Btrfs: Add backrefs and forward refs for subvols and snapshots

[linux-2.6-block.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 93f23a456a361ca0370aa1c44c68c3cfa6686f90..e9c8ebeedd7ee876da479a73e42d28e64e22ff5d 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -831,28 +831,43 @@ static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
        struct btrfs_trans_handle *trans;
        struct inode *parent_inode;
        struct inode *inode;
+       struct btrfs_root *parent_root;
 
        parent_inode = pending->dentry->d_parent->d_inode;
-       trans = btrfs_start_transaction(BTRFS_I(parent_inode)->root, 1);
+       parent_root = BTRFS_I(parent_inode)->root;
+       trans = btrfs_start_transaction(parent_root, 1);
 
        /*
         * insert the directory item
         */
        namelen = strlen(pending->name);
        ret = btrfs_set_inode_index(parent_inode, &index);
-       ret = btrfs_insert_dir_item(trans,
-                           BTRFS_I(parent_inode)->root,
+       ret = btrfs_insert_dir_item(trans, parent_root,
                            pending->name, namelen,
                            parent_inode->i_ino,
                            &pending->root_key, BTRFS_FT_DIR, index);
 
        if (ret)
                goto fail;
-#if 0
-       ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
-                            pending->name, strlen(pending->name), objectid,
-                            root->fs_info->sb->s_root->d_inode->i_ino, 0);
-#endif
+
+       /* 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: