1 files changed, 12 insertions, 26 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index cdbb5022da52..88f866f85e7a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -104,7 +104,6 @@ static noinline int record_root_in_trans(struct btrfs_trans_handle *trans,
 {
         if (root->ref_cows && root->last_trans < trans->transid) {
                 WARN_ON(root == root->fs_info->extent_root);
-                WARN_ON(root->root_item.refs == 0);
                 WARN_ON(root->commit_root != root->node);
 
                 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
@@ -720,7 +719,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
 
         key.objectid = objectid;
-        key.offset = 0;
+        /* record when the snapshot was created in key.offset */
+        key.offset = trans->transid;
         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 
         old = btrfs_lock_root_node(root);
@@ -778,24 +778,14 @@ static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
         ret = btrfs_update_inode(trans, parent_root, parent_inode);
         BUG_ON(ret);
 
-        /* add the backref first */
         ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
                                  pending->root_key.objectid,
-                                 BTRFS_ROOT_BACKREF_KEY,
                                  parent_root->root_key.objectid,
                                  parent_inode->i_ino, index, pending->name,
                                  namelen);
 
         BUG_ON(ret);
 
-        /* now add the forward ref */
-        ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
-                                 parent_root->root_key.objectid,
-                                 BTRFS_ROOT_REF_KEY,
-                                 pending->root_key.objectid,
-                                 parent_inode->i_ino, index, pending->name,
-                                 namelen);
-
         inode = btrfs_lookup_dentry(parent_inode, pending->dentry);
         d_instantiate(pending->dentry, inode);
 fail:
@@ -874,7 +864,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         unsigned long timeout = 1;
         struct btrfs_transaction *cur_trans;
         struct btrfs_transaction *prev_trans = NULL;
-        struct extent_io_tree *pinned_copy;
         DEFINE_WAIT(wait);
         int ret;
         int should_grow = 0;
@@ -915,13 +904,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                 return 0;
         }
 
-        pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
-        if (!pinned_copy)
-                return -ENOMEM;
-
-        extent_io_tree_init(pinned_copy,
-                             root->fs_info->btree_inode->i_mapping, GFP_NOFS);
-
         trans->transaction->in_commit = 1;
         trans->transaction->blocked = 1;
         if (cur_trans->list.prev != &root->fs_info->trans_list) {
@@ -1019,6 +1001,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         ret = commit_cowonly_roots(trans, root);
         BUG_ON(ret);
 
+        btrfs_prepare_extent_commit(trans, root);
+
         cur_trans = root->fs_info->running_transaction;
         spin_lock(&root->fs_info->new_trans_lock);
         root->fs_info->running_transaction = NULL;
@@ -1042,8 +1026,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
                sizeof(root->fs_info->super_copy));
 
-        btrfs_copy_pinned(root, pinned_copy);
-
         trans->transaction->blocked = 0;
 
         wake_up(&root->fs_info->transaction_wait);
@@ -1059,8 +1041,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
          */
         mutex_unlock(&root->fs_info->tree_log_mutex);
 
-        btrfs_finish_extent_commit(trans, root, pinned_copy);
-        kfree(pinned_copy);
+        btrfs_finish_extent_commit(trans, root);
 
         /* do the directory inserts of any pending snapshot creations */
         finish_pending_snapshots(trans, root->fs_info);
@@ -1096,8 +1077,13 @@ int btrfs_clean_old_snapshots(struct btrfs_root *root)
 
         while (!list_empty(&list)) {
                 root = list_entry(list.next, struct btrfs_root, root_list);
-                list_del_init(&root->root_list);
-                btrfs_drop_snapshot(root, 0);
+                list_del(&root->root_list);
+
+                if (btrfs_header_backref_rev(root->node) <
+                    BTRFS_MIXED_BACKREF_REV)
+                        btrfs_drop_snapshot(root, 0);
+                else
+                        btrfs_drop_snapshot(root, 1);
         }
         return 0;
 }