struct btrfs_fs_info *fs_info,
                                      struct btrfs_block_group_cache *cache,
                                      struct btrfs_path *path,
-                                     struct free_space_extent *extents,
+                                     const struct free_space_extent * const extents,
                                      unsigned int num_extents)
 {
        struct btrfs_free_space_info *info;
                                    struct btrfs_fs_info *fs_info,
                                    struct btrfs_block_group_cache *cache,
                                    struct btrfs_path *path,
-                                   struct free_space_extent *extents,
+                                   const struct free_space_extent * const extents,
                                    unsigned int num_extents)
 {
        struct btrfs_free_space_info *info;
                                  struct btrfs_path *path,
                                  u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid, cache->key.offset},
        };
 
                           struct btrfs_path *path,
                           u32 alignment)
 {
-       struct free_space_extent extents[] = {};
+       const struct free_space_extent extents[] = {};
        int ret;
 
        ret = __remove_from_free_space_tree(trans, fs_info, cache, path,
                                 struct btrfs_path *path,
                                 u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid + alignment,
                        cache->key.offset - alignment},
        };
                           struct btrfs_path *path,
                           u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid, cache->key.offset - alignment},
        };
        int ret;
                              struct btrfs_path *path,
                              u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid, alignment},
                {cache->key.objectid + 2 * alignment,
                        cache->key.offset - 2 * alignment},
                           struct btrfs_path *path,
                           u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid, 2 * alignment},
        };
        int ret;
                           struct btrfs_path *path,
                           u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid + alignment, 2 * alignment},
        };
        int ret;
                           struct btrfs_path *path,
                           u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid, 3 * alignment},
        };
        int ret;
                           struct btrfs_path *path,
                           u32 alignment)
 {
-       struct free_space_extent extents[] = {
+       const struct free_space_extent extents[] = {
                {cache->key.objectid, alignment},
                {cache->key.objectid + 2 * alignment, alignment},
                {cache->key.objectid + 4 * alignment, alignment},