From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:40218 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965391AbeE2RuY (ORCPT ); Tue, 29 May 2018 13:50:24 -0400 Date: Tue, 29 May 2018 10:49:49 -0700 From: "Darrick J. Wong" To: Lu Fengqi Cc: Jeff Layton , linux-fsdevel@vger.kernel.org, willy@infradead.org Subject: Re: [PATCH] inode: always initialize mapping->wb_err Message-ID: <20180529174949.GU12940@magnolia> References: <20180526024254.21114-1-lufq.fnst@cn.fujitsu.com> <20180526122934.GA571@fnst.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180526122934.GA571@fnst.localdomain> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Sat, May 26, 2018 at 08:29:35PM +0800, Lu Fengqi wrote: > 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. Yeah, it's in my for-next branch now, will send it to Linus as a last minute fix after it's been through the -next wringer (i.e. tomorrow) unless anyone yells. --D > > -- > Thanks, > Lu > > >-- > >Jeff Layton > > > > > >