1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c
index 83ae9a852f00..61549987ed70 100644
--- a/drivers/s390/char/vmur.c
+++ b/drivers/s390/char/vmur.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/cdev.h>
+#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/cio.h>
@@ -668,7 +669,7 @@ static int ur_open(struct inode *inode, struct file *file)
 
         if (accmode == O_RDWR)
                 return -EACCES;
-
+        lock_kernel();
         /*
          * We treat the minor number as the devno of the ur device
          * to find in the driver tree.
@@ -676,8 +677,10 @@ static int ur_open(struct inode *inode, struct file *file)
         devno = MINOR(file->f_dentry->d_inode->i_rdev);
 
         urd = urdev_get_from_devno(devno);
-        if (!urd)
-                return -ENXIO;
+        if (!urd) {
+                rc = -ENXIO;
+                goto out;
+        }
 
         spin_lock(&urd->open_lock);
         while (urd->open_flag) {
@@ -720,6 +723,7 @@ static int ur_open(struct inode *inode, struct file *file)
                 goto fail_urfile_free;
         urf->file_reclen = rc;
         file->private_data = urf;
+        unlock_kernel();
         return 0;
 
 fail_urfile_free:
@@ -730,6 +734,8 @@ fail_unlock:
         spin_unlock(&urd->open_lock);
 fail_put:
         urdev_put(urd);
+out:
+        unlock_kernel();
         return rc;
 }