From cc60e327c0988a5e5288cf7bb78cd9848db800ab Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 29 Apr 2010 14:47:48 +0200 Subject: [PATCH] qemu-img rebase: Fix output image corruption qemu-img rebase must always give clusters in the COW file priority over those in the backing file. As it failed to use number of non-allocated clusters but assumed the maximum, it was possible that allocated clusters were taken from the backing file instead, leading to a corrupted output image. Signed-off-by: Kevin Wolf --- qemu-img.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index c21d9990e..d3c30a74f 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1136,7 +1136,7 @@ static int img_rebase(int argc, char **argv) if (!unsafe) { uint64_t num_sectors; uint64_t sector; - int n, n1; + int n; uint8_t * buf_old; uint8_t * buf_new; @@ -1155,8 +1155,8 @@ static int img_rebase(int argc, char **argv) } /* If the cluster is allocated, we don't need to take action */ - if (bdrv_is_allocated(bs, sector, n, &n1)) { - n = n1; + ret = bdrv_is_allocated(bs, sector, n, &n); + if (ret) { continue; }