s390/dasd: make number of retries configurable

Instead of having the number of retries hard-coded in the various
functions we should be using a default retry value, which can
be modified via sysfs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

5 files changed, 57 insertions, 6 deletions

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index a71bb8aaca1d..bc3e7afac18b 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -1240,6 +1240,46 @@ dasd_expires_store(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(expires, 0644, dasd_expires_show, dasd_expires_store);
 
+static ssize_t
+dasd_retries_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct dasd_device *device;
+        int len;
+
+        device = dasd_device_from_cdev(to_ccwdev(dev));
+        if (IS_ERR(device))
+                return -ENODEV;
+        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_retries);
+        dasd_put_device(device);
+        return len;
+}
+
+static ssize_t
+dasd_retries_store(struct device *dev, struct device_attribute *attr,
+                   const char *buf, size_t count)
+{
+        struct dasd_device *device;
+        unsigned long val;
+
+        device = dasd_device_from_cdev(to_ccwdev(dev));
+        if (IS_ERR(device))
+                return -ENODEV;
+
+        if ((strict_strtoul(buf, 10, &val) != 0) ||
+            (val > DASD_RETRIES_MAX)) {
+                dasd_put_device(device);
+                return -EINVAL;
+        }
+
+        if (val)
+                device->default_retries = val;
+
+        dasd_put_device(device);
+        return count;
+}
+
+static DEVICE_ATTR(retries, 0644, dasd_retries_show, dasd_retries_store);
+
 static ssize_t dasd_reservation_policy_show(struct device *dev,
                                             struct device_attribute *attr,
                                             char *buf)
@@ -1350,6 +1390,7 @@ static struct attribute * dasd_attrs[] = {
         &dev_attr_erplog.attr,
         &dev_attr_failfast.attr,
         &dev_attr_expires.attr,
+        &dev_attr_retries.attr,
         &dev_attr_reservation_policy.attr,
         &dev_attr_last_known_reservation_state.attr,
         &dev_attr_safe_offline.attr,
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index cc0603358522..154842242c3d 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -359,6 +359,7 @@ dasd_diag_check_device(struct dasd_device *device)
         }
 
         device->default_expires = DIAG_TIMEOUT;
+        device->default_retries = DIAG_MAX_RETRIES;
 
         /* Figure out position of label block */
         switch (private->rdc_data.vdev_class) {
@@ -555,7 +556,7 @@ static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
                         recid++;
                 }
         }
-        cqr->retries = DIAG_MAX_RETRIES;
+        cqr->retries = memdev->default_retries;
         cqr->buildclk = get_tod_clock();
         if (blk_noretry_request(req) ||
             block->base->features & DASD_FEATURE_FAILFAST)
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 696735962938..05f5694c9c49 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -1682,6 +1682,9 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 
         /* set default timeout */
         device->default_expires = DASD_EXPIRES;
+        /* set default retry count */
+        device->default_retries = DASD_RETRIES;
+
         if (private->gneq) {
                 value = 1;
                 for (i = 0; i < private->gneq->timeout.value; i++)
@@ -2659,7 +2662,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
         cqr->block = block;
         cqr->expires = startdev->default_expires * HZ;  /* default 5 minutes */
         cqr->lpm = startdev->path_data.ppm;
-        cqr->retries = 256;
+        cqr->retries = startdev->default_retries;
         cqr->buildclk = get_tod_clock();
         cqr->status = DASD_CQR_FILLED;
         return cqr;
@@ -2834,7 +2837,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track(
         cqr->block = block;
         cqr->expires = startdev->default_expires * HZ;  /* default 5 minutes */
         cqr->lpm = startdev->path_data.ppm;
-        cqr->retries = 256;
+        cqr->retries = startdev->default_retries;
         cqr->buildclk = get_tod_clock();
         cqr->status = DASD_CQR_FILLED;
         return cqr;
@@ -3127,7 +3130,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_track(
         cqr->block = block;
         cqr->expires = startdev->default_expires * HZ;  /* default 5 minutes */
         cqr->lpm = startdev->path_data.ppm;
-        cqr->retries = 256;
+        cqr->retries = startdev->default_retries;
         cqr->buildclk = get_tod_clock();
         cqr->status = DASD_CQR_FILLED;
         return cqr;
@@ -3330,7 +3333,7 @@ static struct dasd_ccw_req *dasd_raw_build_cp(struct dasd_device *startdev,
         cqr->block = block;
         cqr->expires = startdev->default_expires * HZ;
         cqr->lpm = startdev->path_data.ppm;
-        cqr->retries = 256;
+        cqr->retries = startdev->default_retries;
         cqr->buildclk = get_tod_clock();
         cqr->status = DASD_CQR_FILLED;
 
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index 4dd0e2f6047e..d232c83ea95a 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -29,6 +29,8 @@
 #endif                          /* PRINTK_HEADER */
 #define PRINTK_HEADER "dasd(fba):"
 
+#define FBA_DEFAULT_RETRIES 32
+
 #define DASD_FBA_CCW_WRITE 0x41
 #define DASD_FBA_CCW_READ 0x42
 #define DASD_FBA_CCW_LOCATE 0x43
@@ -167,6 +169,7 @@ dasd_fba_check_characteristics(struct dasd_device *device)
         }
 
         device->default_expires = DASD_EXPIRES;
+        device->default_retries = FBA_DEFAULT_RETRIES;
         device->path_data.opm = LPM_ANYPATH;
 
         readonly = dasd_device_is_ro(device);
@@ -369,7 +372,7 @@ static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
         cqr->memdev = memdev;
         cqr->block = block;
         cqr->expires = memdev->default_expires * HZ;    /* default 5 minutes */
-        cqr->retries = 32;
+        cqr->retries = memdev->default_retries;
         cqr->buildclk = get_tod_clock();
         cqr->status = DASD_CQR_FILLED;
         return cqr;
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 0785bd9bd5b6..ad42075868c7 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -224,6 +224,8 @@ struct dasd_ccw_req {
 /* default expiration time*/
 #define DASD_EXPIRES      300
 #define DASD_EXPIRES_MAX  40000000
+#define DASD_RETRIES      256
+#define DASD_RETRIES_MAX  32768
 
 /* per dasd_ccw_req flags */
 #define DASD_CQR_FLAGS_USE_ERP   0      /* use ERP for this request */
@@ -466,6 +468,7 @@ struct dasd_device {
 
         /* default expiration time in s */
         unsigned long default_expires;
+        unsigned long default_retries;
 
         struct dentry *debugfs_dentry;
         struct dasd_profile profile;