Commit 1c01b8a5 authored by Horst Hummel's avatar Horst Hummel Committed by Linus Torvalds
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[PATCH] s390: dasd failfast support 



To properly support multipath-failover handling, the linux block layer has
introduced a special request flag, 'REQ_FAILFAST'.  This flag is now used to
return requests immediately in case the device is not operational.

Signed-off-by: default avatarHorst Hummel <horst.hummel@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 9a7af289

drivers/s390/block/dasd.c

+20 −8
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001

 *

 * $Revision: 1.169 $

 * $Revision: 1.172 $

 */



#include <linux/config.h>
@@ -1224,6 +1224,12 @@ __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 (device->stopped & ~DASD_STOPPED_PENDING &&

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

		cqr->status = DASD_CQR_FAILED;

		dasd_schedule_bh(device);

	}

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

	    (!device->stopped)) {

		/* try to start the first I/O that can be started */
@@ -1750,8 +1756,10 @@ dasd_exit(void) 
 * SECTION: common functions for ccw_driver use

 */



/* initial attempt at a probe function. this can be simplified once

 * the other detection code is gone */

/*

 * Initial attempt at a probe function. this can be simplified once

 * the other detection code is gone.

 */

int

dasd_generic_probe (struct ccw_device *cdev,

		    struct dasd_discipline *discipline)
@@ -1770,8 +1778,10 @@ dasd_generic_probe (struct ccw_device *cdev, 
	return ret;

}



/* this will one day be called from a global not_oper handler.

 * It is also used by driver_unregister during module unload */

/*

 * This will one day be called from a global not_oper handler.

 * It is also used by driver_unregister during module unload.

 */

void

dasd_generic_remove (struct ccw_device *cdev)

{
@@ -1798,9 +1808,11 @@ dasd_generic_remove (struct ccw_device *cdev) 
	dasd_delete_device(device);

}



/* activate a device. This is called from dasd_{eckd,fba}_probe() when either

/*

 * Activate a device. This is called from dasd_{eckd,fba}_probe() when either

 * the device is detected for the first time and is supposed to be used

 * or the user has started activation through sysfs */

 * or the user has started activation through sysfs.

 */

int

dasd_generic_set_online (struct ccw_device *cdev,

			 struct dasd_discipline *discipline)
@@ -1917,7 +1929,6 @@ dasd_generic_notify(struct ccw_device *cdev, int event) 
				if (cqr->status == DASD_CQR_IN_IO)

					cqr->status = DASD_CQR_FAILED;

			device->stopped |= DASD_STOPPED_DC_EIO;

			dasd_schedule_bh(device);

		} else {

			list_for_each_entry(cqr, &device->ccw_queue, list)

				if (cqr->status == DASD_CQR_IN_IO) {
@@ -1927,6 +1938,7 @@ dasd_generic_notify(struct ccw_device *cdev, int event) 
			device->stopped |= DASD_STOPPED_DC_WAIT;

			dasd_set_timer(device, 0);

		}

		dasd_schedule_bh(device);

		ret = 1;

		break;

	case CIO_OPER:

drivers/s390/block/dasd_diag.c

+3 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000

 *

 * $Revision: 1.52 $

 * $Revision: 1.53 $

 */



#include <linux/config.h>
@@ -549,6 +549,8 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req) 
	}

	cqr->retries = DIAG_MAX_RETRIES;

	cqr->buildclk = get_clock();

	if (req->flags & REQ_FAILFAST)

		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->device = device;

	cqr->expires = DIAG_TIMEOUT;

	cqr->status = DASD_CQR_FILLED;

drivers/s390/block/dasd_eckd.c

+6 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000

 *

 * $Revision: 1.71 $

 * $Revision: 1.74 $

 */



#include <linux/config.h>
@@ -1136,6 +1136,8 @@ dasd_eckd_build_cp(struct dasd_device * device, struct request *req) 
			recid++;

		}

	}

	if (req->flags & REQ_FAILFAST)

		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->device = device;

	cqr->expires = 5 * 60 * HZ;	/* 5 minutes */

	cqr->lpm = private->path_data.ppm;
@@ -1252,6 +1254,7 @@ dasd_eckd_release(struct block_device *bdev, int no, long args) 
	cqr->cpaddr->cda = (__u32)(addr_t) cqr->data;

	cqr->device = device;

	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);

	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->retries = 0;

	cqr->expires = 2 * HZ;

	cqr->buildclk = get_clock();
@@ -1296,6 +1299,7 @@ dasd_eckd_reserve(struct block_device *bdev, int no, long args) 
	cqr->cpaddr->cda = (__u32)(addr_t) cqr->data;

	cqr->device = device;

	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);

	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->retries = 0;

	cqr->expires = 2 * HZ;

	cqr->buildclk = get_clock();
@@ -1339,6 +1343,7 @@ dasd_eckd_steal_lock(struct block_device *bdev, int no, long args) 
	cqr->cpaddr->cda = (__u32)(addr_t) cqr->data;

	cqr->device = device;

	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);

	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->retries = 0;

	cqr->expires = 2 * HZ;

	cqr->buildclk = get_clock();

drivers/s390/block/dasd_fba.c

+3 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000

 *

 * $Revision: 1.40 $

 * $Revision: 1.41 $

 */



#include <linux/config.h>
@@ -352,6 +352,8 @@ dasd_fba_build_cp(struct dasd_device * device, struct request *req) 
			recid++;

		}

	}

	if (req->flags & REQ_FAILFAST)

		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->device = device;

	cqr->expires = 5 * 60 * HZ;	/* 5 minutes */

	cqr->retries = 32;

drivers/s390/block/dasd_int.h

+2 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000

 *

 * $Revision: 1.65 $

 * $Revision: 1.68 $

 */



#ifndef DASD_INT_H
@@ -208,6 +208,7 @@ struct dasd_ccw_req { 


/* per dasd_ccw_req flags */

#define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */

#define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */



/* Signature for error recovery functions. */

typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);