On fri, 27 Jul 2012 16:52:21 +0900, Hidetoshi Seto wrote:

quoted

 # ll /mnt/1/snap0/1
 total 0
 [None]
 # cd /mnt/1/snap0/1/snap0
 [Enter a unexisted directory successfully...]

I confirmed that "mkdir snap0" failed with "File exists" and
that rmdir can remove the directory snap0. So it is a kind of
"invisible" rather than "unexisted".

I think it is not like the typically invisible directories on linux, and in the users'
view, this directory should not exist, in other words, it is a unexisted directory to
the users, so I use "unexisted".

(snip)

quoted

@@ -1062,17 +1068,33 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	ret = btrfs_reloc_post_snapshot(trans, pending);
 	if (ret)
 		goto abort_trans;
+
+	ret = btrfs_insert_dir_item(trans, parent_root,
+				    dentry->d_name.name, dentry->d_name.len,
+				    parent_inode, &key,
+				    BTRFS_FT_DIR, index);
+	/* We have check the name at the beginning, so it is impossible. */
+	BUG_ON(ret == -EEXIST);
+	if (ret)
+		goto abort_trans;
+
+	btrfs_i_size_write(parent_inode, parent_inode->i_size +
+					 dentry->d_name.len * 2);
+	ret = btrfs_update_inode(trans, parent_root, parent_inode);
+	if (ret)
+		goto abort_trans;
 fail:
 	dput(parent);
 	trans->block_rsv = rsv;
 no_free_objectid:
 	kfree(new_root_item);
 root_item_alloc_fail:
+	btrfs_free_path(path);
+path_alloc_fail:
 	btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
 	return ret;
 
 abort_trans:
-	dput(parent);

I think you can remove this line in your 1/2 patch.

Yes. will be modified in the next version of the patches.

quoted

 	btrfs_abort_transaction(trans, root, ret);
 	goto fail;
 }

@@ -1386,13 +1408,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	 */
 	mutex_lock(&root->fs_info->reloc_mutex);
 
-	ret = btrfs_run_delayed_items(trans, root);
+	ret = create_pending_snapshots(trans, root->fs_info);
 	if (ret) {
 		mutex_unlock(&root->fs_info->reloc_mutex);
 		goto cleanup_transaction;
 	}
 
-	ret = create_pending_snapshots(trans, root->fs_info);
+	ret = btrfs_run_delayed_items(trans, root);
 	if (ret) {
 		mutex_unlock(&root->fs_info->reloc_mutex);
 		goto cleanup_transaction;

It would be nice to have a patch description to tell why you
have to change the order here.

OK, I will add comment in the next version of the patches.

Thanks for your review.

Miao