Commit d12765dc authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: use label to deduplicate error path at btrfs_force_cow_block() 



At btrfs_force_cow_block() we have several error paths that need to
unlock the "cow" extent buffer, drop the reference on it and then return
an error. This is a bit verbose so add a label where we perform these
tasks and make the error paths jump to that label.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent bb386803

fs/btrfs/ctree.c

+12 −21
Original line number Diff line number Diff line
@@ -588,19 +588,15 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, 


	ret = update_ref_for_cow(trans, root, buf, cow, &last_ref);

	if (ret) {

		btrfs_tree_unlock(cow);

		free_extent_buffer(cow);

		btrfs_abort_transaction(trans, ret);

		return ret;

		goto error_unlock_cow;

	}



	if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) {

		ret = btrfs_reloc_cow_block(trans, root, buf, cow);

		if (ret) {

			btrfs_tree_unlock(cow);

			free_extent_buffer(cow);

			btrfs_abort_transaction(trans, ret);

			return ret;

			goto error_unlock_cow;

		}

	}
@@ -612,10 +608,8 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, 


		ret = btrfs_tree_mod_log_insert_root(root->node, cow, true);

		if (ret < 0) {

			btrfs_tree_unlock(cow);

			free_extent_buffer(cow);

			btrfs_abort_transaction(trans, ret);

			return ret;

			goto error_unlock_cow;

		}

		atomic_inc(&cow->refs);

		rcu_assign_pointer(root->node, cow);
@@ -625,20 +619,16 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, 
		free_extent_buffer(buf);

		add_root_to_dirty_list(root);

		if (ret < 0) {

			btrfs_tree_unlock(cow);

			free_extent_buffer(cow);

			btrfs_abort_transaction(trans, ret);

			return ret;

			goto error_unlock_cow;

		}

	} else {

		WARN_ON(trans->transid != btrfs_header_generation(parent));

		ret = btrfs_tree_mod_log_insert_key(parent, parent_slot,

						    BTRFS_MOD_LOG_KEY_REPLACE);

		if (ret) {

			btrfs_tree_unlock(cow);

			free_extent_buffer(cow);

			btrfs_abort_transaction(trans, ret);

			return ret;

			goto error_unlock_cow;

		}

		btrfs_set_node_blockptr(parent, parent_slot,

					cow->start);
@@ -648,19 +638,15 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, 
		if (last_ref) {

			ret = btrfs_tree_mod_log_free_eb(buf);

			if (ret) {

				btrfs_tree_unlock(cow);

				free_extent_buffer(cow);

				btrfs_abort_transaction(trans, ret);

				return ret;

				goto error_unlock_cow;

			}

		}

		ret = btrfs_free_tree_block(trans, btrfs_root_id(root), buf,

					    parent_start, last_ref);

		if (ret < 0) {

			btrfs_tree_unlock(cow);

			free_extent_buffer(cow);

			btrfs_abort_transaction(trans, ret);

			return ret;

			goto error_unlock_cow;

		}

	}

	if (unlock_orig)
@@ -669,6 +655,11 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, 
	btrfs_mark_buffer_dirty(trans, cow);

	*cow_ret = cow;

	return 0;



error_unlock_cow:

	btrfs_tree_unlock(cow);

	free_extent_buffer(cow);

	return ret;

}



static inline int should_cow_block(struct btrfs_trans_handle *trans,