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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.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 158f1b553acf..fc3cd2656059 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>
@@ -904,6 +905,60 @@ sdev_show_function(queue_depth, "%d\n");
static DEVICE_ATTR(queue_depth, S_IRUGO | S_IWUSR, sdev_show_queue_depth,
sdev_store_queue_depth);
+#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,
@@ -973,6 +1028,9 @@ static struct attribute *scsi_sdev_attrs[] = {
&dev_attr_modalias.attr,
&dev_attr_queue_depth.attr,
&dev_attr_queue_type.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),