On Wed, Feb 16, 2011 at 12:56:55PM -0800, Greg KH wrote:
> On Wed, Feb 16, 2011 at 12:56:22PM -0800, Greg KH wrote:
> > On Mon, Jan 10, 2011 at 01:10:16PM -0700, [email protected] wrote:
> > > From: Dave Chinner <[email protected]>
> > > 
> > > Upstream commit: 4536f2ad8b330453d7ebec0746c4374eadd649b1
> > > 
> > > Commit 7124fe0a5b619d65b739477b3b55a20bf805b06d ("xfs: validate untrusted 
> > > inode
> > > numbers during lookup") changes the inode lookup code to do btree lookups 
> > > for
> > > untrusted inode numbers. This change made an invalid assumption about the
> > > alignment of inodes and hence incorrectly calculated the first inode in 
> > > the
> > > cluster. As a result, some inode numbers were being incorrectly considered
> > > invalid when they were actually valid.
> > > 
> > > The issue was not picked up by the xfstests suite because it always runs 
> > > fsr
> > > and dump (the two utilities that utilise the bulkstat interface) on cache 
> > > hot
> > > inodes and hence the lookup code in the cold cache path was not 
> > > sufficiently
> > > exercised to uncover this intermittent problem.
> > > 
> > > Fix the issue by relaxing the btree lookup criteria and then checking if 
> > > the
> > > record returned contains the inode number we are lookup for. If it we get 
> > > an
> > > incorrect record, then the inode number is invalid.
> > > 
> > > Cc: <[email protected]>
> > > Signed-off-by: Dave Chinner <[email protected]>
> > > Reviewed-by: Christoph Hellwig <[email protected]>
> > > [dannf: Backported to 2.6.32.y]
> > 
> > This still doesn't apply to the .32-longterm tree, care to try again?
> >     patching file fs/xfs/xfs_ialloc.c
> >     Hunk #1 FAILED at 1220.
> >     Hunk #2 FAILED at 1236.
> >     Hunk #3 FAILED at 1255.
> >     3 out of 3 hunks FAILED -- saving rejects to file 
> > fs/xfs/xfs_ialloc.c.rej
> 
> Oh wait, you want the first 5 patches applied first, doh, sorry for the
> noise, I'll work on that after lunch...
> 

Right - though, you might hold off until this is resolved:
  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/692848

Dave has been working with the user to help diagnose the problem; last
I saw he was waiting for some feedback from the user to rule out a
pre-existing fs corruption issue. I just noticed that the user
provided that info a few days ago, which I believe tells us that there
is likely an alignment issue with the backport.

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