Patch "xfs: fix inode validity check in xfs_iflush_cluster" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    xfs: fix inode validity check in xfs_iflush_cluster

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xfs-fix-inode-validity-check-in-xfs_iflush_cluster.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 51b07f30a71c27405259a0248206ed4e22adbee2 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@redhat.com>
Date: Wed, 18 May 2016 13:54:22 +1000
Subject: xfs: fix inode validity check in xfs_iflush_cluster

From: Dave Chinner <dchinner@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 <dchinner@redhat.com>

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@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


Patches currently in stable-queue which might be from dchinner@redhat.com are

queue-4.4/xfs-xfs_iflush_cluster-fails-to-abort-on-error.patch
queue-4.4/xfs-disallow-rw-remount-on-fs-with-unknown-ro-compat-features.patch
queue-4.4/xfs-fix-inode-validity-check-in-xfs_iflush_cluster.patch
queue-4.4/xfs-skip-stale-inodes-in-xfs_iflush_cluster.patch
queue-4.4/xfs-handle-dquot-buffer-readahead-in-log-recovery-correctly.patch
queue-4.4/xfs-don-t-wrap-growfs-agfl-indexes.patch