Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752666AbdCEP3N (ORCPT ); Sun, 5 Mar 2017 10:29:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38422 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348AbdCEP3M (ORCPT ); Sun, 5 Mar 2017 10:29:12 -0500 From: Jeff Layton To: viro@zeniv.linux.org.uk, konishi.ryusuke@lab.ntt.co.jp Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nilfs@vger.kernel.org Subject: [PATCH 2/3] mm: don't TestClearPageError in __filemap_fdatawait_range Date: Sun, 5 Mar 2017 08:35:34 -0500 Message-Id: <20170305133535.6516-3-jlayton@redhat.com> In-Reply-To: <20170305133535.6516-1-jlayton@redhat.com> References: <20170305133535.6516-1-jlayton@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Sun, 05 Mar 2017 13:35:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2341 Lines: 78 The -EIO returned here can end up overriding whatever error is marked in the address space. This means that an -ENOSPC error (AS_ENOSPC) can end up being turned into -EIO if a page gets PG_error set on it during error handling. Arguably, that's a bug in the writeback code, but... Read errors are also tracked on a per page level using PG_error. Suppose we have a read error on a page, and then that page is subsequently dirtied by overwriting the whole page. Writeback doesn't clear PG_error, so we can then end up successfully writing back that page and still return -EIO on fsync. Since the handling of this bit is somewhat inconsistent across subsystems, let's just rely on marking the address space when there are writeback errors. Signed-off-by: Jeff Layton --- mm/filemap.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 3f9afded581b..2b0b4ff4668b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -375,17 +375,16 @@ int filemap_flush(struct address_space *mapping) } EXPORT_SYMBOL(filemap_flush); -static int __filemap_fdatawait_range(struct address_space *mapping, +static void __filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { pgoff_t index = start_byte >> PAGE_SHIFT; pgoff_t end = end_byte >> PAGE_SHIFT; struct pagevec pvec; int nr_pages; - int ret = 0; if (end_byte < start_byte) - goto out; + return; pagevec_init(&pvec, 0); while ((index <= end) && @@ -402,14 +401,10 @@ static int __filemap_fdatawait_range(struct address_space *mapping, continue; wait_on_page_writeback(page); - if (TestClearPageError(page)) - ret = -EIO; } pagevec_release(&pvec); cond_resched(); } -out: - return ret; } /** @@ -429,14 +424,8 @@ static int __filemap_fdatawait_range(struct address_space *mapping, int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { - int ret, ret2; - - ret = __filemap_fdatawait_range(mapping, start_byte, end_byte); - ret2 = filemap_check_errors(mapping); - if (!ret) - ret = ret2; - - return ret; + __filemap_fdatawait_range(mapping, start_byte, end_byte); + return filemap_check_errors(mapping); } EXPORT_SYMBOL(filemap_fdatawait_range); -- 2.9.3