To more support `man fcntl` and the case:

As for F_SETLK, but if a conflicting lock is held on the file, then wait for that lock to be released. If a signal is caught while waiting, then the call is  interrupted and (after the signal handler has returned) returns immediately (with return value -1 and errno set to EINTR; see signal(7)).

we need the cancellation feature that is recently introduced upstream. There is a kernel and a user space dependency to support such handling. This issue is for the dlm user space part to backport commit a6b13f3 ("fs: dlm: implement DLM_PLOCK_OP_CANCEL") https://pagure.io/dlm/c/a6b13f3daedd2de01a7c54ecde665a7996232ae1?branch=main .