Re: XFS reclaim lock order bug

Dave Chinner
2010-11-23T21:11:24Z

On Tue, Nov 23, 2010 at 11:18:02PM +1100, Nick Piggin wrote:
> Hi,
>
> IIRC I've reported this before. Perhaps it is a false positive, but even
> so it is still annoying that it triggers and turns off lockdep for
> subsequent debugging.
>
> Any chance it can get fixed or properly annotated?

It is supposed to be handled by the re-initialisation of the
ip->i_iolock in ->evict_inode (xfs_fs_evict_inode). An inode found
in the reclaim state must have passed through this reinitialisation,
so from a lockdep perspective the iolock in the vfs path is a
different context to the iolock in the reclaim path. That fixed all
the non-reclaim state related lockdep false positives, so Perhaps
there is an issue with the lockdep reclaim state checking that does
not interact well with re-initialised lock contexts?

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com