While testing addition/deletion of the SAN devices, system crashed with error 'Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 0'

Issue

• While trying to test the addition/deletion of the SAN devices using following steps the system crashed with error 'Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 0':

Steps to Reproduce:
1. Boot on the 6.6 kernel
2. Inject faults on the fabric layer and disable/enable targets ports repeatedly
3. Keep rescanning the SAN devices using following script:

    #!/bin/sh -ex
    while true; do
    date
    rescan-scsi-bus.sh -r -a --hosts=7,8
    rescan-scsi-bus.sh -a --hosts=7,8
    sleep 1
    done

3. System panics with following errors:

      rport-7:0-3: blocked FC remote port time out: removing target and saving binding
     scsi 7:0:5:0: Device offlined - not ready after error recovery
     Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 0
     Pid: 603, comm: fc_wq_7 Not tainted 2.6.32-504.3.3.el6.x86_64 #1
     Call Trace:
      <NMI>  [<ffffffff81529277>] ? panic+0xa7/0x16f
      [<ffffffff81014959>] ? sched_clock+0x9/0x10
      [<ffffffff810ea5dd>] ? watchdog_overflow_callback+0xcd/0xd0
      [<ffffffff81120d87>] ? __perf_event_overflow+0xa7/0x240
      [<ffffffff8101dacd>] ? x86_perf_event_set_period+0xdd/0x170
      [<ffffffff811213d4>] ? perf_event_overflow+0x14/0x20
      [<ffffffff81024892>] ? intel_pmu_handle_irq+0x202/0x410
      [<ffffffff8152e579>] ? perf_event_nmi_handler+0x39/0xb0
      [<ffffffff81530035>] ? notifier_call_chain+0x55/0x80
      [<ffffffff8153009a>] ? atomic_notifier_call_chain+0x1a/0x20
      [<ffffffff810a4eae>] ? notify_die+0x2e/0x30
      [<ffffffff8152dcfb>] ? do_nmi+0x1bb/0x340
      [<ffffffff8152d5c0>] ? nmi+0x20/0x30
      [<ffffffff8138ddf3>] ? scsi_remove_target+0x93/0x210
      <<EOE>>  [<ffffffffa0235570>] ? fc_starget_delete+0x0/0x30 [scsi_transport_fc]
      [<ffffffffa0235596>] ? fc_starget_delete+0x26/0x30 [scsi_transport_fc]
      [<ffffffff81097fe0>] ? worker_thread+0x170/0x2a0
      [<ffffffff8109eb00>] ? autoremove_wake_function+0x0/0x40
      [<ffffffff81097e70>] ? worker_thread+0x0/0x2a0
      [<ffffffff8109e66e>] ? kthread+0x9e/0xc0
      [<ffffffff8100c20a>] ? child_rip+0xa/0x20
      [<ffffffff8109e5d0>] ? kthread+0x0/0xc0
      [<ffffffff8100c200>] ? child_rip+0x0/0x20