Re: git: eca39864f702 - main - Add sysctl KERN_LOCKF

From: Ed Maste <emaste_at_freebsd.org>
Date: Wed, 13 Apr 2022 00:54:37 UTC 
On Tue, 12 Apr 2022 at 19:11, John Baldwin <jhb@freebsd.org> wrote:
>
> On 4/9/22 2:48 PM, Konstantin Belousov wrote:
> > The branch main has been updated by kib:
> >
> > URL: https://cgit.FreeBSD.org/src/commit/?id=eca39864f702e577eba3bc7e9992d1e5e56eba58
> >
> > commit eca39864f702e577eba3bc7e9992d1e5e56eba58
> > Author:     Konstantin Belousov <kib@FreeBSD.org>
> > AuthorDate: 2022-04-01 23:23:06 +0000
> > Commit:     Konstantin Belousov <kib@FreeBSD.org>
> > CommitDate: 2022-04-09 21:43:53 +0000
> >
> >      Add sysctl KERN_LOCKF
> >
> >      reporting the shapshot of the active advisory locks.
> >
> >      A new VFS ops method vfs_report_lockf if provided in the mount point
> >      op table.  If it is NULL, as it is currently for all existing
> >      filesystems, vfs_report_lockf() function is used, which gathers
> >      information from the standard implementation inside kern/kern_lockf.c.
> >
> >      Filesystems implementing its own locking (NFSv4 as example) can provide
> >      a custom implementation.
> >
> >      Reviewed by:    markj, rmacklem
> >      Sponsored by:   The FreeBSD Foundation
> >      MFC after:      1 week
> >      Differential revision:  https://reviews.freebsd.org/D34756
>
> Nice!  This is one of the things lsof has still groveled around in /dev/mem
> directly for in the past.  Hopefully the lsof developer will make use of this.

Yep - this is what prompted this effort. The goal is to provide proper
interfaces for everything that lsof used to extract out of /dev/mem.

https://reviews.freebsd.org/D34184
https://reviews.freebsd.org/D34323
https://github.com/lsof-org/lsof/pull/184