aac_blockread
struct aac_blockread *br = (struct aac_blockread *) \
sizeof (struct aac_blockread) + (acp->left_cookien - 1) * \
_NOTE(SCHEME_PROTECTS_DATA("unique per aac_fib", aac_blockread aac_blockwrite \
struct aac_blockread *br =
(struct aac_blockread *)fibp->data;