[LTP] open: remove O_DIRECTORY case (move to fstat test)

[linuxtestproject.agent@gmail.com]

Hi Jinseok,

On Sun, 21 Jun 2026 18:03:59 +0900, Jinseok Kim wrote:
> open: remove O_DIRECTORY case (move to fstat test)

--- [PATCH 2/2] ---

> +/*\
> + * Verify that :manpage:`fstat(2)` correctly identifies various
> + * file types.
> + */

The test uses .needs_root = 1 for mknod() to create device nodes, but
the doc comment does not mention why root is required.

> +	switch (tc->exp_type) {
> +	case S_IFREG:
> +		TST_EXP_EXPR(S_ISREG(buf.st_mode));
> +		break;
> +	case S_IFDIR:
> +		TST_EXP_EXPR(S_ISDIR(buf.st_mode));
> +		break;
> +	case S_IFIFO:
> +		TST_EXP_EXPR(S_ISFIFO(buf.st_mode));
> +		break;
> +	case S_IFCHR:
> +		TST_EXP_EXPR(S_ISCHR(buf.st_mode));
> +		break;
> +	case S_IFBLK:
> +		TST_EXP_EXPR(S_ISBLK(buf.st_mode));
> +		break;
> +	}

Each S_IS*() macro is equivalent to (st_mode & S_IFMT) == S_IF*, and
tc->exp_type already holds the expected S_IF* value. Could the whole
switch be replaced with a single check?

  TST_EXP_EXPR((buf.st_mode & S_IFMT) == tc->exp_type,
      "fstat on %s", tc->path);

This would also give more informative output on failure by
identifying the file being tested.

Verdict - Needs revision

Pre-existing issues in open01.c (not introduced by this series):

- static int fd; should be static int fd = -1;
- cleanup() uses if (fd > 0) which should be if (fd != -1)

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