---

yaml
---
r: 374869
b: refs/heads/master
c: 47fb091
h: refs/heads/master
i:
  374867: 8892587
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 30b0463a9394d9e41596e96def5461fe33222f13
+refs/heads/master: 47fb091fb787420cd195e66f162737401cce023f

trunk/fs/btrfs/ctree.c

@@ -1191,6 +1191,13 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq,
 	btrfs_set_header_nritems(eb, n);
 }
 
+/*
+ * Called with eb read locked. If the buffer cannot be rewinded, the same buffer
+ * is returned. If rewind operations happen, a fresh buffer is returned. The
+ * returned buffer is always read-locked. If the returned buffer is not the
+ * input buffer, the lock on the input buffer is released and the input buffer
+ * is freed (its refcount is decremented).
+ */
 static struct extent_buffer *
 tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb,
 		    u64 time_seq)
@@ -1224,8 +1231,11 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb,
 	}
 
 	extent_buffer_get(eb_rewin);
+	btrfs_tree_read_unlock(eb);
 	free_extent_buffer(eb);
 
+	extent_buffer_get(eb_rewin);
+	btrfs_tree_read_lock(eb_rewin);
 	__tree_mod_log_rewind(eb_rewin, time_seq, tm);
 	WARN_ON(btrfs_header_nritems(eb_rewin) >
 		BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root));
@@ -2794,15 +2804,9 @@ int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key,
 				btrfs_clear_path_blocking(p, b,
 							  BTRFS_READ_LOCK);
 			}
+			b = tree_mod_log_rewind(root->fs_info, b, time_seq);
 			p->locks[level] = BTRFS_READ_LOCK;
 			p->nodes[level] = b;
-			b = tree_mod_log_rewind(root->fs_info, b, time_seq);
-			if (b != p->nodes[level]) {
-				btrfs_tree_unlock_rw(p->nodes[level],
-						     p->locks[level]);
-				p->locks[level] = 0;
-				p->nodes[level] = b;
-			}
 		} else {
 			p->slots[level] = slot;
 			unlock_up(p, level, lowest_unlock, 0, NULL);