qemu/block
Vladimir Sementsov-Ogievskiy ac9d00bf7b block: fix crash on zero-length unaligned write and read
Commit 7a3f542fbd "block/io: refactor padding" occasionally dropped
aligning for zero-length request: bdrv_init_padding() blindly return
false if bytes == 0, like there is nothing to align.

This leads the following command to crash:

./qemu-io --image-opts -c 'write 1 0' \
  driver=blkdebug,align=512,image.driver=null-co,image.size=512

>> qemu-io: block/io.c:1955: bdrv_aligned_pwritev: Assertion
    `(offset & (align - 1)) == 0' failed.
>> Aborted (core dumped)

Prior to 7a3f542fbd we does aligning of such zero requests. Instead of
recovering this behavior let's just do nothing on such requests as it
is useless.

Note that driver may have special meaning of zero-length reqeusts, like
qcow2_co_pwritev_compressed_part, so we can't skip any zero-length
operation. But for unaligned ones, we can't pass it to driver anyway.

This commit also fixes crash in iotest 80 running with -nocache:

./check -nocache -qcow2 80

which crashes on same assertion due to trying to read empty extra data
in qcow2_do_read_snapshots().

Cc: qemu-stable@nongnu.org # v4.2
Fixes: 7a3f542fbd
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20200206164245.17781-1-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-02-07 16:46:59 +00:00
..
Makefile.objs block/io_uring: implements interfaces for io_uring 2020-01-30 20:59:41 +00:00
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-top: fix failure path 2020-02-06 13:47:45 +01:00
backup-top.h block: introduce backup-top filter driver 2019-10-10 10:56:18 +02:00
backup.c block/backup-top: Don't acquire context while dropping top 2020-01-27 17:19:53 +01:00
blkdebug.c blkdebug: Allow taking/unsharing permissions 2020-01-06 13:43:06 +01:00
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: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
block-copy.c block/block-copy: fix s->copy_size for compressed cluster 2019-11-04 09:21:45 +01:00
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 block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
copy-on-read.c block/cor: Drop cor_co_truncate() 2019-10-28 11:59:51 +01:00
create.c block/create: Do not abort if a block driver is not available 2019-09-13 12:18:37 +02:00
crypto.c block: Let format drivers pass @exact 2019-10-28 12:05:30 +01:00
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 bitmap: Enforce maximum bitmap name length 2019-11-18 16:01:34 -06:00
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 block/file-posix.c: extend to use io_uring 2020-01-30 20:59:42 +00:00
file-win32.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
filter-compress.c block: introduce compress filter driver 2020-01-06 13:43:07 +01:00
gluster.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
io.c block: fix crash on zero-length unaligned write and read 2020-02-07 16:46:59 +00:00
io_uring.c block/io_uring: adds userspace completion polling 2020-01-30 20:59:42 +00:00
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 iscsi: Don't access non-existent scsi_lba_status_descriptor 2020-01-27 17:19:53 +01:00
linux-aio.c linux-aio: increasing MAX_EVENTS to a larger hardcoded value 2020-01-13 16:41:45 +00:00
mirror.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
nbd.c nbd: assert that Error** is not NULL in nbd_iter_channel_error 2019-12-18 08:43:19 +01:00
nfs.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
null.c replay: add BH oneshot event for block layer 2019-10-14 17:12:48 +02:00
nvme.c block/nvme: add support for discard 2019-10-28 11:34:35 +01:00
parallels.c Block patches for softfreeze: 2019-10-28 14:40:01 +00:00
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
qcow.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
qcow2-bitmap.c qcow2-bitmaps: fix qcow2_can_store_new_dirty_bitmap 2020-01-06 13:43:06 +01:00
qcow2-cache.c core: replace getpagesize() with qemu_real_host_page_size 2019-10-26 15:38:06 +02:00
qcow2-cluster.c qcow2: Use bs->bl.request_alignment when updating an L1 entry 2020-02-06 13:47:45 +01:00
qcow2-refcount.c qcow2: Don't round the L1 table allocation up to the sector size 2020-02-06 13:47:45 +01:00
qcow2-snapshot.c qcow2: Don't round the L1 table allocation up to the sector size 2020-02-06 13:47:45 +01:00
qcow2-threads.c block/qcow2: refactor encryption code 2019-09-16 15:36:22 +02:00
qcow2.c qcow2: Use BDRV_SECTOR_SIZE instead of the hardcoded value 2020-02-06 13:47:45 +01:00
qcow2.h qcow2: Fix QCOW2_COMPRESSED_SECTOR_MASK 2019-11-07 14:37:46 +01:00
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: Pass truncate exact=true where reasonable 2019-10-28 12:08:45 +01:00
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: Let format drivers pass @exact 2019-10-28 12:05:30 +01:00
rbd.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
replication.c block/backup: use backup-top instead of write notifiers 2019-10-10 10:56:18 +02:00
sheepdog.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
snapshot.c block/snapshot: rename Error ** parameter to more common errp 2019-12-18 08:43:19 +01:00
ssh.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
stream.c job: drop job_drain 2019-09-10 08:58:43 +02:00
throttle-groups.c throttle-groups: fix memory leak in throttle_group_set_limit: 2020-01-06 13:43:06 +01:00
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: add trace events for io_uring 2020-01-30 20:59:42 +00:00
vdi.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
vhdx-endian.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vhdx-log.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
vhdx.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
vhdx.h block/vhdx: Use IEC binary prefixes for size constants 2019-04-30 15:29:00 +02:00
vmdk.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
vpc.c block: Add @exact parameter to bdrv_co_truncate() 2019-10-28 12:00:07 +01:00
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