1 files changed, 15 insertions, 11 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 57390c7666e5..b0b02a501167 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -492,12 +492,19 @@ static bool in_range(struct gntdev_grant_map *map,
         return true;
 }
 
-static void unmap_if_in_range(struct gntdev_grant_map *map,
-                              unsigned long start, unsigned long end)
+static int unmap_if_in_range(struct gntdev_grant_map *map,
+                              unsigned long start, unsigned long end,
+                              bool blockable)
 {
         unsigned long mstart, mend;
         int err;
 
+        if (!in_range(map, start, end))
+                return 0;
+
+        if (!blockable)
+                return -EAGAIN;
+
         mstart = max(start, map->vma->vm_start);
         mend   = min(end,   map->vma->vm_end);
         pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
@@ -508,6 +515,8 @@ static void unmap_if_in_range(struct gntdev_grant_map *map,
                                 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
                                 (mend - mstart) >> PAGE_SHIFT);
         WARN_ON(err);
+
+        return 0;
 }
 
 static int mn_invl_range_start(struct mmu_notifier *mn,
@@ -519,25 +528,20 @@ static int mn_invl_range_start(struct mmu_notifier *mn,
         struct gntdev_grant_map *map;
         int ret = 0;
 
-        /* TODO do we really need a mutex here? */
         if (blockable)
                 mutex_lock(&priv->lock);
         else if (!mutex_trylock(&priv->lock))
                 return -EAGAIN;
 
         list_for_each_entry(map, &priv->maps, next) {
-                if (in_range(map, start, end)) {
-                        ret = -EAGAIN;
+                ret = unmap_if_in_range(map, start, end, blockable);
+                if (ret)
                         goto out_unlock;
-                }
-                unmap_if_in_range(map, start, end);
         }
         list_for_each_entry(map, &priv->freeable_maps, next) {
-                if (in_range(map, start, end)) {
-                        ret = -EAGAIN;
+                ret = unmap_if_in_range(map, start, end, blockable);
+                if (ret)
                         goto out_unlock;
-                }
-                unmap_if_in_range(map, start, end);
         }
 
 out_unlock: