1 files changed, 27 insertions, 1 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 120c448f58f8..3418bb62b996 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -396,6 +396,14 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
         return 0;
 }
 
+int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root)
+{
+        finish_current_insert(trans, root->fs_info->extent_root);
+        del_pending_extents(trans, root->fs_info->extent_root);
+        return 0;
+}
+
 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root, u64 blocknr,
                              u64 num_blocks, u32 *refs)
@@ -1374,7 +1382,25 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
                         BUG_ON(ret);
                         continue;
                 }
-                next = read_tree_block(root, blocknr);
+                next = btrfs_find_tree_block(root, blocknr);
+                if (!next || !buffer_uptodate(next)) {
+                        brelse(next);
+                        mutex_unlock(&root->fs_info->fs_mutex);
+                        next = read_tree_block(root, blocknr);
+                        mutex_lock(&root->fs_info->fs_mutex);
+
+                        /* we dropped the lock, check one more time */
+                        ret = lookup_extent_ref(trans, root, blocknr, 1, &refs);
+                        BUG_ON(ret);
+                        if (refs != 1) {
+                                path->slots[*level]++;
+                                brelse(next);
+                                ret = btrfs_free_extent(trans, root,
+                                                        blocknr, 1, 1);
+                                BUG_ON(ret);
+                                continue;
+                        }
+                }
                 WARN_ON(*level <= 0);
                 if (path->nodes[*level-1])
                         btrfs_block_release(root, path->nodes[*level-1]);