Commit 5f5bcd80 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

block: Don't call ROUND_UP with negative values 



The behaviour of the ROUND_UP macro with negative numbers isn't obvious.
It happens to do the right thing in this please, but better avoid it.

Suggested-by: default avatarLaszlo Ersek <lersek@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarLaszlo Ersek <lersek@redhat.com>
parent af91f9a7

block.c

+2 −2
Original line number Diff line number Diff line
@@ -2915,8 +2915,8 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, 
        }



        total_sectors = DIV_ROUND_UP(len, BDRV_SECTOR_SIZE);

        max_nb_sectors = MAX(0, ROUND_UP(total_sectors - sector_num,

                                         align >> BDRV_SECTOR_BITS));

        max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),

                                  align >> BDRV_SECTOR_BITS);

        if (max_nb_sectors > 0) {

            ret = drv->bdrv_co_readv(bs, sector_num,

                                     MIN(nb_sectors, max_nb_sectors), qiov);