[SCSI] zfcp: fix bug during adapter shutdown

Fixes a race between zfcp_fsf_req_dismiss_all and
zfcp_qdio_reqid_check. During adapter shutdown it occurred that a
request was cleaned up twice. First during its normal
completion. Second when dismiss_all was called.  The fix is to
serialize access to fsf request list between zfcp_fsf_req_dismiss_all
and zfcp_qdio_reqid_check and delete a fsf request from the list if
its completion is triggered.  (Additionally a rwlock was replaced by a
spinlock and fsf_req_cleanup was eliminated.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 6bb4d332b474..c999042dae15 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -520,7 +520,7 @@ zfcp_cfdc_dev_ioctl(struct file *file, unsigned int command,
 
  out:
         if (fsf_req != NULL)
-                zfcp_fsf_req_cleanup(fsf_req);
+                zfcp_fsf_req_free(fsf_req);
 
         if ((adapter != NULL) && (retval != -ENXIO))
                 zfcp_adapter_put(adapter);
@@ -1149,7 +1149,7 @@ zfcp_adapter_enqueue(struct ccw_device *ccw_device)
         INIT_LIST_HEAD(&adapter->port_remove_lh);
 
         /* initialize list of fsf requests */
-        rwlock_init(&adapter->fsf_req_list_lock);
+        spin_lock_init(&adapter->fsf_req_list_lock);
         INIT_LIST_HEAD(&adapter->fsf_req_list_head);
 
         /* initialize abort lock */
@@ -1234,9 +1234,9 @@ zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
         zfcp_sysfs_adapter_remove_files(&adapter->ccw_device->dev);
         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
         /* sanity check: no pending FSF requests */
-        read_lock_irqsave(&adapter->fsf_req_list_lock, flags);
+        spin_lock_irqsave(&adapter->fsf_req_list_lock, flags);
         retval = !list_empty(&adapter->fsf_req_list_head);
-        read_unlock_irqrestore(&adapter->fsf_req_list_lock, flags);
+        spin_unlock_irqrestore(&adapter->fsf_req_list_lock, flags);
         if (retval) {
                 ZFCP_LOG_NORMAL("bug: adapter %s (%p) still in use, "
                                 "%i requests outstanding\n",