android13/external/ltp/testcases/kernel/syscalls/flock/flock04.c

93 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright (c) Wipro Technologies Ltd, 2002. All Rights Reserved.
* Author: Vatsal Avasthi
*
* Test Description:
* This test verifies that flock() behavior with different locking
* combinations along with LOCK_SH and LOCK_EX:
* 1) flock() succeeded in acquiring shared lock on shared lock file.
* 2) flock() failed to acquire exclusive lock on shared lock file.
* 3) flock() failed to acquire shared lock on exclusive lock file.
* 4) flock() failed to acquire exclusive lock on exclusive lock file.
*/
#include <errno.h>
#include <sys/file.h>
#include <stdlib.h>
#include "tst_test.h"
static struct tcase {
int operation;
char *f_lock;
} tcases[] = {
{LOCK_SH, "shared lock"},
{LOCK_EX, "exclusive lock"},
};
static void child(int opt, int should_pass, char *lock)
{
int retval, fd1;
fd1 = SAFE_OPEN("testfile", O_RDWR);
retval = flock(fd1, opt);
if (should_pass) {
tst_res(retval == -1 ? TFAIL : TPASS,
" Child acquiring %s got %d", lock, retval);
} else {
tst_res(retval == -1 ? TPASS : TFAIL,
" Child acquiring %s got %d", lock, retval);
}
SAFE_CLOSE(fd1);
exit(0);
}
static void verify_flock(unsigned n)
{
int fd2;
pid_t pid;
struct tcase *tc = &tcases[n];
fd2 = SAFE_OPEN("testfile", O_RDWR);
TEST(flock(fd2, tc->operation));
if (TST_RET != 0) {
tst_res(TFAIL | TTERRNO, "flock() failed to acquire %s",
tc->f_lock);
SAFE_CLOSE(fd2);
return;
}
tst_res(TPASS, "Parent had %s", tc->f_lock);
pid = SAFE_FORK();
if (pid == 0)
child(LOCK_SH | LOCK_NB, tc->operation & LOCK_SH, "shared lock");
else
tst_reap_children();
pid = SAFE_FORK();
if (pid == 0)
child(LOCK_EX | LOCK_NB, 0, "exclusive lock");
else
tst_reap_children();
SAFE_CLOSE(fd2);
}
static void setup(void)
{
int fd;
fd = SAFE_OPEN("testfile", O_CREAT | O_TRUNC | O_RDWR, 0644);
SAFE_CLOSE(fd);
}
static struct tst_test test = {
.tcnt = ARRAY_SIZE(tcases),
.test = verify_flock,
.needs_tmpdir = 1,
.setup = setup,
.forks_child = 1,
};