1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index b0f9e8fb0052..f914b26cf0c2 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -330,17 +330,26 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
 
 /* ------------------------------------------------------------------ */
 
+static void gntdev_vma_open(struct vm_area_struct *vma)
+{
+        struct grant_map *map = vma->vm_private_data;
+
+        pr_debug("gntdev_vma_open %p\n", vma);
+        atomic_inc(&map->users);
+}
+
 static void gntdev_vma_close(struct vm_area_struct *vma)
 {
         struct grant_map *map = vma->vm_private_data;
 
-        pr_debug("close %p\n", vma);
+        pr_debug("gntdev_vma_close %p\n", vma);
         map->vma = NULL;
         vma->vm_private_data = NULL;
         gntdev_put_map(map);
 }
 
 static struct vm_operations_struct gntdev_vmops = {
+        .open = gntdev_vma_open,
         .close = gntdev_vma_close,
 };
 
@@ -652,7 +661,10 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
 
         vma->vm_ops = &gntdev_vmops;
 
-        vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|VM_DONTEXPAND|VM_PFNMAP;
+        vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND;
+
+        if (use_ptemod)
+                vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP;
 
         vma->vm_private_data = map;