From 4b6c9d80b06057886e35650b904fe332ae14d0bd Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 4 Dec 2013 12:13:10 +0100 Subject: [PATCH 19/37] block: Make zero-after-EOF work with larger alignment Message-id: <1392117622-28812-20-git-send-email-kwolf@redhat.com> Patchwork-id: 57184 O-Subject: [RHEL-7.0 qemu-kvm PATCH v2 19/37] block: Make zero-after-EOF work with larger alignment Bugzilla: 748906 RH-Acked-by: Laszlo Ersek RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Max Reitz 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 Reviewed-by: Max Reitz Reviewed-by: Benoit Canet (cherry picked from commit ec746e10cb2e6276a8d2e036454792fe0674864a) Signed-off-by: Kevin Wolf --- block.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- block.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/block.c b/block.c index feeab4e..6317321 100644 --- a/block.c +++ b/block.c @@ -2748,7 +2748,7 @@ 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; @@ -2796,7 +2796,8 @@ 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); @@ -2882,7 +2883,7 @@ 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); -- 1.7.1