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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=unavailable 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 27F2EECDE3D for ; Fri, 19 Oct 2018 03:36:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDBC92145D for ; Fri, 19 Oct 2018 03:36:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EDBC92145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726903AbeJSLk0 (ORCPT ); Fri, 19 Oct 2018 07:40:26 -0400 Received: from ipmailnode02.adl6.internode.on.net ([150.101.137.148]:55887 "EHLO ipmailnode02.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726478AbeJSLk0 (ORCPT ); Fri, 19 Oct 2018 07:40:26 -0400 Received: from ppp59-167-129-252.static.internode.on.net (HELO dastard) ([59.167.129.252]) by ipmail02.adl6.internode.on.net with ESMTP; 19 Oct 2018 14:06:12 +1030 Received: from dave by dastard with local (Exim 4.80) (envelope-from ) id 1gDLa8-0006bD-Ep; Fri, 19 Oct 2018 14:36:12 +1100 Date: Fri, 19 Oct 2018 14:36:12 +1100 From: Dave Chinner To: Josef Bacik Cc: kernel-team@fb.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, tj@kernel.org, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, riel@fb.com, linux-mm@kvack.org Subject: Re: [PATCH 6/7] mm: allow ->page_mkwrite to do retries Message-ID: <20181019033612.GL18822@dastard> References: <20181018202318.9131-1-josef@toxicpanda.com> <20181018202318.9131-7-josef@toxicpanda.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181018202318.9131-7-josef@toxicpanda.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Oct 18, 2018 at 04:23:17PM -0400, Josef Bacik wrote: > Before we didn't set the retry flag on our vm_fault. We want to allow > file systems to drop the mmap_sem if they so choose, so set this flag > and deal with VM_FAULT_RETRY appropriately. > > Signed-off-by: Josef Bacik > --- > mm/memory.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index 433075f722ea..c5e81edd94f9 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2384,11 +2384,13 @@ static vm_fault_t do_page_mkwrite(struct vm_fault *vmf) > unsigned int old_flags = vmf->flags; > > vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; > + vmf->flags |= old_flags & FAULT_FLAG_ALLOW_RETRY; > > ret = vmf->vma->vm_ops->page_mkwrite(vmf); > /* Restore original flags so that caller is not surprised */ > vmf->flags = old_flags; > - if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) > + if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | > + VM_FAULT_RETRY))) Mess. #define __FAIL_FLAGS (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY) if (ret & __FAIL_FLAGS) Should kill the unlikely() at the same time. -Dave. -- Dave Chinner david@fromorbit.com