The 5.15 kernel has been released

>> the popularity of purportedly “stateless” file-sharing approaches like NFS didn't help, either

About eight or ten years ago I wrote a native Orangefs Apache DAV module that supported
locking by setting and unsetting an extended attribute. It passed the DAV correctness testers (I think one of them's name was "cadaver").

If someone locked a file and then didn't unlock it, that was bad :) ...

At the time I figured if two programs tried to lock a file at the same time,
one would win and one would lose, and my lock code just fired off the
lock request without checking any return codes, then it checked to see
if it got the lock, and then returned success or failure back to the caller.
Ida know if this really addressed the race condition, but that's how it worked.

-Mike "by 'native' I mean using the Orangefs API, not the kernel module"