From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 60EFF7F59 for ; Wed, 30 Jul 2014 11:29:27 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id E122FAC005 for ; Wed, 30 Jul 2014 09:29:26 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id ShlXPyuXpYuJFdoN (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Wed, 30 Jul 2014 09:29:25 -0700 (PDT) Date: Wed, 30 Jul 2014 12:29:14 -0400 From: Brian Foster Subject: Re: [PATCH 1/4 V2] xfs: catch buffers written without verifiers attached Message-ID: <20140730162913.GA2830@bfoster.bfoster> References: <1406684929-11133-1-git-send-email-david@fromorbit.com> <1406684929-11133-2-git-send-email-david@fromorbit.com> <20140730023023.GM26465@dastard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20140730023023.GM26465@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com On Wed, Jul 30, 2014 at 12:30:24PM +1000, Dave Chinner wrote: > From: Dave Chinner > > We recently had a bug where buffers were slipping through log > recovery without any verifier attached to them. This was resulting > in on-disk CRC mismatches for valid data. Add some warning code to > catch this occurrence so that we catch such bugs during development > rather than not being aware they exist. > > Note that we cannot do this verification unconditionally as non-CRC > filesystems don't always attach verifiers to the buffers being > written. e.g. during log recovery we cannot identify all the > different types of buffers correctly on non-CRC filesystems, so we > can't attach the correct verifiers in all cases and so we don't > attach any. Hence we don't want on non-CRC filesystems to avoid > spamming the logs with false indications. > > Signed-off-by: Dave Chinner > --- > fs/xfs/xfs_buf.c | 15 +++++++++++++++ > fs/xfs/xfs_log.c | 7 ++++++- > 2 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index a6dc83e..078b8be 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -1330,6 +1330,21 @@ _xfs_buf_ioapply( > SHUTDOWN_CORRUPT_INCORE); > return; > } > + } else if (bp->b_bn != -1LL) { > + struct xfs_mount *mp = bp->b_target->bt_mount; > + > + /* > + * non-crc filesystems don't attach verifiers during > + * log recovery, so don't warn for such filesystems. > + */ > + if (xfs_sb_version_hascrc(&mp->m_sb)) { > + xfs_warn(mp, > + "%s: no ops on block 0x%llx/0x%llx", > + __func__, bp->b_bn, > + bp->b_maps[0].bm_bn); Are you intending to print both block number values here or the b_bn/bm_len combo? > + xfs_hex_dump(bp->b_addr, 64); > + dump_stack(); > + } > } > } else if (bp->b_flags & XBF_READ_AHEAD) { > rw = READA; > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 149a4a5..9dc92b3 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -1378,8 +1378,13 @@ xlog_alloc_log( > > xlog_get_iclog_buffer_size(mp, log); > > + /* > + * Use a block number of -1 for the extra log buffer used during splits > + * so that it will trigger errors if we ever try to do IO on it without > + * first having set it up properly. > + */ > error = -ENOMEM; > - bp = xfs_buf_alloc(mp->m_logdev_targp, 0, BTOBB(log->l_iclog_size), 0); > + bp = xfs_buf_alloc(mp->m_logdev_targp, -1LL, BTOBB(log->l_iclog_size), 0); How about XFS_BUF_DADDR_NULL (here and above)? Brian > if (!bp) > goto out_free_log; > > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs