[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: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 811060e10c00..efc4cf62496e 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -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();