[S390] dasd: Improve handling of stolen DASD reservation
If a DASD device has been reserved by a Linux system, and later
this reservation is ‘stolen’ by a second system by means of an
unconditional reserve, then the first system receives a
notification about this fact. With this patch such an event can
be either ignored, as before, or it can be used to let the device
fail all I/O request, so that the device will not block anymore.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 8f2067b..f16afe7 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -902,6 +902,16 @@
return rc;
}
device = (struct dasd_device *) cqr->startdev;
+ if (((cqr->block &&
+ test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
+ test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
+ !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+ DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
+ "because of stolen lock", cqr);
+ cqr->status = DASD_CQR_ERROR;
+ cqr->intrc = -EPERM;
+ return -EPERM;
+ }
if (cqr->retries < 0) {
/* internal error 14 - start_IO run out of retries */
sprintf(errorstring, "14 %p", cqr);
@@ -1115,16 +1125,11 @@
}
now = get_clock();
-
- /* check for unsolicited interrupts */
cqr = (struct dasd_ccw_req *) intparm;
- if (!cqr || ((scsw_cc(&irb->scsw) == 1) &&
- (scsw_fctl(&irb->scsw) & SCSW_FCTL_START_FUNC) &&
- ((scsw_stctl(&irb->scsw) == SCSW_STCTL_STATUS_PEND) ||
- (scsw_stctl(&irb->scsw) == (SCSW_STCTL_STATUS_PEND |
- SCSW_STCTL_ALERT_STATUS))))) {
- if (cqr && cqr->status == DASD_CQR_IN_IO)
- cqr->status = DASD_CQR_QUEUED;
+ /* check for conditions that should be handled immediately */
+ if (!cqr ||
+ !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
+ scsw_cstat(&irb->scsw) == 0)) {
if (cqr)
memcpy(&cqr->irb, irb, sizeof(*irb));
device = dasd_device_from_cdev_locked(cdev);
@@ -1135,17 +1140,14 @@
dasd_put_device(device);
return;
}
- device->discipline->dump_sense_dbf(device, irb,
- "unsolicited");
- if ((device->features & DASD_FEATURE_ERPLOG))
- device->discipline->dump_sense(device, cqr,
- irb);
- dasd_device_clear_timer(device);
- device->discipline->handle_unsolicited_interrupt(device,
- irb);
+ device->discipline->dump_sense_dbf(device, irb, "int");
+ if (device->features & DASD_FEATURE_ERPLOG)
+ device->discipline->dump_sense(device, cqr, irb);
+ device->discipline->check_for_device_change(device, cqr, irb);
dasd_put_device(device);
- return;
}
+ if (!cqr)
+ return;
device = (struct dasd_device *) cqr->startdev;
if (!device ||
@@ -1185,13 +1187,6 @@
struct dasd_ccw_req, devlist);
}
} else { /* error */
- memcpy(&cqr->irb, irb, sizeof(struct irb));
- /* log sense for every failed I/O to s390 debugfeature */
- dasd_log_sense_dbf(cqr, irb);
- if (device->features & DASD_FEATURE_ERPLOG) {
- dasd_log_sense(cqr, irb);
- }
-
/*
* If we don't want complex ERP for this request, then just
* reset this and retry it in the fastpath
@@ -1232,13 +1227,13 @@
goto out;
if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
device->state != device->target ||
- !device->discipline->handle_unsolicited_interrupt){
+ !device->discipline->check_for_device_change){
dasd_put_device(device);
goto out;
}
-
- dasd_device_clear_timer(device);
- device->discipline->handle_unsolicited_interrupt(device, irb);
+ if (device->discipline->dump_sense_dbf)
+ device->discipline->dump_sense_dbf(device, irb, "uc");
+ device->discipline->check_for_device_change(device, NULL, irb);
dasd_put_device(device);
out:
return UC_TODO_RETRY;
@@ -1659,7 +1654,12 @@
continue;
if (cqr->status != DASD_CQR_FILLED) /* could be failed */
continue;
-
+ if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+ !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+ cqr->status = DASD_CQR_FAILED;
+ cqr->intrc = -EPERM;
+ continue;
+ }
/* Non-temporary stop condition will trigger fail fast */
if (device->stopped & ~DASD_STOPPED_PENDING &&
test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
@@ -1667,7 +1667,6 @@
cqr->status = DASD_CQR_FAILED;
continue;
}
-
/* Don't try to start requests if device is stopped */
if (interruptible) {
rc = wait_event_interruptible(
@@ -1752,13 +1751,18 @@
int rc;
device = cqr->startdev;
+ if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+ !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+ cqr->status = DASD_CQR_FAILED;
+ cqr->intrc = -EPERM;
+ return -EIO;
+ }
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = _dasd_term_running_cqr(device);
if (rc) {
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
-
cqr->callback = dasd_wakeup_cb;
cqr->callback_data = DASD_SLEEPON_START_TAG;
cqr->status = DASD_CQR_QUEUED;
@@ -2062,6 +2066,13 @@
list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
if (cqr->status != DASD_CQR_FILLED)
continue;
+ if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
+ !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+ cqr->status = DASD_CQR_FAILED;
+ cqr->intrc = -EPERM;
+ dasd_schedule_block_bh(block);
+ continue;
+ }
/* Non-temporary stop condition will trigger fail fast */
if (block->base->stopped & ~DASD_STOPPED_PENDING &&
test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&