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 CBCE17F8D for ; Thu, 31 Jul 2014 07:27:29 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id 39DD0AC003 for ; Thu, 31 Jul 2014 05:27:26 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id sl7kNu2HUKQ8wQuL (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Thu, 31 Jul 2014 05:27:21 -0700 (PDT) Date: Thu, 31 Jul 2014 08:27:16 -0400 From: Brian Foster Subject: Re: [PATCH 1/4] xfs: catch buffers written without verifiers attached Message-ID: <20140731122716.GB43383@bfoster.bfoster> References: <1406768509-32556-1-git-send-email-david@fromorbit.com> <1406768509-32556-2-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1406768509-32556-2-git-send-email-david@fromorbit.com> 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 Thu, Jul 31, 2014 at 11:01:46AM +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 > --- Reviewed-by: Brian Foster > fs/xfs/xfs_buf.c | 14 ++++++++++++++ > fs/xfs/xfs_log.c | 8 +++++++- > 2 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index a6dc83e..cd7b8ca 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -1330,6 +1330,20 @@ _xfs_buf_ioapply( > SHUTDOWN_CORRUPT_INCORE); > return; > } > + } else if (bp->b_bn != XFS_BUF_DADDR_NULL) { > + 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%x", > + __func__, bp->b_bn, bp->b_length); > + 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..ca4fd5b 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -1378,8 +1378,14 @@ xlog_alloc_log( > > xlog_get_iclog_buffer_size(mp, log); > > + /* > + * Use a NULL block 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, XFS_BUF_DADDR_NULL, > + BTOBB(log->l_iclog_size), 0); > if (!bp) > goto out_free_log; > > -- > 2.0.0 > > _______________________________________________ > 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