RESERVE_PRIO
if (fifo_push(&ca->free[RESERVE_PRIO], bucket))
if (reserve <= RESERVE_PRIO) {
if (fifo_full(&ca->free[RESERVE_PRIO]) &&
if (!fifo_push(&ca->free[RESERVE_PRIO],
if (!init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca),
free_fifo(&ca->free[RESERVE_PRIO]);
fifo_used(&ca->free[RESERVE_PRIO]),
size_t avail = fifo_used(&ca->free[RESERVE_PRIO]) +
bucket = bch_bucket_alloc(ca, RESERVE_PRIO, wait);