From patchwork Tue May 9 15:49:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 9718211 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5A8D960236 for ; Tue, 9 May 2017 15:51:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5466C1FF61 for ; Tue, 9 May 2017 15:51:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 44F9B205FB; Tue, 9 May 2017 15:51:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DAF121FF61 for ; Tue, 9 May 2017 15:51:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755704AbdEIPvS (ORCPT ); Tue, 9 May 2017 11:51:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54262 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754410AbdEIPvL (ORCPT ); Tue, 9 May 2017 11:51:11 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1217D7C829; Tue, 9 May 2017 15:51:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 1217D7C829 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jlayton@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 1217D7C829 Received: from tleilax.poochiereds.net (ovpn-121-66.rdu2.redhat.com [10.10.121.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id B3F5117596; Tue, 9 May 2017 15:50:59 +0000 (UTC) From: Jeff Layton To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, jfs-discussion@lists.sourceforge.net, linux-xfs@vger.kernel.org, cluster-devel@redhat.com, linux-f2fs-devel@lists.sourceforge.net, v9fs-developer@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-block@vger.kernel.org Cc: dhowells@redhat.com, akpm@linux-foundation.org, hch@infradead.org, ross.zwisler@linux.intel.com, mawilcox@microsoft.com, jack@suse.com, viro@zeniv.linux.org.uk, corbet@lwn.net, neilb@suse.de, clm@fb.com, tytso@mit.edu, axboe@kernel.dk, josef@toxicpanda.com, hubcap@omnibond.com, rpeterso@redhat.com, bo.li.liu@oracle.com Subject: [PATCH v4 27/27] mm: clean up comments in me_pagecache_dirty Date: Tue, 9 May 2017 11:49:30 -0400 Message-Id: <20170509154930.29524-28-jlayton@redhat.com> In-Reply-To: <20170509154930.29524-1-jlayton@redhat.com> References: <20170509154930.29524-1-jlayton@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 09 May 2017 15:51:06 +0000 (UTC) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This no longer applies with the new writeback error tracking and reporting infrastructure. Signed-off-by: Jeff Layton --- mm/memory-failure.c | 35 +++++------------------------------ 1 file changed, 5 insertions(+), 30 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4b56e53e5378..be5f998a0772 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -642,37 +642,12 @@ static int me_pagecache_dirty(struct page *p, unsigned long pfn) if (mapping) { /* * IO error will be reported by write(), fsync(), etc. - * who check the mapping. - * This way the application knows that something went - * wrong with its dirty file data. + * who check the mapping. This way the application knows that + * something went wrong when writing back its dirty file data. * - * There's one open issue: - * - * The EIO will be only reported on the next IO - * operation and then cleared through the IO map. - * Normally Linux has two mechanisms to pass IO error - * first through the AS_EIO flag in the address space - * and then through the PageError flag in the page. - * Since we drop pages on memory failure handling the - * only mechanism open to use is through AS_AIO. - * - * This has the disadvantage that it gets cleared on - * the first operation that returns an error, while - * the PageError bit is more sticky and only cleared - * when the page is reread or dropped. If an - * application assumes it will always get error on - * fsync, but does other operations on the fd before - * and the page is dropped between then the error - * will not be properly reported. - * - * This can already happen even without hwpoisoned - * pages: first on metadata IO errors (which only - * report through AS_EIO) or when the page is dropped - * at the wrong time. - * - * So right now we assume that the application DTRT on - * the first EIO, but we're not worse than other parts - * of the kernel. + * Note that errors are reported only once per file + * description, but should be reported on all open file + * descriptions for this inode. */ mapping_set_error(mapping, -EIO); }