..ad374a6649 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -92,6 +92,8 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return NULL; } + assert(exp->blk != NULL); + QLIST_INSERT_HEAD(&block_exports, exp, next); return exp; } @@ -114,6 +116,7 @@ static void blk_exp_delete_bh(void *opaque) assert(exp->refcount == 0); QLIST_REMOVE(exp, next); exp->drv->delete(exp); + blk_unref(exp->blk); qapi_event_send_block_export_deleted(exp->id); g_free(exp->id); g_free(exp); diff --git a/include/block/export.h b/include/block/export.h index ff54d35872..7feb02e10d 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -71,6 +71,9 @@ struct BlockExport { /* The AioContext whose lock protects this BlockExport object. */ AioContext *ctx; + /* The block device to export */ + BlockBackend *blk; + /* List entry for block_exports */ QLIST_ENTRY(BlockExport) next; }; diff --git a/nbd/server.c b/nbd/server.c index 1a0e1db401..f9af45c480 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -84,7 +84,6 @@ struct NBDRequestData { struct NBDExport { BlockExport common; - BlockBackend *blk; char *name; char *description; uint64_t size; @@ -643,7 +642,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, Error **errp) * whether this is OPT_INFO or OPT_GO. */ /* minimum - 1 for back-compat, or actual if client will obey it. */ if (client->opt == NBD_OPT_INFO || blocksize) { - check_align = sizes[0] = blk_get_request_alignment(exp->blk); + check_align = sizes[0] = blk_get_request_alignment(exp->common.blk); } else { sizes[0] = 1; } @@ -652,7 +651,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, Error **errp) * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */ sizes[1] = MAX(4096, sizes[0]); /* maximum - At most 32M, but smaller as appropriate. */ - sizes[2] = MIN(blk_get_max_transfer(exp->blk), NBD_MAX_BUFFER_SIZE); + sizes[2] = MIN(blk_get_max_transfer(exp->common.blk), NBD_MAX_BUFFER_SIZE); trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]); sizes[0] = cpu_to_be32(sizes[0]); sizes[1] = cpu_to_be32(sizes[1]); @@ -684,7 +683,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, Error **errp) * tolerate all clients, regardless of alignments. */ if (client->opt == NBD_OPT_INFO && !blocksize && - blk_get_request_alignment(exp->blk) > 1) { + blk_get_request_alignment(exp->common.blk) > 1) { return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_BLOCK_SIZE_REQD, errp, @@ -1557,7 +1556,7 @@ int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, blk_set_allow_aio_context_change(blk, true); QTAILQ_INIT(&exp->clients); - exp->blk = blk; + exp->common.blk = blk; exp->name = g_strdup(name); assert(!desc || strlen(desc) <= NBD_MAX_STRING_SIZE); exp->description = g_strdup(desc); @@ -1679,15 +1678,13 @@ static void nbd_export_delete(BlockExport *blk_exp) g_free(exp->description); exp->description = NULL; - if (exp->blk) { + if (exp->common.blk) { if (exp->eject_notifier_blk) { notifier_remove(&exp->eject_notifier); blk_unref(exp->eject_notifier_blk); } - blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, + blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached, blk_aio_detach, exp); - blk_unref(exp->blk); - exp->blk = NULL; } if (exp->export_bitmap) { @@ -1840,7 +1837,7 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, while (progress < size) { int64_t pnum; - int status = bdrv_block_status_above(blk_bs(exp->blk), NULL, + int status = bdrv_block_status_above(blk_bs(exp->common.blk), NULL, offset + progress, size - progress, &pnum, NULL, NULL); @@ -1872,7 +1869,8 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, stl_be_p(&chunk.length, pnum); ret = nbd_co_send_iov(client, iov, 1, errp); } else { - ret = blk_pread(exp->blk, offset + progress, data + progress, pnum); + ret = blk_pread(exp->common.blk, offset + progress, + data + progress, pnum); if (ret < 0) { error_setg_errno(errp, -ret, "reading from file failed"); break; @@ -2136,7 +2134,8 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, } if (request->type != NBD_CMD_CACHE) { - req->data = blk_try_blockalign(client->exp->blk, request->len); + req->data = blk_try_blockalign(client->exp->common.blk, + request->len); if (req->data == NULL) { error_setg(errp, "No memory"); return -ENOMEM; @@ -2232,7 +2231,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, /* XXX: NBD Protocol only documents use of FUA with WRITE */ if (request->flags & NBD_CMD_FLAG_FUA) { - ret = blk_co_flush(exp->blk); + ret = blk_co_flush(exp->common.blk); if (ret < 0) { return nbd_send_generic_reply(client, request->handle, ret, "flush failed", errp); @@ -2246,7 +2245,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, data, request->len, errp); } - ret = blk_pread(exp->blk, request->from, data, request->len); + ret = blk_pread(exp->common.blk, request->from, data, request->len); if (ret < 0) { return nbd_send_generic_reply(client, request->handle, ret, "reading from file failed", errp); @@ -2281,7 +2280,7 @@ static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request, assert(request->type == NBD_CMD_CACHE); - ret = blk_co_preadv(exp->blk, request->from, request->len, + ret = blk_co_preadv(exp->common.blk, request->from, request->len, NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); return nbd_send_generic_reply(client, request->handle, ret, @@ -2312,7 +2311,8 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, if (request->flags & NBD_CMD_FLAG_FUA) { flags |= BDRV_REQ_FUA; } - ret = blk_pwrite(exp->blk, request->from, data, request->len, flags); + ret = blk_pwrite(exp->common.blk, request->from, data, request->len, + flags); return nbd_send_generic_reply(client, request->handle, ret, "writing to file failed", errp); @@ -2333,7 +2333,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, int align = client->check_align ?: 1; int len = MIN(request->len, QEMU_ALIGN_DOWN(BDRV_REQUEST_MAX_BYTES, align)); - ret = blk_pwrite_zeroes(exp->blk, request->from, len, flags); + ret = blk_pwrite_zeroes(exp->common.blk, request->from, len, flags); request->len -= len; request->from += len; } @@ -2345,7 +2345,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, abort(); case NBD_CMD_FLUSH: - ret = blk_co_flush(exp->blk); + ret = blk_co_flush(exp->common.blk); return nbd_send_generic_reply(client, request->handle, ret, "flush failed", errp); @@ -2356,12 +2356,12 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, int align = client->check_align ?: 1; int len = MIN(request->len, QEMU_ALIGN_DOWN(BDRV_REQUEST_MAX_BYTES, align)); - ret = blk_co_pdiscard(exp->blk, request->from, len); + ret = blk_co_pdiscard(exp->common.blk, request->from, len); request->len -= len; request->from += len; } if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) { - ret = blk_co_flush(exp->blk); + ret = blk_co_flush(exp->common.blk); } return nbd_send_generic_reply(client, request->handle, ret, "discard failed", errp); @@ -2379,7 +2379,8 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, if (client->export_meta.base_allocation) { ret = nbd_co_send_block_status(client, request->handle, - blk_bs(exp->blk), request->from, + blk_bs(exp->common.blk), + request->from, request->len, dont_fragment, !client->export_meta.bitmap, NBD_META_ID_BASE_ALLOCATION, -- cgit v1.2.3-55-g7522 From 331170e0732617b931959f7c617af3823f8fe95e Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:09 +0200 Subject: block/export: Create BlockBackend in blk_exp_add() Every export type will need a BlockBackend, so creating it centrally in blk_exp_add() instead of the .create driver callback avoids duplication. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-24-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 49 +++++++++++++++++++++++++++++++++++++++++++++---- blockdev-nbd.c | 33 ++++----------------------------- include/block/nbd.h | 4 ++-- nbd/server.c | 38 ++++++++++++-------------------------- 4 files changed, 63 insertions(+), 61 deletions(-) (limited to 'include') diff --git a/block/export/export.c b/block/export/export.c index ad374a6649..8702c233f3 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -58,7 +58,10 @@ static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) { const BlockExportDriver *drv; - BlockExport *exp; + BlockExport *exp = NULL; + BlockDriverState *bs; + BlockBackend *blk; + AioContext *ctx; int ret; if (!id_wellformed(export->id)) { @@ -76,6 +79,33 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return NULL; } + bs = bdrv_lookup_bs(NULL, export->node_name, errp); + if (!bs) { + return NULL; + } + + ctx = bdrv_get_aio_context(bs); + aio_context_acquire(ctx); + + /* + * Block exports are used for non-shared storage migration. Make sure + * that BDRV_O_INACTIVE is cleared and the image is ready for write + * access since the export could be available before migration handover. + * ctx was acquired in the caller. + */ + bdrv_invalidate_cache(bs, NULL); + + blk = blk_new(ctx, BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); + ret = blk_insert_bs(blk, bs, errp); + if (ret < 0) { + goto fail; + } + + if (!export->has_writethrough) { + export->writethrough = false; + } + blk_set_enable_write_cache(blk, !export->writethrough); + assert(drv->instance_size >= sizeof(BlockExport)); exp = g_malloc0(drv->instance_size); *exp = (BlockExport) { @@ -83,19 +113,30 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) .refcount = 1, .user_owned = true, .id = g_strdup(export->id), + .ctx = ctx, + .blk = blk, }; ret = drv->create(exp, export, errp); if (ret < 0) { - g_free(exp->id); - g_free(exp); - return NULL; + goto fail; } assert(exp->blk != NULL); QLIST_INSERT_HEAD(&block_exports, exp, next); + + aio_context_release(ctx); return exp; + +fail: + blk_unref(blk); + aio_context_release(ctx); + if (exp) { + g_free(exp->id); + g_free(exp); + } + return NULL; } /* Callers must hold exp->ctx lock */ diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 4a9a1be571..cdbbcdb958 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -177,9 +177,6 @@ int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, Error **errp) { BlockExportOptionsNbd *arg = &exp_args->u.nbd; - BlockDriverState *bs = NULL; - AioContext *aio_context; - int ret; assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); @@ -207,38 +204,16 @@ int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, return -EEXIST; } - bs = bdrv_lookup_bs(NULL, exp_args->node_name, errp); - if (!bs) { - return -ENOENT; - } - - aio_context = bdrv_get_aio_context(bs); - aio_context_acquire(aio_context); - if (!arg->has_writable) { arg->writable = false; } - if (bdrv_is_read_only(bs) && arg->writable) { - ret = -EINVAL; + if (blk_is_read_only(exp->blk) && arg->writable) { error_setg(errp, "Cannot export read-only node as writable"); - goto out; - } - - if (!exp_args->has_writethrough) { - exp_args->writethrough = false; - } - - ret = nbd_export_new(exp, bs, arg->name, arg->description, arg->bitmap, - !arg->writable, !arg->writable, - exp_args->writethrough, errp); - if (ret < 0) { - goto out; + return -EINVAL; } - ret = 0; - out: - aio_context_release(aio_context); - return ret; + return nbd_export_new(exp, arg->name, arg->description, arg->bitmap, + !arg->writable, !arg->writable, errp); } void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) diff --git a/include/block/nbd.h b/include/block/nbd.h index a4dc1f9e54..5270b7eadd 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -332,10 +332,10 @@ typedef struct NBDClient NBDClient; int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, Error **errp); -int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, +int nbd_export_new(BlockExport *blk_exp, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, - bool writethrough, Error **errp); + Error **errp); void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); AioContext *nbd_export_aio_context(NBDExport *exp); diff --git a/nbd/server.c b/nbd/server.c index f9af45c480..6c8532de23 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1507,56 +1507,42 @@ void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); } -int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, +int nbd_export_new(BlockExport *blk_exp, const char *name, const char *desc, const char *bitmap, bool readonly, bool shared, - bool writethrough, Error **errp) + Error **errp) { NBDExport *exp = container_of(blk_exp, NBDExport, common); - AioContext *ctx; - BlockBackend *blk; + BlockBackend *blk = blk_exp->blk; int64_t size; - uint64_t perm; + uint64_t perm, shared_perm; int ret; - size = bdrv_getlength(bs); + size = blk_getlength(blk); if (size < 0) { error_setg_errno(errp, -size, "Failed to determine the NBD export's length"); return size; } - ctx = bdrv_get_aio_context(bs); - blk_exp->ctx = ctx; - - /* - * NBD exports are used for non-shared storage migration. Make sure - * that BDRV_O_INACTIVE is cleared and the image is ready for write - * access since the export could be available before migration handover. - * ctx was acquired in the caller. - */ assert(name && strlen(name) <= NBD_MAX_STRING_SIZE); - bdrv_invalidate_cache(bs, NULL); - /* Don't allow resize while the NBD server is running, otherwise we don't * care what happens with the node. */ - perm = BLK_PERM_CONSISTENT_READ; + blk_get_perm(blk, &perm, &shared_perm); + if (!readonly) { perm |= BLK_PERM_WRITE; } - blk = blk_new(ctx, perm, - BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED | - BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD); - ret = blk_insert_bs(blk, bs, errp); + + ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp); if (ret < 0) { - goto fail; + return ret; } - blk_set_enable_write_cache(blk, !writethrough); + blk_set_allow_aio_context_change(blk, true); QTAILQ_INIT(&exp->clients); - exp->common.blk = blk; exp->name = g_strdup(name); assert(!desc || strlen(desc) <= NBD_MAX_STRING_SIZE); exp->description = g_strdup(desc); @@ -1574,6 +1560,7 @@ int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); if (bitmap) { + BlockDriverState *bs = blk_bs(blk); BdrvDirtyBitmap *bm = NULL; while (bs) { @@ -1620,7 +1607,6 @@ int nbd_export_new(BlockExport *blk_exp, BlockDriverState *bs, return 0; fail: - blk_unref(blk); g_free(exp->name); g_free(exp->description); return ret; -- cgit v1.2.3-55-g7522 From 5b1cb49704551cff8913032b22c9d6566d217cbb Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:12 +0200 Subject: nbd: Merge nbd_export_new() and nbd_export_create() There is no real reason any more why nbd_export_new() and nbd_export_create() should be separate functions. The latter only performs a few checks before it calls the former. What makes the current state stand out is that it's the only function in BlockExportDriver that is not a static function inside nbd/server.c, but a small wrapper in blockdev-nbd.c that then calls back into nbd/server.c for the real functionality. Move all the checks to nbd/server.c and make the resulting function static to improve readability. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-27-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- blockdev-nbd.c | 40 +++++---------------------------------- include/block/nbd.h | 7 +------ nbd/server.c | 54 ++++++++++++++++++++++++++++++++++++++--------------- 3 files changed, 45 insertions(+), 56 deletions(-) (limited to 'include') diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 30e165c23f..8174023e5c 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -37,6 +37,11 @@ void nbd_server_is_qemu_nbd(bool value) is_qemu_nbd = value; } +bool nbd_server_is_running(void) +{ + return nbd_server || is_qemu_nbd; +} + static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) { nbd_client_put(client); @@ -173,41 +178,6 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr, qapi_free_SocketAddress(addr_flat); } -int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, - Error **errp) -{ - BlockExportOptionsNbd *arg = &exp_args->u.nbd; - - assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); - - if (!nbd_server && !is_qemu_nbd) { - error_setg(errp, "NBD server not running"); - return -EINVAL; - } - - if (!arg->has_name) { - arg->name = exp_args->node_name; - } - - if (strlen(arg->name) > NBD_MAX_STRING_SIZE) { - error_setg(errp, "export name '%s' too long", arg->name); - return -EINVAL; - } - - if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { - error_setg(errp, "description '%s' too long", arg->description); - return -EINVAL; - } - - if (nbd_export_find(arg->name)) { - error_setg(errp, "NBD server already has export named '%s'", arg->name); - return -EEXIST; - } - - return nbd_export_new(exp, arg->name, arg->description, arg->bitmap, - !exp_args->writable, !exp_args->writable, errp); -} - void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) { BlockExport *export; diff --git a/include/block/nbd.h b/include/block/nbd.h index 5270b7eadd..3dd9a04546 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -330,12 +330,6 @@ int nbd_errno_to_system_errno(int err); typedef struct NBDExport NBDExport; typedef struct NBDClient NBDClient; -int nbd_export_create(BlockExport *exp, BlockExportOptions *exp_args, - Error **errp); -int nbd_export_new(BlockExport *blk_exp, - const char *name, const char *desc, - const char *bitmap, bool readonly, bool shared, - Error **errp); void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); AioContext *nbd_export_aio_context(NBDExport *exp); @@ -349,6 +343,7 @@ void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); void nbd_server_is_qemu_nbd(bool value); +bool nbd_server_is_running(void); void nbd_server_start(SocketAddress *addr, const char *tls_creds, const char *tls_authz, uint32_t max_connections, Error **errp); diff --git a/nbd/server.c b/nbd/server.c index 465ec9e762..f74766add7 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1507,17 +1507,44 @@ void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); } -int nbd_export_new(BlockExport *blk_exp, - const char *name, const char *desc, - const char *bitmap, bool readonly, bool shared, - Error **errp) +static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, + Error **errp) { NBDExport *exp = container_of(blk_exp, NBDExport, common); + BlockExportOptionsNbd *arg = &exp_args->u.nbd; BlockBackend *blk = blk_exp->blk; int64_t size; uint64_t perm, shared_perm; + bool readonly = !exp_args->writable; + bool shared = !exp_args->writable; int ret; + assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); + + if (!nbd_server_is_running()) { + error_setg(errp, "NBD server not running"); + return -EINVAL; + } + + if (!arg->has_name) { + arg->name = exp_args->node_name; + } + + if (strlen(arg->name) > NBD_MAX_STRING_SIZE) { + error_setg(errp, "export name '%s' too long", arg->name); + return -EINVAL; + } + + if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { + error_setg(errp, "description '%s' too long", arg->description); + return -EINVAL; + } + + if (nbd_export_find(arg->name)) { + error_setg(errp, "NBD server already has export named '%s'", arg->name); + return -EEXIST; + } + size = blk_getlength(blk); if (size < 0) { error_setg_errno(errp, -size, @@ -1525,8 +1552,6 @@ int nbd_export_new(BlockExport *blk_exp, return size; } - assert(name && strlen(name) <= NBD_MAX_STRING_SIZE); - /* Don't allow resize while the NBD server is running, otherwise we don't * care what happens with the node. */ blk_get_perm(blk, &perm, &shared_perm); @@ -1538,9 +1563,8 @@ int nbd_export_new(BlockExport *blk_exp, blk_set_allow_aio_context_change(blk, true); QTAILQ_INIT(&exp->clients); - exp->name = g_strdup(name); - assert(!desc || strlen(desc) <= NBD_MAX_STRING_SIZE); - exp->description = g_strdup(desc); + exp->name = g_strdup(arg->name); + exp->description = g_strdup(arg->description); exp->nbdflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_CACHE); if (readonly) { @@ -1554,12 +1578,12 @@ int nbd_export_new(BlockExport *blk_exp, } exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); - if (bitmap) { + if (arg->bitmap) { BlockDriverState *bs = blk_bs(blk); BdrvDirtyBitmap *bm = NULL; while (bs) { - bm = bdrv_find_dirty_bitmap(bs, bitmap); + bm = bdrv_find_dirty_bitmap(bs, arg->bitmap); if (bm != NULL) { break; } @@ -1569,7 +1593,7 @@ int nbd_export_new(BlockExport *blk_exp, if (bm == NULL) { ret = -ENOENT; - error_setg(errp, "Bitmap '%s' is not found", bitmap); + error_setg(errp, "Bitmap '%s' is not found", arg->bitmap); goto fail; } @@ -1583,15 +1607,15 @@ int nbd_export_new(BlockExport *blk_exp, ret = -EINVAL; error_setg(errp, "Enabled bitmap '%s' incompatible with readonly export", - bitmap); + arg->bitmap); goto fail; } bdrv_dirty_bitmap_set_busy(bm, true); exp->export_bitmap = bm; - assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); + assert(strlen(arg->bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); exp->export_bitmap_context = g_strdup_printf("qemu:dirty-bitmap:%s", - bitmap); + arg->bitmap); assert(strlen(exp->export_bitmap_context) < NBD_MAX_STRING_SIZE); } -- cgit v1.2.3-55-g7522