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 C9B8B7F5D for ; Fri, 19 Jun 2015 08:19:59 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id 48E05AC001 for ; Fri, 19 Jun 2015 06:19:56 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id n8FyYybMKdVUN1Ui (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Fri, 19 Jun 2015 06:19:55 -0700 (PDT) Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 766AB388B67 for ; Fri, 19 Jun 2015 13:19:54 +0000 (UTC) Date: Fri, 19 Jun 2015 09:19:53 -0400 From: Brian Foster Subject: Re: [PATCH] xfs_repair: refuse to unset lazycount on V5 filesystems Message-ID: <20150619131952.GC12833@bfoster.bfoster> References: <5582F962.2090400@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5582F962.2090400@redhat.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: Eric Sandeen Cc: "Richard W.M. Jones" , xfs-oss On Thu, Jun 18, 2015 at 12:01:22PM -0500, Eric Sandeen wrote: > Running "xfs_admin -c 0" on a V5 fs has unfortunate results. > > Before: > versionnum [0xbca5+0x18a] = ... LAZYSBCOUNT,PROJID32BIT,CRC, ... > After: > versionnum [0xbca5+0x188] = ... LAZYSBCOUNT,PROJID32BIT,CRC, ... > > The on-disk feature bit is in fact changed, but xfs_db reports that the > feature is still present. This is because xfs_sb_version_haslazysbcount() > ignores the feature bit, and always reports that the lazy-count feature is > present on a V5 fs. > > i.e. the intent is that this feature is not optional on a V5 fs, yet we > still flip the bit on disk when asked. Not good. > > So, document this, and error out if the user tries to disable lazy-count > on a version 5 filesystem. > > Reported-by: Richard W.M. Jones > Signed-off-by: Eric Sandeen > --- Reviewed-by: Brian Foster > > (hm, xfs_repair should probably also turn the bit back on, if it's off on > V5? I'll save that for another patch.) > Seems reasonable. Brian > diff --git a/man/man8/xfs_admin.8 b/man/man8/xfs_admin.8 > index b393d74..0968196 100644 > --- a/man/man8/xfs_admin.8 > +++ b/man/man8/xfs_admin.8 > @@ -62,6 +62,10 @@ Print the current filesystem UUID (Universally Unique IDentifier). > .TP > .BR "\-c 0" | 1 > Enable (1) or disable (0) lazy-counters in the filesystem. > +.IP > +Lazy-counters may not be disabled on Version 5 superblock filesystems > +(i.e. those with metadata CRCs enabled). > +.IP > This operation may take quite a bit of time on large filesystems as the > entire filesystem needs to be scanned when this option is changed. > .IP > > diff --git a/repair/phase1.c b/repair/phase1.c > index ec75ada..9e7011d 100644 > --- a/repair/phase1.c > +++ b/repair/phase1.c > @@ -121,8 +121,12 @@ phase1(xfs_mount_t *mp) > sb->sb_bad_features2 |= XFS_SB_VERSION2_LAZYSBCOUNTBIT; > primary_sb_modified = 1; > printf(_("Enabling lazy-counters\n")); > - } else > - if (!lazy_count && xfs_sb_version_haslazysbcount(sb)) { > + } else if (!lazy_count && xfs_sb_version_haslazysbcount(sb)) { > + if (XFS_SB_VERSION_NUM(sb) == XFS_SB_VERSION_5) { > + printf( > +_("Cannot disable lazy-counters on V5 fs\n")); > + exit(1); > + } > sb->sb_features2 &= ~XFS_SB_VERSION2_LAZYSBCOUNTBIT; > sb->sb_bad_features2 &= ~XFS_SB_VERSION2_LAZYSBCOUNTBIT; > printf(_("Disabling lazy-counters\n")); > > > _______________________________________________ > 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