---

yaml
---
r: 318865
b: refs/heads/master
c: 594831c
h: refs/heads/master
i:
  318863: 0f86bff
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e64860aa05048fa7a8483ca698b17c2caf5625cf
+refs/heads/master: 594831c4b232b094d645503ecedec2e35dcebdf3

trunk/fs/btrfs/extent_io.c

@@ -4123,11 +4123,10 @@ static void check_buffer_tree_ref(struct extent_buffer *eb)
 	 * So bump the ref count first, then set the bit.  If someone
 	 * beat us to it, drop the ref we added.
 	 */
-	if (!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
+	spin_lock(&eb->refs_lock);
+	if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
 		atomic_inc(&eb->refs);
-		if (test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
-			atomic_dec(&eb->refs);
-	}
+	spin_unlock(&eb->refs_lock);
 }
 
 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
@@ -4239,9 +4238,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 		goto free_eb;
 	}
 	/* add one reference for the tree */
-	spin_lock(&eb->refs_lock);
 	check_buffer_tree_ref(eb);
-	spin_unlock(&eb->refs_lock);
 	spin_unlock(&tree->buffer_lock);
 	radix_tree_preload_end();