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=-5.2 required=3.0 tests=BAYES_00, 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 1A043C432BE for ; Fri, 13 Aug 2021 07:02:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BF88F60FC3 for ; Fri, 13 Aug 2021 07:02:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org BF88F60FC3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 5C6B36B006C; Fri, 13 Aug 2021 03:02:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 576F06B0071; Fri, 13 Aug 2021 03:02:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 48C8C6B0072; Fri, 13 Aug 2021 03:02:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0135.hostedemail.com [216.40.44.135]) by kanga.kvack.org (Postfix) with ESMTP id 327A06B006C for ; Fri, 13 Aug 2021 03:02:35 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id B24DD180AD820 for ; Fri, 13 Aug 2021 07:02:34 +0000 (UTC) X-FDA: 78469164228.33.092CDB6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf25.hostedemail.com (Postfix) with ESMTP id 638F9B009CBE for ; Fri, 13 Aug 2021 07:02:34 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 8132E6736F; Fri, 13 Aug 2021 09:02:31 +0200 (CEST) Date: Fri, 13 Aug 2021 09:02:31 +0200 From: Christoph Hellwig To: Matthew Wilcox Cc: David Howells , "Darrick J. Wong" , Christoph Hellwig , Trond Myklebust , linux-nfs@vger.kernel.org, viro@zeniv.linux.org.uk, jlayton@kernel.org, sfrench@samba.org, torvalds@linux-foundation.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 1/5] nfs: Fix write to swapfile failure due to generic_write_checks() Message-ID: <20210813070231.GA26339@lst.de> References: <162879971699.3306668.8977537647318498651.stgit@warthog.procyon.org.uk> <162879972678.3306668.10709543333474121000.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=none; spf=none (imf25.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de X-Stat-Signature: pueaqae8enqtniixj5adiwfd113gx1m8 X-Rspamd-Queue-Id: 638F9B009CBE X-Rspamd-Server: rspam05 X-HE-Tag: 1628838154-237268 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Aug 13, 2021 at 04:09:39AM +0100, Matthew Wilcox wrote: > On Thu, Aug 12, 2021 at 09:22:06PM +0100, David Howells wrote: > > Trying to use a swapfile on NFS results in every DIO write failing with > > ETXTBSY because generic_write_checks(), as called by nfs_direct_write() > > from nfs_direct_IO(), forbids writes to swapfiles. > > Why does nfs_direct_write() call generic_write_checks()? > > ie call generic_write_checks() earlier, and only swap would bypass them. Yes, something like that is a good idea probably. Additionally I'd like to move to a separate of for swap I/O ASAP given that NFS only implemens ->direct_IO for swap.