- * If not may_change, then this is a 'Grow', and the bitmap
- * must fit after the superblock.
- * If may_change, then this is create, and we can put the bitmap
- * before the superblock if we like, or may move the start.
- * If !may_change, the bitmap MUST live at offset of 1K, until
- * we get a sysfs interface.
+ * If not may_change, then this is a 'Grow' without sysfs support for
+ * bitmaps, and the bitmap must fit after the superblock at 1K offset.
+ * If may_change, then this is create or a Grow with sysfs syupport,
+ * and we can put the bitmap wherever we like.