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 <kw...@redhat.com>
---
qemu-img.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index c21d999..d3c30a7 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;
}
--
1.6.6.1
