Commit 24cb5b48 authored by Cornelia Huck's avatar Cornelia Huck Committed by Martin Schwidefsky
Browse files

[S390] cio: Use path verification for last path gone after vary off. 



If the last path to a device is gone after a chpid has been varied
off, putting it on the slow queue doesn't prevent a device driver
from still attempting to use it (it may stay on the slow queue for a
long time). Instead, trigger a verify event which will prevent I/O
attempts from the device driver immediately.

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 9163bb2e

drivers/s390/cio/chsc.c

+12 −10
Original line number Diff line number Diff line
@@ -744,20 +744,22 @@ __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on) 
				device_trigger_reprobe(sch);

			else if (sch->driver && sch->driver->verify)

				sch->driver->verify(&sch->dev);

		} else {

			break;

		}

		sch->opm &= ~(0x80 >> chp);

		sch->lpm &= ~(0x80 >> chp);

		if (check_for_io_on_path(sch, chp))

			/* Path verification is done after killing. */

			device_kill_io(sch);

		else if (!sch->lpm) {

			if (device_trigger_verify(sch) != 0) {

				if (css_enqueue_subchannel_slow(sch->schid)) {

					css_clear_subchannel_slow_list();

					need_rescan = 1;

				}

			}

		} else if (sch->driver && sch->driver->verify)

			sch->driver->verify(&sch->dev);

		}

		break;

	}

	spin_unlock_irqrestore(&sch->lock, flags);

drivers/s390/cio/css.h

+1 −0
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ void device_trigger_reprobe(struct subchannel *); 
/* Helper functions for vary on/off. */

int device_is_online(struct subchannel *);

void device_kill_io(struct subchannel *);

int device_trigger_verify(struct subchannel *sch);



/* Machine check helper function. */

void device_kill_pending_timer(struct subchannel *);

drivers/s390/cio/device_fsm.c

+11 −0
Original line number Diff line number Diff line
@@ -59,6 +59,17 @@ device_set_disconnected(struct subchannel *sch) 
	cdev->private->state = DEV_STATE_DISCONNECTED;

}



int device_trigger_verify(struct subchannel *sch)

{

	struct ccw_device *cdev;



	cdev = sch->dev.driver_data;

	if (!cdev || !cdev->online)

		return -EINVAL;

	dev_fsm_event(cdev, DEV_EVENT_VERIFY);

	return 0;

}



/*

 * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.

 */

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