Merge branch 'for-5.1/nfit/ars' into libnvdimm-for-next

Merge several updates to the ARS implementation. Highlights include:

* Support retrieval of short-ARS results if the ARS state is "requires
  continuation", and even if the "no_init_ars" module parameter is
  specified.
* Allow busy-polling of the kernel ARS state by allowing root to reset
  the exponential back-off timer.
* Filter potentially stale ARS results by tracking query-ARS relative to
  the previous start-ARS.

1 files changed, 31 insertions, 30 deletions

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 8445b484ae69..b137f27a34d5 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -68,8 +68,10 @@ int ide_end_rq(ide_drive_t *drive, struct request *rq, blk_status_t error,
 	}
 
 	if (!blk_update_request(rq, error, nr_bytes)) {
-		if (rq == drive->sense_rq)
+		if (rq == drive->sense_rq) {
 			drive->sense_rq = NULL;
+			drive->sense_rq_active = false;
+		}
 
 		__blk_mq_end_request(rq, error);
 		return 0;
@@ -451,16 +453,11 @@ void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
 		blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3);
 }
 
-/*
- * Issue a new request to a device.
- */
-blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
-			  const struct blk_mq_queue_data *bd)
+blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq,
+			  bool local_requeue)
 {
-	ide_drive_t	*drive = hctx->queue->queuedata;
-	ide_hwif_t	*hwif = drive->hwif;
+	ide_hwif_t *hwif = drive->hwif;
 	struct ide_host *host = hwif->host;
-	struct request	*rq = bd->rq;
 	ide_startstop_t	startstop;
 
 	if (!blk_rq_is_passthrough(rq) && !(rq->rq_flags & RQF_DONTPREP)) {
@@ -474,8 +471,6 @@ blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (ide_lock_host(host, hwif))
 		return BLK_STS_DEV_RESOURCE;
 
-	blk_mq_start_request(rq);
-
 	spin_lock_irq(&hwif->lock);
 
 	if (!ide_lock_port(hwif)) {
@@ -511,18 +506,6 @@ repeat:
 		drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
 
 		/*
-		 * we know that the queue isn't empty, but this can happen
-		 * if ->prep_rq() decides to kill a request
-		 */
-		if (!rq) {
-			rq = bd->rq;
-			if (!rq) {
-				ide_unlock_port(hwif);
-				goto out;
-			}
-		}
-
-		/*
 		 * Sanity: don't accept a request that isn't a PM request
 		 * if we are currently power managed. This is very important as
 		 * blk_stop_queue() doesn't prevent the blk_fetch_request()
@@ -560,9 +543,12 @@ repeat:
 		}
 	} else {
 plug_device:
+		if (local_requeue)
+			list_add(&rq->queuelist, &drive->rq_list);
 		spin_unlock_irq(&hwif->lock);
 		ide_unlock_host(host);
-		ide_requeue_and_plug(drive, rq);
+		if (!local_requeue)
+			ide_requeue_and_plug(drive, rq);
 		return BLK_STS_OK;
 	}
 
@@ -573,6 +559,26 @@ out:
 	return BLK_STS_OK;
 }
 
+/*
+ * Issue a new request to a device.
+ */
+blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
+			  const struct blk_mq_queue_data *bd)
+{
+	ide_drive_t *drive = hctx->queue->queuedata;
+	ide_hwif_t *hwif = drive->hwif;
+
+	spin_lock_irq(&hwif->lock);
+	if (drive->sense_rq_active) {
+		spin_unlock_irq(&hwif->lock);
+		return BLK_STS_DEV_RESOURCE;
+	}
+	spin_unlock_irq(&hwif->lock);
+
+	blk_mq_start_request(bd->rq);
+	return ide_issue_rq(drive, bd->rq, false);
+}
+
 static int drive_is_ready(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
@@ -893,13 +899,8 @@ EXPORT_SYMBOL_GPL(ide_pad_transfer);
 
 void ide_insert_request_head(ide_drive_t *drive, struct request *rq)
 {
-	ide_hwif_t *hwif = drive->hwif;
-	unsigned long flags;
-
-	spin_lock_irqsave(&hwif->lock, flags);
+	drive->sense_rq_active = true;
 	list_add_tail(&rq->queuelist, &drive->rq_list);
-	spin_unlock_irqrestore(&hwif->lock, flags);
-
 	kblockd_schedule_work(&drive->rq_work);
 }
 EXPORT_SYMBOL_GPL(ide_insert_request_head);