1 files changed, 62 insertions, 89 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 7beda20cf122..1161bbd7eb78 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -725,18 +725,20 @@ static void dasd_profile_start(struct dasd_block *block,
 	 * we count each request only once.
 	 */
 	device = cqr->startdev;
-	if (device->profile.data) {
-		counter = 1; /* request is not yet queued on the start device */
-		list_for_each(l, &device->ccw_queue)
-			if (++counter >= 31)
-				break;
-	}
+	if (!device->profile.data)
+		return;
+
+	spin_lock(get_ccwdev_lock(device->cdev));
+	counter = 1; /* request is not yet queued on the start device */
+	list_for_each(l, &device->ccw_queue)
+		if (++counter >= 31)
+			break;
+	spin_unlock(get_ccwdev_lock(device->cdev));
+
 	spin_lock(&device->profile.lock);
-	if (device->profile.data) {
-		device->profile.data->dasd_io_nr_req[counter]++;
-		if (rq_data_dir(req) == READ)
-			device->profile.data->dasd_read_nr_req[counter]++;
-	}
+	device->profile.data->dasd_io_nr_req[counter]++;
+	if (rq_data_dir(req) == READ)
+		device->profile.data->dasd_read_nr_req[counter]++;
 	spin_unlock(&device->profile.lock);
 }
 
@@ -2826,41 +2828,32 @@ static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
  * Requeue a request back to the block request queue
  * only works for block requests
  */
-static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
+static void _dasd_requeue_request(struct dasd_ccw_req *cqr)
 {
-	struct dasd_block *block = cqr->block;
 	struct request *req;
 
-	if (!block)
-		return -EINVAL;
 	/*
 	 * If the request is an ERP request there is nothing to requeue.
 	 * This will be done with the remaining original request.
 	 */
 	if (cqr->refers)
-		return 0;
+		return;
 	spin_lock_irq(&cqr->dq->lock);
 	req = (struct request *) cqr->callback_data;
-	blk_mq_requeue_request(req, false);
+	blk_mq_requeue_request(req, true);
 	spin_unlock_irq(&cqr->dq->lock);
 
-	return 0;
+	return;
 }
 
-/*
- * Go through all request on the dasd_block request queue, cancel them
- * on the respective dasd_device, and return them to the generic
- * block layer.
- */
-static int dasd_flush_block_queue(struct dasd_block *block)
+static int _dasd_requests_to_flushqueue(struct dasd_block *block,
+					struct list_head *flush_queue)
 {
 	struct dasd_ccw_req *cqr, *n;
-	int rc, i;
-	struct list_head flush_queue;
 	unsigned long flags;
+	int rc, i;
 
-	INIT_LIST_HEAD(&flush_queue);
-	spin_lock_bh(&block->queue_lock);
+	spin_lock_irqsave(&block->queue_lock, flags);
 	rc = 0;
 restart:
 	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
@@ -2875,13 +2868,32 @@ restart:
 		 * is returned from the dasd_device layer.
 		 */
 		cqr->callback = _dasd_wake_block_flush_cb;
-		for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
-			list_move_tail(&cqr->blocklist, &flush_queue);
+		for (i = 0; cqr; cqr = cqr->refers, i++)
+			list_move_tail(&cqr->blocklist, flush_queue);
 		if (i > 1)
 			/* moved more than one request - need to restart */
 			goto restart;
 	}
-	spin_unlock_bh(&block->queue_lock);
+	spin_unlock_irqrestore(&block->queue_lock, flags);
+
+	return rc;
+}
+
+/*
+ * Go through all request on the dasd_block request queue, cancel them
+ * on the respective dasd_device, and return them to the generic
+ * block layer.
+ */
+static int dasd_flush_block_queue(struct dasd_block *block)
+{
+	struct dasd_ccw_req *cqr, *n;
+	struct list_head flush_queue;
+	unsigned long flags;
+	int rc;
+
+	INIT_LIST_HEAD(&flush_queue);
+	rc = _dasd_requests_to_flushqueue(block, &flush_queue);
+
 	/* Now call the callback function of flushed requests */
 restart_cb:
 	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
@@ -3832,75 +3844,36 @@ EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
  */
 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
 {
+	struct dasd_block *block = device->block;
 	struct list_head requeue_queue;
 	struct dasd_ccw_req *cqr, *n;
-	struct dasd_ccw_req *refers;
 	int rc;
 
-	INIT_LIST_HEAD(&requeue_queue);
-	spin_lock_irq(get_ccwdev_lock(device->cdev));
-	rc = 0;
-	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
-		/* Check status and move request to flush_queue */
-		if (cqr->status == DASD_CQR_IN_IO) {
-			rc = device->discipline->term_IO(cqr);
-			if (rc) {
-				/* unable to terminate requeust */
-				dev_err(&device->cdev->dev,
-					"Unable to terminate request %p "
-					"on suspend\n", cqr);
-				spin_unlock_irq(get_ccwdev_lock(device->cdev));
-				dasd_put_device(device);
-				return rc;
-			}
-		}
-		list_move_tail(&cqr->devlist, &requeue_queue);
-	}
-	spin_unlock_irq(get_ccwdev_lock(device->cdev));
-
-	list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
-		wait_event(dasd_flush_wq,
-			   (cqr->status != DASD_CQR_CLEAR_PENDING));
+	if (!block)
+		return 0;
 
-		/*
-		 * requeue requests to blocklayer will only work
-		 * for block device requests
-		 */
-		if (_dasd_requeue_request(cqr))
-			continue;
+	INIT_LIST_HEAD(&requeue_queue);
+	rc = _dasd_requests_to_flushqueue(block, &requeue_queue);
 
-		/* remove requests from device and block queue */
-		list_del_init(&cqr->devlist);
-		while (cqr->refers != NULL) {
-			refers = cqr->refers;
-			/* remove the request from the block queue */
-			list_del(&cqr->blocklist);
-			/* free the finished erp request */
-			dasd_free_erp_request(cqr, cqr->memdev);
-			cqr = refers;
+	/* Now call the callback function of flushed requests */
+restart_cb:
+	list_for_each_entry_safe(cqr, n, &requeue_queue, blocklist) {
+		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
+		/* Process finished ERP request. */
+		if (cqr->refers) {
+			spin_lock_bh(&block->queue_lock);
+			__dasd_process_erp(block->base, cqr);
+			spin_unlock_bh(&block->queue_lock);
+			/* restart list_for_xx loop since dasd_process_erp
+			 * might remove multiple elements
+			 */
+			goto restart_cb;
 		}
-
-		/*
-		 * _dasd_requeue_request already checked for a valid
-		 * blockdevice, no need to check again
-		 * all erp requests (cqr->refers) have a cqr->block
-		 * pointer copy from the original cqr
-		 */
+		_dasd_requeue_request(cqr);
 		list_del_init(&cqr->blocklist);
 		cqr->block->base->discipline->free_cp(
 			cqr, (struct request *) cqr->callback_data);
 	}
-
-	/*
-	 * if requests remain then they are internal request
-	 * and go back to the device queue
-	 */
-	if (!list_empty(&requeue_queue)) {
-		/* move freeze_queue to start of the ccw_queue */
-		spin_lock_irq(get_ccwdev_lock(device->cdev));
-		list_splice_tail(&requeue_queue, &device->ccw_queue);
-		spin_unlock_irq(get_ccwdev_lock(device->cdev));
-	}
 	dasd_schedule_device_bh(device);
 	return rc;
 }