1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index c4b938bc30d3..aa2011b64683 100644
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -22,6 +22,7 @@
 #include <linux/chio.h>                 /* here are all the ioctls */
 #include <linux/mutex.h>
 #include <linux/idr.h>
+#include <linux/smp_lock.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -571,16 +572,19 @@ ch_open(struct inode *inode, struct file *file)
         scsi_changer *ch;
         int minor = iminor(inode);
 
+        lock_kernel();
         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();
                 return -ENXIO;
         }
         spin_unlock(&ch_index_lock);
 
         file->private_data = ch;
+        unlock_kernel();
         return 0;
 }