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 B16797F50 for ; Mon, 6 Apr 2015 10:06:10 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id 4DC06AC002 for ; Mon, 6 Apr 2015 08:06:07 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id s0KYm3qkggBeERAr (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Mon, 06 Apr 2015 08:06:06 -0700 (PDT) Message-ID: <5522A0DB.2010309@redhat.com> Date: Mon, 06 Apr 2015 10:06:03 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: [PATCH] xfs_db: disallow sb UUID write on v5 filesystems 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: xfs-oss , "F. Stoyan" , 782012@bugs.debian.org Do not allow xfs_db (or the xfs_admin frontend) to change the UUID of a V5 filesystem; this will cause UUID mismatches across the filesystem, and we currently have no mechanism to update them all. Changing only the superblock UUID makes all other metadata look invalid, and xfs_repair reacts by junking everything. Addresses-Debian-Bug: 782012 Reported-by: F. Stoyan Signed-off-by: Eric Sandeen --- diff --git a/db/sb.c b/db/sb.c index 6cb665d..f31f4a2 100644 --- a/db/sb.c +++ b/db/sb.c @@ -363,6 +363,18 @@ uuid_f( return 0; } + /* + * For now, changing the UUID of V5 superblock filesystems is + * not supported; we do not have the infrastructure to fix all + * other metadata when a new superblock UUID is generated. + */ + if (xfs_sb_version_hascrc(&mp->m_sb) && + strcasecmp(argv[1], "rewrite")) { + dbprintf(_("%s: only 'rewrite' supported on V5 fs\n"), + progname); + return 0; + } + if (!strcasecmp(argv[1], "generate")) { platform_uuid_generate(&uu); } else if (!strcasecmp(argv[1], "nil")) { _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs