From patchwork Tue May 9 15:49:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 9718261 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 1BEBC60236 for ; Tue, 9 May 2017 15:52:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 12B491FF61 for ; Tue, 9 May 2017 15:52:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 067B5205FB; Tue, 9 May 2017 15:52:50 +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 AF2ED1FF61 for ; Tue, 9 May 2017 15:52:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755535AbdEIPvD (ORCPT ); Tue, 9 May 2017 11:51:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45122 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755483AbdEIPvA (ORCPT ); Tue, 9 May 2017 11:51:00 -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 9BCB33D957; Tue, 9 May 2017 15:50:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9BCB33D957 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jlayton@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 9BCB33D957 Received: from tleilax.poochiereds.net (ovpn-121-66.rdu2.redhat.com [10.10.121.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 77F8983DD8; Tue, 9 May 2017 15:50:57 +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 26/27] mm: flesh out comments over mapping_set_error Date: Tue, 9 May 2017 11:49:29 -0400 Message-Id: <20170509154930.29524-27-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 [10.5.110.30]); Tue, 09 May 2017 15:51:00 +0000 (UTC) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Jeff Layton --- include/linux/pagemap.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 9593eac41499..9b453eae0aa1 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -27,6 +27,20 @@ enum mapping_flags { AS_NO_WRITEBACK_TAGS = 3, }; +/** + * mapping_set_error - record a writeback error in the address_space + * @mapping - the mapping in which an error should be set + * @error - the error to set in the mapping + * + * When writeback fails in some way, we must record that error so that + * userspace can be informed when fsync and the like are called. We endeavor + * to report errors on any file that was open at the time of the error. Some + * internal callers also need to know when writeback errors have occurred. + * + * When a writeback error occurs, most will filesystems will want to call + * mapping_set_error to record the error in the mapping so that it will be + * automatically reported whenever fsync is called on the file. + */ static inline void mapping_set_error(struct address_space *mapping, int error) { return errseq_set(&mapping->wb_err, error);