Add an 'access_state' field to struct scsi_device
and display them in sysfs as 'access_state' and
'preferred_path' attribute.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/scsi/scsi_sysfs.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++
include/scsi/scsi_device.h | 1 +
include/scsi/scsi_proto.h | 12 ++++++++
3 files changed, 87 insertions(+)
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 7e57800..c5ac171 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -81,6 +81,33 @@ const char *scsi_host_state_name(enum scsi_host_state state)
return name;
}
+static const struct {
+ unsigned char value;
+ char *name;
+} sdev_access_states[] = {
+ { SCSI_ACCESS_STATE_OPTIMAL, "active/optimized" },
+ { SCSI_ACCESS_STATE_ACTIVE, "active/non-optimized" },
+ { SCSI_ACCESS_STATE_STANDBY, "standby" },
+ { SCSI_ACCESS_STATE_UNAVAILABLE, "unavailable" },
+ { SCSI_ACCESS_STATE_LBA, "lba-dependent" },
+ { SCSI_ACCESS_STATE_OFFLINE, "offline" },
+ { SCSI_ACCESS_STATE_TRANSITIONING, "transitioning" },
+};
+
+const char *scsi_access_state_name(unsigned char state)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(sdev_access_states); i++) {
+ if (sdev_access_states[i].value == state) {
+ name = sdev_access_states[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
static int check_set(unsigned long long *val, char *src)
{
char *last;
@@ -973,6 +1000,43 @@ sdev_store_dh_state(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR(dh_state, S_IRUGO | S_IWUSR, sdev_show_dh_state,
sdev_store_dh_state);
+
+static ssize_t
+sdev_show_access_state(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ unsigned char access_state;
+ const char *access_state_name;
+
+ if (!sdev->handler)
+ return -EINVAL;
+
+ access_state = (sdev->access_state & SCSI_ACCESS_STATE_MASK);
+ access_state_name = scsi_access_state_name(access_state);
+
+ return sprintf(buf, "%s\n",
+ access_state_name ? access_state_name : "unknown");
+}
+static DEVICE_ATTR(access_state, S_IRUGO, sdev_show_access_state, NULL);
+
+static ssize_t
+sdev_show_preferred_path(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+
+ if (!sdev->handler)
+ return -EINVAL;
+
+ if (sdev->access_state & SCSI_ACCESS_STATE_PREFERRED)
+ return sprintf(buf, "1\n");
+ else
+ return sprintf(buf, "0\n");
+}
+static DEVICE_ATTR(preferred_path, S_IRUGO, sdev_show_preferred_path, NULL);
#endif
static ssize_t
@@ -1020,6 +1084,14 @@ static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
!sdev->host->hostt->change_queue_depth)
return 0;
+#ifdef CONFIG_SCSI_DH
+ if (attr == &dev_attr_access_state.attr &&
+ !sdev->handler)
+ return 0;
+ if (attr == &dev_attr_preferred_path.attr &&
+ !sdev->handler)
+ return 0;
+#endif
return attr->mode;
}
@@ -1063,6 +1135,8 @@ static struct attribute *scsi_sdev_attrs[] = {
&dev_attr_wwid.attr,
#ifdef CONFIG_SCSI_DH
&dev_attr_dh_state.attr,
+ &dev_attr_access_state.attr,
+ &dev_attr_preferred_path.attr,
#endif
&dev_attr_queue_ramp_up_period.attr,
REF_EVT(media_change),
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 4af2b24..c067019 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -201,6 +201,7 @@ struct scsi_device {
struct scsi_device_handler *handler;
void *handler_data;
+ unsigned char access_state;
enum scsi_device_state sdev_state;
unsigned long sdev_data[0];
} __attribute__((aligned(sizeof(unsigned long))));
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index a9fbf1b..c2ae21c 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -277,5 +277,17 @@ struct scsi_lun {
__u8 scsi_lun[8];
};
+/* SPC asymmetric access states */
+#define SCSI_ACCESS_STATE_OPTIMAL 0x00
+#define SCSI_ACCESS_STATE_ACTIVE 0x01
+#define SCSI_ACCESS_STATE_STANDBY 0x02
+#define SCSI_ACCESS_STATE_UNAVAILABLE 0x03
+#define SCSI_ACCESS_STATE_LBA 0x04
+#define SCSI_ACCESS_STATE_OFFLINE 0x0e
+#define SCSI_ACCESS_STATE_TRANSITIONING 0x0f
+
+/* Values for REPORT TARGET GROUP STATES */
+#define SCSI_ACCESS_STATE_MASK 0x0f
+#define SCSI_ACCESS_STATE_PREFERRED 0x80
#endif /* _SCSI_PROTO_H_ */
--
1.8.5.6
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