[SCSI] zfcp: Invalid locking order

Invalid locking order. Kernel hangs after trying to take two locks
which are dependend on each other. Introducing temporary variable
to free requests. Free lock after requests are copied.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 10 insertions, 13 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 067f1519eb04..eabf86bb13f5 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -176,28 +176,25 @@ static void zfcp_fsf_req_dismiss(struct zfcp_adapter *adapter,
 /**
  * zfcp_fsf_req_dismiss_all - dismiss all remaining fsf requests
  */
-int zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
+void zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
 {
         struct zfcp_fsf_req *request, *tmp;
         unsigned long flags;
+        LIST_HEAD(remove_queue);
         unsigned int i, counter;
 
         spin_lock_irqsave(&adapter->req_list_lock, flags);
         atomic_set(&adapter->reqs_active, 0);
-        for (i=0; i<REQUEST_LIST_SIZE; i++) {
-                if (list_empty(&adapter->req_list[i]))
-                        continue;
-
-                counter = 0;
-                list_for_each_entry_safe(request, tmp,
-                                         &adapter->req_list[i], list) {
-                        zfcp_fsf_req_dismiss(adapter, request, counter);
-                        counter++;
-                }
-        }
+        for (i=0; i<REQUEST_LIST_SIZE; i++)
+                list_splice_init(&adapter->req_list[i], &remove_queue);
+
         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 
-        return 0;
+        counter = 0;
+        list_for_each_entry_safe(request, tmp, &remove_queue, list) {
+                zfcp_fsf_req_dismiss(adapter, request, counter);
+                counter++;
+        }
 }
 
 /*