iscsi times out and "task iscsid:xxxx blocked for more than 120 seconds" is logged in /var/log/messages.

Issue

• iscsid is blocked for more than 120 seconds, following trace was logged in /var/log/messages:

     NFO: task iscsid:10420 blocked for more than 120 seconds.
     "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
     iscsid        D ffffffff801566aa     0 10420  10289                     (NOTLB)
      ffff81202d547688 0000000000000086 0000000000000046 ffffffff800a023e
      ffff81202d547610 0000000000000007 ffff81202b25c7a0 ffff813c3fc0f7e0
      000001923030f23a 0000000000008800 ffff81202b25c988 0000001c00000000
     Call Trace:
      [<ffffffff800a023e>] queue_work+0x50/0x59
      [<ffffffff8006ecd9>] do_gettimeofday+0x40/0x90
      [<ffffffff80028bb2>] sync_page+0x0/0x43
      [<ffffffff800637de>] io_schedule+0x3f/0x67
      [<ffffffff80028bf0>] sync_page+0x3e/0x43
      [<ffffffff80063a0a>] __wait_on_bit+0x40/0x6e
      [<ffffffff80034ff7>] wait_on_page_bit+0x6c/0x72
      [<ffffffff800a34d5>] wake_bit_function+0x0/0x23
      [<ffffffff8010fbc5>] read_dev_sector+0x47/0xcf
      [<ffffffff801112f2>] sgi_partition+0x1f/0x119
      [<ffffffff801112d3>] sgi_partition+0x0/0x119
      [<ffffffff8011028d>] rescan_partitions+0x132/0x279
      [<ffffffff800e8dd0>] do_open+0x233/0x311
      [<ffffffff800a34b0>] autoremove_wake_function+0x9/0x2e
      [<ffffffff800e8fbc>] __blkdev_get+0x6a/0x7c
      [<ffffffff8002d079>] wake_up_bit+0x11/0x22
      [<ffffffff801100fe>] register_disk+0x133/0x190
      [<ffffffff8014d6f2>] add_disk+0x34/0x3d
      [<ffffffff880d3478>] :sd_mod:sd_probe+0x2f5/0x351
      [<ffffffff80056983>] netlink_broadcast+0x2a9/0x2f1
      [<ffffffff801cecd8>] driver_probe_device+0x64/0xbc
      [<ffffffff801ced30>] __device_attach+0x0/0x5
      [<ffffffff801ce471>] bus_for_each_drv+0x40/0x72
      [<ffffffff801ced87>] device_attach+0x52/0x5f
      [<ffffffff801ce171>] bus_attach_device+0x21/0x3c
      [<ffffffff801cd42a>] device_add+0x261/0x372
      [<ffffffff880a8642>] :scsi_mod:scsi_sysfs_add_sdev+0x35/0x21b
      [<ffffffff880a6a0f>] :scsi_mod:scsi_probe_and_add_lun+0x8b1/0x9c9
      [<ffffffff880a5047>] :scsi_mod:scsi_execute_req+0x79/0xcf
      [<ffffffff880a740f>] :scsi_mod:__scsi_scan_target+0x410/0x5c7
      [<ffffffff8000a7ab>] __link_path_walk+0xefc/0xf25
      [<ffffffff8000769e>] find_get_page+0x21/0x51
      [<ffffffff880a7884>] :scsi_mod:scsi_scan_target+0x73/0x8a
      [<ffffffff88676ecc>] :scsi_transport_iscsi2:iscsi_user_scan_session+0xcf/0xe2
      [<ffffffff88676dfd>] :scsi_transport_iscsi2:iscsi_user_scan_session+0x0/0xe2
      [<ffffffff801ccd4a>] device_for_each_child+0x1f/0x4e
      [<ffffffff88676de5>] :scsi_transport_iscsi2:iscsi_user_scan+0x25/0x2a
      [<ffffffff880a81d4>] :scsi_mod:store_scan+0x9b/0xc5
      [<ffffffff801129bc>] sysfs_write_file+0xb9/0xe8
      [<ffffffff80016b29>] vfs_write+0xce/0x174
      [<ffffffff800173f2>] sys_write+0x45/0x6e
      [<ffffffff8005d28d>] tracesys+0xd5/0xe0