1 files changed, 6 insertions, 1 deletions

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index da992a3ad6b7..1bcd208c459f 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -33,6 +33,7 @@
 #include "linux/mm.h"
 #include "linux/slab.h"
 #include "linux/vmalloc.h"
+#include "linux/smp_lock.h"
 #include "linux/blkpg.h"
 #include "linux/genhd.h"
 #include "linux/spinlock.h"
@@ -1098,6 +1099,7 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
         struct ubd *ubd_dev = disk->private_data;
         int err = 0;
 
+        lock_kernel();
         if(ubd_dev->count == 0){
                 err = ubd_open_dev(ubd_dev);
                 if(err){
@@ -1115,7 +1117,8 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
                 if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev);
                 err = -EROFS;
         }*/
- out:
+out:
+        unlock_kernel();
         return err;
 }
 
@@ -1123,8 +1126,10 @@ static int ubd_release(struct gendisk *disk, fmode_t mode)
 {
         struct ubd *ubd_dev = disk->private_data;
 
+        lock_kernel();
         if(--ubd_dev->count == 0)
                 ubd_close_dev(ubd_dev);
+        unlock_kernel();
         return 0;
 }