static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque, int is_write) { QCowAIOCB *acb; acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); if (!acb) return NULL; acb->hd_aiocb = NULL; acb->sector_num = sector_num; acb->qiov = qiov; if (qiov->niov > 1) { acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); if (is_write) qemu_iovec_to_buffer(qiov, acb->buf); } else { acb->buf = (uint8_t *)qiov->iov->iov_base; } acb->nb_sectors = nb_sectors; acb->n = 0; acb->cluster_offset = 0; acb->l2meta.nb_clusters = 0; LIST_INIT(&acb->l2meta.dependent_requests); return acb; }