testcases/kernel/syscalls/flock/flock03.c

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2002
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/**********************************************************
 *
 *    TEST IDENTIFIER   : flock03
 *
 *    EXECUTED BY       : anyone
 *
 *    TEST TITLE        : Error condition test for flock(2)
 *
 *    TEST CASE TOTAL   : 1
 *
 *    AUTHOR            : Paul Larson <plars@linuxtestproject.org>
 *
 *    SIGNALS
 *      Uses SIGUSR1 to pause before test if option set.
 *      (See the parse_opts(3) man page).
 *
 *    DESCRIPTION
 * 	This test verifies that flock cannot unlock a file locked
 * 	by another task
 *	
 *	Test:
 * 		Fork a child processes
 * 		The parent flocks a file with LOCK_EX
 * 		Child waits for that to happen, then checks to make sure
 * 		it is locked.  Child then tries to unlock the file. If
 *		the unlock succeeds, the child attempts to lock the
 *		file with LOCK_EX. The test passes if the child is
 *		able to lock the file.
 *
 * USAGE:  <for command-line>
 *      flock03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] [-h] [-f] [-p]
 *                      where,  -c n : Run n copies concurrently
 *                              -f   : Turn off functional testing
 *    				-e   : Turn on errno logging
 *                              -h   : Show help screen
 *				-i n : Execute test n times
 *                              -I x : Execute test for x seconds
 *                              -p   : Pause for SIGUSR1 before starting
 *                              -P x : Pause for x seconds between iterations
 *                              -t   : Turn on syscall timing
 *
 ****************************************************************/

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/wait.h>
#include "test.h"
#include "usctest.h"

void setup(void);
void cleanup(void);
void childfunc(int);

#ifdef UCLINUX
static int fd_uc;
void childfunc_uc()
{
	childfunc(fd_uc);
}
#endif

char *TCID = "flock03";		/* Test program identifier */
int TST_TOTAL = 3;		/* Total number of test cases */
extern int Tst_count;
char filename[100];

int main(int argc, char **argv)
{
	int lc;			/* loop counter */
	char *msg;		/* message returned from parse_opts */
	pid_t pid;
	int status;
	int fd;			/* for opening the temporary file */

	/* parse standard options */
	if ((msg = parse_opts(argc, argv, NULL, NULL)) !=
	    NULL) {
		tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);
	 /*NOTREACHED*/}
#ifdef UCLINUX
	maybe_run_child(&childfunc_uc, "ds", &fd_uc, filename);
#endif

	setup();

	/* The following loop checks looping state if -i option given */

	for (lc = 0; TEST_LOOPING(lc); lc++) {

		/* reset Tst_count in case we are looping */
		Tst_count = 0;

		/* PARENT */
		fd = open(filename, O_RDWR);
		if (fd == -1)
			tst_brkm(TFAIL, cleanup, "parent failed to open the"
				 "file, errno %d", errno);

		pid = FORK_OR_VFORK();
		if (pid == -1)
			tst_brkm(TFAIL, cleanup, "fork() failed, errno %d",
				 errno);
		if (pid == 0) {
#ifdef UCLINUX
			if (self_exec(argv[0], "ds", fd, filename) < 0)
				tst_brkm(TFAIL, cleanup, "self_exec failed, "
					 "errno &d", errno);
#else
			childfunc(fd);
#endif
		}

		TEST(flock(fd, LOCK_EX | LOCK_NB));
		if (TEST_RETURN != 0)
			tst_resm(TFAIL,
				 "Parent: Initial attempt to flock() failed, "
				 "errno %d", TEST_ERRNO);
		else
			tst_resm(TPASS,
				 "Parent: Initial attempt to flock() passed");

		if ((waitpid(pid, &status, 0)) < 0) {
			tst_resm(TFAIL, "wait() failed");
			continue;
		}
		if ((WIFEXITED(status)) && (WEXITSTATUS(status) == 0))
			tst_resm(TPASS, "flock03 Passed");
		else
			tst_resm(TFAIL, "flock03 Failed");

		close(fd);

	}			/* End of TEST_LOOPING */

	cleanup();

	return 0;

}

void childfunc(int fd)
{
	int fd2;

	/* give the parent a chance to lock the file */
	sleep(2);

	fd2 = open(filename, O_RDWR);
	if (fd2 == -1)
		tst_brkm(TFAIL, cleanup, "child failed to open the"
			 "file, errno %d", errno);
	if (flock(fd2, LOCK_EX | LOCK_NB) != -1)
		tst_resm(TFAIL, "Child: The file was not already locked");

	TEST(flock(fd, LOCK_UN));
	/* XXX: LOCK_UN does not return an error if there was nothing to
	 * unlock.
	 */
	if (TEST_RETURN == -1)
		tst_resm(TFAIL,
			 "Child: Unable to unlock file locked by parent, "
			 "errno %d", TEST_ERRNO);
	else
		tst_resm(TPASS, "Child: Unlocked file locked by parent");

	TEST(flock(fd2, LOCK_EX | LOCK_NB));
	if (TEST_RETURN == -1)
		tst_resm(TFAIL, "Child: Unable to relock file after unlocking, "
			 "errno %d", TEST_ERRNO);
	else
		tst_resm(TPASS, "Child: flock after unlocking passed");

	close(fd);
	close(fd2);

	tst_exit();
	/* NOT REACHED */
	return;
}

/*
 * setup()
 *	performs all ONE TIME setup for this test
 */
void setup(void)
{
	int fd;
	/* capture signals */
	tst_sig(FORK, DEF_HANDLER, cleanup);

	/* Pause if that option was specified
	 * TEST_PAUSE contains the code to fork the test with the -i option.
	 * You want to make sure you do this before you create your temporary
	 * directory.
	 */
	TEST_PAUSE;

	/* Create a unique temporary directory and chdir() to it. */
	tst_tmpdir();

	sprintf(filename, "flock03.%d", getpid());

	/* creating temporary file */
	fd = creat(filename, 0666);
	if (fd < 0) {
		tst_resm(TFAIL, "creating a new file failed");

		TEST_CLEANUP;

		/* Removing temp dir */
		tst_rmdir();

		/* exit with return code appropriate for result */
		tst_exit();
	}
	close(fd);
}

/*
 * cleanup()
 *	performs all ONE TIME cleanup for this test at
 * 	completion or premature exit
 */
void cleanup(void)
{
	/*
	 * print timing stats if that option was specified.
	 * print errno log if that option was specified.
	 */
	TEST_CLEANUP;

	unlink(filename);
	tst_rmdir();

	/* exit with return code appropriate for results */
	tst_exit();
 /*NOTREACHED*/}