From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [PATCH 1/2] direct-io: Implement generic deferred AIO completions Date: Tue, 13 Aug 2013 10:11:40 +1000 Message-ID: <20130813001140.GR12779@dastard> References: <1373493739-2243-1-git-send-email-jack@suse.cz> <20130712004421.GE3438@dastard> <20130716210027.GA9595@quack.suse.cz> <20130812161455.GA19471@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com, hch@infradead.org, Jeff Moyer , Al Viro , linux-ext4@vger.kernel.org, Christoph Hellwig To: Jan Kara Return-path: Received: from ipmail05.adl6.internode.on.net ([150.101.137.143]:61008 "EHLO ipmail05.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756038Ab3HMAMy (ORCPT ); Mon, 12 Aug 2013 20:12:54 -0400 Content-Disposition: inline In-Reply-To: <20130812161455.GA19471@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Aug 12, 2013 at 06:14:55PM +0200, Jan Kara wrote: > Hi Dave, > > I remembered about this patch set and realized I didn't get reply from > you regarding the following question (see quoted email below for details): > Do you really need to defer completion of appending direct IO? Because > generic code makes sure appending direct IO isn't async and thus > dio_complete() -> xfs_end_io_direct_write() gets called directly from > do_blockdev_direct_IO(). I.e. from a normal context and not from interrupt. Hi Jan, sorry I haven't got back to you sooner - I've had a lot of stuff to deal with over the past couple of weeks. The issue is that one part of the code expects deferral , and the other part of the code isn't doing a deferral, and I never got around to determining which was correct. I didn't connect the dots between aio/appending and sync dispatch meaning that the way it is operating now is fine - i.e. that the fact it doesn't call the deferral completion path is OK and was intended to operate that way by Christoph. So leaving the code as it is without a deferal is fine. > I've already addressed rest of your comments so this is the only item that > is remaining. Great :) Cheers, Dave. -- Dave Chinner david@fromorbit.com