t_lockf.c revision 291179 
1/*	$NetBSD: t_lockf.c,v 1.9 2013/10/19 17:45:00 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2000 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <atf-c.h>
30#include <err.h>
31#include <errno.h>
32#include <fcntl.h>
33#include <signal.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <unistd.h>
38
39#include <sys/types.h>
40#include <sys/wait.h>
41#include <sys/ptrace.h>
42
43/*
44 * lockf1 regression test:
45 *
46 * Tests:
47 * Fork N child processes, each of which gets M random byte range locks
48 * on a common file.  We ignore all lock errors (practically speaking,
49 * this means EDEADLK or ENOLOCK), but we make numerous passes over all
50 * the children to make sure that they are still awake.  (We do this by
51 * verifying that we can ptrace(ATTACH/DETACH) to the children and get
52 * their status via waitpid().)
53 * When finished, reap all the children.
54 */
55
56#define	nlocks		500	/* number of locks per thread */
57#define	nprocs		10	/* number of processes to spawn */
58#define	npasses		50	/* number of passes to make over the children */
59#define	sleeptime	150000	/* sleep time between locks, usec */
60#define	filesize 	8192	/* size of file to lock */
61
62const char *lockfile = "lockf_test";
63
64static u_int32_t
65random_uint32(void)
66{
67	return lrand48();
68}
69
70static void
71trylocks(int id)
72{
73	int i, fd;
74
75	srand48(getpid());
76
77	fd = open (lockfile, O_RDWR, 0);
78
79	if (fd < 0)
80		err(1, "%s", lockfile);
81
82	printf("%d: start\n", id);
83
84	for (i = 0; i < nlocks; i++) {
85		struct flock fl;
86
87		fl.l_start = random_uint32() % filesize;
88		fl.l_len = random_uint32() % filesize;
89		switch (random_uint32() % 3) {
90		case 0:
91			fl.l_type = F_RDLCK;
92			break;
93		case 1:
94			fl.l_type = F_WRLCK;
95			break;
96		case 2:
97			fl.l_type = F_UNLCK;
98			break;
99		}
100		fl.l_whence = SEEK_SET;
101
102		(void)fcntl(fd, F_SETLKW, &fl);
103
104		if (usleep(sleeptime) < 0)
105#if defined(__FreeBSD__)
106		  if (errno != EINTR)
107#endif
108		  err(1, "usleep");
109	}
110	printf("%d: done\n", id);
111	close (fd);
112}
113
114ATF_TC(randlock);
115ATF_TC_HEAD(randlock, tc)
116{
117
118	atf_tc_set_md_var(tc, "timeout", "300");
119	atf_tc_set_md_var(tc, "descr", "Checks fcntl(2) locking");
120}
121
122ATF_TC_BODY(randlock, tc)
123{
124	int i, j, fd;
125	int pipe_fd[2];
126	pid_t *pid;
127	int status;
128	char pipe_in, pipe_out;
129	const char pipe_errmsg[] = "child: pipe write failed\n";
130
131	(void)unlink(lockfile);
132
133	fd = open (lockfile, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0666);
134	ATF_REQUIRE_MSG(fd >= 0, "open(%s): %s", lockfile, strerror(errno));
135
136	ATF_REQUIRE_MSG(ftruncate(fd, filesize) >= 0,
137	    "ftruncate(%s): %s", lockfile, strerror(errno));
138
139	ATF_REQUIRE_MSG(pipe(pipe_fd) == 0, "pipe: %s", strerror(errno));
140
141	fsync(fd);
142	close(fd);
143
144	pid = malloc(nprocs * sizeof(pid_t));
145
146	for (i = 0; i < nprocs; i++) {
147		pipe_out = (char)('A' + i);
148		pid[i] = fork();
149		switch (pid[i]) {
150		case 0:
151			if (write(pipe_fd[1], &pipe_out, 1) != 1)
152				write(STDERR_FILENO, pipe_errmsg,
153				    __arraycount(pipe_errmsg) - 1);
154			else
155				trylocks(i);
156			_exit(0);
157			break;
158		case -1:
159			atf_tc_fail("fork %d failed", i);
160			break;
161		default:
162			ATF_REQUIRE_MSG(read(pipe_fd[0], &pipe_in, 1) == 1,
163			    "parent: read_pipe(%i): %s", i, strerror(errno));
164			ATF_REQUIRE_MSG(pipe_in == pipe_out,
165			    "parent: pipe does not match");
166			break;
167		}
168	}
169	for (j = 0; j < npasses; j++) {
170		printf("parent: run %i\n", j+1);
171		for (i = 0; i < nprocs; i++) {
172			ATF_REQUIRE_MSG(ptrace(PT_ATTACH, pid[i], 0, 0) >= 0,
173			    "ptrace attach %d", pid[i]);
174			ATF_REQUIRE_MSG(waitpid(pid[i], &status, WUNTRACED) >= 0,
175			    "waitpid(ptrace)");
176			usleep(sleeptime / 3);
177			ATF_REQUIRE_MSG(ptrace(PT_DETACH, pid[i], (caddr_t)1,
178					       0) >= 0,
179			    "ptrace detach %d", pid[i]);
180			usleep(sleeptime / 3);
181		}
182	}
183	for (i = 0; i < nprocs; i++) {
184		printf("reap %d: ", i);
185		fflush(stdout);
186		kill(pid[i], SIGINT);
187		waitpid(pid[i], &status, 0);
188		printf(" status %d\n", status);
189	}
190	atf_tc_pass();
191}
192
193static int
194dolock(int fd, int op, off_t lk_off, off_t lk_size)
195{
196	off_t result;
197	int ret;
198
199	result = lseek(fd, lk_off, SEEK_SET);
200	if (result == -1) {
201		return errno;
202	}
203	ATF_REQUIRE_MSG(result == lk_off, "lseek to wrong offset");
204	ret = lockf(fd, op, lk_size);
205	if (ret == -1) {
206		return errno;
207	}
208	return 0;
209}
210
211ATF_TC(deadlock);
212ATF_TC_HEAD(deadlock, tc)
213{
214
215	atf_tc_set_md_var(tc, "timeout", "30");
216	atf_tc_set_md_var(tc, "descr", "Checks fcntl(2) deadlock detection");
217}
218
219ATF_TC_BODY(deadlock, tc)
220{
221	int fd;
222	int error;
223	int ret;
224	pid_t pid;
225
226	(void)unlink(lockfile);
227
228	fd = open (lockfile, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0666);
229	ATF_REQUIRE_MSG(fd >= 0, "open(%s): %s", lockfile, strerror(errno));
230
231	ATF_REQUIRE_MSG(ftruncate(fd, filesize) >= 0,
232	    "ftruncate(%s): %s", lockfile, strerror(errno));
233
234	fsync(fd);
235
236	error = dolock(fd, F_LOCK, 0, 1);
237	ATF_REQUIRE_MSG(error == 0, "initial dolock: %s", strerror(errno));
238
239	pid = fork();
240	ATF_REQUIRE_MSG(pid != -1, "fork failed: %s", strerror(errno));
241	if (pid == 0) {
242		error = dolock(fd, F_LOCK, 1, 1);
243		ATF_REQUIRE_MSG(error == 0, "child dolock: %s",
244		    strerror(errno));
245		dolock(fd, F_LOCK, 0, 1);	/* will block */
246		atf_tc_fail("child did not block");
247	}
248	sleep(1);	/* give child time to grab its lock then block */
249
250	error = dolock(fd, F_LOCK, 1, 1);
251	ATF_REQUIRE_MSG(error == EDEADLK, "parent did not detect deadlock: %s",
252	    strerror(errno));
253	ret = kill(pid, SIGKILL);
254	ATF_REQUIRE_MSG(ret != -1, "failed to kill child: %s", strerror(errno));
255
256	atf_tc_pass();
257}
258
259ATF_TP_ADD_TCS(tp)
260{
261	ATF_TP_ADD_TC(tp, randlock);
262	ATF_TP_ADD_TC(tp, deadlock);
263
264	return atf_no_error();
265}
266