Commit 39020d8a authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: do not BUG_ON() on tree mod log failure at balance_level() 



At balance_level(), instead of doing a BUG_ON() in case we fail to record
tree mod log operations, do a transaction abort and return the error to
the callers. There's really no need for the BUG_ON() as we can release
all resources in this context, and we have to abort because other future
tree searches that use the tree mod log (btrfs_search_old_slot()) may get
inconsistent results if other operations modify the tree after that
failure and before the tree mod log based search.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
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 40b0a749

fs/btrfs/ctree.c

+14 −3
Original line number Diff line number Diff line
@@ -1054,7 +1054,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, 
		}



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

		BUG_ON(ret < 0);

		if (ret < 0) {

			btrfs_tree_unlock(child);

			free_extent_buffer(child);

			btrfs_abort_transaction(trans, ret);

			goto enospc;

		}

		rcu_assign_pointer(root->node, child);



		add_root_to_dirty_list(root);
@@ -1142,7 +1147,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, 
			btrfs_node_key(right, &right_key, 0);

			ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1,

					BTRFS_MOD_LOG_KEY_REPLACE);

			BUG_ON(ret < 0);

			if (ret < 0) {

				btrfs_abort_transaction(trans, ret);

				goto enospc;

			}

			btrfs_set_node_key(parent, &right_key, pslot + 1);

			btrfs_mark_buffer_dirty(parent);

		}
@@ -1188,7 +1196,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, 
		btrfs_node_key(mid, &mid_key, 0);

		ret = btrfs_tree_mod_log_insert_key(parent, pslot,

						    BTRFS_MOD_LOG_KEY_REPLACE);

		BUG_ON(ret < 0);

		if (ret < 0) {

			btrfs_abort_transaction(trans, ret);

			goto enospc;

		}

		btrfs_set_node_key(parent, &mid_key, pslot);

		btrfs_mark_buffer_dirty(parent);

	}