Commit 968d8b06 authored by Denis V. Lunev's avatar Denis V. Lunev Committed by Stefan Hajnoczi
Browse files

block: fix race in bdrv_co_discard with drive-mirror 



Actually we must set dirty bitmap dirty after we have written all our
zeroes for correct processing in drive mirror code. In the other case
we can face not zeroes in this area in mirror_iteration.

Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Reviewed-by: default avatarVladimir <Sementsov-Ogievskiy&lt;vsementsov@virtuozzo.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Message-id: 1466093381-6120-3-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 3a36e474

block/io.c

+2 −1
Original line number Diff line number Diff line
@@ -2349,7 +2349,6 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, 


    tracked_request_begin(&req, bs, sector_num << BDRV_SECTOR_BITS,

                          nb_sectors << BDRV_SECTOR_BITS, BDRV_TRACKED_DISCARD);

    bdrv_set_dirty(bs, sector_num, nb_sectors);



    max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);

    while (nb_sectors > 0) {
@@ -2398,6 +2397,8 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, 
    }

    ret = 0;

out:

    bdrv_set_dirty(bs, req.offset >> BDRV_SECTOR_BITS,

                   req.bytes >> BDRV_SECTOR_BITS);

    tracked_request_end(&req);

    return ret;

}