1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or https://opensource.org/licenses/CDDL-1.0.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Assertion:
29  *
30  *	A read operation and directory update operation performed
31  *      concurrently on the same directory can lead to deadlock
32  *	on a UFS logging file system, but not on a ZFS file system.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <string.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <unistd.h>
43 #define	TMP_DIR /tmp
44 
45 static char dirpath[256];
46 
47 int
48 main(int argc, char **argv)
49 {
50 	const char *cp1 = "";
51 	int i = 0;
52 	int ret = 0;
53 	int testdd = 0;
54 	pid_t pid;
55 	static const int op_num = 5;
56 
57 	if (argc == 1) {
58 		(void) printf("Usage: %s <mount point>\n", argv[0]);
59 		exit(-1);
60 	}
61 	for (i = 0; i < 256; i++) {
62 		dirpath[i] = 0;
63 	}
64 
65 	cp1 = argv[1];
66 	if (strlen(cp1) >= (sizeof (dirpath) - strlen("/TMP_DIR"))) {
67 		(void) printf("The string length of mount point is "
68 		    "too large\n");
69 		exit(-1);
70 	}
71 	(void) snprintf(dirpath, sizeof (dirpath), "%s/TMP_DIR", cp1);
72 
73 	ret = mkdir(dirpath, 0777);
74 	if (ret != 0) {
75 		if (errno != EEXIST) {
76 			(void) printf("%s: mkdir(<%s>, 0777) failed: errno "
77 			    "(decimal)=%d\n", argv[0], dirpath, errno);
78 			exit(-1);
79 		}
80 	}
81 	testdd = open(dirpath, O_RDONLY|O_RSYNC|O_SYNC|O_DSYNC);
82 	if (testdd < 0) {
83 		(void) printf("%s: open(<%s>, O_RDONLY|O_RSYNC|O_SYNC|O_DSYNC)"
84 		    " failed: errno (decimal)=%d\n", argv[0], dirpath, errno);
85 		exit(-1);
86 	} else {
87 		(void) close(testdd);
88 	}
89 	pid = fork();
90 	if (pid > 0) {
91 		int fd = open(dirpath, O_RDONLY|O_RSYNC|O_SYNC|O_DSYNC);
92 		char buf[16];
93 		int rdret;
94 		int j = 0;
95 
96 		if (fd < 0) {
97 			(void) printf("%s: open <%s> again failed:"
98 			    " errno = %d\n", argv[0], dirpath, errno);
99 			exit(-1);
100 		}
101 
102 		while (j < op_num) {
103 			(void) sleep(1);
104 			rdret = read(fd, buf, 16);
105 			if (rdret == -1) {
106 				(void) printf("readdir failed");
107 			}
108 			j++;
109 		}
110 		(void) close(fd);
111 	} else if (pid == 0) {
112 		int fd = open(dirpath, O_RDONLY);
113 		int chownret;
114 		int k = 0;
115 
116 		if (fd < 0) {
117 			(void) printf("%s: open(<%s>, O_RDONLY) again failed:"
118 			    " errno (decimal)=%d\n", argv[0], dirpath, errno);
119 			exit(-1);
120 		}
121 
122 		while (k < op_num) {
123 			(void) sleep(1);
124 			chownret = fchown(fd, 0, 0);
125 			if (chownret == -1) {
126 				(void) printf("chown failed");
127 			}
128 
129 			k++;
130 		}
131 		(void) close(fd);
132 	}
133 
134 	return (0);
135 }
136