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Commit c5576876 authored by Stefan Haberland's avatar Stefan Haberland Committed by Martin Schwidefsky
Browse files

s390/dasd: fix hanging device after resume with internal error 13 



If too many ccw requests are pre-build before a suspend/resume cycle
the device might not get enough memory to do path verification
during resume.
Requeue requests to the block device request queue on suspend and free
pre-build ccw requests.

Signed-off-by: default avatarStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent d42e1712

drivers/s390/block/dasd.c

+55 −8
Original line number Diff line number Diff line
@@ -2751,6 +2751,26 @@ static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data) 
	wake_up(&dasd_flush_wq);

}



/*

 * Requeue a request back to the block request queue

 * only works for block requests

 */

static int _dasd_requeue_request(struct dasd_ccw_req *cqr)

{

	struct dasd_block *block = cqr->block;

	struct request *req;

	unsigned long flags;



	if (!block)

		return -EINVAL;

	spin_lock_irqsave(&block->queue_lock, flags);

	req = (struct request *) cqr->callback_data;

	blk_requeue_request(block->request_queue, req);

	spin_unlock_irqrestore(&block->queue_lock, flags);



	return 0;

}



/*

 * Go through all request on the dasd_block request queue, cancel them

 * on the respective dasd_device, and return them to the generic
@@ -3469,10 +3489,11 @@ EXPORT_SYMBOL_GPL(dasd_generic_verify_path); 


int dasd_generic_pm_freeze(struct ccw_device *cdev)

{

	struct dasd_device *device = dasd_device_from_cdev(cdev);

	struct list_head freeze_queue;

	struct dasd_ccw_req *cqr, *n;

	struct dasd_ccw_req *refers;

	int rc;

	struct list_head freeze_queue;

	struct dasd_device *device = dasd_device_from_cdev(cdev);



	if (IS_ERR(device))

		return PTR_ERR(device);
@@ -3485,7 +3506,8 @@ int dasd_generic_pm_freeze(struct ccw_device *cdev) 


	/* disallow new I/O  */

	dasd_device_set_stop_bits(device, DASD_STOPPED_PM);

	/* clear active requests */



	/* clear active requests and requeue them to block layer if possible */

	INIT_LIST_HEAD(&freeze_queue);

	spin_lock_irq(get_ccwdev_lock(cdev));

	rc = 0;
@@ -3505,7 +3527,6 @@ int dasd_generic_pm_freeze(struct ccw_device *cdev) 
		}

		list_move_tail(&cqr->devlist, &freeze_queue);

	}



	spin_unlock_irq(get_ccwdev_lock(cdev));



	list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
@@ -3513,12 +3534,38 @@ int dasd_generic_pm_freeze(struct ccw_device *cdev) 
			   (cqr->status != DASD_CQR_CLEAR_PENDING));

		if (cqr->status == DASD_CQR_CLEARED)

			cqr->status = DASD_CQR_QUEUED;



		/* requeue requests to blocklayer will only work for

		   block device requests */

		if (_dasd_requeue_request(cqr))

			continue;



		/* 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;

		}

		if (cqr->block)

			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(&freeze_queue)) {

		/* move freeze_queue to start of the ccw_queue */

		spin_lock_irq(get_ccwdev_lock(cdev));

		list_splice_tail(&freeze_queue, &device->ccw_queue);

		spin_unlock_irq(get_ccwdev_lock(cdev));



	}

	dasd_put_device(device);

	return rc;

}