From: Sagi Grimberg <sagi@grimberg.me>
Date: Tue, 4 Jul 2017 10:00:41 +0300
Subject: mtip32xx: quiesce request queues to make sure no submissions are
 inflight
Patch-mainline: v4.13-rc1
Git-commit: 436c15ab6596b12cfee7618ecaa69a4341ac3c51
References: FATE#322582

Unlike blk_mq_stop_hw_queues, blk_mq_quiesce_queue respects the
submission path rcu grace. quiesce the queue before iterating
on live tags, or performing device io quiescing.

While were at it, verify that the request started in mtip_abort_cmd
amd mtip_queue_cmd tag iteration calls.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/block/mtip32xx/mtip32xx.c |   19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -950,7 +950,7 @@ static int mtip_quiesce_io(struct mtip_p
 	unsigned long to;
 	bool active = true;
 
-	blk_mq_stop_hw_queues(port->dd->queue);
+	blk_mq_quiesce_queue(port->dd->queue);
 
 	to = jiffies + msecs_to_jiffies(timeout);
 	do {
@@ -970,10 +970,10 @@ static int mtip_quiesce_io(struct mtip_p
 			break;
 	} while (time_before(jiffies, to));
 
-	blk_mq_start_stopped_hw_queues(port->dd->queue, true);
+	blk_mq_unquiesce_queue(port->dd->queue);
 	return active ? -EBUSY : 0;
 err_fault:
-	blk_mq_start_stopped_hw_queues(port->dd->queue, true);
+	blk_mq_unquiesce_queue(port->dd->queue);
 	return -EFAULT;
 }
 
@@ -2737,6 +2737,9 @@ static void mtip_abort_cmd(struct reques
 	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(req);
 	struct driver_data *dd = data;
 
+	if (!blk_mq_request_started(req))
+		return;
+
 	dbg_printk(MTIP_DRV_NAME " Aborting request, tag = %d\n", req->tag);
 
 	clear_bit(req->tag, dd->port->cmds_to_issue);
@@ -2749,6 +2752,9 @@ static void mtip_queue_cmd(struct reques
 {
 	struct driver_data *dd = data;
 
+	if (!blk_mq_request_started(req))
+		return;
+
 	set_bit(req->tag, dd->port->cmds_to_issue);
 	blk_abort_request(req);
 }
@@ -2814,6 +2820,8 @@ restart_eh:
 				dev_warn(&dd->pdev->dev,
 					"Completion workers still active!");
 
+			blk_mq_quiesce_queue(dd->queue);
+
 			spin_lock(dd->queue->queue_lock);
 			blk_mq_tagset_busy_iter(&dd->tags,
 							mtip_queue_cmd, dd);
@@ -2826,6 +2834,8 @@ restart_eh:
 							mtip_abort_cmd, dd);
 
 			clear_bit(MTIP_PF_TO_ACTIVE_BIT, &dd->port->flags);
+
+			blk_mq_unquiesce_queue(dd->queue);
 		}
 
 		if (test_bit(MTIP_PF_ISSUE_CMDS_BIT, &port->flags)) {
@@ -3995,8 +4005,9 @@ static int mtip_block_remove(struct driv
 						dd->disk->disk_name);
 
 	blk_freeze_queue_start(dd->queue);
-	blk_mq_stop_hw_queues(dd->queue);
+	blk_mq_quiesce_queue(dd->queue);
 	blk_mq_tagset_busy_iter(&dd->tags, mtip_no_dev_cleanup, dd);
+	blk_mq_unquiesce_queue(dd->queue);
 
 	/*
 	 * Delete our gendisk structure. This also removes the device