Thanks for the explanation! Linux, meanwhile, will[1] in the normal case walk a sequence[2] of hash tables (representing incomplete but up-to-date views of directories) before hitting the filesystem’s vtable or the block I/O layer at all, and on the fast path[3] taking no locks other than the RCU read lock.

[1] https://www.kernel.org/doc/html/latest/filesystems/path-look...

[2] I was under the impression that it could look up an entire path at once when I wrote my grandparent comment; it seems I was wrong, which on reflection makes sense given you can move directories.

[3] https://www.kernel.org/doc/html/latest/filesystems/path-look...