[S390] dasd: add ifcc handling

Adding interface control check (ifcc) handling in error recovery.
First retry up to 255 times and if all retries fail try an alternate
path if possible.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index d640427c74c816172b38cfae6bb2529f7b344e37..ab4f64c49829cd974afe67f534a82b9a5510091a 100644 (file)
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1057,12 +1057,11 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
                if (device->features & DASD_FEATURE_ERPLOG) {
                        dasd_log_sense(cqr, irb);
                }
-               /* If we have no sense data, or we just don't want complex ERP
-                * for this request, but if we have retries left, then just
-                * reset this request and retry it in the fastpath
+               /*
+                * If we don't want complex ERP for this request, then just
+                * reset this and retry it in the fastpath
                 */
-               if (!(cqr->irb.esw.esw0.erw.cons &&
-                     test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) &&
+               if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
                    cqr->retries > 0) {
                        DEV_MESSAGE(KERN_DEBUG, device,
                                    "default ERP in fastpath (%i retries left)",
@@ -1742,12 +1741,8 @@ restart:
 
                /*  Process requests that may be recovered */
                if (cqr->status == DASD_CQR_NEED_ERP) {
-                       if (cqr->irb.esw.esw0.erw.cons &&
-                           test_bit(DASD_CQR_FLAGS_USE_ERP,
-                                    &cqr->flags)) {
-                               erp_fn = base->discipline->erp_action(cqr);
-                               erp_fn(cqr);
-                       }
+                       erp_fn = base->discipline->erp_action(cqr);
+                       erp_fn(cqr);
                        goto restart;
                }
 

diff --git a/drivers/s390/block/dasd_3990_erp.c b/drivers/s390/block/dasd_3990_erp.c
index c361ab69ec0023c3eae201d50b4d10a2acb6b595..f69714a0e9e7bf3ed750e3b497ce429d2f459ffb 100644 (file)
--- a/drivers/s390/block/dasd_3990_erp.c
+++ b/drivers/s390/block/dasd_3990_erp.c
@@ -164,7 +164,7 @@ dasd_3990_erp_alternate_path(struct dasd_ccw_req * erp)
 
                /* reset status to submit the request again... */
                erp->status = DASD_CQR_FILLED;
-               erp->retries = 1;
+               erp->retries = 10;
        } else {
                DEV_MESSAGE(KERN_ERR, device,
                            "No alternate channel path left (lpum=%x / "
@@ -301,8 +301,7 @@ dasd_3990_erp_action_4(struct dasd_ccw_req * erp, char *sense)
                erp->function = dasd_3990_erp_action_4;
 
        } else {
-
-               if (sense[25] == 0x1D) {        /* state change pending */
+               if (sense && (sense[25] == 0x1D)) { /* state change pending */
 
                        DEV_MESSAGE(KERN_INFO, device,
                                    "waiting for state change pending "
@@ -311,7 +310,7 @@ dasd_3990_erp_action_4(struct dasd_ccw_req * erp, char *sense)
 
                        dasd_3990_erp_block_queue(erp, 30*HZ);
 
-                } else if (sense[25] == 0x1E) {        /* busy */
+               } else if (sense && (sense[25] == 0x1E)) {      /* busy */
                        DEV_MESSAGE(KERN_INFO, device,
                                    "busy - redriving request later, "
                                    "%d retries left",
@@ -2119,6 +2118,34 @@ dasd_3990_erp_inspect_32(struct dasd_ccw_req * erp, char *sense)
  *****************************************************************************
  */
 
+/*
+ * DASD_3990_ERP_CONTROL_CHECK
+ *
+ * DESCRIPTION
+ *   Does a generic inspection if a control check occured and sets up
+ *   the related error recovery procedure
+ *
+ * PARAMETER
+ *   erp               pointer to the currently created default ERP
+ *
+ * RETURN VALUES
+ *   erp_filled                pointer to the erp
+ */
+
+static struct dasd_ccw_req *
+dasd_3990_erp_control_check(struct dasd_ccw_req *erp)
+{
+       struct dasd_device *device = erp->startdev;
+
+       if (erp->refers->irb.scsw.cstat & (SCHN_STAT_INTF_CTRL_CHK
+                                          | SCHN_STAT_CHN_CTRL_CHK)) {
+               DEV_MESSAGE(KERN_DEBUG, device, "%s",
+                           "channel or interface control check");
+               erp = dasd_3990_erp_action_4(erp, NULL);
+       }
+       return erp;
+}
+
 /*
  * DASD_3990_ERP_INSPECT
  *
@@ -2145,8 +2172,11 @@ dasd_3990_erp_inspect(struct dasd_ccw_req * erp)
        if (erp_new)
                return erp_new;
 
+       /* check if no concurrent sens is available */
+       if (!erp->refers->irb.esw.esw0.erw.cons)
+               erp_new = dasd_3990_erp_control_check(erp);
        /* distinguish between 24 and 32 byte sense data */
-       if (sense[27] & DASD_SENSE_BIT_0) {
+       else if (sense[27] & DASD_SENSE_BIT_0) {
 
                /* inspect the 24 byte sense data */
                erp_new = dasd_3990_erp_inspect_24(erp, sense);
@@ -2285,6 +2315,17 @@ dasd_3990_erp_error_match(struct dasd_ccw_req *cqr1, struct dasd_ccw_req *cqr2)
                //      return 0;       /* CCW doesn't match */
        }
 
+       if (cqr1->irb.esw.esw0.erw.cons != cqr2->irb.esw.esw0.erw.cons)
+               return 0;
+
+       if ((cqr1->irb.esw.esw0.erw.cons == 0) &&
+           (cqr2->irb.esw.esw0.erw.cons == 0)) {
+               if ((cqr1->irb.scsw.cstat & (SCHN_STAT_INTF_CTRL_CHK |
+                                            SCHN_STAT_CHN_CTRL_CHK)) ==
+                   (cqr2->irb.scsw.cstat & (SCHN_STAT_INTF_CTRL_CHK |
+                                            SCHN_STAT_CHN_CTRL_CHK)))
+                       return 1; /* match with ifcc*/
+       }
        /* check sense data; byte 0-2,25,27 */
        if (!((memcmp (cqr1->irb.ecw, cqr2->irb.ecw, 3) == 0) &&
              (cqr1->irb.ecw[27] == cqr2->irb.ecw[27]) &&
@@ -2560,17 +2601,6 @@ dasd_3990_erp_action(struct dasd_ccw_req * cqr)
 
                return cqr;
        }
-       /* check if sense data are available */
-       if (!cqr->irb.ecw) {
-               DEV_MESSAGE(KERN_DEBUG, device,
-                           "ERP called witout sense data avail ..."
-                           "request %p - NO ERP possible", cqr);
-
-               cqr->status = DASD_CQR_FAILED;
-
-               return cqr;
-
-       }
 
        /* check if error happened before */
        erp = dasd_3990_erp_in_erp(cqr);