Node crash with kernel BUG at block/cfq-iosched.c:2806 error

Hello!

We have node with 2.6.32-042stab104.1 kernel.
It crashed with error -

<4>[28282589.724150] ------------[ cut here ]------------
<2>[28282589.724178] kernel BUG at block/cfq-iosched.c:2806!
<4>[28282589.724194] invalid opcode: 0000 [#1] SMP
<4>[28282589.724223] last sysfs file: /sys/devices/virtual/block/ploop23491/dev
<4>[28282589.724242] CPU 5
<4>[28282589.724253] Modules linked in: kcare(U) xt_conntrack iptable_raw ipmi_devintf nf_conntrack_ftp xt_connlimit ipt_REDIRECT nf_conntrack_ipv6 nf_defrag_ipv6 ipt_MASQUERADE freq_table mperf coretemp xt_MARK xt_mark xt_TCPMSS xt_DSCP ip6t_LOG xt_hl ip6t_rt xt_limit ipt_addrtype sch_sfq cls_u32 sch_htb xt_multiport xt_comment ipt_REJECT iptable_mangle vzethdev pio_nfs pio_direct pfmt_raw pfmt_ploop1 ploop simfs vziolimit vzdquota ip6t_REJECT ip6table_mangle vzevent netconsole configfs vznetdev bonding 8021q garp stp llc iptable_filter ip6table_filter ip6_tables ipip tunnel4 xt_recent vzrst vzcpt vzmon vzdev nfs lockd fscache auth_rpcgss nfs_acl sunrpc xt_owner xt_state ipt_LOG xfrm_ipcomp xfrm4_mode_transport pppol2tp pppox xfrm6_mode_tunnel xfrm4_mode_tunnel esp6 ipv6 esp4 af_key arc4 ecb ppp_mppe ppp_deflate zlib_deflate ppp_async ppp_generic slhc crc_ccitt fuse iptable_nat nf_nat ip_tables nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 tun iTCO_wdt iTCO_vendor_support power_meter acpi_ipmi ipmi_si ipmi_msghandler dcdbas sg shpchp tg3 ptp pps_core sb_edac edac_core lpc_ich mfd_core ext4 jbd2 mbcache sd_mod crc_t10dif wmi megaraid_sas dm_mirror dm_region_hash dm_log dm_mod [last unloaded: kcare]
<4>[28282589.725669]
<4>[28282589.726136] Pid: 148833, comm: ploop19741 veid: 0 Tainted: G W --------------- 2.6.32-042stab104.1 #1 042stab104 Dell Inc. PowerEdge R720xd/0W7JN5
<4>[28282589.738894] RIP: 0010:[<ffffffff81293ed0>] [<ffffffff81293ed0>] cfq_put_queue+0x120/0x130
<4>[28282589.739843] RSP: 0018:ffff88014b5377a0 EFLAGS: 00010046
<4>[28282589.740319] RAX: 0000000000000000 RBX: ffff882ae8acf270 RCX: 0000000000000b24
<4>[28282589.741257] RDX: 0000000000000286 RSI: ffff882fc0720d18 RDI: ffff882ae8acf270
<4>[28282589.742192] RBP: ffff88014b5377c0 R08: ffff885ff3242480 R09: 000071e304540000
<4>[28282589.743134] R10: ffff8e1d1824c115 R11: 0000000000000000 R12: ffff883012e55800
<4>[28282589.744072] R13: ffff882ae8acf270 R14: 0000000000000286 R15: ffff883012e55800
<4>[28282589.745012] FS: 0000000000000000(0000) GS:ffff8830f1080000(0000) knlGS:0000000000000000
<4>[28282589.745954] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
<4>[28282589.746432] CR2: 00007f139d359098 CR3: 0000005e538ab000 CR4: 00000000001407e0
<4>[28282589.747374] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
<4>[28282589.748320] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
<4>[28282589.749262] Process ploop19741 (pid: 148833, veid: 0, threadinfo ffff88014b536000, task ffff88015959ebc0)
<4>[28282589.750297] Stack:
<4>[28282589.750763] ffff882fc0720d18 ffff883012e5aeb8 ffff882ae8acf270 0000000000000286
<4>[28282589.751260] <d> ffff88014b537800 ffffffff81293fd7 0000000000021000 ffff882fc0720d18
<4>[28282589.752227] <d> ffff883012e55800 ffff882fc0720d70 ffff885f42739df0 000000000001adb0
<4>[28282589.753658] Call Trace:
<4>[28282589.754144] [<ffffffff81293fd7>] changed_cgroup+0x67/0xd0
<4>[28282589.754627] [<ffffffff812967c2>] cfq_set_request+0x4d2/0x560
<4>[28282589.755111] [<ffffffff8113f335>] ? mempool_alloc_slab+0x15/0x20
<4>[28282589.755596] [<ffffffff8113f4d7>] ? mempool_alloc+0x67/0x170
<4>[28282589.756087] [<ffffffff81274f3b>] elv_set_request+0x1b/0x30
<4>[28282589.756570] [<ffffffff8127cac2>] get_request+0x302/0x400
<4>[28282589.757054] [<ffffffff8129aac7>] ? kobject_put+0x27/0x60
<4>[28282589.757542] [<ffffffff8127cbea>] get_request_wait+0x2a/0x1d0
<4>[28282589.758034] [<ffffffff8127683e>] ? elv_merge+0x18e/0x1d0
<4>[28282589.758522] [<ffffffff8127ce29>] blk_queue_bio+0x99/0x600
<4>[28282589.759016] [<ffffffffa031d62e>] ? __map_extent+0x18e/0x470 [pio_direct]
<4>[28282589.759507] [<ffffffff8127be50>] generic_make_request+0x240/0x550
<4>[28282589.759992] [<ffffffff8113f335>] ? mempool_alloc_slab+0x15/0x20
<4>[28282589.760483] [<ffffffff8127c1e3>] submit_bio+0x83/0x190
<4>[28282589.760970] [<ffffffffa031c410>] dio_io_page+0x250/0x370 [pio_direct]
<4>[28282589.761461] [<ffffffffa031c59c>] dio_read_page+0x1c/0x20 [pio_direct]
<4>[28282589.761945] [<ffffffffa027b057>] ploop1_read_index+0x17/0x20 [pfmt_ploop1]
<4>[28282589.762890] [<ffffffffa04e50d9>] ploop_read_map+0x169/0x270 [ploop]
<4>[28282589.763381] [<ffffffffa04e630b>] ploop_find_map+0x7b/0x170 [ploop]
<4>[28282589.763866] [<ffffffffa04dedbf>] ploop_entry_request+0x32f/0xf50 [ploop]
<4>[28282589.764449] [<ffffffff81532fd0>] ? thread_return+0xbe/0x8ee
<4>[28282589.764931] [<ffffffffa04dfe48>] ploop_req_state_process+0x468/0x860 [ploop]
<4>[28282589.765886] [<ffffffffa04e456a>] ploop_thread+0x1ca/0x770 [ploop]
<4>[28282589.766380] [<ffffffff810a80c0>] ? autoremove_wake_function+0x0/0x40
<4>[28282589.766868] [<ffffffffa04e43a0>] ? ploop_thread+0x0/0x770 [ploop]
<4>[28282589.767352] [<ffffffff810a7cce>] kthread+0x9e/0xc0
<4>[28282589.767843] [<ffffffff8100c34a>] child_rip+0xa/0x20
<4>[28282589.768332] [<ffffffff810a7c30>] ? kthread+0x0/0xc0
<4>[28282589.768811] [<ffffffff8100c340>] ? child_rip+0x0/0x20
<4>[28282589.769292] Code: 00 25 00 01 00 00 4c 8d 86 7a 01 00 00 48 c7 c6 aa 37 7e 81 83 f8 01 19 c9 31 c0 83 e1 ee 83 c1 53 e8 a5 11 e9 ff e9 2e ff ff ff <0f> 0b eb fe 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41
<1>[28282589.771128] RIP [<ffffffff81293ed0>] cfq_put_queue+0x120/0x130
<4>[28282589.771620] RSP <ffff88014b5377a0>


We can upload coredump, if it need.