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