From: Jeff Layton 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> References: <20170509154930.29524-1-jlayton@redhat.com> Cc: axboe@kernel.dk, tytso@mit.edu, mawilcox@microsoft.com, neilb@suse.de, corbet@lwn.net, josef@toxicpanda.com, dhowells@redhat.com, clm@fb.com, bo.li.liu@oracle.com, viro@zeniv.linux.org.uk, jack@suse.com, akpm@linux-foundation.org, ross.zwisler@linux.intel.com, hubcap@omnibond.com 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 Return-path: In-Reply-To: <20170509154930.29524-1-jlayton@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cluster-devel-bounces@redhat.com Errors-To: cluster-devel-bounces@redhat.com List-Id: linux-ext4.vger.kernel.org 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); } -- 2.9.3