diff options
author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2020-10-21 17:58:39 +0300 |
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committer | Max Reitz <mreitz@redhat.com> | 2020-12-18 12:35:55 +0100 |
commit | 2153994e2efad92092a60bf6d1947f4a721ae46d (patch) | |
tree | bb917f84ccac6a46f9d015a9911d7a38076f5c4e /include/block/block.h | |
parent | 071b474f5457c166f90a2c379508dc92b92dc1ae (diff) | |
download | qemu-2153994e2efad92092a60bf6d1947f4a721ae46d.zip |
block: simplify comment to BDRV_REQ_SERIALISING
1. BDRV_REQ_NO_SERIALISING doesn't exist already, don't mention it.
2. We are going to add one more user of BDRV_REQ_SERIALISING, so
comment about backup becomes a bit confusing here. The use case in
backup is documented in block/backup.c, so let's just drop
duplication here.
3. The fact that BDRV_REQ_SERIALISING is only for write requests is
omitted. Add a note.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20201021145859.11201-2-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'include/block/block.h')
-rw-r--r-- | include/block/block.h | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/include/block/block.h b/include/block/block.h index 5b81e33e94..a3f3dcc88f 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -63,16 +63,7 @@ typedef enum { * content. */ BDRV_REQ_WRITE_UNCHANGED = 0x40, - /* - * BDRV_REQ_SERIALISING forces request serialisation for writes. - * It is used to ensure that writes to the backing file of a backup process - * target cannot race with a read of the backup target that defers to the - * backing file. - * - * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to - * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be - * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long. - */ + /* Forces request serialisation. Use only with write requests. */ BDRV_REQ_SERIALISING = 0x80, /* Execute the request only if the operation can be offloaded or otherwise |