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Date: Fri, 8 Aug 2014 11:15:28 +0200
From: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20140808091527.GE4118@noname.redhat.com>
References: <1407444475-19516-1-git-send-email-mreitz@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 3/3] block: Catch !bs->drv in bdrv_check()
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To: Max Reitz <mreitz@redhat.com>
Cc: qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>

Am 07.08.2014 um 22:47 hat Max Reitz geschrieben:
> qemu-img check calls bdrv_check() twice if the first run repaired some
> inconsistencies. If the first run however again triggered corruption
> prevention (on qcow2) due to very bad inconsistencies, bs->drv may be
> NULL afterwards. Thus, bdrv_check() should check whether bs->drv is set.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>

I suppose there was a real case of this happening? I think bdrv_check()
triggering corruption prevention is a rather bad sign. The most
important point for image repair should be that it doesn't make the
situation any worse. Smells like a follow-up patch to the qcow2 code.

Kevin