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Date: Thu, 13 Aug 2015 15:32:46 +0200
From: Jan Kara <jack@suse.cz>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Kara <jack@suse.cz>, 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
Message-ID: <20150813133246.GB1091@quack.suse.cz>
References: <20150811170343.GA26881@redhat.com>
 <20150811170358.GA26901@redhat.com>
 <20150813094552.GC26599@quack.suse.cz>
 <20150813095617.GD26599@quack.suse.cz>
 <20150813131744.GA15609@redhat.com>
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On Thu 13-08-15 15:17:44, Oleg Nesterov wrote:
> 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?

OK, drop _nowait - maybe:

__sb_writers_acquired()

(note the additional 'd' at the end) to suggest that we already hold the lock
and only want to tell lockdep about it?

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR