From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 14 Aug 2016 09:36:52 +1000 From: Dave Chinner To: Ben Hutchings Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, akpm@linux-foundation.org, Christoph Hellwig , Shyam Kaushik , Dave Chinner Subject: Re: [PATCH 3.16 102/305] xfs: xfs_iflush_cluster fails to abort on error Message-ID: <20160813233652.GU19025@dastard> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: On Sat, Aug 13, 2016 at 06:42:51PM +0100, Ben Hutchings wrote: > 3.16.37-rc1 review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Dave Chinner > > commit b1438f477934f5a4d5a44df26f3079a7575d5946 upstream. > > When a failure due to an inode buffer occurs, the error handling > fails to abort the inode writeback correctly. This can result in the > inode being reclaimed whilst still in the AIL, leading to > use-after-free situations as well as filesystems that cannot be > unmounted as the inode log items left in the AIL never get removed. > > Fix this by ensuring fatal errors from xfs_imap_to_bp() result in > the inode flush being aborted correctly. .... > > /* > - * Get the buffer containing the on-disk inode. > + * Get the buffer containing the on-disk inode. We are doing a try-lock > + * operation here, so we may get an EAGAIN error. In that case, we > + * simply want to return with the inode still dirty. > + * > + * If we get any other error, we effectively have a corruption situation > + * and we cannot flush the inode, so we treat it the same as failing > + * xfs_iflush_int(). > */ > error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK, > 0); > - if (error || !bp) { > + if (error == -EAGAIN) { Wrong. As was pointed out for other -stable trees after users reported regressions, the error signs in XFS changed from positive to negative in 3.17-rc1. -Dave. -- Dave Chinner david@fromorbit.com