userns: Simplify insert_extent

Consolidate the code to write to the new mapping at the end of the
function to remove the duplication.  Move the increase in the number
of mappings into insert_extent, keeping the logic together.

Just a small increase in readability and maintainability.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 1d0298870ee3..899c31060ff3 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -758,12 +758,7 @@ static bool mappings_overlap(struct uid_gid_map *new_map,
  */
 static int insert_extent(struct uid_gid_map *map, struct uid_gid_extent *extent)
 {
-        if (map->nr_extents < UID_GID_MAP_MAX_BASE_EXTENTS) {
-                map->extent[map->nr_extents].first = extent->first;
-                map->extent[map->nr_extents].lower_first = extent->lower_first;
-                map->extent[map->nr_extents].count = extent->count;
-                return 0;
-        }
+        struct uid_gid_extent *dest;
 
         if (map->nr_extents == UID_GID_MAP_MAX_BASE_EXTENTS) {
                 struct uid_gid_extent *forward;
@@ -784,9 +779,13 @@ static int insert_extent(struct uid_gid_map *map, struct uid_gid_extent *extent)
                 map->reverse = NULL;
         }
 
-        map->forward[map->nr_extents].first = extent->first;
-        map->forward[map->nr_extents].lower_first = extent->lower_first;
-        map->forward[map->nr_extents].count = extent->count;
+        if (map->nr_extents < UID_GID_MAP_MAX_BASE_EXTENTS)
+                dest = &map->extent[map->nr_extents];
+        else
+                dest = &map->forward[map->nr_extents];
+
+        *dest = *extent;
+        map->nr_extents++;
         return 0;
 }
 
@@ -968,8 +967,6 @@ static ssize_t map_write(struct file *file, const char __user *buf,
                 if (ret < 0)
                         goto out;
                 ret = -EINVAL;
-
-                new_map.nr_extents++;
         }
         /* Be very certaint the new map actually exists */
         if (new_map.nr_extents == 0)