dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit()

No functional change but makes the code easier to read.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-mpath.c

@@ -612,6 +612,14 @@ static void process_queued_bios(struct work_struct *work)
 	blk_finish_plug(&plug);
 }
 
+static void assign_bit(bool value, long nr, unsigned long *addr)
+{
+	if (value)
+		set_bit(nr, addr);
+	else
+		clear_bit(nr, addr);
+}
+
 /*
  * If we run out of usable paths, should we queue I/O or error it?
  */
@@ -621,23 +629,11 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-
-	if (save_old_value) {
-		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
-			set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-		else
-			clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-	} else {
-		if (queue_if_no_path)
-			set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-		else
-			clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-	}
-	if (queue_if_no_path || dm_noflush_suspending(m->ti))
-		set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
-	else
-		clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
-
+	assign_bit((save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) ||
+		   (!save_old_value && queue_if_no_path),
+		   MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
+	assign_bit(queue_if_no_path || dm_noflush_suspending(m->ti),
+		   MPATHF_QUEUE_IF_NO_PATH, &m->flags);
 	spin_unlock_irqrestore(&m->lock, flags);
 
 	if (!queue_if_no_path) {
@@ -1589,10 +1585,8 @@ static void multipath_resume(struct dm_target *ti)
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-	if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags))
-		set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
-	else
-		clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
+	assign_bit(test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags),
+		   MPATHF_QUEUE_IF_NO_PATH, &m->flags);
 	spin_unlock_irqrestore(&m->lock, flags);
 }