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* backup-top: Refuse I/O in inactive stateMax Reitz2021-03-081-0/+10
| | | | | | | | | | | | | | | | | | | When the backup-top node transitions from active to inactive in bdrv_backup_top_drop(), the BlockCopyState is freed and the filtered child is removed, so the node effectively becomes unusable. However, noone told its I/O functions this, so they will happily continue accessing bs->backing and s->bcs. Prevent that by aborting early when s->active is false. (After the preceding patch, the node should be gone after bdrv_backup_top_drop(), so this should largely be a theoretical problem. But still, better to be safe than sorry, and also I think it just makes sense to check s->active in the I/O functions.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210219153348.41861-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: use return status of bdrv_append()Vladimir Sementsov-Ogievskiy2021-02-121-12/+11Star
| | | | | | | | | | Now bdrv_append returns status and we can drop all the local_err things around it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20210202124956.63146-3-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* block/block-copy: drop unused argument of block_copy()Vladimir Sementsov-Ogievskiy2021-01-261-1/+1
| | | | | | | Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210116214705.822267-21-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/block-copy: add ratelimit to block-copyVladimir Sementsov-Ogievskiy2021-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are going to directly use one async block-copy operation for backup job, so we need rate limiter. We want to maintain current backup behavior: only background copying is limited and copy-before-write operations only participate in limit calculation. Therefore we need one rate limiter for block-copy state and boolean flag for block-copy call state for actual limitation. Note, that we can't just calculate each chunk in limiter after successful copying: it will not save us from starting a lot of async sub-requests which will exceed limit too much. Instead let's use the following scheme on sub-request creation: 1. If at the moment limit is not exceeded, create the request and account it immediately. 2. If at the moment limit is already exceeded, drop create sub-request and handle limit instead (by sleep). With this approach we'll never exceed the limit more than by one sub-request (which pretty much matches current backup behavior). Note also, that if there is in-flight block-copy async call, block_copy_kick() should be used after set-speed to apply new setup faster. For that block_copy_kick() published in this patch. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210116214705.822267-7-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* qapi: backup: add perf.use-copy-range parameterVladimir Sementsov-Ogievskiy2021-01-261-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Experiments show, that copy_range is not always making things faster. So, to make experimentation simpler, let's add a parameter. Some more perf parameters will be added soon, so here is a new struct. For now, add new backup qmp parameter with x- prefix for the following reasons: - We are going to add more performance parameters, some will be related to the whole block-copy process, some only to background copying in backup (ignored for copy-before-write operations). - On the other hand, we are going to use block-copy interface in other block jobs, which will need performance options as well.. And it should be the same structure or at least somehow related. So, there are too much unclean things about how the interface and now we need the new options mostly for testing. Let's keep them experimental for a while. In do_backup_common() new x-perf parameter handled in a way to make further options addition simpler. We add use-copy-range with default=true, and we'll change the default in further patch, after moving backup to use block-copy. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210116214705.822267-2-vsementsov@virtuozzo.com> [mreitz: s/5\.2/6.0/] Signed-off-by: Max Reitz <mreitz@redhat.com>
* block: Inline bdrv_co_block_status_from_*()Max Reitz2020-09-071-2/+0Star
| | | | | | | | | | | | | | With bdrv_filter_bs(), we can easily handle this default filter behavior in bdrv_co_block_status(). blkdebug wants to have an additional assertion, so it keeps its own implementation, except bdrv_co_block_status_from_file() needs to be inlined there. Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
* backup: Deal with filtersMax Reitz2020-09-071-1/+1
| | | | | Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
* block: Drop @child_class from bdrv_child_perm()Max Reitz2020-05-181-2/+1Star
| | | | | | | | | Implementations should decide the necessary permissions based on @role. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-35-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Use bdrv_default_perms()Max Reitz2020-05-181-2/+2
| | | | | | | | | | | | | | | | | | bdrv_default_perms() can decide which permission profile to use based on the BdrvChildRole, so block drivers do not need to select it explicitly. The blkverify driver now no longer shares the WRITE permission for the image to verify. We thus have to adjust two places in test-block-iothread not to take it. (Note that in theory, blkverify should behave like quorum in this regard and share neither WRITE nor RESIZE for both of its children. In practice, it does not really matter, because blkverify is used only for debugging, so we might as well keep its permissions rather liberal.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-30-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Use child_of_bds in remaining placesMax Reitz2020-05-181-2/+2
| | | | | | | | | | Replace child_file by child_of_bds in all remaining places (excluding tests). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-28-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Make backing files child_of_bds childrenMax Reitz2020-05-181-1/+1
| | | | | | | | | | | | Make all parents of backing files pass the appropriate BdrvChildRole. By doing so, we can switch their BdrvChildClass over to the generic child_of_bds, which will do the right thing when given a correct BdrvChildRole. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-24-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Pass BdrvChildRole to bdrv_child_perm()Max Reitz2020-05-181-1/+2
| | | | | | | | | | For now, all callers pass 0 and no callee evaluates this value. Later patches will change both. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-7-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Add BdrvChildRole to BdrvChildMax Reitz2020-05-181-1/+2
| | | | | | | | | | For now, it is always set to 0. Later patches in this series will ensure that all callers pass an appropriate combination of flags. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Rename BdrvChildRole to BdrvChildClassMax Reitz2020-05-181-4/+4
| | | | | | | | | | | | | | This structure nearly only contains parent callbacks for child state changes. It cannot really reflect a child's role, because different roles may overlap (as we will see when real roles are introduced), and because parents can have custom callbacks even when the child fulfills a standard role. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* backup: Make sure that source and target size matchKevin Wolf2020-05-081-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the introduction of a backup filter node in commit 00e30f05d, the backup block job crashes when the target image is smaller than the source image because it will try to write after the end of the target node without having BLK_PERM_RESIZE. (Previously, the BlockBackend layer would have caught this and errored out gracefully.) We can fix this and even do better than the old behaviour: Check that source and target have the same image size at the start of the block job and unshare BLK_PERM_RESIZE. (This permission was already unshared before the same commit 00e30f05d, but the BlockBackend that was used to make the restriction was removed without a replacement.) This will immediately error out when starting the job instead of only when writing to a block that doesn't exist in the target. Longer target than source would technically work because we would never write to blocks that don't exist, but semantically these are invalid, too, because a backup is supposed to create a copy, not just an image that starts with a copy. Fixes: 00e30f05de1d19586345ec373970ef4c192c6270 Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1778593 Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430142755.315494-4-kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/block-copy: hide structure definitionsVladimir Sementsov-Ogievskiy2020-03-111-2/+4
| | | | | | | | | | | Hide structure definitions and add explicit API instead, to keep an eye on the scope of the shared fields. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200311103004.7649-10-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/backup-top: fix flags handlingVladimir Sementsov-Ogievskiy2020-02-201-11/+20
| | | | | | | | | | | | | | backup-top "supports" write-unchanged, by skipping CBW operation in backup_top_co_pwritev. But it forgets to do the same in backup_top_co_pwrite_zeroes, as well as declare support for BDRV_REQ_WRITE_UNCHANGED. Fix this, and, while being here, declare also support for flags supported by source child. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200207161231.32707-1-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/backup-top: fix failure pathVladimir Sementsov-Ogievskiy2020-02-061-9/+12
| | | | | | | | | | | | | | | | | | | | | We can't access top after call bdrv_backup_top_drop, as it is already freed at this time. Also, no needs to unref target child by hand, it will be unrefed on bdrv_close() automatically. So, just do bdrv_backup_top_drop if append succeed and one bdrv_unref otherwise. Note, that in !appended case bdrv_unref(top) moved into drained section on source. It doesn't really matter, but just for code simplicity. Fixes: 7df7868b96404 Cc: qemu-stable@nongnu.org # v4.2.0 Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20200121142802.21467-2-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/backup: fix memory leak in bdrv_backup_top_append()Eiichi Tsukata2020-01-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | bdrv_open_driver() allocates bs->opaque according to drv->instance_size. There is no need to allocate it and overwrite opaque in bdrv_backup_top_append(). Reproducer: $ QTEST_QEMU_BINARY=./x86_64-softmmu/qemu-system-x86_64 valgrind -q --leak-check=full tests/test-replication -p /replication/secondary/start ==29792== 24 bytes in 1 blocks are definitely lost in loss record 52 of 226 ==29792== at 0x483AB1A: calloc (vg_replace_malloc.c:762) ==29792== by 0x4B07CE0: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.6000.7) ==29792== by 0x12BAB9: bdrv_open_driver (block.c:1289) ==29792== by 0x12BEA9: bdrv_new_open_driver (block.c:1359) ==29792== by 0x1D15CB: bdrv_backup_top_append (backup-top.c:190) ==29792== by 0x1CC11A: backup_job_create (backup.c:439) ==29792== by 0x1CD542: replication_start (replication.c:544) ==29792== by 0x1401B9: replication_start_all (replication.c:52) ==29792== by 0x128B50: test_secondary_start (test-replication.c:427) ... Fixes: 7df7868b9640 ("block: introduce backup-top filter driver") Signed-off-by: Eiichi Tsukata <devel@etsukata.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/backup-top: Don't acquire context while dropping topSergio Lopez2020-01-271-5/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All paths that lead to bdrv_backup_top_drop(), except for the call from backup_clean(), imply that the BDS AioContext has already been acquired, so doing it there too can potentially lead to QEMU hanging on AIO_WAIT_WHILE(). An easy way to trigger this situation is by issuing a two actions transaction, with a proper and a bogus blockdev-backup, so the second one will trigger a rollback. This will trigger a hang with an stack trace like this one: #0 0x00007fb680c75016 in __GI_ppoll (fds=0x55e74580f7c0, nfds=1, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39 #1 0x000055e743386e09 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77 #2 0x000055e743386e09 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at util/qemu-timer.c:336 #3 0x000055e743388dc4 in aio_poll (ctx=0x55e7458925d0, blocking=blocking@entry=true) at util/aio-posix.c:669 #4 0x000055e743305dea in bdrv_flush (bs=bs@entry=0x55e74593c0d0) at block/io.c:2878 #5 0x000055e7432be58e in bdrv_close (bs=0x55e74593c0d0) at block.c:4017 #6 0x000055e7432be58e in bdrv_delete (bs=<optimized out>) at block.c:4262 #7 0x000055e7432be58e in bdrv_unref (bs=bs@entry=0x55e74593c0d0) at block.c:5644 #8 0x000055e743316b9b in bdrv_backup_top_drop (bs=bs@entry=0x55e74593c0d0) at block/backup-top.c:273 #9 0x000055e74331461f in backup_job_create (job_id=0x0, bs=bs@entry=0x55e7458d5820, target=target@entry=0x55e74589f640, speed=0, sync_mode=MIRROR_SYNC_MODE_FULL, sync_bitmap=sync_bitmap@entry=0x0, bitmap_mode=BITMAP_SYNC_MODE_ON_SUCCESS, compress=false, filter_node_name=0x0, on_source_error=BLOCKDEV_ON_ERROR_REPORT, on_target_error=BLOCKDEV_ON_ERROR_REPORT, creation_flags=0, cb=0x0, opaque=0x0, txn=0x0, errp=0x7ffddfd1efb0) at block/backup.c:478 #10 0x000055e74315bc52 in do_backup_common (backup=backup@entry=0x55e746c066d0, bs=bs@entry=0x55e7458d5820, target_bs=target_bs@entry=0x55e74589f640, aio_context=aio_context@entry=0x55e7458a91e0, txn=txn@entry=0x0, errp=errp@entry=0x7ffddfd1efb0) at blockdev.c:3580 #11 0x000055e74315c37c in do_blockdev_backup (backup=backup@entry=0x55e746c066d0, txn=0x0, errp=errp@entry=0x7ffddfd1efb0) at /usr/src/debug/qemu-kvm-4.2.0-2.module+el8.2.0+5135+ed3b2489.x86_64/./qapi/qapi-types-block-core.h:1492 #12 0x000055e74315c449 in blockdev_backup_prepare (common=0x55e746a8de90, errp=0x7ffddfd1f018) at blockdev.c:1885 #13 0x000055e743160152 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x55e7467fe2c0, errp=errp@entry=0x7ffddfd1f088) at blockdev.c:2340 #14 0x000055e743287ff5 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffddfd1f0f8) at qapi/qapi-commands-transaction.c:44 #15 0x000055e74333de6c in do_qmp_dispatch (errp=0x7ffddfd1f0f0, allow_oob=<optimized out>, request=<optimized out>, cmds=0x55e743c28d60 <qmp_commands>) at qapi/qmp-dispatch.c:132 #16 0x000055e74333de6c in qmp_dispatch (cmds=0x55e743c28d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175 #17 0x000055e74325c061 in monitor_qmp_dispatch (mon=0x55e745908030, req=<optimized out>) at monitor/qmp.c:145 #18 0x000055e74325c6fa in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:234 #19 0x000055e743385866 in aio_bh_call (bh=0x55e745807ae0) at util/async.c:117 #20 0x000055e743385866 in aio_bh_poll (ctx=ctx@entry=0x55e7458067a0) at util/async.c:117 #21 0x000055e743388c54 in aio_dispatch (ctx=0x55e7458067a0) at util/aio-posix.c:459 #22 0x000055e743385742 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260 #23 0x00007fb68543e67d in g_main_dispatch (context=0x55e745893a40) at gmain.c:3176 #24 0x00007fb68543e67d in g_main_context_dispatch (context=context@entry=0x55e745893a40) at gmain.c:3829 #25 0x000055e743387d08 in glib_pollfds_poll () at util/main-loop.c:219 #26 0x000055e743387d08 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242 #27 0x000055e743387d08 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518 #28 0x000055e74316a3c1 in main_loop () at vl.c:1828 #29 0x000055e743016a72 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504 Fix this by not acquiring the AioContext there, and ensuring all paths leading to it have it already acquired (backup_clean()). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782111 Signed-off-by: Sergio Lopez <slp@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* backup-top: Begin drain earlierMax Reitz2020-01-061-2/+2
| | | | | | | | | | | | | When dropping backup-top, we need to drain the node before freeing the BlockCopyState. Otherwise, requests may still be in flight and then the assertion in shres_destroy() will fail. (This becomes visible in intermittent failure of 056.) Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191219182638.104621-1-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* block/backup: use backup-top instead of write notifiersVladimir Sementsov-Ogievskiy2019-10-101-13/+8Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop write notifiers and use filter node instead. = Changes = 1. Add filter-node-name argument for backup qmp api. We have to do it in this commit, as 257 needs to be fixed. 2. There are no more write notifiers here, so is_write_notifier parameter is dropped from block-copy paths. 3. To sync with in-flight requests at job finish we now have drained removing of the filter, we don't need rw-lock. 4. Block-copy is now using BdrvChildren instead of BlockBackends 5. As backup-top owns these children, we also move block-copy state into backup-top's ownership. = Iotest changes = 56: op-blocker doesn't shoot now, as we set it on source, but then check on filter, when trying to start second backup. To keep the test we instead can catch another collision: both jobs will get 'drive0' job-id, as job-id parameter is unspecified. To prevent interleaving with file-posix locks (as they are dependent on config) let's use another target for second backup. Also, it's obvious now that we'd like to drop this op-blocker at all and add a test-case for two backups from one node (to different destinations) actually works. But not in these series. 141: Output changed: prepatch, "Node is in use" comes from bdrv_has_blk check inside qmp_blockdev_del. But we've dropped block-copy blk objects, so no more blk objects on source bs (job blk is on backup-top filter bs). New message is from op-blocker, which is the next check in qmp_blockdev_add. 257: The test wants to emulate guest write during backup. They should go to filter node, not to original source node, of course. Therefore we need to specify filter node name and use it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191001131409.14202-6-vsementsov@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* block: introduce backup-top filter driverVladimir Sementsov-Ogievskiy2019-10-101-0/+281
Backup-top filter caches write operations and does copy-before-write operations. The driver will be used in backup instead of write-notifiers. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20191001131409.14202-5-vsementsov@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>