From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org ([198.137.202.133]:47714 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752344AbeESPgW (ORCPT ); Sat, 19 May 2018 11:36:22 -0400 Date: Sat, 19 May 2018 08:36:19 -0700 From: Matthew Wilcox Subject: Re: [PATCH] fs: clear writeback errors in inode_init_always Message-ID: <20180519153619.GA24698@bombadil.infradead.org> References: <20180518225037.GA26206@thunk.org> <630faadb74f608aa5a42649b81657e8b62d46bc3.camel@kernel.org> <20180519152700.GB4507@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180519152700.GB4507@magnolia> Sender: fstests-owner@vger.kernel.org To: "Darrick J. Wong" Cc: Jeff Layton , "Theodore Y. Ts'o" , linux-fsdevel@vger.kernel.org, fstests@vger.kernel.org, xfs List-ID: On Sat, May 19, 2018 at 08:27:00AM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > In inode_init_always(), we clear the inode mapping flags, which clears > any retained error (AS_EIO, AS_ENOSC) bits. Unfortunately, we do not typo of ENOSPC in case you do a new version > also clear wb_err, which means that old mapping errors can leak through > to new inodes. > > This is crucial for the XFS inode allocation path because we recycle old > in-core inodes and we do not want error state from an old file to leak > into the new file. This bug was discovered by running generic/036 and > generic/047 in a loop and noticing that the EIOs generated by the > collision of direct and buffered writes in generic/036 would survive the > remount between 036 and 047, and get reported to the fsyncs (on > different files on a reformatted fs!) in generic/047. > > Since we're changing the semantics of inode_init_always, we must also > change xfs_reinit_inode to retain the writeback error state when we go > to recover an inode that has been torn down in the vfs but not yet > disposed of by XFS. Don't you also need to preserve inode->i_mapping->flags across the reinitialisation for the users which aren't yet using ->wb_err? > +++ b/fs/xfs/xfs_icache.c > @@ -298,6 +298,7 @@ xfs_reinit_inode( > uint64_t version = inode_peek_iversion(inode); > umode_t mode = inode->i_mode; > dev_t dev = inode->i_rdev; > + errseq_t old_err = inode->i_mapping->wb_err; > > error = inode_init_always(mp->m_super, inode); > > @@ -306,6 +307,7 @@ xfs_reinit_inode( > inode_set_iversion_queried(inode, version); > inode->i_mode = mode; > inode->i_rdev = dev; > + inode->i_mapping->wb_err = old_err; > return error; > } >