Another trial to rerproduce  by running `sudo dd if=/dev/sdc bs=512k | pv > /dev/null `

[ 5038.082712] usb 2-3.2: new SuperSpeed USB device number 4 using xhci_hcd
[ 5038.098605] usb 2-3.2: New USB device found, idVendor=357d, idProduct=7788
[ 5038.098609] usb 2-3.2: New USB device strings: Mfr=10, Product=11, SerialNumber=3
[ 5038.098612] usb 2-3.2: Product: USB to ATA/ATAPI Bridge
[ 5038.098614] usb 2-3.2: Manufacturer: JMicron
[ 5038.098617] usb 2-3.2: SerialNumber: 000012345678
[ 5038.099307] scsi host7: uas
[ 5038.100812] scsi 7:0:0:0: Direct-Access     HITACHI  HTS723232L9SA60  0100 PQ: 0 ANSI: 6
[ 5038.103505] sd 7:0:0:0: Attached scsi generic sg2 type 0
[ 5038.104095] sd 7:0:0:0: [sdc] 625142448 512-byte logical blocks: (320 GB/298 GiB)
[ 5038.104097] sd 7:0:0:0: [sdc] 4096-byte physical blocks
[ 5038.107271] sd 7:0:0:0: [sdc] Write Protect is off
[ 5038.107276] sd 7:0:0:0: [sdc] Mode Sense: 67 00 10 08
[ 5038.108506] sd 7:0:0:0: [sdc] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 5038.138724]  sdc: sdc1 sdc3
[ 5038.198344] sd 7:0:0:0: [sdc] Attached SCSI disk
[ 5043.598011] EXT4-fs (dm-0): recovery complete
[ 5043.598349] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: (null)
[ 5843.599371] sd 7:0:0:0: [sdc] data cmplt err -71 uas-tag 2 inflight: CMD 
[ 5843.599377] sd 7:0:0:0: [sdc] CDB: 
[ 5843.599379] Read(10): 28 00 07 2e 29 08 00 01 00 00
[ 5843.602869] xhci_hcd 0000:00:14.0: ERROR Transfer event for disabled endpoint or incorrect stream ring
[ 5843.602875] xhci_hcd 0000:00:14.0: @00000002112f5440 00000000 00000000 04000000 07078001
[ 5874.466888] sd 7:0:0:0: [sdc] uas_eh_abort_handler 0 uas-tag 2 inflight: CMD 
[ 5874.466894] sd 7:0:0:0: [sdc] CDB: 
[ 5874.466897] Read(10): 28 00 07 2e 29 08 00 01 00 00
[ 5874.466909] sd 7:0:0:0: [sdc] uas_eh_abort_handler 0 uas-tag 1 inflight: CMD IN 
[ 5874.466911] sd 7:0:0:0: [sdc] CDB: 
[ 5874.466912] Read(10): 28 00 07 2e 2a 08 00 01 00 00
[ 5874.467023] scsi host7: uas_eh_bus_reset_handler start
[ 5874.612301] scsi host7: uas_post_reset: alloc streams error -19 after reset
[ 5874.612553] usb 2-3.2: USB disconnect, device number 4
[ 5875.051447] blk_update_request: I/O error, dev sdc, sector 0
[ 5875.138449] sd 7:0:0:0: [sdc] Synchronizing SCSI cache
[ 6001.747203] INFO: task kworker/0:1:8476 blocked for more than 120 seconds.
[ 6001.747207]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6001.747207] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6001.747209] kworker/0:1     D ffff880175a5fb58     0  8476      2 0x00000000
[ 6001.747216] Workqueue: usb_hub_wq hub_event
[ 6001.747217]  ffff880175a5fb58 ffff8800da884e80 0000000000014200 ffff880175a5ffd8
[ 6001.747219]  0000000000014200 ffffffff81c1a580 ffff8800da884e80 00000000ebb8eeb0
[ 6001.747220]  ffff88016696d0f0 ffff88016696d0f4 ffff8800da884e80 00000000ffffffff
[ 6001.747222] Call Trace:
[ 6001.747227]  [<ffffffff817c36c9>] schedule_preempt_disabled+0x29/0x70
[ 6001.747229]  [<ffffffff817c5585>] __mutex_lock_slowpath+0x95/0x100
[ 6001.747231]  [<ffffffff817c5613>] mutex_lock+0x23/0x40
[ 6001.747233]  [<ffffffff815b3453>] usb_disconnect+0x53/0x2e0
[ 6001.747235]  [<ffffffff815bce84>] ? usb_control_msg+0xd4/0x110
[ 6001.747237]  [<ffffffff815b518c>] hub_port_connect+0x6c/0xa50
[ 6001.747239]  [<ffffffff815af7a8>] ? hub_port_status+0xd8/0x120
[ 6001.747240]  [<ffffffff815b5eb4>] port_event+0x344/0x7e0
[ 6001.747242]  [<ffffffff815b655d>] hub_event+0x20d/0x400
[ 6001.747245]  [<ffffffff8108eb48>] process_one_work+0x158/0x430
[ 6001.747246]  [<ffffffff8108f5db>] worker_thread+0x5b/0x530
[ 6001.747248]  [<ffffffff8108f580>] ? rescuer_thread+0x3a0/0x3a0
[ 6001.747250]  [<ffffffff81094679>] kthread+0xc9/0xe0
[ 6001.747252]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6001.747254]  [<ffffffff817c7a3c>] ret_from_fork+0x7c/0xb0
[ 6001.747256]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6001.747258] INFO: task umount:8799 blocked for more than 120 seconds.
[ 6001.747259]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6001.747260] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6001.747260] umount          D ffff8801d4087c28     0  8799   1389 0x00000000
[ 6001.747262]  ffff8801d4087c28 ffff88010c360000 0000000000014200 ffff8801d4087fd8
[ 6001.747264]  0000000000014200 ffffffff81c1a580 ffff88010c360000 ffff8801760fe050
[ 6001.747265]  ffff8801d4087d68 7fffffffffffffff ffff8801d4087d60 ffff88010c360000
[ 6001.747266] Call Trace:
[ 6001.747268]  [<ffffffff817c3179>] schedule+0x29/0x70
[ 6001.747270]  [<ffffffff817c673c>] schedule_timeout+0x20c/0x280
[ 6001.747272]  [<ffffffff81385beb>] ? blk_queue_bio+0x36b/0x370
[ 6001.747274]  [<ffffffff817c4b34>] wait_for_completion+0xa4/0x170
[ 6001.747276]  [<ffffffff810a1c70>] ? wake_up_state+0x20/0x20
[ 6001.747279]  [<ffffffff8137a60c>] submit_bio_wait+0x5c/0x70
[ 6001.747281]  [<ffffffff81387851>] blkdev_issue_flush+0x61/0x90
[ 6001.747284]  [<ffffffff8128c857>] ext4_sync_fs+0x127/0x1b0
[ 6001.747287]  [<ffffffff81224c72>] sync_filesystem+0x82/0xc0
[ 6001.747290]  [<ffffffff811f52c4>] generic_shutdown_super+0x34/0x100
[ 6001.747293]  [<ffffffff811f56c7>] kill_block_super+0x27/0x80
[ 6001.747294]  [<ffffffff811f5a09>] deactivate_locked_super+0x49/0x60
[ 6001.747295]  [<ffffffff811f5e5c>] deactivate_super+0x6c/0x80
[ 6001.747298]  [<ffffffff81213c53>] cleanup_mnt+0x43/0xa0
[ 6001.747299]  [<ffffffff81213d02>] __cleanup_mnt+0x12/0x20
[ 6001.747301]  [<ffffffff81092c44>] task_work_run+0xd4/0xf0
[ 6001.747304]  [<ffffffff81015007>] do_notify_resume+0x97/0xb0
[ 6001.747306]  [<ffffffff817c7d8f>] int_signal+0x12/0x17
[ 6121.781305] INFO: task kworker/0:1:8476 blocked for more than 120 seconds.
[ 6121.781309]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6121.781310] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6121.781311] kworker/0:1     D ffff880175a5fb58     0  8476      2 0x00000000
[ 6121.781319] Workqueue: usb_hub_wq hub_event
[ 6121.781320]  ffff880175a5fb58 ffff8800da884e80 0000000000014200 ffff880175a5ffd8
[ 6121.781322]  0000000000014200 ffffffff81c1a580 ffff8800da884e80 00000000ebb8eeb0
[ 6121.781324]  ffff88016696d0f0 ffff88016696d0f4 ffff8800da884e80 00000000ffffffff
[ 6121.781325] Call Trace:
[ 6121.781331]  [<ffffffff817c36c9>] schedule_preempt_disabled+0x29/0x70
[ 6121.781333]  [<ffffffff817c5585>] __mutex_lock_slowpath+0x95/0x100
[ 6121.781335]  [<ffffffff817c5613>] mutex_lock+0x23/0x40
[ 6121.781337]  [<ffffffff815b3453>] usb_disconnect+0x53/0x2e0
[ 6121.781340]  [<ffffffff815bce84>] ? usb_control_msg+0xd4/0x110
[ 6121.781342]  [<ffffffff815b518c>] hub_port_connect+0x6c/0xa50
[ 6121.781344]  [<ffffffff815af7a8>] ? hub_port_status+0xd8/0x120
[ 6121.781346]  [<ffffffff815b5eb4>] port_event+0x344/0x7e0
[ 6121.781348]  [<ffffffff815b655d>] hub_event+0x20d/0x400
[ 6121.781351]  [<ffffffff8108eb48>] process_one_work+0x158/0x430
[ 6121.781352]  [<ffffffff8108f5db>] worker_thread+0x5b/0x530
[ 6121.781354]  [<ffffffff8108f580>] ? rescuer_thread+0x3a0/0x3a0
[ 6121.781356]  [<ffffffff81094679>] kthread+0xc9/0xe0
[ 6121.781358]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6121.781361]  [<ffffffff817c7a3c>] ret_from_fork+0x7c/0xb0
[ 6121.781362]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6121.781365] INFO: task umount:8799 blocked for more than 120 seconds.
[ 6121.781366]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6121.781367] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6121.781367] umount          D ffff8801d4087c28     0  8799   1389 0x00000000
[ 6121.781369]  ffff8801d4087c28 ffff88010c360000 0000000000014200 ffff8801d4087fd8
[ 6121.781371]  0000000000014200 ffffffff81c1a580 ffff88010c360000 ffff8801760fe050
[ 6121.781372]  ffff8801d4087d68 7fffffffffffffff ffff8801d4087d60 ffff88010c360000
[ 6121.781373] Call Trace:
[ 6121.781375]  [<ffffffff817c3179>] schedule+0x29/0x70
[ 6121.781377]  [<ffffffff817c673c>] schedule_timeout+0x20c/0x280
[ 6121.781380]  [<ffffffff81385beb>] ? blk_queue_bio+0x36b/0x370
[ 6121.781382]  [<ffffffff817c4b34>] wait_for_completion+0xa4/0x170
[ 6121.781384]  [<ffffffff810a1c70>] ? wake_up_state+0x20/0x20
[ 6121.781387]  [<ffffffff8137a60c>] submit_bio_wait+0x5c/0x70
[ 6121.781389]  [<ffffffff81387851>] blkdev_issue_flush+0x61/0x90
[ 6121.781393]  [<ffffffff8128c857>] ext4_sync_fs+0x127/0x1b0
[ 6121.781396]  [<ffffffff81224c72>] sync_filesystem+0x82/0xc0
[ 6121.781399]  [<ffffffff811f52c4>] generic_shutdown_super+0x34/0x100
[ 6121.781401]  [<ffffffff811f56c7>] kill_block_super+0x27/0x80
[ 6121.781403]  [<ffffffff811f5a09>] deactivate_locked_super+0x49/0x60
[ 6121.781404]  [<ffffffff811f5e5c>] deactivate_super+0x6c/0x80
[ 6121.781407]  [<ffffffff81213c53>] cleanup_mnt+0x43/0xa0
[ 6121.781408]  [<ffffffff81213d02>] __cleanup_mnt+0x12/0x20
[ 6121.781410]  [<ffffffff81092c44>] task_work_run+0xd4/0xf0
[ 6121.781413]  [<ffffffff81015007>] do_notify_resume+0x97/0xb0
[ 6121.781415]  [<ffffffff817c7d8f>] int_signal+0x12/0x17
[ 6241.815503] INFO: task kworker/0:1:8476 blocked for more than 120 seconds.
[ 6241.815507]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6241.815508] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6241.815510] kworker/0:1     D ffff880175a5fb58     0  8476      2 0x00000000
[ 6241.815517] Workqueue: usb_hub_wq hub_event
[ 6241.815518]  ffff880175a5fb58 ffff8800da884e80 0000000000014200 ffff880175a5ffd8
[ 6241.815520]  0000000000014200 ffffffff81c1a580 ffff8800da884e80 00000000ebb8eeb0
[ 6241.815521]  ffff88016696d0f0 ffff88016696d0f4 ffff8800da884e80 00000000ffffffff
[ 6241.815523] Call Trace:
[ 6241.815529]  [<ffffffff817c36c9>] schedule_preempt_disabled+0x29/0x70
[ 6241.815531]  [<ffffffff817c5585>] __mutex_lock_slowpath+0x95/0x100
[ 6241.815533]  [<ffffffff817c5613>] mutex_lock+0x23/0x40
[ 6241.815534]  [<ffffffff815b3453>] usb_disconnect+0x53/0x2e0
[ 6241.815538]  [<ffffffff815bce84>] ? usb_control_msg+0xd4/0x110
[ 6241.815539]  [<ffffffff815b518c>] hub_port_connect+0x6c/0xa50
[ 6241.815541]  [<ffffffff815af7a8>] ? hub_port_status+0xd8/0x120
[ 6241.815543]  [<ffffffff815b5eb4>] port_event+0x344/0x7e0
[ 6241.815545]  [<ffffffff815b655d>] hub_event+0x20d/0x400
[ 6241.815548]  [<ffffffff8108eb48>] process_one_work+0x158/0x430
[ 6241.815550]  [<ffffffff8108f5db>] worker_thread+0x5b/0x530
[ 6241.815551]  [<ffffffff8108f580>] ? rescuer_thread+0x3a0/0x3a0
[ 6241.815554]  [<ffffffff81094679>] kthread+0xc9/0xe0
[ 6241.815556]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6241.815558]  [<ffffffff817c7a3c>] ret_from_fork+0x7c/0xb0
[ 6241.815560]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6241.815562] INFO: task umount:8799 blocked for more than 120 seconds.
[ 6241.815563]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6241.815564] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6241.815565] umount          D ffff8801d4087c28     0  8799   1389 0x00000000
[ 6241.815567]  ffff8801d4087c28 ffff88010c360000 0000000000014200 ffff8801d4087fd8
[ 6241.815568]  0000000000014200 ffffffff81c1a580 ffff88010c360000 ffff8801760fe050
[ 6241.815570]  ffff8801d4087d68 7fffffffffffffff ffff8801d4087d60 ffff88010c360000
[ 6241.815571] Call Trace:
[ 6241.815573]  [<ffffffff817c3179>] schedule+0x29/0x70
[ 6241.815575]  [<ffffffff817c673c>] schedule_timeout+0x20c/0x280
[ 6241.815577]  [<ffffffff81385beb>] ? blk_queue_bio+0x36b/0x370
[ 6241.815580]  [<ffffffff817c4b34>] wait_for_completion+0xa4/0x170
[ 6241.815582]  [<ffffffff810a1c70>] ? wake_up_state+0x20/0x20
[ 6241.815584]  [<ffffffff8137a60c>] submit_bio_wait+0x5c/0x70
[ 6241.815587]  [<ffffffff81387851>] blkdev_issue_flush+0x61/0x90
[ 6241.815591]  [<ffffffff8128c857>] ext4_sync_fs+0x127/0x1b0
[ 6241.815594]  [<ffffffff81224c72>] sync_filesystem+0x82/0xc0
[ 6241.815597]  [<ffffffff811f52c4>] generic_shutdown_super+0x34/0x100
[ 6241.815600]  [<ffffffff811f56c7>] kill_block_super+0x27/0x80
[ 6241.815601]  [<ffffffff811f5a09>] deactivate_locked_super+0x49/0x60
[ 6241.815603]  [<ffffffff811f5e5c>] deactivate_super+0x6c/0x80
[ 6241.815605]  [<ffffffff81213c53>] cleanup_mnt+0x43/0xa0
[ 6241.815606]  [<ffffffff81213d02>] __cleanup_mnt+0x12/0x20
[ 6241.815608]  [<ffffffff81092c44>] task_work_run+0xd4/0xf0
[ 6241.815612]  [<ffffffff81015007>] do_notify_resume+0x97/0xb0
[ 6241.815614]  [<ffffffff817c7d8f>] int_signal+0x12/0x17
[ 6361.849873] INFO: task kworker/0:1:8476 blocked for more than 120 seconds.
[ 6361.849877]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6361.849878] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6361.849879] kworker/0:1     D ffff880175a5fb58     0  8476      2 0x00000000
[ 6361.849886] Workqueue: usb_hub_wq hub_event
[ 6361.849887]  ffff880175a5fb58 ffff8800da884e80 0000000000014200 ffff880175a5ffd8
[ 6361.849889]  0000000000014200 ffffffff81c1a580 ffff8800da884e80 00000000ebb8eeb0
[ 6361.849891]  ffff88016696d0f0 ffff88016696d0f4 ffff8800da884e80 00000000ffffffff
[ 6361.849892] Call Trace:
[ 6361.849897]  [<ffffffff817c36c9>] schedule_preempt_disabled+0x29/0x70
[ 6361.849900]  [<ffffffff817c5585>] __mutex_lock_slowpath+0x95/0x100
[ 6361.849902]  [<ffffffff817c5613>] mutex_lock+0x23/0x40
[ 6361.849903]  [<ffffffff815b3453>] usb_disconnect+0x53/0x2e0
[ 6361.849906]  [<ffffffff815bce84>] ? usb_control_msg+0xd4/0x110
[ 6361.849908]  [<ffffffff815b518c>] hub_port_connect+0x6c/0xa50
[ 6361.849910]  [<ffffffff815af7a8>] ? hub_port_status+0xd8/0x120
[ 6361.849912]  [<ffffffff815b5eb4>] port_event+0x344/0x7e0
[ 6361.849914]  [<ffffffff815b655d>] hub_event+0x20d/0x400
[ 6361.849917]  [<ffffffff8108eb48>] process_one_work+0x158/0x430
[ 6361.849919]  [<ffffffff8108f5db>] worker_thread+0x5b/0x530
[ 6361.849921]  [<ffffffff8108f580>] ? rescuer_thread+0x3a0/0x3a0
[ 6361.849923]  [<ffffffff81094679>] kthread+0xc9/0xe0
[ 6361.849925]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6361.849928]  [<ffffffff817c7a3c>] ret_from_fork+0x7c/0xb0
[ 6361.849929]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6361.849932] INFO: task umount:8799 blocked for more than 120 seconds.
[ 6361.849933]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6361.849934] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6361.849934] umount          D ffff8801d4087c28     0  8799   1389 0x00000000
[ 6361.849936]  ffff8801d4087c28 ffff88010c360000 0000000000014200 ffff8801d4087fd8
[ 6361.849938]  0000000000014200 ffffffff81c1a580 ffff88010c360000 ffff8801760fe050
[ 6361.849939]  ffff8801d4087d68 7fffffffffffffff ffff8801d4087d60 ffff88010c360000
[ 6361.849941] Call Trace:
[ 6361.849943]  [<ffffffff817c3179>] schedule+0x29/0x70
[ 6361.849945]  [<ffffffff817c673c>] schedule_timeout+0x20c/0x280
[ 6361.849947]  [<ffffffff81385beb>] ? blk_queue_bio+0x36b/0x370
[ 6361.849949]  [<ffffffff817c4b34>] wait_for_completion+0xa4/0x170
[ 6361.849951]  [<ffffffff810a1c70>] ? wake_up_state+0x20/0x20
[ 6361.849954]  [<ffffffff8137a60c>] submit_bio_wait+0x5c/0x70
[ 6361.849956]  [<ffffffff81387851>] blkdev_issue_flush+0x61/0x90
[ 6361.849960]  [<ffffffff8128c857>] ext4_sync_fs+0x127/0x1b0
[ 6361.849963]  [<ffffffff81224c72>] sync_filesystem+0x82/0xc0
[ 6361.849967]  [<ffffffff811f52c4>] generic_shutdown_super+0x34/0x100
[ 6361.849969]  [<ffffffff811f56c7>] kill_block_super+0x27/0x80
[ 6361.849970]  [<ffffffff811f5a09>] deactivate_locked_super+0x49/0x60
[ 6361.849972]  [<ffffffff811f5e5c>] deactivate_super+0x6c/0x80
[ 6361.849974]  [<ffffffff81213c53>] cleanup_mnt+0x43/0xa0
[ 6361.849976]  [<ffffffff81213d02>] __cleanup_mnt+0x12/0x20
[ 6361.849978]  [<ffffffff81092c44>] task_work_run+0xd4/0xf0
[ 6361.849981]  [<ffffffff81015007>] do_notify_resume+0x97/0xb0
[ 6361.849983]  [<ffffffff817c7d8f>] int_signal+0x12/0x17
[ 6481.884376] INFO: task kworker/0:1:8476 blocked for more than 120 seconds.
[ 6481.884380]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6481.884381] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6481.884382] kworker/0:1     D ffff880175a5fb58     0  8476      2 0x00000000
[ 6481.884389] Workqueue: usb_hub_wq hub_event
[ 6481.884391]  ffff880175a5fb58 ffff8800da884e80 0000000000014200 ffff880175a5ffd8
[ 6481.884392]  0000000000014200 ffffffff81c1a580 ffff8800da884e80 00000000ebb8eeb0
[ 6481.884394]  ffff88016696d0f0 ffff88016696d0f4 ffff8800da884e80 00000000ffffffff
[ 6481.884396] Call Trace:
[ 6481.884401]  [<ffffffff817c36c9>] schedule_preempt_disabled+0x29/0x70
[ 6481.884403]  [<ffffffff817c5585>] __mutex_lock_slowpath+0x95/0x100
[ 6481.884405]  [<ffffffff817c5613>] mutex_lock+0x23/0x40
[ 6481.884407]  [<ffffffff815b3453>] usb_disconnect+0x53/0x2e0
[ 6481.884410]  [<ffffffff815bce84>] ? usb_control_msg+0xd4/0x110
[ 6481.884412]  [<ffffffff815b518c>] hub_port_connect+0x6c/0xa50
[ 6481.884414]  [<ffffffff815af7a8>] ? hub_port_status+0xd8/0x120
[ 6481.884416]  [<ffffffff815b5eb4>] port_event+0x344/0x7e0
[ 6481.884418]  [<ffffffff815b655d>] hub_event+0x20d/0x400
[ 6481.884421]  [<ffffffff8108eb48>] process_one_work+0x158/0x430
[ 6481.884422]  [<ffffffff8108f5db>] worker_thread+0x5b/0x530
[ 6481.884424]  [<ffffffff8108f580>] ? rescuer_thread+0x3a0/0x3a0
[ 6481.884426]  [<ffffffff81094679>] kthread+0xc9/0xe0
[ 6481.884429]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6481.884431]  [<ffffffff817c7a3c>] ret_from_fork+0x7c/0xb0
[ 6481.884433]  [<ffffffff810945b0>] ? kthread_create_on_node+0x1c0/0x1c0
[ 6481.884435] INFO: task umount:8799 blocked for more than 120 seconds.
[ 6481.884436]       Tainted: P     U  W  OE  3.19.0-9-generic #9-Ubuntu
[ 6481.884437] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6481.884438] umount          D ffff8801d4087c28     0  8799   1389 0x00000000
[ 6481.884440]  ffff8801d4087c28 ffff88010c360000 0000000000014200 ffff8801d4087fd8
[ 6481.884441]  0000000000014200 ffffffff81c1a580 ffff88010c360000 ffff8801760fe050
[ 6481.884442]  ffff8801d4087d68 7fffffffffffffff ffff8801d4087d60 ffff88010c360000
[ 6481.884444] Call Trace:
[ 6481.884446]  [<ffffffff817c3179>] schedule+0x29/0x70
[ 6481.884448]  [<ffffffff817c673c>] schedule_timeout+0x20c/0x280
[ 6481.884450]  [<ffffffff81385beb>] ? blk_queue_bio+0x36b/0x370
[ 6481.884452]  [<ffffffff817c4b34>] wait_for_completion+0xa4/0x170
[ 6481.884454]  [<ffffffff810a1c70>] ? wake_up_state+0x20/0x20
[ 6481.884457]  [<ffffffff8137a60c>] submit_bio_wait+0x5c/0x70
[ 6481.884459]  [<ffffffff81387851>] blkdev_issue_flush+0x61/0x90
[ 6481.884463]  [<ffffffff8128c857>] ext4_sync_fs+0x127/0x1b0
[ 6481.884466]  [<ffffffff81224c72>] sync_filesystem+0x82/0xc0
[ 6481.884470]  [<ffffffff811f52c4>] generic_shutdown_super+0x34/0x100
[ 6481.884472]  [<ffffffff811f56c7>] kill_block_super+0x27/0x80
[ 6481.884473]  [<ffffffff811f5a09>] deactivate_locked_super+0x49/0x60
[ 6481.884475]  [<ffffffff811f5e5c>] deactivate_super+0x6c/0x80
[ 6481.884477]  [<ffffffff81213c53>] cleanup_mnt+0x43/0xa0
[ 6481.884478]  [<ffffffff81213d02>] __cleanup_mnt+0x12/0x20
[ 6481.884480]  [<ffffffff81092c44>] task_work_run+0xd4/0xf0
[ 6481.884484]  [<ffffffff81015007>] do_notify_resume+0x97/0xb0
[ 6481.884486]  [<ffffffff817c7d8f>] int_signal+0x12/0x17