swblk_iter_next
sb = swblk_iter_next(&blks)) {
sb = swblk_iter_next(&blks);
sb != NULL; sb = swblk_iter_next(&srcblks), start = 0) {
sb != NULL; sb = swblk_iter_next(&blks), start = 0) {
if ((sb = swblk_iter_next(blks)) == NULL)
sb != NULL; sb = swblk_iter_next(&blks), start = 0) {