In response to a request to a file system to perform a requested update, a lock of a first node in a file system can be acquired, and an update of the first node can be performed while the lock of the first node is held. Also in response to the request, a lock of a second node can be acquired, and an update of the second node, which reflects the update of the first node, can be performed while the lock of the second node is held. The update of the first node can be independent of acquiring the lock of the second node. A file system can allow a pair of update operations to be performed in parallel where both operations include updating the same container node. Additionally, while a file system is running, new namespace types can be defined, and the file system can be extended to manage nodes within the new namespace types.