Re: [Qemu-devel] [PATCH for-2.8 v2] qcow2: Don't strand clusters near 2G intervals during commit

[Kevin Wolf]

Am 05.12.2016 um 16:49 hat Eric Blake geschrieben:
> The qcow2_make_empty() function is reached during 'qemu-img commit',
> in order to clear out ALL clusters of an image.  However, if the
> image cannot use the fast code path (true if the image is format
> 0.10, or if the image contains a snapshot), the cluster size is
> larger than 512, and the image is larger than 2G in size, then our
> choice of sector_step causes problems.  Since it is not cluster
> aligned, but qcow2_discard_clusters() silently ignores an unaligned
> head or tail, we are leaving clusters allocated.
> 
> Enhance the testsuite to expose the flaw, and patch the problem by
> ensuring our step size is aligned.
> 
> Signed-off-by: Eric Blake <address@hidden>

Thanks, applied to the block branch.

Kevin