2 files changed, 26 insertions, 4 deletions

diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c
index a7ffdfe19fc9..f6832f46aea4 100644
--- a/drivers/xen/gntalloc.c
+++ b/drivers/xen/gntalloc.c
@@ -427,6 +427,17 @@ static long gntalloc_ioctl(struct file *filp, unsigned int cmd,
         return 0;
 }
 
+static void gntalloc_vma_open(struct vm_area_struct *vma)
+{
+        struct gntalloc_gref *gref = vma->vm_private_data;
+        if (!gref)
+                return;
+
+        spin_lock(&gref_lock);
+        gref->users++;
+        spin_unlock(&gref_lock);
+}
+
 static void gntalloc_vma_close(struct vm_area_struct *vma)
 {
         struct gntalloc_gref *gref = vma->vm_private_data;
@@ -441,6 +452,7 @@ static void gntalloc_vma_close(struct vm_area_struct *vma)
 }
 
 static struct vm_operations_struct gntalloc_vmops = {
+        .open = gntalloc_vma_open,
         .close = gntalloc_vma_close,
 };
 
@@ -471,8 +483,6 @@ static int gntalloc_mmap(struct file *filp, struct vm_area_struct *vma)
         vma->vm_private_data = gref;
 
         vma->vm_flags |= VM_RESERVED;
-        vma->vm_flags |= VM_DONTCOPY;
-        vma->vm_flags |= VM_PFNMAP | VM_PFN_AT_MMAP;
 
         vma->vm_ops = &gntalloc_vmops;
 
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index d96d311b858e..687761f65e5c 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -358,17 +358,26 @@ 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,
 };
 
@@ -680,7 +689,10 @@ 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;