+ bad_blocks
+ This gives the list of all known bad blocks in the form of
+ start address and length (in sectors respectively). If output
+ is too big to fit in a page, it will be truncated. Writing
+ "sector length" to this file adds new acknowledged (i.e.
+ recorded to disk safely) bad blocks.
+
+ unacknowledged_bad_blocks
+ This gives the list of known-but-not-yet-saved-to-disk bad
+ blocks in the same form of 'bad_blocks'. If output is too big
+ to fit in a page, it will be truncated. Writing to this file
+ adds bad blocks without acknowledging them. This is largely
+ for testing.
+