From: Stefan Haberland <sth@linux.vnet.ibm.com>
Date: Tue, 19 Dec 2017 16:18:38 +0100
Subject: [PATCH] s390/dasd: configurable IFCC handling
References: bsc#1097808, FATE#326362
Git-commit: ddc1c9453550eabd6284021b167f708982df3ca9
Patch-mainline: v4.17-rc1
Make the behavior in case of constant IFCC/CCC errors configurable.
Add a sysfs attribute to switch between path disabled after threshold
exceeded (default) and message only.
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
arch/s390/include/uapi/asm/dasd.h | 38 +++++++++++++++++----------------
drivers/s390/block/dasd_3990_erp.c | 17 +++++++++++++--
drivers/s390/block/dasd_devmap.c | 43 +++++++++++++++++++++++++++++++++++++-
3 files changed, 77 insertions(+), 21 deletions(-)
diff --git a/arch/s390/include/uapi/asm/dasd.h b/arch/s390/include/uapi/asm/dasd.h
index ab5797cdc1b7..8615d8e13360 100644
--- a/arch/s390/include/uapi/asm/dasd.h
+++ b/arch/s390/include/uapi/asm/dasd.h
@@ -67,25 +67,27 @@ typedef struct dasd_information2_t {
#define DASD_FORMAT_CDL 2
/*
* values to be used for dasd_information_t.features
- * 0x00: default features
- * 0x01: readonly (ro)
- * 0x02: use diag discipline (diag)
- * 0x04: set the device initially online (internal use only)
- * 0x08: enable ERP related logging
- * 0x10: allow I/O to fail on lost paths
- * 0x20: allow I/O to fail when a lock was stolen
- * 0x40: give access to raw eckd data
- * 0x80: enable discard support
+ * 0x100: default features
+ * 0x001: readonly (ro)
+ * 0x002: use diag discipline (diag)
+ * 0x004: set the device initially online (internal use only)
+ * 0x008: enable ERP related logging
+ * 0x010: allow I/O to fail on lost paths
+ * 0x020: allow I/O to fail when a lock was stolen
+ * 0x040: give access to raw eckd data
+ * 0x080: enable discard support
+ * 0x100: enable autodisable for IFCC errors (default)
*/
-#define DASD_FEATURE_DEFAULT 0x00
-#define DASD_FEATURE_READONLY 0x01
-#define DASD_FEATURE_USEDIAG 0x02
-#define DASD_FEATURE_INITIAL_ONLINE 0x04
-#define DASD_FEATURE_ERPLOG 0x08
-#define DASD_FEATURE_FAILFAST 0x10
-#define DASD_FEATURE_FAILONSLCK 0x20
-#define DASD_FEATURE_USERAW 0x40
-#define DASD_FEATURE_DISCARD 0x80
+#define DASD_FEATURE_READONLY 0x001
+#define DASD_FEATURE_USEDIAG 0x002
+#define DASD_FEATURE_INITIAL_ONLINE 0x004
+#define DASD_FEATURE_ERPLOG 0x008
+#define DASD_FEATURE_FAILFAST 0x010
+#define DASD_FEATURE_FAILONSLCK 0x020
+#define DASD_FEATURE_USERAW 0x040
+#define DASD_FEATURE_DISCARD 0x080
+#define DASD_FEATURE_PATH_AUTODISABLE 0x100
+#define DASD_FEATURE_DEFAULT DASD_FEATURE_PATH_AUTODISABLE
#define DASD_PARTN_BITS 2
diff --git a/drivers/s390/block/dasd_3990_erp.c b/drivers/s390/block/dasd_3990_erp.c
index 6d26ad3ac406..c53ad9f2ba25 100644
--- a/drivers/s390/block/dasd_3990_erp.c
+++ b/drivers/s390/block/dasd_3990_erp.c
@@ -2213,15 +2213,28 @@ static void dasd_3990_erp_disable_path(struct dasd_device *device, __u8 lpum)
{
int pos = pathmask_to_pos(lpum);
+ if (!(device->features & DASD_FEATURE_PATH_AUTODISABLE)) {
+ dev_err(&device->cdev->dev,
+ "Path %x.%02x (pathmask %02x) is operational despite excessive IFCCs\n",
+ device->path[pos].cssid, device->path[pos].chpid, lpum);
+ goto out;
+ }
+
/* no remaining path, cannot disable */
- if (!(dasd_path_get_opm(device) & ~lpum))
- return;
+ if (!(dasd_path_get_opm(device) & ~lpum)) {
+ dev_err(&device->cdev->dev,
+ "Last path %x.%02x (pathmask %02x) is operational despite excessive IFCCs\n",
+ device->path[pos].cssid, device->path[pos].chpid, lpum);
+ goto out;
+ }
dev_err(&device->cdev->dev,
"Path %x.%02x (pathmask %02x) is disabled - IFCC threshold exceeded\n",
device->path[pos].cssid, device->path[pos].chpid, lpum);
dasd_path_remove_opm(device, lpum);
dasd_path_add_ifccpm(device, lpum);
+
+out:
device->path[pos].errorclk = 0;
atomic_set(&device->path[pos].error_count, 0);
}
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index f407be1a311e..3041abb8b0a7 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -1528,9 +1528,49 @@ dasd_path_threshold_store(struct device *dev, struct device_attribute *attr,
dasd_put_device(device);
return count;
}
-
static DEVICE_ATTR(path_threshold, 0644, dasd_path_threshold_show,
dasd_path_threshold_store);
+
+/*
+ * configure if path is disabled after IFCC/CCC error threshold is
+ * exceeded
+ */
+static ssize_t
+dasd_path_autodisable_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dasd_devmap *devmap;
+ int flag;
+
+ devmap = dasd_find_busid(dev_name(dev));
+ if (!IS_ERR(devmap))
+ flag = (devmap->features & DASD_FEATURE_PATH_AUTODISABLE) != 0;
+ else
+ flag = (DASD_FEATURE_DEFAULT &
+ DASD_FEATURE_PATH_AUTODISABLE) != 0;
+ return snprintf(buf, PAGE_SIZE, flag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_path_autodisable_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned int val;
+ int rc;
+
+ if (kstrtouint(buf, 0, &val) || val > 1)
+ return -EINVAL;
+
+ rc = dasd_set_feature(to_ccwdev(dev),
+ DASD_FEATURE_PATH_AUTODISABLE, val);
+
+ return rc ? : count;
+}
+
+static DEVICE_ATTR(path_autodisable, 0644,
+ dasd_path_autodisable_show,
+ dasd_path_autodisable_store);
/*
* interval for IFCC/CCC checks
* meaning time with no IFCC/CCC error before the error counter
@@ -1601,6 +1641,7 @@ static struct attribute * dasd_attrs[] = {
&dev_attr_host_access_count.attr,
&dev_attr_path_masks.attr,
&dev_attr_path_threshold.attr,
+ &dev_attr_path_autodisable.attr,
&dev_attr_path_interval.attr,
&dev_attr_path_reset.attr,
&dev_attr_hpf.attr,
--
2.12.3