[S390] dasd: Add support for raw ECKD access.
Normal I/O operations through the DASD device driver give only access
to the data fields of an ECKD device even for track based I/O.
This patch extends the DASD device driver to give access to whole
ECKD tracks including count, key and data fields.
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_devmap.c b/drivers/s390/block/dasd_devmap.c
index 47fc886..cb6a67b 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -208,6 +208,8 @@
features |= DASD_FEATURE_READONLY;
else if (len == 4 && !strncmp(str, "diag", 4))
features |= DASD_FEATURE_USEDIAG;
+ else if (len == 3 && !strncmp(str, "raw", 3))
+ features |= DASD_FEATURE_USERAW;
else if (len == 6 && !strncmp(str, "erplog", 6))
features |= DASD_FEATURE_ERPLOG;
else if (len == 8 && !strncmp(str, "failfast", 8))
@@ -857,7 +859,7 @@
spin_lock(&dasd_devmap_lock);
/* Changing diag discipline flag is only allowed in offline state. */
rc = count;
- if (!devmap->device) {
+ if (!devmap->device && !(devmap->features & DASD_FEATURE_USERAW)) {
if (val)
devmap->features |= DASD_FEATURE_USEDIAG;
else
@@ -870,6 +872,56 @@
static DEVICE_ATTR(use_diag, 0644, dasd_use_diag_show, dasd_use_diag_store);
+/*
+ * use_raw controls whether the driver should give access to raw eckd data or
+ * operate in standard mode
+ */
+static ssize_t
+dasd_use_raw_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct dasd_devmap *devmap;
+ int use_raw;
+
+ devmap = dasd_find_busid(dev_name(dev));
+ if (!IS_ERR(devmap))
+ use_raw = (devmap->features & DASD_FEATURE_USERAW) != 0;
+ else
+ use_raw = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USERAW) != 0;
+ return sprintf(buf, use_raw ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_use_raw_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct dasd_devmap *devmap;
+ ssize_t rc;
+ unsigned long val;
+
+ devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+ if (IS_ERR(devmap))
+ return PTR_ERR(devmap);
+
+ if ((strict_strtoul(buf, 10, &val) != 0) || val > 1)
+ return -EINVAL;
+
+ spin_lock(&dasd_devmap_lock);
+ /* Changing diag discipline flag is only allowed in offline state. */
+ rc = count;
+ if (!devmap->device && !(devmap->features & DASD_FEATURE_USEDIAG)) {
+ if (val)
+ devmap->features |= DASD_FEATURE_USERAW;
+ else
+ devmap->features &= ~DASD_FEATURE_USERAW;
+ } else
+ rc = -EPERM;
+ spin_unlock(&dasd_devmap_lock);
+ return rc;
+}
+
+static DEVICE_ATTR(raw_track_access, 0644, dasd_use_raw_show,
+ dasd_use_raw_store);
+
static ssize_t
dasd_discipline_show(struct device *dev, struct device_attribute *attr,
char *buf)
@@ -1232,6 +1284,7 @@
&dev_attr_vendor.attr,
&dev_attr_uid.attr,
&dev_attr_use_diag.attr,
+ &dev_attr_raw_track_access.attr,
&dev_attr_eer_enabled.attr,
&dev_attr_erplog.attr,
&dev_attr_failfast.attr,