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Date: Thu, 27 Apr 2017 16:13:02 +0200
From: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20170427141302.GG4805@noname.str.redhat.com>
References: <20170413154334.23708-1-mreitz@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH for-2.10?] block: Do not unref bs->file on
 error in BD's open
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To: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>, qemu-stable@nongnu.org

Am 13.04.2017 um 17:43 hat Max Reitz geschrieben:
> The block layer takes care of removing the bs->file child if the block
> driver's bdrv_open()/bdrv_file_open() implementation fails. The block
> driver therefore does not need to do so, and indeed should not unless it
> sets bs->file to NULL afterwards -- because if this is not done, the
> bdrv_unref_child() in bdrv_open_inherit() will dereference the freed
> memory block at bs->file afterwards, which is not good.
> 
> We can now decide whether to add a "bs->file = NULL;" after each of the
> offending bdrv_unref_child() invocations, or just drop them altogether.
> The latter is simpler, so let's do that.
> 
> Cc: qemu-stable <qemu-stable@nongnu.org>
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Thanks, applied to block-next.

Kevin