Le Friday 17 Jan 2014 à 15:15:06 (+0100), Kevin Wolf a écrit :
> Odd file sizes could make bdrv_aligned_preadv() shorten the request in
> non-aligned ways. Fix it by rounding to the required alignment instead
> of 512 bytes.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> ---
> block.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/block.c b/block.c
> index 18dcd43..d7156ce 100644
> --- a/block.c
> +++ b/block.c
> @@ -2730,7 +2730,7 @@ err:
> */
> static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
> BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
> - QEMUIOVector *qiov, int flags)
> + int64_t align, QEMUIOVector *qiov, int flags)
> {
> BlockDriver *drv = bs->drv;
> int ret;
> @@ -2778,7 +2778,8 @@ static int coroutine_fn
> bdrv_aligned_preadv(BlockDriverState *bs,
> }
>
> total_sectors = DIV_ROUND_UP(len, BDRV_SECTOR_SIZE);
> - max_nb_sectors = MAX(0, total_sectors - sector_num);
> + max_nb_sectors = MAX(0, ROUND_UP(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);
> @@ -2864,7 +2865,7 @@ static int coroutine_fn
> bdrv_co_do_preadv(BlockDriverState *bs,
> }
>
> tracked_request_begin(&req, bs, offset, bytes, false);
> - ret = bdrv_aligned_preadv(bs, &req, offset, bytes,
> + ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
> use_local_qiov ? &local_qiov : qiov,
> flags);
> tracked_request_end(&req);
> --
> 1.8.1.4
>
>
Reviewed-by: Benoit Canet <ben...@irqsave.net>
