[SCSI] zfcp: Hold queue lock when checking port/unit handle for task management cmd

We need to hold the queue-lock when checking whether we still have a valid
unit/port handle for the task management command, i.e whether we can issue this
request for this unit/port. If the error recovery is about to close this
unit/port, then it competes for the queue-lock. If the close request issued by
the error recovery wins, then it is guaranteed that this unit/port has been
blocked for other requests.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 17c251cb10aa2b4cea88acece37b96b3ec100a1a..fe57941ab55d2f452bf9d0aafdae176ff5c9d0e8 100644 (file)
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -3774,6 +3774,10 @@ zfcp_fsf_send_fcp_command_task_management(struct zfcp_adapter *adapter,
                goto out;
        }
 
+       if (unlikely(!atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
+                       &unit->status)))
+               goto unit_blocked;
+
        /*
         * Used to decide on proper handler in the return path,
         * could be either zfcp_fsf_send_fcp_command_task_handler or
@@ -3807,25 +3811,13 @@ zfcp_fsf_send_fcp_command_task_management(struct zfcp_adapter *adapter,
 
        zfcp_fsf_start_timer(fsf_req, ZFCP_SCSI_ER_TIMEOUT);
        retval = zfcp_fsf_req_send(fsf_req);
-       if (retval) {
-               ZFCP_LOG_INFO("error: Could not send an FCP-command (task "
-                             "management) on adapter %s, port 0x%016Lx for "
-                             "unit LUN 0x%016Lx\n",
-                             zfcp_get_busid_by_adapter(adapter),
-                             unit->port->wwpn,
-                             unit->fcp_lun);
-               zfcp_fsf_req_free(fsf_req);
-               fsf_req = NULL;
+       if (!retval)
                goto out;
-       }
 
-       ZFCP_LOG_TRACE("Send FCP Command (task management function) initiated "
-                      "(adapter %s, port 0x%016Lx, unit 0x%016Lx, "
-                      "tm_flags=0x%x)\n",
-                      zfcp_get_busid_by_adapter(adapter),
-                      unit->port->wwpn,
-                      unit->fcp_lun,
-                      tm_flags);
+ unit_blocked:
+       zfcp_fsf_req_free(fsf_req);
+       fsf_req = NULL;
+
  out:
        write_unlock_irqrestore(&adapter->request_queue.queue_lock, lock_flags);
        return fsf_req;