userns: rename insert_extent() and sort_idmaps()

The KUnit test suite turned insert_extent() and sort_idmaps() into global
symbols and declared them in include/linux/user_namespace.h. That header
is pulled in nearly everywhere through linux/cgroup.h and the btrfs
self-tests carry a static insert_extent() of their own, so any config
with both test suites enabled fails to build:

  fs/btrfs/tests/inode-tests.c:16:13: error: conflicting types for 'insert_extent'
  include/linux/user_namespace.h:212:12: note: previous declaration of 'insert_extent'

A global symbol needs a prefix. Rename them to
uid_gid_map_insert_extent() and uid_gid_map_sort(). It's the better name
anyway.

No functional changes.

Fixes: f6f1a2496ba5 ("userns: Add KUnit test suite for uid_gid_map")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202609110843.okbPe7GM-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202609110937.zHKPPXJk-lkp@intel.com/
Link: https://patch.msgid.link/20260911-suggerieren-suchaktion-fliehen-87b9cdf1d169@brauner
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

2 files changed, 13 insertions, 12 deletions

diff --git a/kernel/tests/user_ns_map_kunit.c b/kernel/tests/user_ns_map_kunit.c
index 24c21e43a36c..033dccc6a535 100644
--- a/kernel/tests/user_ns_map_kunit.c
+++ b/kernel/tests/user_ns_map_kunit.c
@@ -24,7 +24,7 @@ static void user_ns_map_insert(struct kunit *test)
 		extent.lower_first = i * 100;
 		extent.count = 5;
 
-		ret = insert_extent(&map, &extent);
+		ret = uid_gid_map_insert_extent(&map, &extent);
 		KUNIT_ASSERT_EQ(test, ret, 0);
 	}
 
@@ -54,14 +54,14 @@ static void user_ns_map_insert_extended(struct kunit *test)
 		extent.lower_first = value * 100;
 		extent.count = 5;
 
-		ret = insert_extent(&map, &extent);
+		ret = uid_gid_map_insert_extent(&map, &extent);
 		KUNIT_ASSERT_EQ(test, ret, 0);
 	}
 
 	KUNIT_EXPECT_EQ(test, map.nr_extents, NR_EXTENTS);
 
 	/* Now sort the map to set up reverse mapping */
-	ret = sort_idmaps(&map);
+	ret = uid_gid_map_sort(&map);
 	KUNIT_ASSERT_EQ(test, ret, 0);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, map.reverse);
 
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index f9cbb4b92b48..98b0279b6cc6 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -780,12 +780,13 @@ static bool mappings_overlap(struct uid_gid_map *new_map,
 }
 
 /*
- * insert_extent - Safely insert a new idmap extent into struct uid_gid_map.
+ * uid_gid_map_insert_extent - Safely insert a new idmap extent into
+ * struct uid_gid_map.
  * Takes care to allocate a 4K block of memory if the number of mappings exceeds
  * UID_GID_MAP_MAX_BASE_EXTENTS.
  */
-VISIBLE_IF_KUNIT int insert_extent(struct uid_gid_map *map,
-				   struct uid_gid_extent *extent)
+VISIBLE_IF_KUNIT int uid_gid_map_insert_extent(struct uid_gid_map *map,
+					       struct uid_gid_extent *extent)
 {
 	struct uid_gid_extent *dest;
 
@@ -821,7 +822,7 @@ VISIBLE_IF_KUNIT int insert_extent(struct uid_gid_map *map,
 	*dest = *extent;
 	return 0;
 }
-EXPORT_SYMBOL_IF_KUNIT(insert_extent);
+EXPORT_SYMBOL_IF_KUNIT(uid_gid_map_insert_extent);
 
 /* cmp function to sort() forward mappings */
 static int cmp_extents_forward(const void *a, const void *b)
@@ -854,10 +855,10 @@ static int cmp_extents_reverse(const void *a, const void *b)
 }
 
 /*
- * sort_idmaps - Sorts an array of idmap entries.
+ * uid_gid_map_sort - Sorts an array of idmap entries.
  * Can only be called if number of mappings exceeds UID_GID_MAP_MAX_BASE_EXTENTS.
  */
-VISIBLE_IF_KUNIT int sort_idmaps(struct uid_gid_map *map)
+VISIBLE_IF_KUNIT int uid_gid_map_sort(struct uid_gid_map *map)
 {
 	if (map->nr_extents <= UID_GID_MAP_MAX_BASE_EXTENTS)
 		return 0;
@@ -878,7 +879,7 @@ VISIBLE_IF_KUNIT int sort_idmaps(struct uid_gid_map *map)
 
 	return 0;
 }
-EXPORT_SYMBOL_IF_KUNIT(sort_idmaps);
+EXPORT_SYMBOL_IF_KUNIT(uid_gid_map_sort);
 
 /**
  * verify_root_map() - check the uid 0 mapping
@@ -1047,7 +1048,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 		    (next_line != NULL))
 			goto out;
 
-		ret = insert_extent(&new_map, &extent);
+		ret = uid_gid_map_insert_extent(&new_map, &extent);
 		if (ret < 0)
 			goto out;
 		ret = -EINVAL;
@@ -1091,7 +1092,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 	 * If we want to use binary search for lookup, this clones the extent
 	 * array and sorts both copies.
 	 */
-	ret = sort_idmaps(&new_map);
+	ret = uid_gid_map_sort(&new_map);
 	if (ret < 0)
 		goto out;