[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, 41 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 1629b27c48ab..f576f243cd93 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -715,10 +715,51 @@ dasd_discipline_show(struct device *dev, struct device_attribute *attr, char *bu
 
 static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);
 
+/*
+ * extended error-reporting
+ */
+static ssize_t
+dasd_eer_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct dasd_devmap *devmap;
+        int eer_flag;
+
+        devmap = dasd_find_busid(dev->bus_id);
+        if (!IS_ERR(devmap) && devmap->device)
+                eer_flag = dasd_eer_enabled(devmap->device);
+        else
+                eer_flag = 0;
+        return snprintf(buf, PAGE_SIZE, eer_flag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_eer_store(struct device *dev, struct device_attribute *attr,
+               const char *buf, size_t count)
+{
+        struct dasd_devmap *devmap;
+        int rc;
+
+        devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+        if (IS_ERR(devmap))
+                return PTR_ERR(devmap);
+        if (!devmap->device)
+                return count;
+        if (buf[0] == '1') {
+                rc = dasd_eer_enable(devmap->device);
+                if (rc)
+                        return rc;
+        } else
+                dasd_eer_disable(devmap->device);
+        return count;
+}
+
+static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);
+
 static struct attribute * dasd_attrs[] = {
         &dev_attr_readonly.attr,
         &dev_attr_discipline.attr,
         &dev_attr_use_diag.attr,
+        &dev_attr_eer_enabled.attr,
         NULL,
 };