[bug report] scsi: aacraid: Added support for hotplug

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Raghava Aditya Renukunta,

The patch 6223a39fe6fb: "scsi: aacraid: Added support for hotplug"
from Feb 2, 2017, leads to the following static checker warning:

	drivers/scsi/aacraid/commsup.c:2243 aac_process_events()
	error: double unlock 'spin_lock:t_lock'

drivers/scsi/aacraid/commsup.c
  2130          spin_lock_irqsave(t_lock, flags);
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  2131  
  2132          while (!list_empty(&(dev->queues->queue[HostNormCmdQueue].cmdq))) {
  2133                  struct list_head *entry;
  2134                  struct aac_aifcmd *aifcmd;
  2135                  unsigned int  num;
  2136                  struct hw_fib **hw_fib_pool, **hw_fib_p;
  2137                  struct fib **fib_pool, **fib_p;
  2138  
  2139                  set_current_state(TASK_RUNNING);
  2140  
  2141                  entry = dev->queues->queue[HostNormCmdQueue].cmdq.next;
  2142                  list_del(entry);
  2143  
  2144                  t_lock = dev->queues->queue[HostNormCmdQueue].lock;
  2145                  spin_unlock_irqrestore(t_lock, flags);
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  2146  
  2147                  fib = list_entry(entry, struct fib, fiblink);
  2148                  hw_fib = fib->hw_fib_va;
  2149                  if (dev->sa_firmware) {
  2150                          /* Thor AIF */
  2151                          aac_handle_sa_aif(dev, fib);
  2152                          aac_fib_adapter_complete(fib, (u16)sizeof(u32));
  2153                          continue;

The locking isn't right here.  We should re-take the spinlock before
continuing.

  2154                  }
  2155                  /*
  2156                   *      We will process the FIB here or pass it to a
  2157                   *      worker thread that is TBD. We Really can't
  2158                   *      do anything at this point since we don't have
  2159                   *      anything defined for this thread to do.
  2160                   */

	[ snip ]

  2221  free_mem:
  2222                  /* Free up the remaining resources */
  2223                  hw_fib_p = hw_fib_pool;
  2224                  fib_p = fib_pool;
  2225                  while (hw_fib_p < &hw_fib_pool[num]) {
  2226                          kfree(*hw_fib_p);
  2227                          kfree(*fib_p);
  2228                          ++fib_p;
  2229                          ++hw_fib_p;
  2230                  }
  2231                  kfree(fib_pool);
  2232  free_hw_fib_pool:
  2233                  kfree(hw_fib_pool);
  2234  free_fib:
  2235                  kfree(fib);
  2236                  t_lock = dev->queues->queue[HostNormCmdQueue].lock;
  2237                  spin_lock_irqsave(t_lock, flags);
  2238          }
  2239          /*
  2240           *      There are no more AIF's
  2241           */
  2242          t_lock = dev->queues->queue[HostNormCmdQueue].lock;
  2243          spin_unlock_irqrestore(t_lock, flags);

Otherwise it is a double unlock bug.

  2244  }


regards,
dan carpenter