arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
arc_buf_contents_t type);
arc_buf_t *arc_loan_buf(spa_t *spa, int size);
arc_buf_t *arc_buf_alloc(spa_t *spa, int size, void *tag,
arc_buf_contents_t type);
arc_buf_t *arc_loan_buf(spa_t *spa, int size);