[LTP] [PATCH] name_to_handle_at: Add test cases for AT_HANDLE_FID

[Amir Goldstein]

On Wed, Oct 1, 2025 at 4:56 PM Jan Kara <jack@suse.cz> wrote:
>
> Add a few testcases verifying AT_HANDLE_FID flag.
>
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  include/lapi/fcntl.h                          |  4 +
>  .../name_to_handle_at/name_to_handle_at03.c   | 88 +++++++++++++++++++
>  2 files changed, 92 insertions(+)
>  create mode 100644 testcases/kernel/syscalls/name_to_handle_at/name_to_handle_at03.c
>
> This is actually a testcase for a kernel regression, the kernel fix is on the
> way.

Best that we wait for fix to land before merging the test so that we can
add linux-git tag to the test (or can add it later)

With minor nits below fixed, feel free to add:
Reviewed-by: Amir Goldstein <amir73il@gmail.com>

Thanks for covering my test debt!!
Amir.

>
> diff --git a/include/lapi/fcntl.h b/include/lapi/fcntl.h
> index 7c050248892e..55a5e8b40432 100644
> --- a/include/lapi/fcntl.h
> +++ b/include/lapi/fcntl.h
> @@ -98,6 +98,10 @@
>  # define AT_HANDLE_FID         AT_REMOVEDIR
>  #endif
>
> +#ifndef AT_HANDLE_CONNECTABLE
> +# define AT_HANDLE_CONNECTABLE 0x002
> +#endif
> +
>  #ifndef AT_SYMLINK_FOLLOW
>  # define AT_SYMLINK_FOLLOW     0x400
>  #endif
> diff --git a/testcases/kernel/syscalls/name_to_handle_at/name_to_handle_at03.c b/testcases/kernel/syscalls/name_to_handle_at/name_to_handle_at03.c
> new file mode 100644
> index 000000000000..4a6df5e46fd7
> --- /dev/null
> +++ b/testcases/kernel/syscalls/name_to_handle_at/name_to_handle_at03.c
> @@ -0,0 +1,88 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2020 Viresh Kumar <viresh.kumar@linaro.org>
> + */
> +
> +/*\
> + * Basic name_to_handle_at() tests.
> + *
> + * [Algorithm]
> + *  - Check that EOVERFLOW is returned as expected by name_to_handle_at().
> + *  - Check that we were able to access a file's stat with name_to_handle_at()
> + *    and open_by_handle_at().

stale description

> + */
> +
> +#define _GNU_SOURCE
> +#include <sys/stat.h>
> +#include "lapi/name_to_handle_at.h"
> +
> +#define TEST_FILE "test_file"
> +
> +static int fd_atcwd = AT_FDCWD;
> +static struct file_handle *fhp;
> +
> +static struct tcase {
> +       const char *name;
> +       int *dfd;
> +       const char *pathname;
> +       int name_flags;
> +       int exp_errno;
> +} tcases[] = {
> +       {"test-file", &fd_atcwd, TEST_FILE, AT_HANDLE_FID, 0},
> +       {"unexportable-file", &fd_atcwd, "/proc/filesystems", AT_HANDLE_FID, 0},
> +       {"test-file-connectable", &fd_atcwd, TEST_FILE, AT_HANDLE_FID | AT_HANDLE_CONNECTABLE, EINVAL},
> +};
> +
> +static bool handle_type_supported(unsigned int flag, const char *name)
> +{
> +       if (name_to_handle_at(-1, ".", NULL, NULL, flag) && errno == EINVAL) {

explain that -1 would fail with EBADF if flags are supported?

> +               tst_brk(TCONF, "%s not supported by the kernel.", name);
> +               return false;
> +       }
> +       return true;
> +}
> +
> +#define REQUIRE_HANDLE_TYPE_SUPPORT(flag) handle_type_supported(flag, #flag)
> +
> +static void setup(void)
> +{
> +       SAFE_TOUCH(TEST_FILE, 0600, NULL);
> +       fhp = malloc(MAX_HANDLE_SZ);
> +       if (!fhp)
> +               tst_brk(TBROK, "malloc failed");
> +
> +       REQUIRE_HANDLE_TYPE_SUPPORT(AT_HANDLE_FID);
> +       REQUIRE_HANDLE_TYPE_SUPPORT(AT_HANDLE_CONNECTABLE);
> +}
> +
> +static void run(unsigned int n)
> +{
> +       struct tcase *tc = &tcases[n];
> +       int mount_id;
> +
> +       fhp->handle_bytes = MAX_HANDLE_SZ;
> +       TEST(name_to_handle_at(*tc->dfd, tc->pathname, fhp, &mount_id,
> +                              tc->name_flags));
> +       if (!tc->exp_errno) {
> +               if (TST_RET)
> +                       tst_res(TFAIL | TTERRNO, "%s: name_to_handle_at() failed", tc->name);
> +               else
> +                       tst_res(TPASS, "%s: name_to_handle_at() passed", tc->name);
> +               return;
> +       }
> +
> +       if (TST_RET != -1)
> +               tst_res(TFAIL, "%s: name_to_handle_at() unexpectedly succeeded", tc->name);
> +       else if (TST_ERR != tc->exp_errno)
> +               tst_res(TFAIL | TTERRNO, "%s: name_to_handle_at() should fail with errno %s",
> +                       tc->name, tst_strerrno(tc->exp_errno));
> +       else
> +               tst_res(TPASS, "%s: name_to_handle_at() failed as expected", tc->name);
> +}
> +
> +static struct tst_test test = {
> +       .tcnt = ARRAY_SIZE(tcases),
> +       .test = run,
> +       .setup = setup,
> +       .needs_tmpdir = 1,
> +};
> --
> 2.51.0
>