xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/fcntl/fcntl38.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2020 CTERA Networks. All Rights Reserved.
 *
 * Started by Amir Goldstein <[email protected]>
 *
 * DESCRIPTION
 *     Check that dnotify event is reported to both parent and subdir
 */

#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include "tst_test.h"
#include "lapi/fcntl.h"

#define	TEST_DIR	"test_dir"

#define TEST_SIG SIGRTMIN+1

static int parent_fd, subdir_fd;
static int got_parent_event, got_subdir_event;

static void dnotify_handler(int sig, siginfo_t *si, void *data __attribute__((unused)))
{
	if (si->si_fd == parent_fd)
		got_parent_event = 1;
	else if (si->si_fd == subdir_fd)
		got_subdir_event = 1;
	else
		tst_brk(TBROK, "Got unexpected signal %d with si_fd %d", sig, si->si_fd);
}

static void setup_dnotify(int fd)
{
	struct sigaction act;

	act.sa_sigaction = dnotify_handler;
	sigemptyset(&act.sa_mask);
	act.sa_flags = SA_SIGINFO;
	sigaction(TEST_SIG, &act, NULL);

	TEST(fcntl(fd, F_SETSIG, TEST_SIG));
	if (TST_RET != 0) {
		tst_brk(TBROK, "F_SETSIG failed errno = %d : %s",
			TST_ERR, strerror(TST_ERR));
	}
	TEST(fcntl(fd, F_NOTIFY, DN_ATTRIB|DN_MULTISHOT));
	if (TST_RET != 0) {
		tst_brk(TBROK, "F_NOTIFY failed errno = %d : %s",
			TST_ERR, strerror(TST_ERR));
	}
}

static void verify_dnotify(void)
{
	parent_fd = SAFE_OPEN(".", O_RDONLY);
	subdir_fd = SAFE_OPEN(TEST_DIR, O_RDONLY);
	/* Watch "." and its children for changes */
	setup_dnotify(parent_fd);
	/* Also watch subdir itself for changes */
	setup_dnotify(subdir_fd);
	/* Generate DN_ATTRIB event on subdir that should send a signal on both fds */
	SAFE_CHMOD(TEST_DIR, 0755);
	if (got_parent_event)
		tst_res(TPASS, "Got event on parent as expected");
	else
		tst_res(TFAIL, "Missing event on parent");
	if (got_subdir_event)
		tst_res(TPASS, "Got event on subdir as expected");
	else
		tst_res(TFAIL, "Missing event on subdir");
	SAFE_CLOSE(parent_fd);
	SAFE_CLOSE(subdir_fd);
}

static void setup(void)
{
	SAFE_MKDIR(TEST_DIR, 00700);
}

static void cleanup(void)
{
	if (parent_fd > 0)
		SAFE_CLOSE(parent_fd);
	if (subdir_fd > 0)
		SAFE_CLOSE(subdir_fd);
}

static struct tst_test test = {
	.needs_tmpdir = 1,
	.setup = setup,
	.cleanup = cleanup,
	.test_all = verify_dnotify,
	.needs_kconfigs = (const char *[]) { "CONFIG_DNOTIFY=y", NULL },
};