Btrfs: Avoid extent_buffer lru corruption

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index c976615dcda3..754bc42c162a 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -2047,7 +2047,7 @@ static int add_lru(struct extent_map_tree *tree, struct extent_buffer *eb)
                         rm = list_entry(tree->buffer_lru.prev,
                                         struct extent_buffer, lru);
                         tree->lru_size--;
-                        list_del(&rm->lru);
+                        list_del_init(&rm->lru);
                         free_extent_buffer(rm);
                 }
         } else
@@ -2187,6 +2187,9 @@ lru_add:
         return eb;
 
 fail:
+        spin_lock(&tree->lru_lock);
+        list_del_init(&eb->lru);
+        spin_unlock(&tree->lru_lock);
         if (!atomic_dec_and_test(&eb->refs))
                 return NULL;
         for (index = 0; index < i; index++) {
@@ -2246,6 +2249,9 @@ lru_add:
         spin_unlock(&tree->lru_lock);
         return eb;
 fail:
+        spin_lock(&tree->lru_lock);
+        list_del_init(&eb->lru);
+        spin_unlock(&tree->lru_lock);
         if (!atomic_dec_and_test(&eb->refs))
                 return NULL;
         for (index = 0; index < i; index++) {