Re: [PATCH 3/4] locks: Set FL_CLOSE when removing flock locks on close()

[Jeff Layton <jlayton@redhat.com>]

On Wed, 2017-02-22 at 07:13 -0500, Jeff Layton wrote:
> On Tue, 2017-02-21 at 10:39 -0500, Benjamin Coddington wrote:
> > Set FL_CLOSE in fl_flags as in locks_remove_posix() when clearing locks.
> > NFS will check for this flag to ensure an unlock is sent in a following
> > patch.
> > 
> > Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
> > ---
> >  fs/locks.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/fs/locks.c b/fs/locks.c
> > index 26811321d39b..af2031a1fcff 100644
> > --- a/fs/locks.c
> > +++ b/fs/locks.c
> > @@ -2504,7 +2504,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx)
> >  		.fl_owner = filp,
> >  		.fl_pid = current->tgid,
> >  		.fl_file = filp,
> > -		.fl_flags = FL_FLOCK,
> > +		.fl_flags = FL_FLOCK | FL_CLOSE,
> >  		.fl_type = F_UNLCK,
> >  		.fl_end = OFFSET_MAX,
> >  	};
> 
> Looks good. I'm fine with merging this one via the NFS tree, btw...
> 
> Reviewed-by: Jeff Layton <jlayton@redhat.com>
> 

(cc'ing linux-fsdevel and Miklos)

Hmm, that said, this potentially may affect other filesystems. If you do
any more postings of this set, please cc linux-fsdevel.

In particular, I'll note that fuse has this:

        /* Unlock on close is handled by the flush method */
        if (fl->fl_flags & FL_CLOSE)
                return 0;

I don't see any lock handling in fuse_flush (though it does pass down a
lockowner). I guess the expectation is that the userland driver should
close down POSIX locks when the flush method is called.

Miklos, does this also apply to flock locks? Would Ben's patch cause any
grief here?

Thanks,
-- 
Jeff Layton <jlayton@redhat.com>