[PATCH] s390: dasd extended error reporting

The DASD extended error reporting is a facility that allows to get detailed
information about certain problems in the DASD I/O.  This information can be
used to implement fail-over applications that can recover these problems.

Signed-off-by: Stefan Weinhuber <wein@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, 28 insertions, 1 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 9e0b371ebe69..f32f7447588b 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -151,6 +151,8 @@ dasd_state_new_to_known(struct dasd_device *device)
 static inline void
 dasd_state_known_to_new(struct dasd_device * device)
 {
+        /* Disable extended error reporting for this device. */
+        dasd_eer_disable(device);
         /* Forget the discipline information. */
         if (device->discipline)
                 module_put(device->discipline->owner);
@@ -892,6 +894,9 @@ dasd_handle_state_change_pending(struct dasd_device *device)
         struct dasd_ccw_req *cqr;
         struct list_head *l, *n;
 
+        /* First of all start sense subsystem status request. */
+        dasd_eer_snss(device);
+
         device->stopped &= ~DASD_STOPPED_PENDING;
 
         /* restart all 'running' IO on queue */
@@ -1111,6 +1116,19 @@ restart:
                         }
                         goto restart;
                 }
+
+                /* First of all call extended error reporting. */
+                if (dasd_eer_enabled(device) &&
+                    cqr->status == DASD_CQR_FAILED) {
+                        dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
+
+                        /* restart request  */
+                        cqr->status = DASD_CQR_QUEUED;
+                        cqr->retries = 255;
+                        device->stopped |= DASD_STOPPED_QUIESCE;
+                        goto restart;
+                }
+
                 /* Process finished ERP request. */
                 if (cqr->refers) {
                         __dasd_process_erp(device, cqr);
@@ -1248,7 +1266,8 @@ __dasd_start_head(struct dasd_device * device)
         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)) {
+            test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+            (!dasd_eer_enabled(device))) {
                 cqr->status = DASD_CQR_FAILED;
                 dasd_schedule_bh(device);
         }
@@ -1807,6 +1826,7 @@ dasd_exit(void)
 #ifdef CONFIG_PROC_FS
         dasd_proc_exit();
 #endif
+        dasd_eer_exit();
         if (dasd_page_cache != NULL) {
                 kmem_cache_destroy(dasd_page_cache);
                 dasd_page_cache = NULL;
@@ -2003,6 +2023,9 @@ dasd_generic_notify(struct ccw_device *cdev, int event)
         switch (event) {
         case CIO_GONE:
         case CIO_NO_PATH:
+                /* First of all call extended error reporting. */
+                dasd_eer_write(device, NULL, DASD_EER_NOPATH);
+
                 if (device->state < DASD_STATE_BASIC)
                         break;
                 /* Device is active. We want to keep it. */
@@ -2060,6 +2083,7 @@ dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
         put_driver(drv);
 }
 
+
 static int __init
 dasd_init(void)
 {
@@ -2092,6 +2116,9 @@ dasd_init(void)
         rc = dasd_parse();
         if (rc)
                 goto failed;
+        rc = dasd_eer_init();
+        if (rc)
+                goto failed;
 #ifdef CONFIG_PROC_FS
         rc = dasd_proc_init();
         if (rc)