static int ahci_dma_rw_buf(IDEDMA *dma, int is_write)
{
    AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma);
    IDEState *s = &ad->port.ifs[0];
    uint8_t *p = s->io_buffer + s->io_buffer_index;
    int l = s->io_buffer_size - s->io_buffer_index;

    if (ahci_populate_sglist(ad, &s->sg, ad->cur_cmd, l, s->io_buffer_offset)) {
        return 0;
    }

    if (is_write) {
        dma_buf_read(p, l, &s->sg);
    } else {
        dma_buf_write(p, l, &s->sg);
    }

    /* free sglist, update byte count */
    dma_buf_commit(s, l);

    s->io_buffer_index += l;

    DPRINTF(ad->port_no, "len=%#x\n", l);

    return 1;
}

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.