xfs: fix inode validity check in xfs_iflush_cluster

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 <dchinner@redhat.com>

cc: <stable@vger.kernel.org> # 3.10.x-
Discovered-by: Brain Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Dave Chinner 2016-05-18 13:54:22 +10:00 committed by Dave Chinner
parent b1438f4779
commit 51b07f30a7

View File

@ -3205,13 +3205,13 @@ 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