There are a few statically initialized arrays that can be made const.
The remaining (like file_system_type, sysfs attributes or prop handlers)
do not allow that due to type mismatch when passed to the APIs or
because the structures are modified through other members.
Signed-off-by: David Sterba <dsterba@suse.com>
 /* csum types */
 #define BTRFS_CSUM_TYPE_CRC32  0
 
-static int btrfs_csum_sizes[] = { 4 };
+static const int btrfs_csum_sizes[] = { 4 };
 
 /* four bytes for CRC32 */
 #define BTRFS_EMPTY_DIR_SIZE 0
 
 struct kmem_cache *btrfs_free_space_cachep;
 
 #define S_SHIFT 12
-static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
        [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
        [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
        [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
 
 static int btrfs_ioctl_get_supported_features(struct file *file,
                                              void __user *arg)
 {
-       static struct btrfs_ioctl_feature_flags features[3] = {
+       static const struct btrfs_ioctl_feature_flags features[3] = {
                INIT_FEATURE_FLAGS(SUPP),
                INIT_FEATURE_FLAGS(SAFE_SET),
                INIT_FEATURE_FLAGS(SAFE_CLEAR)
 
        Opt_err,
 };
 
-static match_table_t tokens = {
+static const match_table_t tokens = {
        {Opt_degraded, "degraded"},
        {Opt_subvol, "subvol=%s"},
        {Opt_subvolid, "subvolid=%s"},