diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index d653218..e805c8f 100644
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -22,7 +22,6 @@
 #include <linux/chio.h>			/* here are all the ioctls */
 #include <linux/mutex.h>
 #include <linux/idr.h>
-#include <linux/smp_lock.h>
 #include <linux/slab.h>
 
 #include <scsi/scsi.h>
@@ -44,6 +43,7 @@
 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_CHANGER_MAJOR);
 MODULE_ALIAS_SCSI_DEVICE(TYPE_MEDIUM_CHANGER);
 
+static DEFINE_MUTEX(ch_mutex);
 static int init = 1;
 module_param(init, int, 0444);
 MODULE_PARM_DESC(init, \
@@ -581,19 +581,19 @@
 	scsi_changer *ch;
 	int minor = iminor(inode);
 
-	lock_kernel();
+	mutex_lock(&ch_mutex);
 	spin_lock(&ch_index_lock);
 	ch = idr_find(&ch_index_idr, minor);
 
 	if (NULL == ch || scsi_device_get(ch->device)) {
 		spin_unlock(&ch_index_lock);
-		unlock_kernel();
+		mutex_unlock(&ch_mutex);
 		return -ENXIO;
 	}
 	spin_unlock(&ch_index_lock);
 
 	file->private_data = ch;
-	unlock_kernel();
+	mutex_unlock(&ch_mutex);
 	return 0;
 }