wiplukeshu/9p-read-multi-iovec

1 files changed, 13 insertions, 6 deletions

diff --git a/lib9p/srv.c b/lib9p/srv.c
index 50d0b78..2c26ffe 100644
--- a/lib9p/srv.c
+++ b/lib9p/srv.c
@@ -980,13 +980,20 @@ static void handle_Tread(struct _lib9p_srv_req *ctx,
 		fidinfo->dir.idx = idx+num;
 		fidinfo->dir.off = req->offset + len;
 	} else {
-		struct iovec iov;
-		LO_CALL(fidinfo->file.io, pread, &ctx->ctx, req->count, req->offset, &iov);
+		LO_CALL(fidinfo->file.io, pread, &ctx->ctx, req->count, req->offset,
+		        &resp->iov, &resp->iovcnt);
 		if (!lib9p_ctx_has_error(&ctx->ctx.basectx)) {
-			resp->count = iov.iov_len;
-			resp->data = iov.iov_base;
-			if (resp->count > req->count)
-				resp->count = req->count;
+			resp->count = 0;
+			assert(resp->iovcnt >= 0);
+			if (resp->iovcnt) {
+				assert(resp->iov);
+				for (int i = 0; i < resp->iovcnt; i++) {
+					assert(resp->iov[i].iov_len == 0 || resp->iov[i].iov_base);
+					bool overflowed = __builtin_add_overflow(resp->count, resp->iov[i].iov_len, &resp->count);
+					assert(!overflowed);
+				}
+			}
+			assert(resp->count <= req->count);
 		}
 	}
 }