Re: [PATCH hurd 0/6] Add file record locking support

[Svante Signell]

On Tue, 2015-01-20 at 01:37 +0100, Samuel Thibault wrote:
> Hello,
> 
> Thanks for reviving this, it'll definitely be useful!
> 
> Svante Signell, le Thu 08 Jan 2015 12:28:05 +0100, a écrit :
> > 1) l_pid of struct flock is not set. According to the manpage (and
> > posix) the PID of the process blocking the lock should be reported. Can
> > maybe be solved by a shared memory solution in glibc or as indicated in
> > task 1022.
> 
> We can not trust a shared memory solution, we need an io_reidentify
> round through the proc server.

Can you give more information about how to implement this?

> > 2) fork(2) does not create a process without the locks set for the
> > child.
> 
> > (This is probably the main cause tdbtorture in tdb does not work well
> > with the current file record locking patches.)
> 
> I don't think tdbtorture forks with locks held: AIUI it just starts
> several processes and let them play at will with locks, without creating
> or terminating them.

Looking at the code of tdbtorture.c it forks a lot of processes (and
assumes the locks are not kept) while the current implementation does
not release them. With num_procs=1 tdbtorture works fine. Is the correct
solution to add a hook in fork.c code to release these locks?