Re: [PATCH 3.16 51/63] xfs: catch inode allocation state mismatch corruption

[Ben Hutchings]

On Sat, 2018-09-22 at 15:25 +1000, Dave Chinner wrote:
> On Sat, Sep 22, 2018 at 01:15:42AM +0100, Ben Hutchings wrote:
> > 3.16.58-rc1 review patch.  If anyone has any objections, please let
> > me know.
> > 
> > ------------------
> > 
> > From: Dave Chinner <dchinner@xxxxxxxxxx>
> > 
> > commit ee457001ed6c6f31ddad69c24c1da8f377d8472d upstream.
> > 
> > We recently came across a V4 filesystem causing memory corruption
> > due to a newly allocated inode being setup twice and being added to
> > the superblock inode list twice. From code inspection, the only way
> > this could happen is if a newly allocated inode was not marked as
> > free on disk (i.e. di_mode wasn't zero).
> 
> ....
> > Signed-Off-By: Dave Chinner <dchinner@xxxxxxxxxx>
> > Reviewed-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> > Tested-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> > Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > [bwh: Backported to 3.16:
> >  - Look up mode in XFS inode, not VFS inode
> >  - Use positive error codes, and EIO instead of EFSCORRUPTED]
> 
> Why EIO?

I believe EIO was the usual error code used for filesystem errors
before EFSCORRUPTED was added.  But now I see xfs had its own private
definition of EFSCORRUPTED.  I'll change this back.

Ben.

-- 
Ben Hutchings
Any sufficiently advanced bug is indistinguishable from a feature.

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