From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.cn.fujitsu.com ([183.91.158.132]:31076 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1031508AbeEZM3q (ORCPT ); Sat, 26 May 2018 08:29:46 -0400 Date: Sat, 26 May 2018 20:29:35 +0800 From: Lu Fengqi To: Jeff Layton CC: , , "Darrick J. Wong" Subject: Re: [PATCH] inode: always initialize mapping->wb_err Message-ID: <20180526122934.GA571@fnst.localdomain> References: <20180526024254.21114-1-lufq.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Sat, May 26, 2018 at 07:42:46AM -0400, Jeff Layton wrote: >On Sat, 2018-05-26 at 10:42 +0800, Lu Fengqi wrote: >> Creating a file reuses the inode object by kmem_cache_alloc without >> initializing maping->wb_err. If it contains an unseen writeback error, >> fsync will report an error on the file, even if no error has ever occurred >> after the file was created. >> >> Before commit b4678df184b3 ("errseq: Always report a writeback error >> once"), any errors that occur before the file descriptor is opened will be >> ignored, causing the issue not to be found. Afterward, any unseen writeback >> error will be reported once, including, of course, the uninitialized >> maping->wb_err, which exposes this problem. >> >> Signed-off-by: Lu Fengqi >> --- >> fs/inode.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/fs/inode.c b/fs/inode.c >> index 13ceb98c3bd3..bf02dc9d1837 100644 >> --- a/fs/inode.c >> +++ b/fs/inode.c >> @@ -182,6 +182,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode) >> mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); >> mapping->private_data = NULL; >> mapping->writeback_index = 0; >> + mapping->wb_err = 0; >> inode->i_private = NULL; >> inode->i_mapping = mapping; >> INIT_HLIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */ > >(cc'ing Darrick) > >I think Darrick had a similar patch that also fixed up some related >inode reuse issues in xfs. Darrick, were you planning to get that >merged for v4.17? Oh, I missed Darrick's patch. Thanks for your reminder. -- Thanks, Lu >-- >Jeff Layton > >