[PATCH 2/2] scsi: scsi_debug: fix sparse lock warnings in sdebug_blk_mq_poll()

[Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>]

The use of the locked boolean variable to control locking and unlocking
of the qc_lock of struct sdebug_queue confuses sparse, leading to a
warning about an unexpected unlock. Simplify the qc_lock lock/unlock
handling code of this function to avoid this warning by removing the
locked boolean variable.

Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
---
 drivers/scsi/scsi_debug.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index f4e97f2224b2..acb32f3e38eb 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -7509,7 +7509,6 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
 {
 	bool first;
 	bool retiring = false;
-	bool locked = false;
 	int num_entries = 0;
 	unsigned int qc_idx = 0;
 	unsigned long iflags;
@@ -7525,18 +7524,17 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
 	if (qc_idx >= sdebug_max_queue)
 		return 0;
 
+	spin_lock_irqsave(&sqp->qc_lock, iflags);
+
 	for (first = true; first || qc_idx + 1 < sdebug_max_queue; )   {
-		if (!locked) {
-			spin_lock_irqsave(&sqp->qc_lock, iflags);
-			locked = true;
-		}
 		if (first) {
 			first = false;
 			if (!test_bit(qc_idx, sqp->in_use_bm))
 				continue;
-		} else {
-			qc_idx = find_next_bit(sqp->in_use_bm, sdebug_max_queue, qc_idx + 1);
 		}
+
+		qc_idx = find_next_bit(sqp->in_use_bm, sdebug_max_queue,
+				       qc_idx + 1);
 		if (qc_idx >= sdebug_max_queue)
 			break;
 
@@ -7586,14 +7584,15 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
 		}
 		WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);
 		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
-		locked = false;
 		scsi_done(scp); /* callback to mid level */
 		num_entries++;
+		spin_lock_irqsave(&sqp->qc_lock, iflags);
 		if (find_first_bit(sqp->in_use_bm, sdebug_max_queue) >= sdebug_max_queue)
 			break;	/* if no more then exit without retaking spinlock */
 	}
-	if (locked)
-		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
+
+	spin_unlock_irqrestore(&sqp->qc_lock, iflags);
+
 	if (num_entries > 0)
 		atomic_add(num_entries, &sdeb_mq_poll_count);
 	return num_entries;
-- 
2.35.1