xen/gntdev: Fix off-by-one error when unmapping with holes

If the requested range has a hole, the calculation of the number of
pages to unmap is off by one. Fix it.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 57efbd3b053b..d3391a1e3796 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -380,10 +380,8 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
                 }
                 range = 0;
                 while (range < pages) {
-                        if (map->unmap_ops[offset+range].handle == -1) {
-                                range--;
+                        if (map->unmap_ops[offset+range].handle == -1)
                                 break;
-                        }
                         range++;
                 }
                 err = __unmap_grant_pages(map, offset, range);