Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754057AbdCHQzP (ORCPT ); Wed, 8 Mar 2017 11:55:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752905AbdCHQzK (ORCPT ); Wed, 8 Mar 2017 11:55:10 -0500 From: Jeff Layton To: viro@zeniv.linux.org.uk, akpm@linux-foundation.org Cc: konishi.ryusuke@lab.ntt.co.jp, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nilfs@vger.kernel.org, ross.zwisler@linux.intel.com, jack@suse.cz, neilb@suse.com, openosd@gmail.com, adilger@dilger.ca, James.Bottomley@HansenPartnership.com Subject: [PATCH v2 9/9] Documentation: document what to do on a writeback error Date: Wed, 8 Mar 2017 11:29:34 -0500 Message-Id: <20170308162934.21989-10-jlayton@redhat.com> In-Reply-To: <20170308162934.21989-1-jlayton@redhat.com> References: <20170308162934.21989-1-jlayton@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 08 Mar 2017 16:30:22 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1124 Lines: 28 There's no real guidance on this for filesystem authors, so add a paragraph to vfs.txt that explains how this should be handled. Signed-off-by: Jeff Layton --- Documentation/filesystems/vfs.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 569211703721..527370fbab39 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -577,6 +577,13 @@ should clear PG_Dirty and set PG_Writeback. It can be actually written at any point after PG_Dirty is clear. Once it is known to be safe, PG_Writeback is cleared. +If there is an error during writeback, then the address_space should be +marked with an AS_EIO or AS_ENOSPC error, in order to ensure that the +error will be reported to the application at fsync or close. Most +writepage callers will do this automatically if writepage returns an +error, but writepages implementations generally need to ensure this +themselves. + Writeback makes use of a writeback_control structure... struct address_space_operations -- 2.9.3