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Commit a2ace466 authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Martin Schwidefsky
Browse files

s390/dasd: Implement block timeout handling 



This patch implements generic block layer timeout handling
callbacks for DASDs. When the timeout expires the respective
cqr is aborted.

With this timeout handler time-critical request abort
is guaranteed as the abort does not depend on the internal
state of the various DASD driver queues.

Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Acked-by: default avatarStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: default avatarStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 1fbdb8be

drivers/s390/block/dasd.c

+76 −0
Original line number Diff line number Diff line
@@ -2573,8 +2573,10 @@ static void __dasd_process_request_queue(struct dasd_block *block) 
		 */

		cqr->callback_data = (void *) req;

		cqr->status = DASD_CQR_FILLED;

		req->completion_data = cqr;

		blk_start_request(req);

		list_add_tail(&cqr->blocklist, &block->ccw_queue);

		INIT_LIST_HEAD(&cqr->devlist);

		dasd_profile_start(block, cqr, req);

	}

}
@@ -2861,6 +2863,80 @@ static void do_dasd_request(struct request_queue *queue) 
	spin_unlock(&block->queue_lock);

}



/*

 * Block timeout callback, called from the block layer

 *

 * request_queue lock is held on entry.

 *

 * Return values:

 * BLK_EH_RESET_TIMER if the request should be left running

 * BLK_EH_NOT_HANDLED if the request is handled or terminated

 *		      by the driver.

 */

enum blk_eh_timer_return dasd_times_out(struct request *req)

{

	struct dasd_ccw_req *cqr = req->completion_data;

	struct dasd_block *block = req->q->queuedata;

	struct dasd_device *device;

	int rc = 0;



	if (!cqr)

		return BLK_EH_NOT_HANDLED;



	device = cqr->startdev ? cqr->startdev : block->base;

	DBF_DEV_EVENT(DBF_WARNING, device,

		      " dasd_times_out cqr %p status %x",

		      cqr, cqr->status);



	spin_lock(&block->queue_lock);

	spin_lock(get_ccwdev_lock(device->cdev));

	cqr->retries = -1;

	cqr->intrc = -ETIMEDOUT;

	if (cqr->status >= DASD_CQR_QUEUED) {

		spin_unlock(get_ccwdev_lock(device->cdev));

		rc = dasd_cancel_req(cqr);

	} else if (cqr->status == DASD_CQR_FILLED ||

		   cqr->status == DASD_CQR_NEED_ERP) {

		cqr->status = DASD_CQR_TERMINATED;

		spin_unlock(get_ccwdev_lock(device->cdev));

	} else if (cqr->status == DASD_CQR_IN_ERP) {

		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;



		list_for_each_entry_safe(searchcqr, nextcqr,

					 &block->ccw_queue, blocklist) {

			tmpcqr = searchcqr;

			while (tmpcqr->refers)

				tmpcqr = tmpcqr->refers;

			if (tmpcqr != cqr)

				continue;

			/* searchcqr is an ERP request for cqr */

			searchcqr->retries = -1;

			searchcqr->intrc = -ETIMEDOUT;

			if (searchcqr->status >= DASD_CQR_QUEUED) {

				spin_unlock(get_ccwdev_lock(device->cdev));

				rc = dasd_cancel_req(searchcqr);

				spin_lock(get_ccwdev_lock(device->cdev));

			} else if ((searchcqr->status == DASD_CQR_FILLED) ||

				   (searchcqr->status == DASD_CQR_NEED_ERP)) {

				searchcqr->status = DASD_CQR_TERMINATED;

				rc = 0;

			} else if (searchcqr->status == DASD_CQR_IN_ERP) {

				/*

				 * Shouldn't happen; most recent ERP

				 * request is at the front of queue

				 */

				continue;

			}

			break;

		}

		spin_unlock(get_ccwdev_lock(device->cdev));

	}

	dasd_schedule_block_bh(block);

	spin_unlock(&block->queue_lock);



	return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;

}



/*

 * Allocate and initialize request queue and default I/O scheduler.

 */

drivers/s390/block/dasd_diag.c

+4 −1
Original line number Diff line number Diff line
@@ -583,6 +583,9 @@ dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req) 


static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)

{

	if (cqr->retries < 0)

		cqr->status = DASD_CQR_FAILED;

	else

		cqr->status = DASD_CQR_FILLED;

};

drivers/s390/block/dasd_eckd.c

+4 −0
Original line number Diff line number Diff line
@@ -2381,6 +2381,10 @@ dasd_eckd_format_device(struct dasd_device *base, 


static void dasd_eckd_handle_terminated_request(struct dasd_ccw_req *cqr)

{

	if (cqr->retries < 0) {

		cqr->status = DASD_CQR_FAILED;

		return;

	}

	cqr->status = DASD_CQR_FILLED;

	if (cqr->block && (cqr->startdev != cqr->block->base)) {

		dasd_eckd_reset_ccw_to_base_io(cqr);

drivers/s390/block/dasd_fba.c

+4 −1
Original line number Diff line number Diff line
@@ -428,6 +428,9 @@ dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req) 


static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)

{

	if (cqr->retries < 0)

		cqr->status = DASD_CQR_FAILED;

	else

		cqr->status = DASD_CQR_FILLED;

};