remmap
bitstr_t *remmap = __DECONST(bitstr_t *, buf);
bit_ffs(remmap, amp->am_nextents, &ext);
if (!bit_test(remmap, ext))
if ((p1 = m1 = remmap(m1, fd1, off1)) == NULL) {
if ((p2 = m2 = remmap(m2, fd2, off2)) == NULL) {
static u_char *remmap(u_char *, int, off_t);
if ((m1 = remmap(NULL, fd1, off1)) == NULL) {
if ((m2 = remmap(NULL, fd2, off2)) == NULL) {