requestor: do not return EAGAIN for errors when waiting

src/knot/nameserver/requestor.c

@@ -86,9 +86,9 @@ static int request_send(struct request *request, const struct timeval *timeout)
 	/* Each request has unique timeout. */
 	struct timeval tv = { timeout->tv_sec, timeout->tv_usec };
 
-	/* Wait for writeability. */
+	/* Wait for writeability or error. */
 	int ret = request_wait(request->data.fd, NS_PROC_FULL, &tv);
-	if (ret <= 0) {
+	if (ret == 0) {
 		return KNOT_EAGAIN;
 	}
 

src/knot/server/tcp-handler.c

@@ -242,7 +242,7 @@ int tcp_recv_data(int fd, uint8_t *buf, int len, struct timeval *timeout)
 			if (ret) {
 				continue;
 			} else {
-				return KNOT_EAGAIN;
+				return KNOT_EBUSY;
 			}
 		} else {
 			return KNOT_ECONN;