Re: [Qemu-devel] [PATCH] qcow2: Fix refcount block allocation during qcow2_allocate_cluster_at()

[Marcelo Tosatti]

On Fri, Apr 20, 2012 at 03:56:01PM +0200, Kevin Wolf wrote:
> Refcount block allocation and refcount table growth rely on
> s->free_cluster_index pointing to somewhere after the current
> allocation. Change qcow2_allocate_cluster_at() to fulfill this
> assumption.
> 
> Without this change it could happen that a newly allocated refcount
> block and the allocated data block point to the same area in the image
> file, causing data corruption in the long run.
> 
> This fixes a bug that became first visible after commit 250196f1.
> 
> Signed-off-by: Kevin Wolf <address@hidden>

Kevin,

This patch fixes explicit filesystem errors (qemu-img check also OK), 
but autotest is still failing, see attached screenshot. It is not
reproducible without

f081987ad20a8c8dc391deded55161ea8d38be5f

f8-64-failure.png
Description: PNG image