4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dave Chinner <dchin...@redhat.com> commit 51b07f30a71c27405259a0248206ed4e22adbee2 upstream. Some careless idiot(*) wrote crap code in commit 1a3e8f3 ("xfs: convert inode cache lookups to use RCU locking") back in late 2010, and so xfs_iflush_cluster checks the wrong inode for whether it is still valid under RCU protection. Fix it to lock and check the correct inode. (*) Careless-idiot: Dave Chinner <dchin...@redhat.com> Discovered-by: Brain Foster <bfos...@redhat.com> Signed-off-by: Dave Chinner <dchin...@redhat.com> Reviewed-by: Christoph Hellwig <h...@lst.de> Signed-off-by: Dave Chinner <da...@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- fs/xfs/xfs_inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -3220,13 +3220,13 @@ xfs_iflush_cluster( * We need to check under the i_flags_lock for a valid inode * here. Skip it if it is not valid or the wrong inode. */ - spin_lock(&ip->i_flags_lock); - if (!ip->i_ino || + spin_lock(&iq->i_flags_lock); + if (!iq->i_ino || (XFS_INO_TO_AGINO(mp, iq->i_ino) & mask) != first_index) { - spin_unlock(&ip->i_flags_lock); + spin_unlock(&iq->i_flags_lock); continue; } - spin_unlock(&ip->i_flags_lock); + spin_unlock(&iq->i_flags_lock); /* * Do an un-protected check to see if the inode is dirty and