From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fengguang Wu Subject: Re: [PATCH] writeback: Fix data corruption on NFS Date: Sat, 14 Dec 2013 13:45:39 +0800 Message-ID: <20131214054539.GA21310@localhost> References: <1386791976-2286-1-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, Dan Duval , trond.myklebust@primarydata.com, chuck.lever@oracle.com, Jan Kara To: Jan Kara Return-path: Received: from mga02.intel.com ([134.134.136.20]:49301 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753575Ab3LOC4O (ORCPT ); Sat, 14 Dec 2013 21:56:14 -0500 Content-Disposition: inline In-Reply-To: <1386791976-2286-1-git-send-email-jack@suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Dec 11, 2013 at 08:59:36PM +0100, Jan Kara wrote: > Commit 4f8ad655dbc8 "writeback: Refactor writeback_single_inode()" added > a condition to skip clean inode. However this is wrong in WB_SYNC_ALL > mode because there we also want to wait for outstanding writeback on > possibly clean inode. This was causing occasional data corruption issues > on NFS because it uses sync_inode() to make sure all outstanding writes > are flushed to the server before truncating the inode and with > sync_inode() returning prematurely file was sometimes extended back > by an outstanding write after it was truncated. > > So modify the test to also check for pages under writeback in > WB_SYNC_ALL mode. Applied to the writeback tree. Thank you, Jan! Regards, Fengguang > CC: stable@vger.kernel.org # >= 3.5 > Fixes: 4f8ad655dbc82cf05d2edc11e66b78a42d38bf93 > Reported-and-tested-by: Dan Duval > Signed-off-by: Jan Kara > --- > fs/fs-writeback.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > Fenguang, can you please merge this patch? Thanks! > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 1f4a10ece2f1..e0259a163f98 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -516,13 +516,16 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, > } > WARN_ON(inode->i_state & I_SYNC); > /* > - * Skip inode if it is clean. We don't want to mess with writeback > - * lists in this function since flusher thread may be doing for example > - * sync in parallel and if we move the inode, it could get skipped. So > - * here we make sure inode is on some writeback list and leave it there > - * unless we have completely cleaned the inode. > + * Skip inode if it is clean and we have no outstanding writeback in > + * WB_SYNC_ALL mode. We don't want to mess with writeback lists in this > + * function since flusher thread may be doing for example sync in > + * parallel and if we move the inode, it could get skipped. So here we > + * make sure inode is on some writeback list and leave it there unless > + * we have completely cleaned the inode. > */ > - if (!(inode->i_state & I_DIRTY)) > + if (!(inode->i_state & I_DIRTY) && > + (wbc->sync_mode != WB_SYNC_ALL || > + !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))) > goto out; > inode->i_state |= I_SYNC; > spin_unlock(&inode->i_lock); > -- > 1.8.1.4