If a snapshot is deleted and the parent directory is fsynced, the log cannot be replayed during the next mount operation, which prevents the file system from mounting. This issue is solvable by wiping the log trees with the btrfs-zero-log tool, but this method is very inconvenient, as it results in the loss of any data and metadata that was fsynced before the parent directory was fsynced. (Bug ID 24424719)