block: Fix is_allocated_above with resized files

Submitted by Vishvananda Ishaya on Jan. 24, 2013, 6:02 p.m.

Details

Message ID 1359050528-52668-1-git-send-email-vishvananda@gmail.com
State New
Headers show

Commit Message

Vishvananda Ishaya Jan. 24, 2013, 6:02 p.m.
In an image chain, if the base image is smaller than the current
image, we need to make sure to use the current images count of
unallocated blocks once we get to the end of the base image. Without
this change the code will return 0 blocks when it gets to the end
of the base image and mirror_run will fail its assertion.

Signed-off-by: Vishvananda Ishaya <vishvananda@gmail.com>
---
Fixes https://bugs.launchpad.net/qemu/+bug/1103868

 block.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Stefan Hajnoczi Jan. 29, 2013, 2:51 p.m.
On Thu, Jan 24, 2013 at 10:02:08AM -0800, Vishvananda Ishaya wrote:
> In an image chain, if the base image is smaller than the current
> image, we need to make sure to use the current images count of
> unallocated blocks once we get to the end of the base image. Without
> this change the code will return 0 blocks when it gets to the end
> of the base image and mirror_run will fail its assertion.
> 
> Signed-off-by: Vishvananda Ishaya <vishvananda@gmail.com>
> ---
> Fixes https://bugs.launchpad.net/qemu/+bug/1103868
> 
>  block.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan

Patch hide | download patch | download mbox

diff --git a/block.c b/block.c
index 6fa7c90..6474d9e 100644
--- a/block.c
+++ b/block.c
@@ -2831,7 +2831,9 @@  int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
          *
          * [sector_num+x, nr_sectors] allocated.
          */
-        if (n > pnum_inter) {
+        if (n > pnum_inter &&
+            (intermediate == top ||
+             sector_num + pnum_inter < intermediate->total_sectors)) {
             n = pnum_inter;
         }