[SCSI] zfcp: revert previous patch for sbal counting

The current sbal counting can be wrong if a fsf request is
waiting for free sbals and at the same time qdio request queue
is shutdown and re-opened. Revering a previous patch fixes this
issue.

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

1 files changed, 14 insertions, 14 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index bd2b23766894..3f365ace7711 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -645,30 +645,30 @@ static void zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *req)
         }
 }
 
-static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter)
-        __releases(&adapter->req_q_lock)
-        __acquires(&adapter->req_q_lock)
+static int zfcp_fsf_sbal_check(struct zfcp_adapter *adapter)
 {
         struct zfcp_qdio_queue *req_q = &adapter->req_q;
-        long ret;
 
-        if (atomic_read(&req_q->count) <= -REQUEST_LIST_SIZE)
-                return -EIO;
-        if (atomic_read(&req_q->count) > 0)
-                return 0;
+        spin_lock_bh(&adapter->req_q_lock);
+        if (atomic_read(&req_q->count))
+                return 1;
+        spin_unlock_bh(&adapter->req_q_lock);
+        return 0;
+}
+
+static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter)
+{
+        long ret;
 
-        atomic_dec(&req_q->count);
         spin_unlock_bh(&adapter->req_q_lock);
         ret = wait_event_interruptible_timeout(adapter->request_wq,
-                                        atomic_read(&req_q->count) >= 0,
-                                        5 * HZ);
-        spin_lock_bh(&adapter->req_q_lock);
-        atomic_inc(&req_q->count);
-
+                               zfcp_fsf_sbal_check(adapter), 5 * HZ);
         if (ret > 0)
                 return 0;
         if (!ret)
                 atomic_inc(&adapter->qdio_outb_full);
+
+        spin_lock_bh(&adapter->req_q_lock);
         return -EIO;
 }