20.06.2023 17:02, Jeff Layton пишет:
Suppose I start a process (call it pid 100), and then spawn a thread (101). I then have 101 open a file and set an OFD lock on it (such that the resulting fl_pid field in the file_lock is set to 101).
How come? There are multiple places in locks.c with this line: fl->fl_pid = current->tgid; And I've yet to see the line like: fl->fl_pid = current->pid; Its simply not there. No, we put tgid into l_pid! tgid will still be 100, no matter how many threads you spawn or destroy. Or what am I misseng?
That's just one example, of course. The underlying problem is that OFD locks are not owned by processes in the same way that traditional POSIX locks are, so reporting a pid there is unreliable, at best.
But we report tgid. It doesn't depend on threads. I don't understand. :)
