/*
 * Copyright (c) 2019 Alexey Dobriyan <adobriyan@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
/* Test that open(O_TMPFILE), linkat() doesn't screw accounting. */
#include <errno.h>
#include <sched.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mount.h>
#include <unistd.h>

#include "kselftest.h"

int main(void)
{
        int fd;

        // Setting up kselftest framework
        ksft_print_header();
        ksft_set_plan(1);

        // Check if test is run as root
        if (geteuid()) {
                ksft_exit_skip("This test needs root to run!\n");
                return 1;
        }

        if (unshare(CLONE_NEWNS) == -1) {
                if (errno == ENOSYS || errno == EPERM) {
                        ksft_exit_skip("unshare() error: unshare, errno %d\n", errno);
                } else {
                        ksft_exit_fail_msg("unshare() error: unshare, errno %d\n", errno);
                }
        }

        if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
                ksft_exit_fail_msg("mount() error: Root filesystem private mount: Fail %d\n", errno);
        }

        /* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */
        if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) {
                ksft_exit_fail_msg("mount() error: Mounting tmpfs on /tmp: Fail %d\n", errno);
        }

        fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
        if (fd == -1) {
                ksft_exit_fail_msg("openat() error: Open first temporary file: Fail %d\n", errno);
        }

        if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
                ksft_exit_fail_msg("linkat() error: Linking the temporary file: Fail %d\n", errno);
                /* Ensure fd is closed on failure */
                close(fd);
        }
        close(fd);

        fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
        if (fd == -1) {
                ksft_exit_fail_msg("openat() error: Opening the second temporary file: Fail %d\n", errno);
        }
        ksft_test_result_pass(" ");
        ksft_exit_pass();
        return 0;
}