scsi_dh: move 'dh_state' sysfs attribute to generic code

As scsi_dh.c is now always compiled in we should be moving
the 'dh_state' attribute to the generic code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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),