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| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2022-02-15 13:16:09 +0100 |
|---|---|---|
| committer | Hanna Reitz <hreitz@redhat.com> | 2022-03-07 09:19:20 +0100 |
| commit | 45e62b464a5fa62f0f005b76f59ad587944cd55f (patch) | |
| tree | 6d36c058260d83f60888847b76cd19d017639b0e /include/block | |
| parent | b0ea6c98fa2431b9e24b3a53b8b42c960ccf3dba (diff) | |
| download | qemu-45e62b464a5fa62f0f005b76f59ad587944cd55f.zip qemu-45e62b464a5fa62f0f005b76f59ad587944cd55f.tar.gz qemu-45e62b464a5fa62f0f005b76f59ad587944cd55f.tar.bz2 | |
block: fix preallocate filter: don't do unaligned preallocate requests
There is a bug in handling BDRV_REQ_NO_WAIT flag: we still may wait in
wait_serialising_requests() if request is unaligned. And this is
possible for the only user of this flag (preallocate filter) if
underlying file is unaligned to its request_alignment on start.
So, we have to fix preallocate filter to do only aligned preallocate
requests.
Next, we should fix generic block/io.c somehow. Keeping in mind that
preallocate is the only user of BDRV_REQ_NO_WAIT and that we have to
fix its behavior now, it seems more safe to just assert that we never
use BDRV_REQ_NO_WAIT with unaligned requests and add corresponding
comment. Let's do so.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Message-Id: <20220215121609.38570-1-vsementsov@virtuozzo.com>
[hreitz: Rebased on block GS/IO split]
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Diffstat (limited to 'include/block')
| -rw-r--r-- | include/block/block-common.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/block/block-common.h b/include/block/block-common.h index 0c5dc4a..fdb7306 100644 --- a/include/block/block-common.h +++ b/include/block/block-common.h @@ -112,7 +112,8 @@ typedef enum { /* * If we need to wait for other requests, just fail immediately. Used - * only together with BDRV_REQ_SERIALISING. + * only together with BDRV_REQ_SERIALISING. Used only with requests aligned + * to request_alignment (corresponding assertions are in block/io.c). */ BDRV_REQ_NO_WAIT = 0x400, |