From f0623f334b23dc9334ac9d227cc467c266b8b2c6 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Wed, 9 Oct 2013 09:50:21 +0200 Subject: [PATCH 09/11] block: don't lose data from last incomplete sector RH-Author: Fam Zheng Message-id: <1381312223-7074-2-git-send-email-famz@redhat.com> Patchwork-id: 54793 O-Subject: [RHEL-7 qemu-kvm PATCH 1/3] block: don't lose data from last incomplete sector Bugzilla: 1017049 RH-Acked-by: Paolo Bonzini RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Miroslav Rezanina To read the last sector that is not aligned to sector boundary, current code for growable backends, since commit 893a8f6 "block: Produce zeros when protocols reading beyond end of file", drops the data and directly returns zeroes. That is incorrect. Signed-off-by: Fam Zheng Signed-off-by: Stefan Hajnoczi (cherry picked from commit bcb9d66e8590151967e1dbe3724eec7ec71392e0) Signed-off-by: Fam Zheng --- block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Signed-off-by: Miroslav Rezanina --- block.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/block.c b/block.c index a3bc800..bd52c13 100644 --- a/block.c +++ b/block.c @@ -2567,7 +2567,7 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, goto out; } - total_sectors = len >> BDRV_SECTOR_BITS; + total_sectors = (len + BDRV_SECTOR_SIZE - 1) >> BDRV_SECTOR_BITS; max_nb_sectors = MAX(0, total_sectors - sector_num); if (max_nb_sectors > 0) { ret = drv->bdrv_co_readv(bs, sector_num, -- 1.7.1