+ ret = blk_co_preadv(job->target, start * VMA_CLUSTER_SIZE,
+ readlen, &qiov, 0);
+ if (ret < 0) {
-+ vma_writer_set_error(job->vmaw, "read error", -1);
++ vma_writer_set_error(job->vmaw, "read error");
+ goto out;
+ }
+
+ size_t zb = 0;
+ if (vma_writer_write(job->vmaw, job->dev_id, start, buf, &zb) < 0) {
-+ vma_writer_set_error(job->vmaw, "backup_dump_cb vma_writer_write failed", -1);
++ vma_writer_set_error(job->vmaw, "backup_dump_cb vma_writer_write failed");
+ goto out;
+ }
+ }
+int coroutine_fn vma_writer_flush_output(VmaWriter *vmaw);
+
+int vma_writer_get_status(VmaWriter *vmaw, VmaStatus *status);
-+void vma_writer_set_error(VmaWriter *vmaw, const char *fmt, ...);
++void vma_writer_set_error(VmaWriter *vmaw, const char *fmt, ...) G_GNUC_PRINTF(2, 3);
+
+
+VmaReader *vma_reader_create(const char *filename, Error **errp);