From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760537AbYARLDD (ORCPT ); Fri, 18 Jan 2008 06:03:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759297AbYARLCj (ORCPT ); Fri, 18 Jan 2008 06:02:39 -0500 Received: from cantor2.suse.de ([195.135.220.15]:34720 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753606AbYARLCh (ORCPT ); Fri, 18 Jan 2008 06:02:37 -0500 From: NeilBrown To: Andrew Morton Date: Fri, 18 Jan 2008 22:02:30 +1100 Message-Id: <1080118110230.30467@suse.de> X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9Dpersistent flag for md devices more consistently. References: <20080118215531.30136.patches@notabene> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If you try to start an array for which the number of raid disks is listed as zero, md will currently try to read metadata off any devices that have been given. This was done because the value of raid_disks is used to signal whether array details have been provided by userspace (raid_disks > 0) or must be read from the devices (raid_disks == 0). However for an array without persistent metadata (or with externally managed metadata) this is the wrong thing to do. So we add a test in do_md_run to give an error if raid_disks is zero for non-persistent arrays. This requires that mddev->persistent is set corrently at this point, which it currently isn't for in-kernel autodetected arrays. So set ->persistent for autodetect arrays, and remove the settign in super_*_validate which is now redundant. Also clear ->persistent when stopping an array so it is consistently zero when starting an array. Signed-off-by: Neil Brown ### Diffstat output ./drivers/md/md.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff .prev/drivers/md/md.c ./drivers/md/md.c --- .prev/drivers/md/md.c 2008-01-18 10:46:49.000000000 +1100 +++ ./drivers/md/md.c 2008-01-18 11:03:15.000000000 +1100 @@ -779,7 +779,6 @@ static int super_90_validate(mddev_t *md mddev->major_version = 0; mddev->minor_version = sb->minor_version; mddev->patch_version = sb->patch_version; - mddev->persistent = 1; mddev->external = 0; mddev->chunk_size = sb->chunk_size; mddev->ctime = sb->ctime; @@ -1159,7 +1158,6 @@ static int super_1_validate(mddev_t *mdd if (mddev->raid_disks == 0) { mddev->major_version = 1; mddev->patch_version = 0; - mddev->persistent = 1; mddev->external = 0; mddev->chunk_size = le32_to_cpu(sb->chunksize) << 9; mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1); @@ -3219,8 +3217,11 @@ static int do_md_run(mddev_t * mddev) /* * Analyze all RAID superblock(s) */ - if (!mddev->raid_disks) + if (!mddev->raid_disks) { + if (!mddev->persistent) + return -EINVAL; analyze_sbs(mddev); + } chunk_size = mddev->chunk_size; @@ -3627,6 +3628,7 @@ static int do_md_stop(mddev_t * mddev, i mddev->resync_max = MaxSector; mddev->reshape_position = MaxSector; mddev->external = 0; + mddev->persistent = 0; } else if (mddev->pers) printk(KERN_INFO "md: %s switched to read-only mode.\n", @@ -3735,6 +3737,7 @@ static void autorun_devices(int part) mddev_unlock(mddev); } else { printk(KERN_INFO "md: created %s\n", mdname(mddev)); + mddev->persistent = 1; ITERATE_RDEV_GENERIC(candidates,rdev,tmp) { list_del_init(&rdev->same_set); if (bind_rdev_to_array(rdev, mddev))