From: Horst Hummel <[email protected]>
[patch 5/17] 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: Horst Hummel <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---
drivers/s390/block/dasd.c | 28 ++++++++++++++++++++--------
drivers/s390/block/dasd_diag.c | 4 +++-
drivers/s390/block/dasd_eckd.c | 7 ++++++-
drivers/s390/block/dasd_fba.c | 4 +++-
drivers/s390/block/dasd_int.h | 3 ++-
5 files changed, 34 insertions(+), 12 deletions(-)
diff -urpN linux-2.6/drivers/s390/block/dasd.c linux-2.6-patched/drivers/s390/block/dasd.c
--- linux-2.6/drivers/s390/block/dasd.c 2005-12-09 14:24:15.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd.c 2005-12-09 14:24:24.000000000 +0100
@@ -7,7 +7,7 @@
* Bugreports.to..: <[email protected]>
* (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 * d
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 *c
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 *
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 *c
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 *c
device->stopped |= DASD_STOPPED_DC_WAIT;
dasd_set_timer(device, 0);
}
+ dasd_schedule_bh(device);
ret = 1;
break;
case CIO_OPER:
diff -urpN linux-2.6/drivers/s390/block/dasd_diag.c linux-2.6-patched/drivers/s390/block/dasd_diag.c
--- linux-2.6/drivers/s390/block/dasd_diag.c 2005-12-09 14:24:16.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd_diag.c 2005-12-09 14:24:24.000000000 +0100
@@ -6,7 +6,7 @@
* Bugreports.to..: <[email protected]>
* (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 *
}
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;
diff -urpN linux-2.6/drivers/s390/block/dasd_eckd.c linux-2.6-patched/drivers/s390/block/dasd_eckd.c
--- linux-2.6/drivers/s390/block/dasd_eckd.c 2005-10-28 02:02:08.000000000 +0200
+++ linux-2.6-patched/drivers/s390/block/dasd_eckd.c 2005-12-09 14:24:24.000000000 +0100
@@ -7,7 +7,7 @@
* Bugreports.to..: <[email protected]>
* (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 *
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 *b
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 *b
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
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();
diff -urpN linux-2.6/drivers/s390/block/dasd_fba.c linux-2.6-patched/drivers/s390/block/dasd_fba.c
--- linux-2.6/drivers/s390/block/dasd_fba.c 2005-10-28 02:02:08.000000000 +0200
+++ linux-2.6-patched/drivers/s390/block/dasd_fba.c 2005-12-09 14:24:24.000000000 +0100
@@ -4,7 +4,7 @@
* Bugreports.to..: <[email protected]>
* (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 * d
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;
diff -urpN linux-2.6/drivers/s390/block/dasd_int.h linux-2.6-patched/drivers/s390/block/dasd_int.h
--- linux-2.6/drivers/s390/block/dasd_int.h 2005-10-28 02:02:08.000000000 +0200
+++ linux-2.6-patched/drivers/s390/block/dasd_int.h 2005-12-09 14:24:24.000000000 +0100
@@ -6,7 +6,7 @@
* Bugreports.to..: <[email protected]>
* (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 *);