[LTP] [PATCH v7] io_submit04: Add test case for RWF_NOWAIT flag

[Cyril Hrubis]

Hi!
> --- /dev/null
> +++ b/testcases/kernel/syscalls/io_submit/io_submit04.c
> @@ -0,0 +1,99 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2025 Wei Gao <wegao@suse.com>
> + */
> +
> +/*\
> + * Test RWF_NOWAIT support in io_submit(), verifying that an
> + * asynchronous read operation on a blocking resource (empty pipe)
> + * will cause -EAGAIN. This is done by checking that io_getevents()
> + * :manpage:`io_getevents(2)` syscall returns immediately and
> + * io_event.res is equal to -EAGAIN.
> + */
> +
> +#include "config.h"
> +#include "tst_test.h"
> +#include "lapi/syscalls.h"
> +#include "lapi/aio_abi.h"
> +
> +#define BUF_SIZE 100
> +
> +static int fd[2] = {-1, -1};
> +static aio_context_t ctx;
> +static char *buf;
> +static iocb *cb;
> +static iocb **iocbs;
> +
> +static void setup(void)
> +{
> +	if (tst_syscall(__NR_io_setup, 1, &ctx))
> +		tst_brk(TBROK | TERRNO, "io_setup failed");

Sorry if that was asked in previous reviews. Why are we using
tst_syscall() instead of the libaio functions like we do in the rest of
the tests?

> +	SAFE_PIPE(fd);
> +
> +	cb->aio_fildes = fd[0];
> +	cb->aio_lio_opcode = IOCB_CMD_PREAD;
> +	cb->aio_buf = TST_PTR_TO_UINT(buf);
> +	cb->aio_offset = 0;
> +	cb->aio_nbytes = BUF_SIZE;
> +	cb->aio_rw_flags = RWF_NOWAIT;
> +
> +	iocbs[0] = cb;
> +}
> +
> +static void cleanup(void)
> +{
> +	if (fd[0] != -1)
> +		SAFE_CLOSE(fd[0]);
> +
> +	if (fd[1] != -1)
> +		SAFE_CLOSE(fd[1]);
> +
> +	if (ctx && tst_syscall(__NR_io_destroy, ctx))
> +		tst_brk(TBROK | TERRNO, "io_destroy() failed");
> +}
> +
> +static void run(void)
> +{
> +	struct io_event evbuf;
> +	struct timespec timeout = { .tv_sec = 1 };
> +	long nr = 1;
> +
> +	TEST(tst_syscall(__NR_io_submit, ctx, nr, iocbs));
> +
> +	if (TST_RET == -1 && TST_ERR == EOPNOTSUPP) {
> +		tst_brk(TCONF, "RWF_NOWAIT not supported by kernel");
> +	} else if (TST_RET != nr) {
> +		tst_brk(TBROK | TTERRNO, "io_submit() returns %ld, expected %ld",
> +				TST_RET, nr);
> +	}
> +
> +	TEST(tst_syscall(__NR_io_getevents, ctx, 1, 1, &evbuf, &timeout));
> +
> +	if (TST_RET != 1) {
> +		tst_res(TFAIL | TTERRNO, "io_getevents() failed to get 1 event");
> +		return;
> +	}
> +
> +	if (evbuf.res == -EAGAIN)
> +		tst_res(TPASS, "io_getevents() returned EAGAIN on read event");
> +	else
> +		tst_res(TFAIL, "io_getevents() returned with %s instead of EAGAIN",
> +			strerror(-evbuf.res));
                            ^
			    tst_strerrno()

Other than these two minor issues I do not see any problems in the code,
the rest looks fine.

-- 
Cyril Hrubis
chrubis@suse.cz