From: Cornelia Huck <[email protected]>
[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: Cornelia Huck <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---
drivers/s390/cio/chsc.c | 22 ++++++++++++----------
drivers/s390/cio/css.h | 1 +
drivers/s390/cio/device_fsm.c | 11 +++++++++++
3 files changed, 24 insertions(+), 10 deletions(-)
diff -urpN linux-2.6/drivers/s390/cio/chsc.c linux-2.6-patched/drivers/s390/cio/chsc.c
--- linux-2.6/drivers/s390/cio/chsc.c 2006-12-04 14:50:48.000000000 +0100
+++ linux-2.6-patched/drivers/s390/cio/chsc.c 2006-12-04 14:51:04.000000000 +0100
@@ -744,20 +744,22 @@ __s390_subchannel_vary_chpid(struct subc
device_trigger_reprobe(sch);
else if (sch->driver && sch->driver->verify)
sch->driver->verify(&sch->dev);
- } else {
- 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) {
+ 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);
- }
+ }
+ } else if (sch->driver && sch->driver->verify)
+ sch->driver->verify(&sch->dev);
break;
}
spin_unlock_irqrestore(&sch->lock, flags);
diff -urpN linux-2.6/drivers/s390/cio/css.h linux-2.6-patched/drivers/s390/cio/css.h
--- linux-2.6/drivers/s390/cio/css.h 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6-patched/drivers/s390/cio/css.h 2006-12-04 14:51:04.000000000 +0100
@@ -171,6 +171,7 @@ void device_trigger_reprobe(struct subch
/* 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 *);
diff -urpN linux-2.6/drivers/s390/cio/device_fsm.c linux-2.6-patched/drivers/s390/cio/device_fsm.c
--- linux-2.6/drivers/s390/cio/device_fsm.c 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6-patched/drivers/s390/cio/device_fsm.c 2006-12-04 14:51:04.000000000 +0100
@@ -59,6 +59,17 @@ device_set_disconnected(struct subchanne
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.
*/