diff mbox series

[v3,5/8] scsi: don't wait for quiesce in scsi_stop_queue()

Message ID 20230607182249.22623-6-mwilck@suse.com (mailing list archive)
State New, archived
Headers show
Series scsi: fixes for targets with many LUNs, and scsi_target_block rework | expand

Commit Message

Martin Wilck June 7, 2023, 6:22 p.m. UTC 
From: Martin Wilck <mwilck@suse.com>

scsi_stop_queue() has just two callers, one with and one without
"nowait". As blk_mq_quiesce_queue() comes down to
blk_mq_quiesce_queue_nowait() followed by blk_mq_wait_quiesce_done(),
we might as well open-code this in scsi_device_block().

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 drivers/scsi/scsi_lib.c | 24 +++++++++---------------
 1 file changed, 9 insertions(+), 15 deletions(-)

Comments

Christoph Hellwig June 8, 2023, 5:46 a.m. UTC | #1 
Looks good.  Per the discussion on the last patch it probably makes
sense to move this patch before the replacement for patch 2.

Btw, your mail address for Bart is very, very outdated.
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 26e7ce25fa05..657d10c57205 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2726,24 +2726,16 @@  void scsi_start_queue(struct scsi_device *sdev)
 		blk_mq_unquiesce_queue(sdev->request_queue);
 }
 
-static void scsi_stop_queue(struct scsi_device *sdev, bool nowait)
+static void scsi_stop_queue(struct scsi_device *sdev)
 {
 	/*
 	 * The atomic variable of ->queue_stopped covers that
 	 * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue.
 	 *
-	 * However, we still need to wait until quiesce is done
-	 * in case that queue has been stopped.
+	 * After return, we still need to wait until quiesce is done.
 	 */
-	if (!cmpxchg(&sdev->queue_stopped, 0, 1)) {
-		if (nowait)
-			blk_mq_quiesce_queue_nowait(sdev->request_queue);
-		else
-			blk_mq_quiesce_queue(sdev->request_queue);
-	} else {
-		if (!nowait)
-			blk_mq_wait_quiesce_done(sdev->request_queue->tag_set);
-	}
+	if (!cmpxchg(&sdev->queue_stopped, 0, 1))
+		blk_mq_quiesce_queue_nowait(sdev->request_queue);
 }
 
 /**
@@ -2770,7 +2762,7 @@  int scsi_internal_device_block_nowait(struct scsi_device *sdev)
 	 * request queue.
 	 */
 	if (!ret)
-		scsi_stop_queue(sdev, true);
+		scsi_stop_queue(sdev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
@@ -2796,8 +2788,10 @@  static void scsi_device_block(struct scsi_device *sdev, void *data)
 	mutex_lock(&sdev->state_mutex);
 	err = __scsi_internal_device_block_nowait(sdev);
 	mutex_unlock(&sdev->state_mutex);
-	if (err == 0)
-		scsi_stop_queue(sdev, false);
+	if (err == 0) {
+		scsi_stop_queue(sdev);
+		blk_mq_wait_quiesce_done(sdev->request_queue->tag_set);
+	}
 
 	WARN_ONCE(err, "__scsi_internal_device_block_nowait(%s) failed: err = %d\n",
 		  dev_name(&sdev->sdev_gendev), err);