From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fransum.emea.sgi.com (fransum.emea.sgi.com [144.253.208.10]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id n6D9WPBA038570 for ; Mon, 13 Jul 2009 04:32:26 -0500 Subject: Re: [PATCH, RFC] xfs_repair - clear inodes in incorrect btree format References: <4A582070.9040907@sandeen.net> From: Olaf Weber Date: Mon, 13 Jul 2009 11:33:02 +0200 In-Reply-To: <4A582070.9040907@sandeen.net> (Eric Sandeen's message of "Sat, 11 Jul 2009 00:17:36 -0500") Message-ID: MIME-Version: 1.0 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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Eric Sandeen Cc: xfs-oss Eric Sandeen writes: [...] > But questions remain... > 1) How'd it get into this state? ... but maybe more importantly... > 2) Should these really get cleared? It's possibly a sane extent list, > it's just that it -could- be in extents rather than btree format... > 3) By the same token, should the kernel really be choking on it? It is not clear to me yet how you could get into this state, but this is clearly an invariant the kernel actively maintains. If the kernel "just" missed the underflow and kept the extents in btree format, then I don't see an apriori reason why the extent list as such would be invalid (as opposed to inefficiently stored). If that's the primary model for getting into this state, then the file contents can be rescued and kernel-side the event should be survivable. But if the kernel tried to convert, failed, and didn't properly detect failure... Without having a good answer for (1) I find it hard to convince myself that to be more forgiving wrt to (2) and (3) is safe. Olaf > Signed-off-by: Eric Sandeen Acked-By: Olaf Weber > --- > diff --git a/repair/dinode.c b/repair/dinode.c > index 84e1d05..3fc6cac 100644 > --- a/repair/dinode.c > +++ b/repair/dinode.c > @@ -1280,6 +1280,14 @@ process_btinode( > last_key = cursor.level[level-1].first_key; > } > } > + if (*nex <= XFS_DFORK_SIZE(dip, mp, whichfork) / sizeof(xfs_bmbt_rec_t)) { > + do_warn(_("extent count for ino %lld %s fork too low " > + "(%d) for file format\n"), > + lino, > + whichfork == XFS_DATA_FORK ? _("data") : _("attr"), > + *nex); > + return(1); > + } > /* > * Check that the last child block's forward sibling pointer > * is NULL. -- Olaf Weber SGI Phone: +31(0)30-6696752 Veldzigt 2b Fax: +31(0)30-6696799 Technical Lead 3454 PW de Meern Vnet: 955-7151 Storage Software The Netherlands Email: olaf@sgi.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs