inode: move inode to a different list inside lock

When removing an element from the lru, this will be done today after the lock
is released. This is a clear mistake, although we are not sure if the bugs we
are seeing are related to this. All list manipulations are done inside the
lock, and so should this one.
Signed-off-by: NGlauber Costa <glommer@openvz.org>
Tested-by: NMichal Hocko <mhocko@suse.cz>
Cc: Dave Chinner <dchinner@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/inode.c

@@ -735,9 +735,9 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
 
 	WARN_ON(inode->i_state & I_NEW);
 	inode->i_state |= I_FREEING;
+	list_move(&inode->i_lru, freeable);
 	spin_unlock(&inode->i_lock);
 
-	list_move(&inode->i_lru, freeable);
 	this_cpu_dec(nr_unused);
 	return LRU_REMOVED;
 }