Btrfs: Avoid extent_buffer lru corruption

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

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index c976615..754bc42 100644 (file)
--- 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++) {