[SCSI] zfcp: Fix sparse warning by providing new entry in dbf

drivers/s390/scsi/zfcp_dbf.c:692:2: warning: context imbalance in
'zfcp_rec_dbf_event_thread' - different lock contexts for basic block

Replace the parameter indicating if the lock is held with a new entry
function that only acquires the lock. This makes the lock handling
more visible and removes the sparse warning.

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>

1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index e908c0631ace..558dae9639f3 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -670,24 +670,20 @@ static struct debug_view zfcp_rec_dbf_view = {
  * zfcp_rec_dbf_event_thread - trace event related to recovery thread operation
  * @id2: identifier for event
  * @adapter: adapter
- * @lock: non-zero value indicates that erp_lock has not yet been acquired
+ * This function assumes that the caller is holding erp_lock.
  */
-void zfcp_rec_dbf_event_thread(u8 id2, struct zfcp_adapter *adapter, int lock)
+void zfcp_rec_dbf_event_thread(u8 id2, struct zfcp_adapter *adapter)
 {
         struct zfcp_rec_dbf_record *r = &adapter->rec_dbf_buf;
         unsigned long flags = 0;
         struct list_head *entry;
         unsigned ready = 0, running = 0, total;
 
-        if (lock)
-                read_lock_irqsave(&adapter->erp_lock, flags);
         list_for_each(entry, &adapter->erp_ready_head)
                 ready++;
         list_for_each(entry, &adapter->erp_running_head)
                 running++;
         total = adapter->erp_total_count;
-        if (lock)
-                read_unlock_irqrestore(&adapter->erp_lock, flags);
 
         spin_lock_irqsave(&adapter->rec_dbf_lock, flags);
         memset(r, 0, sizeof(*r));
@@ -700,6 +696,21 @@ void zfcp_rec_dbf_event_thread(u8 id2, struct zfcp_adapter *adapter, int lock)
         spin_unlock_irqrestore(&adapter->rec_dbf_lock, flags);
 }
 
+/**
+ * zfcp_rec_dbf_event_thread - trace event related to recovery thread operation
+ * @id2: identifier for event
+ * @adapter: adapter
+ * This function assumes that the caller does not hold erp_lock.
+ */
+void zfcp_rec_dbf_event_thread_lock(u8 id2, struct zfcp_adapter *adapter)
+{
+        unsigned long flags;
+
+        read_lock_irqsave(&adapter->erp_lock, flags);
+        zfcp_rec_dbf_event_thread(id2, adapter);
+        read_unlock_irqrestore(&adapter->erp_lock, flags);
+}
+
 static void zfcp_rec_dbf_event_target(u8 id2, void *ref,
                                       struct zfcp_adapter *adapter,
                                       atomic_t *status, atomic_t *erp_count,