Re: Fw: [Bugme-new] [Bug 7662] New: AOE filesystem corruption on Alpha

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Thu, Dec 14, 2006 at 05:48:26PM -0500, Ed L. Cashin wrote:
> ... and when using ext3 on the device.  However, we see problems when
> using XFS.  It appears that the XFS problem is unrelated, because the
> kernel's new lock debugging sees some problems that appear in the
> attached netconsole log.
> 
> XFS passes us a bio with a pointer to a page that has a reference
> count of zero which causes problems when __pskb_pull_tail does a put
> on the page.  With ext3, we only got pages with a reference count
> greater than zero.

It's a kmalloced page.  The same can happen with ext3 aswell, but only
when doing log recovery.  The last time this came up (vs iscsi) the
conclusion was that the driver needs to handle this case.