int sd_read_object(uint64_t oid, void *data, unsigned int datalen, uint64_t offset, bool direct) { struct sd_req hdr; struct sd_rsp *rsp = (struct sd_rsp *)&hdr; int ret; sd_init_req(&hdr, SD_OP_READ_OBJ); hdr.data_length = datalen; hdr.obj.oid = oid; hdr.obj.offset = offset; if (direct) hdr.flags |= SD_FLAG_CMD_DIRECT; ret = dog_exec_req(sdhost, sdport, &hdr, data); if (ret < 0) { sd_err("Failed to read object %" PRIx64, oid); return SD_RES_EIO; } if (rsp->result != SD_RES_SUCCESS) { sd_err("Failed to read object %" PRIx64 " %s", oid, sd_strerror(rsp->result)); return rsp->result; } untrim_zero_blocks(data, rsp->obj.offset, rsp->data_length, datalen); return SD_RES_SUCCESS; }
int read_backend_object(uint64_t oid, char *data, unsigned int datalen, uint64_t offset) { struct sd_req hdr; struct sd_rsp *rsp = (struct sd_rsp *)&hdr; int ret; sd_init_req(&hdr, SD_OP_READ_OBJ); hdr.data_length = datalen; hdr.obj.oid = oid; hdr.obj.offset = offset; hdr.obj.copies = get_vdi_copy_number(oid_to_vid(oid)); ret = exec_local_req(&hdr, data); if (ret != SD_RES_SUCCESS) sd_eprintf("failed to read object %" PRIx64 ", %s", oid, sd_strerror(ret)); untrim_zero_blocks(data, rsp->obj.offset, rsp->data_length, datalen); return ret; }
/* * Try our best to read one copy and read local first. * * Return success if any read succeed. We don't call gateway_forward_request() * because we only read once. */ int gateway_read_obj(struct request *req) { int i, ret = SD_RES_SUCCESS; struct sd_req fwd_hdr; struct sd_rsp *rsp = (struct sd_rsp *)&fwd_hdr; const struct sd_vnode *v; const struct sd_vnode *my_v; const struct sd_vnode *obj_vnodes[SD_MAX_COPIES]; const struct sd_vnode *my_obj_vnodes[SD_MAX_COPIES]; uint64_t oid = req->rq.obj.oid; int nr_copies, j; //PRINT_TO_LOG("WYH\n"); if (sys->enable_object_cache && !req->local && !bypass_object_cache(req)) { ret = object_cache_handle_request(req); goto out; } nr_copies = get_req_copy_number(req); if (nr_copies == 0) { sd_debug("there is no living nodes"); return SD_RES_HALT; } oid_to_vnodes(req->vinfo->vnodes, req->vinfo->nr_vnodes, oid, nr_copies, obj_vnodes); //PRINT_TO_LOG("out:%s\n", addr_to_str(obj_vnodes[0]->nid.addr,obj_vnodes[0]->nid.port)); oid_to_vnodes(req->vinfo->my_vnodes, req->vinfo->my_nr_vnodes, oid, nr_copies, my_obj_vnodes); my_v = my_obj_vnodes[0]; //PRINT_TO_LOG("out:%s\n", addr_to_str(my_v->nid.addr,my_v->nid.port)); for (i = 0; i < nr_copies; i++) { v = obj_vnodes[0]; my_v = my_obj_vnodes[0]; //PRINT_TO_LOG("phy:%s\n", addr_to_str(v->nid.addr,v->nid.port)); //PRINT_TO_LOG("vir:%s\n", addr_to_str(my_v->nid.addr, my_v->nid.port)); //PRINT_TO_LOG("%d,%d\n", req->vinfo->nr_vnodes, req->vinfo->my_nr_vnodes); if (!vnode_is_local(v)) continue; ret = peer_read_obj(req); if (ret == SD_RES_SUCCESS) goto out; sd_err("local read %"PRIx64" failed, %s", oid, sd_strerror(ret)); break; } /* * Read random copy from cluster for better load balance, useful for * reading base VM's COW objects */ j = random(); for (i = 0; i < nr_copies; i++) { int idx = (i + j) % nr_copies; v = obj_vnodes[idx]; if (vnode_is_local(v)) continue; /* * We need to re-init it because rsp and req share the same * structure. */ gateway_init_fwd_hdr(&fwd_hdr, &req->rq); ret = sheep_exec_req(&v->nid, &fwd_hdr, req->data); if (ret != SD_RES_SUCCESS) continue; /* Read success */ memcpy(&req->rp, rsp, sizeof(*rsp)); break; } out: if (ret == SD_RES_SUCCESS && req->rq.proto_ver < SD_PROTO_VER_TRIM_ZERO_SECTORS) { /* the client doesn't support trimming zero bytes */ untrim_zero_blocks(req->data, req->rp.obj.offset, req->rp.data_length, req->rq.data_length); req->rp.data_length = req->rq.data_length; req->rp.obj.offset = 0; } return ret; }