static void scsi_do_read(SCSIDiskReq *r, int ret) { SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); SCSIDiskClass *sdc = (SCSIDiskClass *) object_get_class(OBJECT(s)); assert (r->req.aiocb == NULL); if (r->req.io_canceled) { scsi_req_cancel_complete(&r->req); goto done; } if (ret < 0) { if (scsi_handle_rw_error(r, -ret, false)) { goto done; } } /* The request is used as the AIO opaque value, so add a ref. */ scsi_req_ref(&r->req); if (r->req.sg) { dma_acct_start(s->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_READ); r->req.resid -= r->req.sg->size; r->req.aiocb = dma_blk_io(blk_get_aio_context(s->qdev.conf.blk), r->req.sg, r->sector << BDRV_SECTOR_BITS, sdc->dma_readv, r, scsi_dma_complete, r, DMA_DIRECTION_FROM_DEVICE); } else { scsi_init_iovec(r, SCSI_DMA_BUF_SIZE); block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct, r->qiov.size, BLOCK_ACCT_READ); r->req.aiocb = sdc->dma_readv(r->sector, &r->qiov, scsi_read_complete, r, r); } done: scsi_req_unref(&r->req); }