From 2727ccc950ae17375b15005403e1c35ba8fec1df Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Fri, 25 Jun 2010 11:08:40 +1000 Subject: [PATCH] xfs: unregister inode shrinker before freeing filesystem structures Currently we don't remove the XFS mount from the shrinker list until late in the unmount path. By this time, we have already torn down the internals of the filesystem (e.g. the per-ag structures), and hence if the shrinker is executed between the teardown and the unregistering, the shrinker will get NULL per-ag structure pointers and panic trying to dereference them. Fix this by removing the xfs mount from the shrinker list before tearing down it's internal structures. Signed-off-by: Dave Chinner Reviewed-by: Eric Sandeen Signed-off-by: Alex Elder --- fs/xfs/linux-2.6/xfs_super.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c index 22faaea5f3e1..c734bc6cf32e 100644 --- a/fs/xfs/linux-2.6/xfs_super.c +++ b/fs/xfs/linux-2.6/xfs_super.c @@ -1156,9 +1156,13 @@ xfs_fs_put_super( XFS_bflush(mp->m_ddev_targp); + /* + * Unregister the memory shrinker before we tear down the mount + * structure so we don't have memory reclaim racing with us here. + */ + xfs_inode_shrinker_unregister(mp); xfs_unmountfs(mp); xfs_freesb(mp); - xfs_inode_shrinker_unregister(mp); xfs_icsb_destroy_counters(mp); xfs_close_devices(mp); xfs_free_fsname(mp); -- 2.20.1