From bd6ce734563c0308b021c013f1e622ff185be60b Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 6 Aug 2018 16:35:52 +0200 Subject: [PATCH 03/13] qemu-img: Fix assert when mapping unaligned raw file RH-Author: Max Reitz Message-id: <20180806163553.13344-2-mreitz@redhat.com> Patchwork-id: 81647 O-Subject: [RHV-7.6 qemu-kvm-rhev PATCH 1/2] qemu-img: Fix assert when mapping unaligned raw file Bugzilla: 1601310 RH-Acked-by: Eric Blake RH-Acked-by: Kevin Wolf RH-Acked-by: John Snow From: Eric Blake Commit a290f085 exposed a latent bug in qemu-img map introduced during the conversion of block status to be byte-based. Earlier in commit 5e344dd8, the internal interface get_block_status() switched to take byte-based parameters, but still called a sector-based block layer function; as such, rounding was added in the lone caller to obey the contract. However, commit 237d78f8 changed get_block_status() to truly be byte-based, at which point rounding to sector boundaries can result in calling bdrv_block_status() with 'bytes == 0' (a coding error) when the boundary between data and a hole falls mid-sector (true for the past-EOF implicit hole present in POSIX files). Fix things by removing the rounding that is now no longer necessary. See also https://bugzilla.redhat.com/1589738 Fixes: 237d78f8 Reported-by: Dan Kenigsberg Reported-by: Nir Soffer Reported-by: Maor Lipchuk CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake Signed-off-by: Kevin Wolf (cherry picked from commit e0b371ed5e2db079051139136fd0478728b6a58f) Signed-off-by: Max Reitz Signed-off-by: Miroslav Rezanina --- qemu-img.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/qemu-img.c b/qemu-img.c index c9ccc1e..f42750a 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2925,7 +2925,7 @@ static int img_map(int argc, char **argv) int64_t n; /* Probe up to 1 GiB at a time. */ - n = QEMU_ALIGN_DOWN(MIN(1 << 30, length - offset), BDRV_SECTOR_SIZE); + n = MIN(1 << 30, length - offset); ret = get_block_status(bs, offset, n, &next); if (ret < 0) { -- 1.8.3.1