[patch] fs: inode: fix icache pruning locked inode spin protection

[Johannes Weiner <hannes@cmpxchg.org>]

Inodes are added to the head of the superblock LRU list and reclaimed
from the tail.  If trylocking an inode during reclaim fails, it has to
be moved to the head of the list, not the tail, to prevent spinning on
it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
 fs/inode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index 14084b7..852bcbf 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -722,10 +722,10 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
 		/*
 		 * we are inverting the sb->s_inode_lru_lock/inode->i_lock here,
 		 * so use a trylock. If we fail to get the lock, just move the
-		 * inode to the back of the list so we don't spin on it.
+		 * inode to the other end of the list so we don't spin on it.
 		 */
 		if (!spin_trylock(&inode->i_lock)) {
-			list_move_tail(&inode->i_lru, &sb->s_inode_lru);
+			list_move(&inode->i_lru, &sb->s_inode_lru);
 			continue;
 		}
 
-- 
1.7.11.7