Re: [PATCH v2 1/8] introduce __sb_{acquire,release}_write() helpers

From: Oleg Nesterov <oleg@redhat.com>
To: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Dave Chinner <david@fromorbit.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/8] introduce __sb_{acquire,release}_write() helpers
Date: Thu, 13 Aug 2015 15:17:44 +0200	[thread overview]
Message-ID: <20150813131744.GA15609@redhat.com> (raw)
In-Reply-To: <20150813095617.GD26599@quack.suse.cz>

On 08/13, Jan Kara wrote:
>
> On Thu 13-08-15 11:45:52, Jan Kara wrote:
> > On Tue 11-08-15 19:03:58, Oleg Nesterov wrote:
> > > Preparation to hide the sb->s_writers internals from xfs and btrfs.
> > > Add 2 trivial define's they can use rather than play with ->s_writers
> > > directly. No changes in btrfs/transaction.o and xfs/xfs_aops.o.
> > >
> > > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> >
> > Looks good. You can add:
> >
> > Reviewed-by: Jan Kara <jack@suse.com>
>
> One comment when looking at other patches - I'd prefer somewhat better name
> than __sb_acquire_write().

Yes, __sb_acquire_write() doesn't look nice and I agree with any
naming.

> It doesn't tell that it's only a trylock
> acquisition. Maybe something like

But it is not actually "trylock"... This lock was already locked but
not by us. __sb_release_write + __sb_acquire_write is used to transfer
the ownership,

> __sb_writers_acquire_nowait()
>
> and then
>
> __sb_writers_release()?

so I agree with any naming, I'll update this patch... but perhaps
__sb_writers_acquire() without "_nowait" make more sense?

Oleg.