Re: iscsi_trx going into D state

[Robert LeBlanc <robert@leblancnet.us>]

I looked at this code and it is quiet above my ability. I created this
patch, but I don't know how to interrogate the queue to see how many
items there are. If you can give me some more direction on what to
try, I can keep fumbling around with this until someone smarter than
me can figure it out. This is now a blocker for me so I'm going to
beat my head on this until it is fixed.

Thanks for being patient with me.

diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index 8368764..9e5bd4b 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -1954,22 +1954,27 @@ static void __ib_drain_sq(struct ib_qp *qp)
                return;
        }

+       printk("Setting up drain callback.");
        swr.wr_cqe = &sdrain.cqe;
        sdrain.cqe.done = ib_drain_qp_done;
+       printk("Starting init_completion.");
        init_completion(&sdrain.done);

+       printk("Calling ib_modify_qp.");
        ret = ib_modify_qp(qp, &attr, IB_QP_STATE);
        if (ret) {
                WARN_ONCE(ret, "failed to drain send queue: %d\n", ret);
                return;
        }

+       printk("Calling ib_post_send.");
        ret = ib_post_send(qp, &swr, &bad_swr);
        if (ret) {
                WARN_ONCE(ret, "failed to drain send queue: %d\n", ret);
                return;
        }

+       printk("Starting wait_for_completion.");
        wait_for_completion(&sdrain.done);
 }

I get the same processes in D state (and same backtrace) and this is
what shows up in dmesg:

[  920.317401] isert: isert_rdma_accept: rdma_accept() failed with: -110
[  920.325554] ------------[ cut here ]------------
[  920.330188] WARNING: CPU: 11 PID: 705 at
drivers/infiniband/core/verbs.c:303 ib_dealloc_pd+0x58/0xa0 [ib_core]
[  920.340210] Modules linked in: target_core_user target_core_pscsi
target_core_file target_core_iblock 8021q garp mrp rpcrdma sunrpc
ib_isert ib_iser ib_srpt ib_srp scsi_transport_srp ib_ipoib
iptable_filter rdma_ucm i
b_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm sb_edac edac_core
x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ext4
ipmi_devintf irqbypass crct10dif_pclmul crc32_pclmul
ghash_clmulni_intel aesni_intel jbd2 lr
w gf128mul glue_helper mbcache iTCO_wdt ablk_helper mei_me
iTCO_vendor_support cryptd joydev sg mei i2c_i801 lpc_ich pcspkr
mfd_core ioatdma shpchp i2c_smbus ipmi_si wmi ipmi_msghandler
acpi_power_meter acpi_pad ip_table
s xfs libcrc32c raid1 mlx4_en mlx4_ib mlx5_ib sd_mod ib_core ast
drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm
mlx5_core igb mlx4_core
[  920.412347]  ahci ptp drm libahci pps_core libata dca i2c_algo_bit
be2iscsi bnx2i cnic uio qla4xxx iscsi_boot_sysfs
[  920.421744] CPU: 11 PID: 705 Comm: kworker/11:2 Not tainted 4.9.0+ #3
[  920.428199] Hardware name: Supermicro SYS-6028TP-HTFR/X10DRT-PIBF,
BIOS 1.1 08/03/2015
[  920.436126] Workqueue: ib_cm cm_work_handler [ib_cm]
[  920.441113]  ffffc90032a03a40 ffffffff8134d45f 0000000000000000
0000000000000000
[  920.448583]  ffffc90032a03a80 ffffffff81083371 0000012fa04a1c4a
ffff883f5e886e80
[  920.456073]  ffff887f1eaa4400 ffff887f1eaa5800 ffffc90032a03b08
00000000ffffff92
[  920.463535] Call Trace:
[  920.465993]  [<ffffffff8134d45f>] dump_stack+0x63/0x84
[  920.471144]  [<ffffffff81083371>] __warn+0xd1/0xf0
[  920.475941]  [<ffffffff810834ad>] warn_slowpath_null+0x1d/0x20
[  920.481790]  [<ffffffffa026cf58>] ib_dealloc_pd+0x58/0xa0 [ib_core]
[  920.488072]  [<ffffffffa0695000>] isert_device_put+0x50/0xc0 [ib_isert]
[  920.494693]  [<ffffffffa069838e>] isert_connect_request+0x68e/0xd40
[ib_isert]
[  920.501924]  [<ffffffffa0699683>] isert_cma_handler+0xe3/0x3b0 [ib_isert]
[  920.508725]  [<ffffffffa042c5d6>] ? cma_new_conn_id+0x276/0x4b0 [rdma_cm]
[  920.515521]  [<ffffffffa0427050>] cma_listen_handler+0x20/0x30 [rdma_cm]
[  920.522227]  [<ffffffffa042ca05>] cma_req_handler+0x1f5/0x4c0 [rdma_cm]
[  920.528851]  [<ffffffffa03fb0f5>] cm_process_work+0x25/0xf0 [ib_cm]
[  920.535125]  [<ffffffffa03fba94>] cm_req_handler+0x8d4/0xc70 [ib_cm]
[  920.541485]  [<ffffffffa03fc1ce>] cm_work_handler+0x1ce/0x1648 [ib_cm]
[  920.548021]  [<ffffffff8109cc02>] process_one_work+0x152/0x400
[  920.553861]  [<ffffffff8109d4f5>] worker_thread+0x125/0x4b0
[  920.559443]  [<ffffffff8109d3d0>] ? rescuer_thread+0x380/0x380
[  920.565284]  [<ffffffff810a3059>] kthread+0xd9/0xf0
[  920.570178]  [<ffffffff810a2f80>] ? kthread_park+0x60/0x60
[  920.576389]  [<ffffffff817732d5>] ret_from_fork+0x25/0x30
[  920.582473] ---[ end trace 1f5a1831f9d2d964 ]---
[  920.587907] ------------[ cut here ]------------
[  920.593213] WARNING: CPU: 11 PID: 705 at
drivers/infiniband/core/cq.c:189 ib_free_cq+0x97/0xc0 [ib_core]
[  920.603383] Modules linked in: target_core_user target_core_pscsi
target_core_file target_core_iblock 8021q garp mrp rpcrdma sunrpc
ib_isert ib_iser ib_srpt ib_srp scsi_transport_srp ib_ipoib
iptable_filter rdma_ucm i
b_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm sb_edac edac_core
x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ext4
ipmi_devintf irqbypass crct10dif_pclmul crc32_pclmul
ghash_clmulni_intel aesni_intel jbd2 lr
w gf128mul glue_helper mbcache iTCO_wdt ablk_helper mei_me
iTCO_vendor_support cryptd joydev sg mei i2c_i801 lpc_ich pcspkr
mfd_core ioatdma shpchp i2c_smbus ipmi_si wmi ipmi_msghandler
acpi_power_meter acpi_pad ip_table
s xfs libcrc32c raid1 mlx4_en mlx4_ib mlx5_ib sd_mod ib_core ast
drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm
mlx5_core igb mlx4_core
[  920.679694]  ahci ptp drm libahci pps_core libata dca i2c_algo_bit
be2iscsi bnx2i cnic uio qla4xxx iscsi_boot_sysfs
[  920.690579] CPU: 11 PID: 705 Comm: kworker/11:2 Tainted: G        W
      4.9.0+ #3
[  920.699008] Hardware name: Supermicro SYS-6028TP-HTFR/X10DRT-PIBF,
BIOS 1.1 08/03/2015
[  920.707701] Workqueue: ib_cm cm_work_handler [ib_cm]
[  920.713438]  ffffc90032a03a18 ffffffff8134d45f 0000000000000000
0000000000000000
[  920.721648]  ffffc90032a03a58 ffffffff81083371 000000bd5e886e80
ffff887f1eaa6800
[  920.729850]  ffff883f5e886e20 ffff883f5e886e18 ffffc90032a03b08
00000000ffffff92
[  920.738026] Call Trace:
[  920.741188]  [<ffffffff8134d45f>] dump_stack+0x63/0x84
[  920.747027]  [<ffffffff81083371>] __warn+0xd1/0xf0
[  920.752488]  [<ffffffff810834ad>] warn_slowpath_null+0x1d/0x20
[  920.758989]  [<ffffffffa026e037>] ib_free_cq+0x97/0xc0 [ib_core]
[  920.765649]  [<ffffffffa0694f88>]
isert_free_comps.isra.26+0x38/0x60 [ib_isert]
[  920.773609]  [<ffffffffa069500d>] isert_device_put+0x5d/0xc0 [ib_isert]
[  920.780868]  [<ffffffffa069838e>] isert_connect_request+0x68e/0xd40
[ib_isert]
[  920.788734]  [<ffffffffa0699683>] isert_cma_handler+0xe3/0x3b0 [ib_isert]
[  920.796157]  [<ffffffffa042c5d6>] ? cma_new_conn_id+0x276/0x4b0 [rdma_cm]
[  920.803586]  [<ffffffffa0427050>] cma_listen_handler+0x20/0x30 [rdma_cm]
[  920.810916]  [<ffffffffa042ca05>] cma_req_handler+0x1f5/0x4c0 [rdma_cm]
[  920.818167]  [<ffffffffa03fb0f5>] cm_process_work+0x25/0xf0 [ib_cm]
[  920.825063]  [<ffffffffa03fba94>] cm_req_handler+0x8d4/0xc70 [ib_cm]
[  920.832051]  [<ffffffffa03fc1ce>] cm_work_handler+0x1ce/0x1648 [ib_cm]
[  920.839208]  [<ffffffff8109cc02>] process_one_work+0x152/0x400
[  920.845669]  [<ffffffff8109d4f5>] worker_thread+0x125/0x4b0
[  920.851880]  [<ffffffff8109d3d0>] ? rescuer_thread+0x380/0x380
[  920.858352]  [<ffffffff810a3059>] kthread+0xd9/0xf0
[  920.863857]  [<ffffffff810a2f80>] ? kthread_park+0x60/0x60
[  920.869975]  [<ffffffff817732d5>] ret_from_fork+0x25/0x30
[  920.876006] ---[ end trace 1f5a1831f9d2d965 ]---
[  920.884335] isert: isert_cma_handler: failed handle connect request -110
[ 1639.592451] Setting up drain callback.
[ 1639.596073] Starting init_completion.
[ 1639.600683] Calling ib_modify_qp.
[ 1639.602616] Calling ib_post_send.
[ 1639.606550] Starting wait_for_completion.
[ 1656.976015] iSCSI Login timeout on Network Portal 0.0.0.0:3260
[ 1674.254027] Setting up drain callback.
[ 1674.257634] Starting init_completion.
[ 1674.262107] Calling ib_modify_qp.
[ 1674.264011] Calling ib_post_send.
[ 1674.267969] Starting wait_for_completion.
[ 1691.583888] Setting up drain callback.
[ 1691.588490] Starting init_completion.
[ 1691.590677] Calling ib_modify_qp.
[ 1691.594766] Calling ib_post_send.
[ 1691.596607] Starting wait_for_completion.
[ 1708.913356] Setting up drain callback.
[ 1708.915658] Starting init_completion.
[ 1708.920152] Calling ib_modify_qp.
[ 1708.922041] Calling ib_post_send.
[ 1708.926048] Starting wait_for_completion.
[ 1726.244365] Setting up drain callback.
[ 1726.248973] Starting init_completion.
[ 1726.251165] Calling ib_modify_qp.
[ 1726.255189] Calling ib_post_send.
[ 1726.257031] Starting wait_for_completion.
[ 1743.574751] Setting up drain callback.
[ 1743.577044] Starting init_completion.
[ 1743.581496] Calling ib_modify_qp.
[ 1743.583404] Calling ib_post_send.
[ 1743.587346] Starting wait_for_completion.
[ 1760.904470] Setting up drain callback.
[ 1760.908991] Starting init_completion.
[ 1760.911206] Calling ib_modify_qp.
[ 1760.915214] Calling ib_post_send.
[ 1760.917062] Starting wait_for_completion.
[ 1778.230821] Setting up drain callback.
[ 1778.233116] Starting init_completion.
[ 1778.237510] Calling ib_modify_qp.
[ 1778.239413] Calling ib_post_send.
.... [keeps repeating]
----------------
Robert LeBlanc
PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1


On Thu, Dec 22, 2016 at 12:15 PM, Doug Ledford <dledford@redhat.com> wrote:
> On 12/21/2016 6:39 PM, Robert LeBlanc wrote:
>> I hit a new backtrace today, hopefully it adds something.
>>
>> # cat /proc/19659/stack
>> [<ffffffff815304d1>] iscsit_stop_session+0x1b1/0x1c0
>> [<ffffffff81521c62>] iscsi_check_for_session_reinstatement+0x1e2/0x270
>> [<ffffffff81524660>] iscsi_target_check_for_existing_instances+0x30/0x40
>> [<ffffffff815247a8>] iscsi_target_do_login+0x138/0x630
>> [<ffffffff815259be>] iscsi_target_start_negotiation+0x4e/0xa0
>> [<ffffffff8152355e>] __iscsi_target_login_thread+0x83e/0xf20
>> [<ffffffff81523c64>] iscsi_target_login_thread+0x24/0x30
>> [<ffffffff810a3059>] kthread+0xd9/0xf0
>> [<ffffffff817732d5>] ret_from_fork+0x25/0x30
>> [<ffffffffffffffff>] 0xffffffffffffffff
>>
>> # cat /proc/21342/stack
>> [<ffffffffa0292b10>] __ib_drain_sq+0x190/0x1c0 [ib_core]
>> [<ffffffffa0292b65>] ib_drain_sq+0x25/0x30 [ib_core]
>> [<ffffffffa0292d72>] ib_drain_qp+0x12/0x30 [ib_core]
>> [<ffffffffa062c5ff>] isert_wait_conn+0x5f/0x2d0 [ib_isert]
>> [<ffffffff815309b7>] iscsit_close_connection+0x157/0x860
>> [<ffffffff8151f10b>] iscsit_take_action_for_connection_exit+0x7b/0xf0
>> [<ffffffff81530265>] iscsi_target_rx_thread+0x95/0xa0
>> [<ffffffff810a3059>] kthread+0xd9/0xf0
>> [<ffffffff817732d5>] ret_from_fork+0x25/0x30
>> [<ffffffffffffffff>] 0xffffffffffffffff
>>
>> # ps aux | grep iscsi | grep D
>> root     19659  0.0  0.0      0     0 ?        D    16:12   0:00 [iscsi_np]
>> root     21342  0.0  0.0      0     0 ?        D    16:29   0:00 [iscsi_trx]
>> ----------------
>> Robert LeBlanc
>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
>
> That looks suspiciously like the __ib_drain_sq is stuck forever waiting
> on a completion that never comes.
>
>>
>> On Thu, Dec 15, 2016 at 1:38 PM, Robert LeBlanc <robert@leblancnet.us> wrote:
>>> Nicholas,
>>>
>>> I've found that the kernels I used were not able to be inspected using
>>> crash and I could not build the debug info for them. So I built a new
>>> 4.9 kernel and verified that I could inspect the crash. It is located
>>> at [1].
>>>
>>> [1] http://mirrors.betterservers.com/trace/crash2.tar.xz
>>> ----------------
>>> Robert LeBlanc
>>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
>>>
>>>
>>> On Mon, Dec 12, 2016 at 4:57 PM, Robert LeBlanc <robert@leblancnet.us> wrote:
>>>> Nicholas,
>>>>
>>>> After lots of set backs and having to give up trying to get kernel
>>>> dumps on our "production" systems, I've been able to work out the
>>>> issues we had with kdump and replicate the issue on my dev boxes. I
>>>> have dumps from 4.4.30 and 4.9-rc8 (makedumpfile would not dump, so it
>>>> is a straight copy of /proc/vmcore from the crash kernel). In each
>>>> crash directory, I put a details.txt file that has the process IDs
>>>> that were having problems and a brief description of the set-up at the
>>>> time. This was mostly replicated by starting fio and pulling the
>>>> Infiniband cable until fio gave up. This hardware also has Mellanox
>>>> ConnectX4-LX cards and I also replicated the issue over RoCE using 4.9
>>>> since it has the drivers in-box. Please let me know if you need more
>>>> info, I can test much faster now. The cores/kernels/modules are
>>>> located at [1].
>>>>
>>>> [1] http://mirrors.betterservers.com/trace/crash.tar.xz
>>>>
>>>> Thanks,
>>>> Robert
>>>> ----------------
>>>> Robert LeBlanc
>>>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
>>>>
>>>>
>>>> On Fri, Nov 4, 2016 at 3:57 PM, Robert LeBlanc <robert@leblancnet.us> wrote:
>>>>> We hit this yesterday, this time it was on the tx thread (the other
>>>>> ones before seem to be on the rx thread). We weren't able to get a
>>>>> kernel dump on this. We'll try to get one next time.
>>>>>
>>>>> # ps axuw | grep "D.*iscs[i]"
>>>>> root     12383  0.0  0.0      0     0 ?        D    Nov03   0:04 [iscsi_np]
>>>>> root     23016  0.0  0.0      0     0 ?        D    Nov03   0:00 [iscsi_ttx]
>>>>> root     23018  0.0  0.0      0     0 ?        D    Nov03   0:00 [iscsi_ttx]
>>>>> # cat /proc/12383/stack
>>>>> [<ffffffff814f24af>] iscsit_stop_session+0x19f/0x1d0
>>>>> [<ffffffff814e3c66>] iscsi_check_for_session_reinstatement+0x1e6/0x270
>>>>> [<ffffffff814e6620>] iscsi_target_check_for_existing_instances+0x30/0x40
>>>>> [<ffffffff814e6770>] iscsi_target_do_login+0x140/0x640
>>>>> [<ffffffff814e7b0c>] iscsi_target_start_negotiation+0x1c/0xb0
>>>>> [<ffffffff814e585b>] iscsi_target_login_thread+0xa9b/0xfc0
>>>>> [<ffffffff8109d7c8>] kthread+0xd8/0xf0
>>>>> [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70
>>>>> [<ffffffffffffffff>] 0xffffffffffffffff
>>>>> # cat /proc/23016/stack
>>>>> [<ffffffff814ce0d9>] target_wait_for_sess_cmds+0x49/0x1a0
>>>>> [<ffffffffa058b92b>] isert_wait_conn+0x1ab/0x2f0 [ib_isert]
>>>>> [<ffffffff814f2642>] iscsit_close_connection+0x162/0x870
>>>>> [<ffffffff814e110f>] iscsit_take_action_for_connection_exit+0x7f/0x100
>>>>> [<ffffffff814f122a>] iscsi_target_tx_thread+0x1aa/0x1d0
>>>>> [<ffffffff8109d7c8>] kthread+0xd8/0xf0
>>>>> [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70
>>>>> [<ffffffffffffffff>] 0xffffffffffffffff
>>>>> # cat /proc/23018/stack
>>>>> [<ffffffff814ce0d9>] target_wait_for_sess_cmds+0x49/0x1a0
>>>>> [<ffffffffa058b92b>] isert_wait_conn+0x1ab/0x2f0 [ib_isert]
>>>>> [<ffffffff814f2642>] iscsit_close_connection+0x162/0x870
>>>>> [<ffffffff814e110f>] iscsit_take_action_for_connection_exit+0x7f/0x100
>>>>> [<ffffffff814f122a>] iscsi_target_tx_thread+0x1aa/0x1d0
>>>>> [<ffffffff8109d7c8>] kthread+0xd8/0xf0
>>>>> [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70
>>>>> [<ffffffffffffffff>] 0xffffffffffffffff
>>>>>
>>>>> From dmesg:
>>>>> [  394.476332] INFO: rcu_sched self-detected stall on CPU
>>>>> [  394.476334]  20-...: (23976 ticks this GP)
>>>>> idle=edd/140000000000001/0 softirq=292/292 fqs=18788
>>>>> [  394.476336]   (t=24003 jiffies g=3146 c=3145 q=0)
>>>>> [  394.476337] Task dump for CPU 20:
>>>>> [  394.476338] kworker/u68:2   R  running task        0 12906      2 0x00000008
>>>>> [  394.476345] Workqueue: isert_comp_wq isert_cq_work [ib_isert]
>>>>> [  394.476346]  ffff883f2fe38000 00000000f805705e ffff883f7fd03da8
>>>>> ffffffff810ac8ff
>>>>> [  394.476347]  0000000000000014 ffffffff81adb680 ffff883f7fd03dc0
>>>>> ffffffff810af239
>>>>> [  394.476348]  0000000000000015 ffff883f7fd03df0 ffffffff810e1cd0
>>>>> ffff883f7fd17b80
>>>>> [  394.476348] Call Trace:
>>>>> [  394.476354]  <IRQ>  [<ffffffff810ac8ff>] sched_show_task+0xaf/0x110
>>>>> [  394.476355]  [<ffffffff810af239>] dump_cpu_task+0x39/0x40
>>>>> [  394.476357]  [<ffffffff810e1cd0>] rcu_dump_cpu_stacks+0x80/0xb0
>>>>> [  394.476359]  [<ffffffff810e6100>] rcu_check_callbacks+0x540/0x820
>>>>> [  394.476360]  [<ffffffff810afe11>] ? account_system_time+0x81/0x110
>>>>> [  394.476363]  [<ffffffff810faa60>] ? tick_sched_do_timer+0x50/0x50
>>>>> [  394.476364]  [<ffffffff810eb599>] update_process_times+0x39/0x60
>>>>> [  394.476365]  [<ffffffff810fa815>] tick_sched_handle.isra.17+0x25/0x60
>>>>> [  394.476366]  [<ffffffff810faa9d>] tick_sched_timer+0x3d/0x70
>>>>> [  394.476368]  [<ffffffff810ec182>] __hrtimer_run_queues+0x102/0x290
>>>>> [  394.476369]  [<ffffffff810ec668>] hrtimer_interrupt+0xa8/0x1a0
>>>>> [  394.476372]  [<ffffffff81052c65>] local_apic_timer_interrupt+0x35/0x60
>>>>> [  394.476374]  [<ffffffff8172423d>] smp_apic_timer_interrupt+0x3d/0x50
>>>>> [  394.476376]  [<ffffffff817224f7>] apic_timer_interrupt+0x87/0x90
>>>>> [  394.476379]  <EOI>  [<ffffffff810d71be>] ? console_unlock+0x41e/0x4e0
>>>>> [  394.476380]  [<ffffffff810d757c>] vprintk_emit+0x2fc/0x500
>>>>> [  394.476382]  [<ffffffff810d78ff>] vprintk_default+0x1f/0x30
>>>>> [  394.476384]  [<ffffffff81174dde>] printk+0x5d/0x74
>>>>> [  394.476388]  [<ffffffff814bce21>] transport_lookup_cmd_lun+0x1d1/0x200
>>>>> [  394.476390]  [<ffffffff814ee8c0>] iscsit_setup_scsi_cmd+0x230/0x540
>>>>> [  394.476392]  [<ffffffffa058dbf3>] isert_rx_do_work+0x3f3/0x7f0 [ib_isert]
>>>>> [  394.476394]  [<ffffffffa058e174>] isert_cq_work+0x184/0x770 [ib_isert]
>>>>> [  394.476396]  [<ffffffff8109740f>] process_one_work+0x14f/0x400
>>>>> [  394.476397]  [<ffffffff81097c84>] worker_thread+0x114/0x470
>>>>> [  394.476398]  [<ffffffff8171d32a>] ? __schedule+0x34a/0x7f0
>>>>> [  394.476399]  [<ffffffff81097b70>] ? rescuer_thread+0x310/0x310
>>>>> [  394.476400]  [<ffffffff8109d7c8>] kthread+0xd8/0xf0
>>>>> [  394.476402]  [<ffffffff8109d6f0>] ? kthread_park+0x60/0x60
>>>>> [  394.476403]  [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70
>>>>> [  394.476404]  [<ffffffff8109d6f0>] ? kthread_park+0x60/0x60
>>>>> [  405.716632] Unexpected ret: -104 send data 360
>>>>> [  405.721711] tx_data returned -32, expecting 360.
>>>>> ----------------
>>>>> Robert LeBlanc
>>>>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
>
> When you combine this trace with the newest one, it really makes me
> thing there is something of a bad interaction between the new drain cq
> API and the iser/isert implementation to use said API.  Sagi, Christoph?
>
> --
> Doug Ledford <dledford@redhat.com>
>     GPG Key ID: B826A3330E572FDD
>     Key fingerprint = AE6B 1BDA 122B 23B4 265B  1274 B826 A333 0E57 2FDD
>