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path: root/drivers/scsi/scsi_sysfs.c
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Diffstat (limited to 'drivers/scsi/scsi_sysfs.c')
-rw-r--r--drivers/scsi/scsi_sysfs.c90
1 files changed, 85 insertions, 5 deletions
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index c8115b4fe..00bc7218a 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -17,6 +17,7 @@
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_dh.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_driver.h>
@@ -760,11 +761,15 @@ show_vpd_##_page(struct file *filp, struct kobject *kobj, \
{ \
struct device *dev = container_of(kobj, struct device, kobj); \
struct scsi_device *sdev = to_scsi_device(dev); \
+ int ret; \
if (!sdev->vpd_##_page) \
return -EINVAL; \
- return memory_read_from_buffer(buf, count, &off, \
- sdev->vpd_##_page, \
+ rcu_read_lock(); \
+ ret = memory_read_from_buffer(buf, count, &off, \
+ rcu_dereference(sdev->vpd_##_page), \
sdev->vpd_##_page##_len); \
+ rcu_read_unlock(); \
+ return ret; \
} \
static struct bin_attribute dev_attr_vpd_##_page = { \
.attr = {.name = __stringify(vpd_##_page), .mode = S_IRUGO }, \
@@ -901,6 +906,76 @@ static DEVICE_ATTR(queue_depth, S_IRUGO | S_IWUSR, sdev_show_queue_depth,
sdev_store_queue_depth);
static ssize_t
+sdev_show_wwid(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ ssize_t count;
+
+ count = scsi_vpd_lun_id(sdev, buf, PAGE_SIZE);
+ if (count > 0) {
+ buf[count] = '\n';
+ count++;
+ }
+ return count;
+}
+static DEVICE_ATTR(wwid, S_IRUGO, sdev_show_wwid, NULL);
+
+#ifdef CONFIG_SCSI_DH
+static ssize_t
+sdev_show_dh_state(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+
+ if (!sdev->handler)
+ return snprintf(buf, 20, "detached\n");
+
+ return snprintf(buf, 20, "%s\n", sdev->handler->name);
+}
+
+static ssize_t
+sdev_store_dh_state(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ int err = -EINVAL;
+
+ if (sdev->sdev_state == SDEV_CANCEL ||
+ sdev->sdev_state == SDEV_DEL)
+ return -ENODEV;
+
+ if (!sdev->handler) {
+ /*
+ * Attach to a device handler
+ */
+ err = scsi_dh_attach(sdev->request_queue, buf);
+ } else if (!strncmp(buf, "activate", 8)) {
+ /*
+ * Activate a device handler
+ */
+ if (sdev->handler->activate)
+ err = sdev->handler->activate(sdev, NULL, NULL);
+ else
+ err = 0;
+ } else if (!strncmp(buf, "detach", 6)) {
+ /*
+ * Detach from a device handler
+ */
+ sdev_printk(KERN_WARNING, sdev,
+ "can't detach handler %s.\n",
+ sdev->handler->name);
+ err = -EINVAL;
+ }
+
+ return err < 0 ? err : count;
+}
+
+static DEVICE_ATTR(dh_state, S_IRUGO | S_IWUSR, sdev_show_dh_state,
+ sdev_store_dh_state);
+#endif
+
+static ssize_t
sdev_show_queue_ramp_up_period(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -969,6 +1044,10 @@ static struct attribute *scsi_sdev_attrs[] = {
&dev_attr_modalias.attr,
&dev_attr_queue_depth.attr,
&dev_attr_queue_type.attr,
+ &dev_attr_wwid.attr,
+#ifdef CONFIG_SCSI_DH
+ &dev_attr_dh_state.attr,
+#endif
&dev_attr_queue_ramp_up_period.attr,
REF_EVT(media_change),
REF_EVT(inquiry_change_reported),
@@ -1058,11 +1137,12 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
}
error = scsi_dh_add_device(sdev);
- if (error) {
+ if (error)
+ /*
+ * device_handler is optional, so any error can be ignored
+ */
sdev_printk(KERN_INFO, sdev,
"failed to add device handler: %d\n", error);
- return error;
- }
device_enable_async_suspend(&sdev->sdev_dev);
error = device_add(&sdev->sdev_dev);