Re: [PATCH bpf-next 2/2] selftests: bpf: test RENAME_EXCHANGE and RENAME_NOREPLACE on bpffs

[Andrii Nakryiko]

On Wed, Oct 20, 2021 at 1:30 AM Lorenz Bauer <lmb@xxxxxxxxxxxxxx> wrote:
>
> Add tests to exercise the behaviour of RENAME_EXCHANGE and RENAME_NOREPLACE
> on bpffs. The former checks that after an exchange the inode of two
> directories has changed. The latter checks that the source still exists
> after a failed rename.
>
> Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
> ---
>  .../selftests/bpf/prog_tests/test_bpffs.c     | 39 +++++++++++++++++++
>  1 file changed, 39 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c
> index 172c999e523c..9c28ae9589bf 100644
> --- a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c
> +++ b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /* Copyright (c) 2020 Facebook */
>  #define _GNU_SOURCE
> +#include <stdio.h>
>  #include <sched.h>
>  #include <sys/mount.h>
>  #include <sys/stat.h>
> @@ -29,6 +30,7 @@ static int read_iter(char *file)
>
>  static int fn(void)
>  {
> +       struct stat a, b;
>         int err, duration = 0;
>
>         err = unshare(CLONE_NEWNS);
> @@ -67,6 +69,43 @@ static int fn(void)
>         err = read_iter(TDIR "/fs2/progs.debug");
>         if (CHECK(err, "reading " TDIR "/fs2/progs.debug", "failed\n"))
>                 goto out;
> +
> +       err = mkdir(TDIR "/fs1/a", 0777);
> +       if (CHECK(err, "creating " TDIR "/fs1/a", "failed\n"))
> +               goto out;
> +       err = mkdir(TDIR "/fs1/a/1", 0777);
> +       if (CHECK(err, "creating " TDIR "/fs1/a/1", "failed\n"))
> +               goto out;
> +       err = mkdir(TDIR "/fs1/b", 0777);
> +       if (CHECK(err, "creating " TDIR "/fs1/b", "failed\n"))
> +               goto out;
> +
> +       /* Check that RENAME_EXCHANGE works. */
> +       err = stat(TDIR "/fs1/a", &a);
> +       if (CHECK(err, "stat(" TDIR "/fs1/a)", "failed\n"))
> +               goto out;
> +       err = renameat2(0, TDIR "/fs1/a", 0, TDIR "/fs1/b", RENAME_EXCHANGE);
> +       if (CHECK(err, "renameat2(RENAME_EXCHANGE)", "failed\n"))
> +               goto out;
> +       err = stat(TDIR "/fs1/b", &b);
> +       if (CHECK(err, "stat(" TDIR "/fs1/b)", "failed\n"))
> +               goto out;
> +       if (CHECK(a.st_ino != b.st_ino, "b should have a's inode", "failed\n"))
> +               goto out;
> +       err = access(TDIR "/fs1/b/1", F_OK);
> +       if (CHECK(err, "access(" TDIR "/fs1/b/1)", "failed\n"))
> +               goto out;
> +
> +       /* Check that RENAME_NOREPLACE works. */
> +       err = renameat2(0, TDIR "/fs1/b", 0, TDIR "/fs1/a", RENAME_NOREPLACE);
> +       if (CHECK(!err, "renameat2(RENAME_NOREPLACE)", "succeeded\n")) {
> +               err = -EINVAL;
> +               goto out;
> +       }
> +       err = access(TDIR "/fs1/b", F_OK);
> +       if (CHECK(err, "access(" TDIR "/fs1/b)", "failed\n"))
> +               goto out;
> +

Please use ASSERT_xxx() for new code.

>  out:
>         umount(TDIR "/fs1");
>         umount(TDIR "/fs2");
> --
> 2.30.2
>