Commit 25ee4cf8 authored by Peter Oberparleiter's avatar Peter Oberparleiter Committed by Linus Torvalds
Browse files

[PATCH] s390: fail-fast requests on quiesced devices 



Using the fail-fast flag in i/o requests on a dasd disk which has been
quiesced leads to kernel panics.  Modify the request start function to only
work on requests in a valid state.

Signed-off-by: default avatarPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent dafd87aa

drivers/s390/block/dasd.c

+16 −13
Original line number Diff line number Diff line
@@ -1257,16 +1257,20 @@ __dasd_start_head(struct dasd_device * device) 
	if (list_empty(&device->ccw_queue))

		return;

	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);

        /* check FAILFAST */

	if (cqr->status != DASD_CQR_QUEUED)

		return;

	/* Non-temporary stop condition will trigger fail fast */

	if (device->stopped & ~DASD_STOPPED_PENDING &&

	    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&

	    (!dasd_eer_enabled(device))) {

		cqr->status = DASD_CQR_FAILED;

		dasd_schedule_bh(device);

		return;

	}

	if ((cqr->status == DASD_CQR_QUEUED) &&

	    (!device->stopped)) {

		/* try to start the first I/O that can be started */

	/* Don't try to start requests if device is stopped */

	if (device->stopped)

		return;



	rc = device->discipline->start_IO(cqr);

	if (rc == 0)

		dasd_set_timer(device, cqr->expires);
@@ -1276,7 +1280,6 @@ __dasd_start_head(struct dasd_device * device) 
		/* Hmpf, try again in 1/2 sec */

		dasd_set_timer(device, 50);

}

}



/*

 * Remove requests from the ccw queue.

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