kernel BUG at /build/buildd/linux-3.4.0/drivers/md/md.c:6958

Release: Quantal

Test environment:
sda, sdc and sdd are in a Intel Matrix Storage Manager (fakeraid) RAID5 setup (Volume0). Volume0 contains two partitions (NTFS and LVM2 PV).
The LVM PV is the only disk in a VG (datavg01) which contains filesystems and VM disk images.

From the installer, mdadm is run first and creates a md456 RAID5 setup which is still read-only when the partition scanning seems to mount/unmount LVs in the VG on top of the RAID. This causes the following BUG:

[ 100.230030] ------------[ cut here ]------------
[ 100.230034] kernel BUG at /build/buildd/linux-3.4.0/drivers/md/md.c:6958!
[ 100.230038] invalid opcode: 0000 [#1] SMP
[ 100.230041] CPU 4
[ 100.230043] Modules linked in: xfs reiserfs jfs btrfs zlib_deflate libcrc32c ntfs ext2 raid456 async_pq async_xor xor async_memcpy async_raid6_recov raid6_pq async_tx r8169 nls_iso8859_1 nls_cp437 vfat fat isofs vesafb firewire_ohci firewire_core crc_itu_t pata_jmicron usbhid hid usb_storage
[ 100.230069]
[ 100.230072] Pid: 19081, comm: umount Not tainted 3.4.0-3-generic #8-Ubuntu Gigabyte Technology Co., Ltd. EX58-UD3R/EX58-UD3R
[ 100.230077] RIP: 0010:[<ffffffff8150296b>] [<ffffffff8150296b>] md_write_start+0x1bb/0x1c0
[ 100.230086] RSP: 0018:ffff880206f9faa8 EFLAGS: 00010246
[ 100.230089] RAX: 0000000000000001 RBX: ffff880211283400 RCX: 0000000000000001
[ 100.230092] RDX: 0000000000000001 RSI: ffff880210f115c0 RDI: ffff880211283400
[ 100.230095] RBP: ffff880206f9faf8 R08: ffffe8ffffc809d0 R09: 0000000000000246
[ 100.230097] R10: ffffc90005f78040 R11: ffff880210f6d408 R12: ffff880211283400
[ 100.230100] R13: ffff880210f115c0 R14: ffff880210d99800 R15: 0000000000000001
[ 100.230103] FS: 00007f37e50e8700(0000) GS:ffff88021fc80000(0000) knlGS:0000000000000000
[ 100.230106] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 100.230109] CR2: 0000000000795568 CR3: 0000000206ff4000 CR4: 00000000000007e0
[ 100.230112] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 100.230115] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 100.230118] Process umount (pid: 19081, threadinfo ffff880206f9e000, task ffff880206ed8000)
[ 100.230122] Stack:
[ 100.230123] ffff8802094d9f18 0000000000100000 000000000fc00005 ffff88021169b410
[ 100.230127] ffff880206f9faf8 ffffffff812ef118 ffff880210f115c0 ffff880211283400
[ 100.230129] ffff880211283400 ffff880210f115c0 ffff880206f9fbc8 ffffffffa00f12d4
[ 100.230132] Call Trace:
[ 100.230137] [<ffffffff812ef118>] ? generic_make_request+0x18/0x110
[ 100.230141] [<ffffffffa00f12d4>] make_request+0x44/0x490 [raid456]
[ 100.230145] [<ffffffff81089d40>] ? enqueue_entity+0xc0/0x460
[ 100.230147] [<ffffffff814fb863>] md_make_request+0xc3/0x200
[ 100.230150] [<ffffffff8150cd7f>] ? dm_request+0xff/0x1a0
[ 100.230152] [<ffffffff812ef1bf>] generic_make_request+0xbf/0x110
[ 100.230154] [<ffffffff812ef295>] submit_bio+0x85/0x110
[ 100.230158] [<ffffffff811aef5a>] ? bio_alloc_bioset+0x5a/0xf0
[ 100.230160] [<ffffffff811a92e4>] submit_bh+0xf4/0x130
[ 100.230164] [<ffffffff8126403e>] jbd2_write_superblock+0x6e/0x130
[ 100.230166] [<ffffffff812641ae>] jbd2_mark_journal_empty+0x5e/0x90
[ 100.230169] [<ffffffff812644b0>] jbd2_journal_destroy+0x210/0x240
[ 100.230172] [<ffffffff810733c0>] ? finish_wait+0x80/0x80
[ 100.230178] [<ffffffff81231e1c>] ext4_put_super+0x6c/0x340
[ 100.230182] [<ffffffff8117c281>] generic_shutdown_super+0x61/0xf0
[ 100.230184] [<ffffffff8117c340>] kill_block_super+0x30/0x80
[ 100.230186] [<ffffffff8117bcc7>] deactivate_locked_super+0x57/0x90
[ 100.230189] [<ffffffff8117bf3e>] deactivate_super+0x4e/0x70
[ 100.230192] [<ffffffff811981b7>] mntput_no_expire+0xd7/0x130
[ 100.230194] [<ffffffff81198fa6>] sys_umount+0x76/0x370
[ 100.230198] [<ffffffff81682029>] system_call_fastpath+0x16/0x1b
[ 100.230199] Code: c7 83 bc 01 00 00 00 00 00 00 f0 80 4b 28 02 f0 80 4b 28 04 48 8b bb 48 01 00 00 41 bc 01 00 00 00 e8 1a 72 ff ff e9 60 ff ff ff <0f> 0b 0f 1f 00 55 48 89 e5 48 83 ec 40 48 89 5d d8 4c 89 65 e0
[ 100.230221] RIP [<ffffffff8150296b>] md_write_start+0x1bb/0x1c0
[ 100.230223] RSP <ffff880206f9faa8>
[ 100.230225] ---[ end trace 7f6b54827f764358 ]---
[ 100.320504] md: md126 switched to read-write mode.