1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d285a5481965..f3c636d23718 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -67,6 +67,7 @@
 #include <linux/compat.h>
 #include <linux/suspend.h>
 #include <linux/freezer.h>
+#include <linux/smp_lock.h>
 #include <linux/writeback.h>
 #include <linux/buffer_head.h>          /* for invalidate_bdev() */
 #include <linux/completion.h>
@@ -1408,9 +1409,11 @@ static int lo_open(struct block_device *bdev, fmode_t mode)
 {
         struct loop_device *lo = bdev->bd_disk->private_data;
 
+        lock_kernel();
         mutex_lock(&lo->lo_ctl_mutex);
         lo->lo_refcnt++;
         mutex_unlock(&lo->lo_ctl_mutex);
+        unlock_kernel();
 
         return 0;
 }
@@ -1420,6 +1423,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
         struct loop_device *lo = disk->private_data;
         int err;
 
+        lock_kernel();
         mutex_lock(&lo->lo_ctl_mutex);
 
         if (--lo->lo_refcnt)
@@ -1444,6 +1448,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
 out:
         mutex_unlock(&lo->lo_ctl_mutex);
 out_unlocked:
+        lock_kernel();
         return 0;
 }