xemu-project/xemu
1
0
Fork 0
mirror of https://github.com/xemu-project/xemu.git synced 2024-11-24 12:09:58 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
dbdf699cad
xemu/block
History
Vladimir Sementsov-Ogievskiy dbdf699cad block/mirror: support unaligned write in active mirror 
Prior 9adc1cb49a do_sync_target_write had a bug: it reset aligned-up
region in the dirty bitmap, which means that we may not copy some bytes
and assume them copied, which actually leads to producing corrupted
target.

So 9adc1cb49a forced dirty bitmap granularity to be
request_alignment for mirror-top filter, so we are not working with
unaligned requests. However forcing large alignment obviously decreases
performance of unaligned requests.

This commit provides another solution for the problem: if unaligned
padding is already dirty, we can safely ignore it, as
1. It's dirty, it will be copied by mirror_iteration anyway
2. It's dirty, so skipping it now we don't increase dirtiness of the
   bitmap and therefore don't damage "synchronicity" of the
   write-blocking mirror.

If unaligned padding is not dirty, we just write it, no reason to touch
dirty bitmap if we succeed (on failure we'll set the whole region
ofcourse, but we loss "synchronicity" on failure anyway).

Note: we need to disable dirty_bitmap, otherwise we will not be able to
see in do_sync_target_write bitmap state before current operation. We
may of course check dirty bitmap before the operation in
bdrv_mirror_top_do_write and remember it, but we don't need active
dirty bitmap for write-blocking mirror anyway.

New code-path is unused until the following commit reverts
9adc1cb49a.

Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191011090711.19940-5-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 11:22:30 +01:00
..
accounting.c block: add empty account cookie type 2019-10-10 10:56:18 +02:00
aio_task.c block: introduce aio task pool 2019-10-10 10:56:17 +02:00
backup-top.c block/backup: use backup-top instead of write notifiers 2019-10-10 10:56:18 +02:00
backup-top.h block: introduce backup-top filter driver 2019-10-10 10:56:18 +02:00
backup.c block/backup: drop dead code from backup_job_create 2019-10-25 15:15:01 +02:00
blkdebug.c blkdebug: Inject errors on .bdrv_co_block_status() 2019-06-14 14:16:57 +02:00
blklogwrites.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
blkreplay.c block: implement bdrv_snapshot_goto for blkreplay 2019-10-14 17:12:48 +02:00
blkverify.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
block-backend.c block/block-backend: add blk_co_pwritev_part 2019-10-28 11:22:30 +01:00
block-copy.c block/dirty-bitmap: add bs link 2019-10-17 17:02:32 -04:00
bochs.c block: Use QEMU_IS_ALIGNED 2019-09-16 14:48:30 +02:00
cloop.c block: Use QEMU_IS_ALIGNED 2019-09-16 14:48:30 +02:00
commit.c job: drop job_drain 2019-09-10 08:58:43 +02:00
copy-on-read.c block/copy-on-read: Fix permissions for inactive node 2019-07-30 12:25:43 +02:00
create.c block/create: Do not abort if a block driver is not available 2019-09-13 12:18:37 +02:00
crypto.c LUKS: support preallocation 2019-08-19 17:13:26 +02:00
crypto.h Clean up ill-advised or unusual header guards 2019-05-13 08:58:55 +02:00
curl.c curl: Check curl_multi_add_handle()'s return code 2019-09-16 15:31:12 +02:00
dirty-bitmap.c block/qcow2-bitmap: get rid of bdrv_has_changed_persistent_bitmaps 2019-10-17 17:02:32 -04:00
dmg-bz2.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
dmg-lzfse.c block: adding lzfse decompressing support as a module. 2018-12-14 11:52:40 +01:00
dmg.c block: Use QEMU_IS_ALIGNED 2019-09-16 14:48:30 +02:00
dmg.h Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
file-posix.c qapi: query-blockstat: add driver specific file-posix stats 2019-10-10 10:56:18 +02:00
file-win32.c block: Implement .bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
gluster.c block: Implement .bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
io.c block: Reject misaligned write requests with BDRV_REQ_NO_FALLBACK 2019-10-14 17:12:48 +02:00
iscsi-opts.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
iscsi.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
linux-aio.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
Makefile.objs block: introduce backup-top filter driver 2019-10-10 10:56:18 +02:00
mirror.c block/mirror: support unaligned write in active mirror 2019-10-28 11:22:30 +01:00
nbd.c block/nbd: nbd reconnect 2019-10-22 09:22:07 -05:00
nfs.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
null.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
nvme.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
parallels.c block: Use bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
parallels.h Clean up includes 2018-02-09 05:05:11 +01:00
qapi.c qapi: query-blockstat: add driver specific file-posix stats 2019-10-10 10:56:18 +02:00
qcow2-bitmap.c block/qcow2-bitmap: fix and improve qcow2_reopen_bitmaps_rw 2019-10-17 17:53:28 -04:00
qcow2-cache.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qcow2-cluster.c qcow2: Limit total allocation range to INT_MAX 2019-10-14 17:12:48 +02:00
qcow2-refcount.c qcow2: Fix corruption bug in qcow2_detect_metadata_preallocation() 2019-10-25 15:18:55 +02:00
qcow2-snapshot.c qcow2.h: add missing include 2019-05-28 20:30:55 +02:00
qcow2-threads.c block/qcow2: refactor encryption code 2019-09-16 15:36:22 +02:00
qcow2.c qcow2: Fix corruption bug in qcow2_detect_metadata_preallocation() 2019-10-25 15:18:55 +02:00
qcow2.h block/qcow2-bitmap: do not remove bitmaps on reopen-ro 2019-10-17 17:02:32 -04:00
qcow.c block/qcow: Improve error when opening qcow2 files as qcow 2019-07-08 16:00:26 +02:00
qed-check.c block/qed: add missed coroutine_fn markers 2019-04-30 15:29:00 +02:00
qed-cluster.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-l2-cache.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-table.c block/qed: add missed coroutine_fn markers 2019-04-30 15:29:00 +02:00
qed.c block: Implement .bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
qed.h block/qed: add missed coroutine_fn markers 2019-04-30 15:29:00 +02:00
quorum.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
raw-format.c block: Implement .bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
rbd.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
replication.c block/backup: use backup-top instead of write notifiers 2019-10-10 10:56:18 +02:00
sheepdog.c block: Implement .bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
snapshot.c block/snapshot: Restrict set of snapshot nodes 2019-10-04 11:52:40 +02:00
ssh.c block: Implement .bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
stream.c job: drop job_drain 2019-09-10 08:58:43 +02:00
throttle-groups.c Include qemu/main-loop.h less 2019-08-16 13:31:52 +02:00
throttle.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
trace-events block: move block_copy from block/backup.c to separate file 2019-10-10 10:56:17 +02:00
vdi.c vdi: Make block_status recurse for fixed images 2019-08-19 17:13:26 +02:00
vhdx-endian.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vhdx-log.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
vhdx.c block/vhdx: add check for truncated image files 2019-10-14 17:12:48 +02:00
vhdx.h block/vhdx: Use IEC binary prefixes for size constants 2019-04-30 15:29:00 +02:00
vmdk.c vmdk: Reject invalid compressed writes 2019-09-03 14:55:35 +02:00
vpc.c vpc: Return 0 from vpc_co_create() on success 2019-09-10 08:58:43 +02:00
vvfat.c block: Use QEMU_IS_ALIGNED 2019-09-16 14:48:30 +02:00
vxhs.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
win32-aio.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
write-threshold.c qapi: Drop qapi_event_send_FOO()'s Error ** argument 2018-08-28 18:21:38 +02:00