Patch http://review.whamcloud.com/#change,4156 introduced a kernel oops when mounting a MGT on a stand alone MGS system. The oops is:
2012-10-05 09:52:05 [ 355.128991] Lustre: DEBUG MARKER: mkdir -p /tmp/lustre/mgs
2012-10-05 09:52:05 [ 355.485941] Lustre: DEBUG MARKER: test -b /dev/sda1
2012-10-05 09:52:05 [ 355.830922] Lustre: DEBUG MARKER: mkdir -p /tmp/lustre/mgs; mount -t lustre ^I^I /dev/sda1 /tmp/lustre/mgs
2012-10-05 09:52:06 [ 356.265280] LDISKFS-fs (sda1): mounted filesystem with ordered data mode. quota=on. Opts:
2012-10-05 09:52:06 [ 356.381871] LustreError: 8414:0:(qsd_lib.c:355:qsd_init()) MGS: fail to extract filesystem name
2012-10-05 09:52:06 [ 356.449872] BUG: unable to handle kernel NULL pointer dereference at (null)
2012-10-05 09:52:06 [ 356.457029] IP: [<ffffffffa0cdf43a>] osd_oi_table_put+0x10a/0x1d0 [osd_ldiskfs]
2012-10-05 09:52:06 [ 356.464534] PGD 5c85dc067 PUD 5c96f8067 PMD 0
2012-10-05 09:52:06 [ 356.469223] Oops: 0000 1 SMP
2012-10-05 09:52:06 [ 356.472645] last sysfs file: /sys/module/ldiskfs/initstate
2012-10-05 09:52:06 [ 356.478213] CPU 2
2012-10-05 09:52:06 [ 356.480088] Modules linked in: fsfilt_ldiskfs(U) exportfs osd_ldiskfs(U) mdd(U) ldiskfs(U) mbcache jbd2 lustre(U) lov(U) osc(U) mdc(U) lquo
ta(U) fid(U) fld(U) ptlrpc(U) obdclass(U) lvfs(U) ko2iblnd(U) lnet(U) sha512_generic sha256_generic libcfs(U) autofs4 ib_srp scsi_transport_srp scsi_tgt ipmi_devintf ipmi_si ipmi_msghandler nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_addr ib_sa mlx4_ib ib_mad ib_core dm_mirror dm_region_hash dm_log dm_multipath dm_mod sg power_meter sr_mod cdrom sd_mod crc_t10dif ses enclosure microcode dcdbas serio_raw ata_generic pata_acpi ata_piix iTCO_wdt iTCO_vendor_support megaraid_sas i7core_edac edac_core ipv6 nfs lockd fscache nfs_acl auth_rpcgss sunrpc mlx4_en mlx4_core bnx2 [last unloaded: scsi_wait_scan]
2012-10-05 09:52:06 [ 356.565516]
2012-10-05 09:52:06 [ 356.567099] Pid: 8414, comm: mount.lustre Not tainted 2.6.32-279.9.1.el6.head.x86_64 #1 Dell Inc. PowerEdge R610/0F0XJ6
2012-10-05 09:52:06 [ 356.578177] RIP: 0010:[<ffffffffa0cdf43a>] [<ffffffffa0cdf43a>] osd_oi_table_put+0x10a/0x1d0 [osd_ldiskfs]
2012-10-05 09:52:06 [ 356.588109] RSP: 0018:ffff8805c463d948 EFLAGS: 00010246
2012-10-05 09:52:06 [ 356.593503] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
2012-10-05 09:52:06 [ 356.600717] RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8805c4590000
2012-10-05 09:52:06 [ 356.607930] RBP: ffff8805c463d978 R08: 0000000000000000 R09: ffff8805f0091c80
2012-10-05 09:52:06 [ 356.615156] R10: ffff880330096440 R11: 0000000000000000 R12: 0000000000000000
2012-10-05 09:52:06 [ 356.622371] R13: 0000000000000040 R14: 0000000000000000 R15: 5a5a5a5a5a5a5a5a
2012-10-05 09:52:06 [ 356.629590] FS: 00007f371446e700(0000) GS:ffff88033ac20000(0000) knlGS:0000000000000000
2012-10-05 09:52:06 [ 356.637820] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
2012-10-05 09:52:06 [ 356.643649] CR2: 0000000000000000 CR3: 000000031701a000 CR4: 00000000000006e0
2012-10-05 09:52:06 [ 356.650864] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
2012-10-05 09:52:06 [ 356.658077] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
2012-10-05 09:52:06 [ 356.665297] Process mount.lustre (pid: 8414, threadinfo ffff8805c463c000, task ffff8805c466f500)
2012-10-05 09:52:06 [ 356.674219] Stack:
2012-10-05 09:52:06 [ 356.676322] ffff8805c463d968 ffff8805ca6da000 ffff8805c463da08 00000000ffffffea
2012-10-05 09:52:06 [ 356.683788] <d> ffff8805ca6da000 ffff8805ca6db4e8 ffff8805c463d998 ffffffffa0cdf51d
2012-10-05 09:52:06 [ 356.691845] <d> ffff8805c463da08 ffff8805ca6da000 ffff8805c463d9e8 ffffffffa0cd373e
2012-10-05 09:52:06 [ 356.701234] Call Trace:
2012-10-05 09:52:06 [ 356.703777] [<ffffffffa0cdf51d>] osd_oi_fini+0x1d/0x120 [osd_ldiskfs]
2012-10-05 09:52:06 [ 356.710395] [<ffffffffa0cd373e>] osd_device_alloc+0x43e/0x810 [osd_ldiskfs]
2012-10-05 09:52:06 [ 356.717559] [<ffffffffa055acf7>] obd_setup+0x1d7/0x2f0 [obdclass]
2012-10-05 09:52:06 [ 356.723846] [<ffffffffa055b018>] class_setup+0x208/0x890 [obdclass]
2012-10-05 09:52:06 [ 356.730304] [<ffffffffa05625cc>] class_process_config+0xc0c/0x1ca0 [obdclass]
2012-10-05 09:52:06 [ 356.737678] [<ffffffffa03a8be0>] ? cfs_alloc+0x30/0x60 [libcfs]
2012-10-05 09:52:06 [ 356.743791] [<ffffffffa0569b63>] ? lustre_cfg_new+0x353/0x710 [obdclass]
2012-10-05 09:52:06 [ 356.750685] [<ffffffffa056a4b9>] do_lcfg+0x149/0x480 [obdclass]
2012-10-05 09:52:06 [ 356.756796] [<ffffffffa056a884>] lustre_start_simple+0x94/0x200 [obdclass]
2012-10-05 09:52:06 [ 356.763862] [<ffffffffa057b0a3>] lustre_fill_super+0x1093/0x1af0 [obdclass]
2012-10-05 09:52:06 [ 356.770996] [<ffffffff8116a48c>] ? pcpu_alloc+0x3ac/0xa50
2012-10-05 09:52:06 [ 356.776570] [<ffffffff8127a22a>] ? strlcpy+0x4a/0x60
2012-10-05 09:52:06 [ 356.781715] [<ffffffff8117de33>] ? sget+0x3e3/0x480
2012-10-05 09:52:06 [ 356.786764] [<ffffffff8117cf10>] ? set_anon_super+0x0/0x100
2012-10-05 09:52:06 [ 356.792527] [<ffffffffa057a010>] ? lustre_fill_super+0x0/0x1af0 [obdclass]
2012-10-05 09:52:06 [ 356.799572] [<ffffffff8117e37f>] get_sb_nodev+0x5f/0xa0
2012-10-05 09:52:06 [ 356.804993] [<ffffffffa05656a5>] lustre_get_sb+0x25/0x30 [obdclass]
2012-10-05 09:52:06 [ 356.811430] [<ffffffff8117dfdb>] vfs_kern_mount+0x7b/0x1b0
2012-10-05 09:52:06 [ 356.817090] [<ffffffff8117e182>] do_kern_mount+0x52/0x130
2012-10-05 09:52:06 [ 356.822665] [<ffffffff8119c862>] do_mount+0x2d2/0x8d0
2012-10-05 09:52:06 [ 356.827890] [<ffffffff8119cef0>] sys_mount+0x90/0xe0
2012-10-05 09:52:06 [ 356.833030] [<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b
2012-10-05 09:52:06 [ 356.839120] Code: f8 b9 19 00 00 00 48 89 d7 f3 48 ab 48 8b 3b e8 7d 97 6c ff 48 c7 03 00 00 00 00 41 83 c4 01 45 39 e5 76 3d 49 63 c4 49 8d 1c c6 <48> 8b 03 48 85 c0 74 e8 48 8b 38 48 85 ff 74 35 48 3b 78 08 0f
2012-10-05 09:52:06 [ 356.861652] RIP [<ffffffffa0cdf43a>] osd_oi_table_put+0x10a/0x1d0 [osd_ldiskfs]
2012-10-05 09:52:06 [ 356.869243] RSP <ffff8805c463d948>
2012-10-05 09:52:06 [ 356.872820] CR2: 0000000000000000
2012-10-05 09:52:07 [ 0.000000] Initializing cgroup subsys cpuset
2012-10-05 09:52:07 [ 0.000000] Initializing cgroup subsys cpu
Patch for the oi scrub init issue (independent of quota) is available here:
b2_3: http://review.whamcloud.com/#change,4218
master: http://review.whamcloud.com/#change,4219