From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:28209 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751841AbdJXSSb (ORCPT ); Tue, 24 Oct 2017 14:18:31 -0400 Date: Tue, 24 Oct 2017 11:18:27 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH] xfs: validate sb_logsunit is a multiple of the fs blocksize Message-ID: <20171024181827.GO5483@magnolia> References: <20171024002844.GM5483@magnolia> <20171024125412.GC56184@bfoster.bfoster> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171024125412.GC56184@bfoster.bfoster> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Brian Foster Cc: xfs On Tue, Oct 24, 2017 at 08:54:13AM -0400, Brian Foster wrote: > On Mon, Oct 23, 2017 at 05:28:44PM -0700, Darrick J. Wong wrote: > > Make sure the log stripe unit is sane before proceeding with mounting. > > AFAICT this means that logsunit has to be 0, 1, or a multiple of the fs > > block size. Found this by setting the LSB of logsunit in xfs/350 and > > watching the system crash as soon as we try to write to the log. > > > > Signed-off-by: Darrick J. Wong > > --- > > fs/xfs/xfs_log.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > > index d729e00..da4dcab 100644 > > --- a/fs/xfs/xfs_log.c > > +++ b/fs/xfs/xfs_log.c > > @@ -659,6 +659,12 @@ xfs_log_mount( > > XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks), > > XFS_MAX_LOG_BYTES); > > error = -EINVAL; > > + } else if (mp->m_sb.sb_logsunit > 1 && > > + mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) { > > + xfs_warn(mp, > > + "log stripe unit %u bytes must be a multiple of block size", > > + mp->m_sb.sb_logsunit); > > + error = -EINVAL; > > Looks fine, but I notice that the error handling just below only fails > the mount on v5 filesystems. Otherwise we warn and carry on. I'm not > sure why that is.. but is this a crash vector on v4 filesystems as well? It is a crash vector on v4 as well, so I'll be stricter about failing the mount. I was trying to be cautious about this since there haven't been general complaints about v4 filesystems, but ... eh. A crash is a crash. :) --D > > Brian > > > } > > if (error) { > > if (xfs_sb_version_hascrc(&mp->m_sb)) { > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html