From patchwork Thu Jun 29 13:19:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 9816837 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 9EFF66020A for ; Thu, 29 Jun 2017 13:21:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 91AA41FFB2 for ; Thu, 29 Jun 2017 13:21:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8657128710; Thu, 29 Jun 2017 13:21:35 +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=unavailable 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 3DD801FFB2 for ; Thu, 29 Jun 2017 13:21:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753212AbdF2NUm (ORCPT ); Thu, 29 Jun 2017 09:20:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:60128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753181AbdF2NU1 (ORCPT ); Thu, 29 Jun 2017 09:20:27 -0400 Received: from tleilax.poochiereds.net (cpe-45-37-196-243.nc.res.rr.com [45.37.196.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15B5622BE0; Thu, 29 Jun 2017 13:20:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 15B5622BE0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jlayton@kernel.org From: jlayton@kernel.org To: Andrew Morton , Al Viro , Jan Kara , tytso@mit.edu, axboe@kernel.dk, mawilcox@microsoft.com, ross.zwisler@linux.intel.com, corbet@lwn.net, Chris Mason , Josef Bacik , David Sterba , "Darrick J . Wong" Cc: Carlos Maiolino , Eryu Guan , David Howells , Christoph Hellwig , Liu Bo , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-block@vger.kernel.org Subject: [PATCH v8 11/18] mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error Date: Thu, 29 Jun 2017 09:19:47 -0400 Message-Id: <20170629131954.28733-12-jlayton@kernel.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170629131954.28733-1-jlayton@kernel.org> References: <20170629131954.28733-1-jlayton@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jeff Layton When a writeback error occurs, we want later callers to be able to pick up that fact when they go to wait on that writeback to complete. Traditionally, we've used AS_EIO/AS_ENOSPC flags to track that, but that's problematic since only one "checker" will be informed when an error occurs. In later patches, we're going to want to convert many of these callers to check for errors since a well-defined point in time. For now, ensure that we can handle both sorts of checks by both setting errors in both places when there is a writeback failure. Signed-off-by: Jeff Layton --- include/linux/pagemap.h | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 316a19f6b635..28acc94e0f81 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -28,14 +28,33 @@ enum mapping_flags { AS_NO_WRITEBACK_TAGS = 5, }; +/** + * 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 filesystems will want to call + * mapping_set_error to record the error in the mapping so that it can be + * reported when the application calls fsync(2). + */ static inline void mapping_set_error(struct address_space *mapping, int error) { - if (unlikely(error)) { - if (error == -ENOSPC) - set_bit(AS_ENOSPC, &mapping->flags); - else - set_bit(AS_EIO, &mapping->flags); - } + if (likely(!error)) + return; + + /* Record in wb_err for checkers using errseq_t based tracking */ + filemap_set_wb_err(mapping, error); + + /* Record it in flags for now, for legacy callers */ + if (error == -ENOSPC) + set_bit(AS_ENOSPC, &mapping->flags); + else + set_bit(AS_EIO, &mapping->flags); } static inline void mapping_set_unevictable(struct address_space *mapping)