1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 9119cd3d56a4..91374282755d 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -41,6 +41,7 @@
 #include <linux/cdrom.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/smp_lock.h>
 #include <linux/scatterlist.h>
 
 #include <xen/xen.h>
@@ -1018,13 +1019,18 @@ static int blkfront_is_ready(struct xenbus_device *dev)
 static int blkif_open(struct block_device *bdev, fmode_t mode)
 {
         struct blkfront_info *info = bdev->bd_disk->private_data;
+
+        lock_kernel();
         info->users++;
+        unlock_kernel();
+
         return 0;
 }
 
 static int blkif_release(struct gendisk *disk, fmode_t mode)
 {
         struct blkfront_info *info = disk->private_data;
+        lock_kernel();
         info->users--;
         if (info->users == 0) {
                 /* Check whether we have been instructed to close.  We will
@@ -1036,6 +1042,7 @@ static int blkif_release(struct gendisk *disk, fmode_t mode)
                 if (state == XenbusStateClosing && info->is_ready)
                         blkfront_closing(dev);
         }
+        unlock_kernel();
         return 0;
 }