Commit f13ce1be authored by Denis V. Lunev's avatar Denis V. Lunev Committed by Kevin Wolf
Browse files

block: fix alignment calculations in bdrv_co_do_zero_pwritev 



tail_padding_bytes is calculated wrong. F.e. for
    offset = 0
    bytes = 2048
    align = 512
we will have tail_padding_bytes = 512 which is definitely wrong. The patch
fixes that arithmetics.

Fortunately this problem is harmless, we will have 1 extra allocation and
free thus there is no need to put this into stable. The problem is here
from the very beginning.

Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent de234897

block/io.c

+1 −1
Original line number Diff line number Diff line
@@ -1444,7 +1444,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child, 
    int ret = 0;



    head_padding_bytes = offset & (align - 1);

    tail_padding_bytes = align - ((offset + bytes) & (align - 1));

    tail_padding_bytes = (align - (offset + bytes)) & (align - 1);





    assert(flags & BDRV_REQ_ZERO_WRITE);