io-wq: only exit on fatal signals

If the application uses io_uring and also relies heavily on signals
for communication, that can cause io-wq workers to spuriously exit
just because the parent has a signal pending. Just ignore signals
unless they are fatal.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io-wq.c

@@ -575,7 +575,9 @@ static int io_wqe_worker(void *data)
 
 			if (!get_signal(&ksig))
 				continue;
-			break;
+			if (fatal_signal_pending(current))
+				break;
+			continue;
 		}
 		if (ret)
 			continue;