From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46A34C3F68F for ; Wed, 11 Dec 2019 00:28:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18A6D207FF for ; Wed, 11 Dec 2019 00:28:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726925AbfLKA2V (ORCPT ); Tue, 10 Dec 2019 19:28:21 -0500 Received: from mail104.syd.optusnet.com.au ([211.29.132.246]:54936 "EHLO mail104.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726598AbfLKA2V (ORCPT ); Tue, 10 Dec 2019 19:28:21 -0500 Received: from dread.disaster.area (pa49-195-139-249.pa.nsw.optusnet.com.au [49.195.139.249]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id 459837EA491; Wed, 11 Dec 2019 11:28:19 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1ieprT-0006Z1-IC; Wed, 11 Dec 2019 11:28:15 +1100 Date: Wed, 11 Dec 2019 11:28:15 +1100 From: Dave Chinner To: Jens Axboe Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org Subject: Re: [PATCH 3/5] mm: make buffered writes work with RWF_UNCACHED Message-ID: <20191211002815.GD19213@dread.disaster.area> References: <20191210162454.8608-1-axboe@kernel.dk> <20191210162454.8608-4-axboe@kernel.dk> <20191211002349.GC19213@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191211002349.GC19213@dread.disaster.area> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=X6os11be c=1 sm=1 tr=0 a=KoypXv6BqLCQNZUs2nCMWg==:117 a=KoypXv6BqLCQNZUs2nCMWg==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=pxVhFHJ0LMsA:10 a=7-415B0cAAAA:8 a=YySyZI0ml3ss4FvGJbkA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Dec 11, 2019 at 11:23:49AM +1100, Dave Chinner wrote: > On Tue, Dec 10, 2019 at 09:24:52AM -0700, Jens Axboe wrote: > > If RWF_UNCACHED is set for io_uring (or pwritev2(2)), we'll drop the > > cache instantiated for buffered writes. If new pages aren't > > instantiated, we leave them alone. This provides similar semantics to > > reads with RWF_UNCACHED set. > > So what about filesystems that don't use generic_perform_write()? > i.e. Anything that uses the iomap infrastructure (i.e. > iomap_file_buffered_write()) instead of generic_file_write_iter()) > will currently ignore RWF_UNCACHED. That's XFS and gfs2 right now, > but there are likely to be more in the near future as more > filesystems are ported to the iomap infrastructure. Hmmm - I'm missing part of this patchset, and I see a second version has been posted that has iomap stuff in it. I'll go look at that now... Cheers, Dave. -- Dave Chinner david@fromorbit.com