[S390] dasd: fix unconditional reserve handling.

The reserve/release IOCTLs sometimes do not work. If second system
does a 'steal lock' the pending unit check (Format 3 Msg F) is
delivered. Since ERP is disabled for reserve/release, the IOCTL call
fails. We have to allow basic ERP (retries) for reserve/release IOCTLs.
Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd.c

@@ -1022,8 +1022,6 @@ dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 		 irb->scsw.cstat == 0 &&
 		 !irb->esw.esw0.erw.cons)
 		era = dasd_era_none;
-	else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
- 	        era = dasd_era_fatal; /* don't recover this request */
 	else if (irb->esw.esw0.erw.cons)
 		era = device->discipline->examine_error(cqr, irb);
 	else
@@ -1127,7 +1125,9 @@ __dasd_process_ccw_queue(struct dasd_device * device,
 				cqr->status = DASD_CQR_FAILED;
 				cqr->stopclk = get_clock();
 			} else {
-				if (cqr->irb.esw.esw0.erw.cons) {
+				if (cqr->irb.esw.esw0.erw.cons &&
+				    test_bit(DASD_CQR_FLAGS_USE_ERP,
+					     &cqr->flags)) {
 					erp_fn = device->discipline->
 						erp_action(cqr);
 					erp_fn(cqr);

drivers/s390/block/dasd_eckd.c

@@ -1380,7 +1380,7 @@ dasd_eckd_release(struct dasd_device *device)
 	cqr->device = device;
 	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
-	cqr->retries = 0;
+	cqr->retries = 2;	/* set retry counter to enable basic ERP */
 	cqr->expires = 2 * HZ;
 	cqr->buildclk = get_clock();
 	cqr->status = DASD_CQR_FILLED;
@@ -1420,7 +1420,7 @@ dasd_eckd_reserve(struct dasd_device *device)
 	cqr->device = device;
 	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
-	cqr->retries = 0;
+	cqr->retries = 2;	/* set retry counter to enable basic ERP */
 	cqr->expires = 2 * HZ;
 	cqr->buildclk = get_clock();
 	cqr->status = DASD_CQR_FILLED;
@@ -1459,7 +1459,7 @@ dasd_eckd_steal_lock(struct dasd_device *device)
 	cqr->device = device;
 	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
 	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
-	cqr->retries = 0;
+	cqr->retries = 2;	/* set retry counter to enable basic ERP */
 	cqr->expires = 2 * HZ;
 	cqr->buildclk = get_clock();
 	cqr->status = DASD_CQR_FILLED;