Comment 2 for bug 972960

High -> Bug in essential component (md)

From the attached dmesg:

[ 156.969800] md/raid1:md126: active with 2 out of 2 mirrors
[ 156.969813] md126: detected capacity change from 0 to 500104691712
[ 156.970535] md126: unknown partition table
[ 157.034071] md: md0 stopped.
[ 157.034963] md: bind<sdc1>
[ 157.035336] md: bind<sdd1>
[ 157.036078] md/raid1:md0: active with 2 out of 2 mirrors
[ 157.036093] md0: detected capacity change from 0 to 1000202174464
[ 157.037434] md0: unknown partition table
[ 159.001714] ------------[ cut here ]------------
[ 159.001717] kernel BUG at /build/buildd/linux-3.2.0/drivers/md/md.c:6920!
[ 159.001719] invalid opcode: 0000 [#1] SMP
[ 159.001720] CPU 0
[ 159.001721] Modules linked in: raid1 xfs reiserfs jfs btrfs zlib_deflate libcrc32c ntfs vfat fat ext2 e1000e mpt2sas scsi_transport_sas raid_class nls_utf8 isofs vesafb usb_storage usbhid hid
[ 159.001731]
[ 159.001733] Pid: 14365, comm: parted_devices Not tainted 3.2.0-20-generic #33-Ubuntu Supermicro X9SCL/X9SCM/X9SCL/X9SCM
[ 159.001736] RIP: 0010:[<ffffffff814e7eec>] [<ffffffff814e7eec>] md_write_start+0x1c/0x20
[ 159.001742] RSP: 0018:ffff880417edfcb8 EFLAGS: 00010246
[ 159.001743] RAX: 0000000000000010 RBX: 0000000000000001 RCX: 0000000000000001
[ 159.001744] RDX: 0000000000000000 RSI: ffff880417e430c0 RDI: ffff88042179fc00
[ 159.001746] RBP: ffff880417edfcb8 R08: 0000000000000246 R09: 0000000000000077
[ 159.001747] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880417e430c0
[ 159.001748] R13: 0000000000000000 R14: ffff88041accc840 R15: 0000000000000800
[ 159.001750] FS: 00007f1a3af4e740(0000) GS:ffff88043fc00000(0000) knlGS:0000000000000000
[ 159.001751] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 159.001752] CR2: 0000000001d6f098 CR3: 0000000419772000 CR4: 00000000000406f0
[ 159.001754] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 159.001755] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 159.001757] Process parted_devices (pid: 14365, threadinfo ffff880417ede000, task ffff880417c1c4d0)
[ 159.001758] Stack:
[ 159.001759] ffff880417edfda8 ffffffffa01a6eaa 0000000000000000 0000000000000000
[ 159.001762] ffff880417edfce8 ffffffff8105fae2 ffff880417edfd08 0000000000000010
[ 159.001764] ffff880417edfd18 ffffffff81300936 ffff880417e430c0 ffff880417e430c0
[ 159.001767] Call Trace:
[ 159.001771] [<ffffffffa01a6eaa>] make_request+0x4a/0xa60 [raid1]
[ 159.001775] [<ffffffff8105fae2>] ? default_wake_function+0x12/0x20
[ 159.001777] [<ffffffff81300936>] ? throtl_find_tg+0x46/0x60
[ 159.001779] [<ffffffff81301b20>] ? blk_throtl_bio+0x1c0/0x4e0
[ 159.001782] [<ffffffff8104dec3>] ? __wake_up+0x53/0x70
[ 159.001784] [<ffffffff814e1fd0>] md_make_request+0xd0/0x200
[ 159.001788] [<ffffffff8111a035>] ? mempool_alloc_slab+0x15/0x20
[ 159.001791] [<ffffffff812efb24>] generic_make_request.part.50+0x74/0xb0
[ 159.001793] [<ffffffff812eff38>] generic_make_request+0x68/0x70
[ 159.001795] [<ffffffff812effc5>] submit_bio+0x85/0x110
[ 159.001798] [<ffffffff811adf3a>] ? bio_alloc_bioset+0x5a/0xf0
[ 159.001800] [<ffffffff812f4942>] blkdev_issue_flush+0x92/0xe0
[ 159.001802] [<ffffffff811af5fe>] blkdev_fsync+0x3e/0x50
[ 159.001805] [<ffffffff811a6436>] do_fsync+0x56/0x80
[ 159.001807] [<ffffffff811a6760>] sys_fsync+0x10/0x20
[ 159.001810] [<ffffffff81664502>] system_call_fastpath+0x16/0x1b
[ 159.001811] Code: e8 9a 7b ff ff e9 56 ff ff ff 0f 1f 44 00 00 55 48 89 e5 66 66 66 66 90 f6 46 20 01 74 0b 83 7f 38 01 74 07 e8 56 fe ff ff 5d c3 <0f> 0b 66 90 55 48 89 e5 53 48 83 ec 18 66 66 66 66 90 48 89 fb
[ 159.001831] RIP [<ffffffff814e7eec>] md_write_start+0x1c/0x20
[ 159.001834] RSP <ffff880417edfcb8>
[ 159.001849] ---[ end trace cce129ba795d84aa ]---