1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2018 CTERA Networks. All Rights Reserved.
4 * Author: Amir Goldstein <amir73il@gmail.com>
5 *
6 * DESCRIPTION
7 * Check that inotify work for an overlayfs directory after copy up and
8 * drop caches.
9 *
10 * An inotify watch pins the directory inode in cache, but not the dentry.
11 * The watch will not report events on the directory if overlayfs does not
12 * obtain the pinned inode to the new allocated dentry after drop caches.
13 *
14 * The problem has been fixed by commit:
15 * 31747eda41ef "ovl: hash directory inodes for fsnotify"
16 *
17 * ALGORITHM
18 * Add watch on an overlayfs lower directory then chmod directory and drop
19 * dentry and inode caches. Execute operations on directory and child and
20 * expect events to be reported on directory watch.
21 */
22
23 #include "config.h"
24
25 #if defined(HAVE_SYS_INOTIFY_H)
26 # include <sys/inotify.h>
27 #endif
28 #include <stdio.h>
29 #include <sys/stat.h>
30 #include <sys/types.h>
31 #include <fcntl.h>
32 #include <errno.h>
33 #include <string.h>
34 #include <sys/syscall.h>
35 #include <sys/mount.h>
36 #include <limits.h>
37 #include "tst_test.h"
38 #include "inotify.h"
39
40 #if defined(HAVE_SYS_INOTIFY_H)
41
42 #define EVENT_MAX 1024
43 /* size of the event structure, not counting name */
44 #define EVENT_SIZE (sizeof (struct inotify_event))
45 /* reasonable guess as to size of 1024 events */
46 #define EVENT_BUF_LEN (EVENT_MAX * (EVENT_SIZE + 16))
47
48 #define BUF_SIZE 256
49 static int fd_notify, reap_wd;
50 static int wd;
51
52 struct event_t {
53 char name[BUF_SIZE];
54 unsigned int mask;
55 };
56
57 #define DIR_NAME "test_dir"
58 #define DIR_PATH OVL_MNT"/"DIR_NAME
59 #define FILE_NAME "test_file"
60 #define FILE_PATH OVL_MNT"/"DIR_NAME"/"FILE_NAME
61
62 static const char mntpoint[] = OVL_BASE_MNTPOINT;
63 static struct event_t event_set[EVENT_MAX];
64 static char event_buf[EVENT_BUF_LEN];
65
verify_inotify(void)66 void verify_inotify(void)
67 {
68 int test_cnt = 0;
69
70 /*
71 * generate sequence of events
72 */
73 SAFE_CHMOD(DIR_PATH, 0755);
74 event_set[test_cnt].mask = IN_ISDIR | IN_ATTRIB;
75 strcpy(event_set[test_cnt].name, "");
76 test_cnt++;
77
78 SAFE_TOUCH(FILE_PATH, 0644, NULL);
79 event_set[test_cnt].mask = IN_OPEN;
80 strcpy(event_set[test_cnt].name, FILE_NAME);
81 test_cnt++;
82 event_set[test_cnt].mask = IN_CLOSE_WRITE;
83 strcpy(event_set[test_cnt].name, FILE_NAME);
84 test_cnt++;
85 event_set[test_cnt].mask = IN_ATTRIB;
86 strcpy(event_set[test_cnt].name, FILE_NAME);
87 test_cnt++;
88
89 int len = read(fd_notify, event_buf, EVENT_BUF_LEN);
90 if (len == -1 && errno != EAGAIN) {
91 tst_brk(TBROK | TERRNO,
92 "read(%d, buf, %zu) failed",
93 fd_notify, EVENT_BUF_LEN);
94 }
95
96 int i = 0, test_num = 0;
97 while (i < len) {
98 struct inotify_event *event;
99 event = (struct inotify_event *)&event_buf[i];
100 if (test_num >= test_cnt) {
101 tst_res(TFAIL,
102 "get unnecessary event: "
103 "wd=%d mask=%08x cookie=%-5u len=%-2u"
104 "name=\"%.*s\"", event->wd, event->mask,
105 event->cookie, event->len, event->len,
106 event->name);
107 } else if ((event_set[test_num].mask == event->mask)
108 &&
109 (!strncmp
110 (event_set[test_num].name, event->name,
111 event->len))) {
112 tst_res(TPASS,
113 "get event: wd=%d mask=%08x "
114 "cookie=%-5u len=%-2u name=\"%.*s\"",
115 event->wd, event->mask,
116 event->cookie, event->len,
117 event->len, event->name);
118 } else {
119 tst_res(TFAIL, "get event: wd=%d mask=%08x "
120 "(expected %x) cookie=%-5u len=%-2u "
121 "name=\"%.*s\" (expected \"%s\") %d",
122 event->wd, event->mask,
123 event_set[test_num].mask,
124 event->cookie, event->len, event->len,
125 event->name, event_set[test_num].name,
126 strcmp(event_set[test_num].name,
127 event->name));
128 }
129 test_num++;
130 i += EVENT_SIZE + event->len;
131 }
132
133 for (; test_num < test_cnt; test_num++) {
134 tst_res(TFAIL, "didn't get event: mask=%08x ",
135 event_set[test_num].mask);
136 }
137 }
138
setup(void)139 static void setup(void)
140 {
141 struct stat buf;
142
143 /* Setup an overlay mount with lower dir and file */
144 SAFE_UMOUNT(OVL_MNT);
145 SAFE_MKDIR(OVL_LOWER"/"DIR_NAME, 0755);
146 SAFE_TOUCH(OVL_LOWER"/"DIR_NAME"/"FILE_NAME, 0644, NULL);
147 SAFE_MOUNT_OVERLAY();
148
149 fd_notify = SAFE_MYINOTIFY_INIT1(O_NONBLOCK);
150
151 /* Setup a watch on an overlayfs lower directory */
152 wd = SAFE_MYINOTIFY_ADD_WATCH(fd_notify, DIR_PATH, IN_ALL_EVENTS);
153 reap_wd = 1;
154
155 SAFE_STAT(DIR_PATH, &buf);
156 tst_res(TINFO, DIR_PATH " ino=%lu", buf.st_ino);
157
158 /* Drop dentry caches, so overlayfs will allocate a new dentry */
159 SAFE_FILE_PRINTF("/proc/sys/vm/drop_caches", "2");
160
161 /* Copy up directory to make it a merge directory */
162 SAFE_CHMOD(DIR_PATH, 0700);
163
164 /* Lookup directory and see if we got the watched directory inode */
165 SAFE_STAT(DIR_PATH, &buf);
166 tst_res(TINFO, DIR_PATH " ino=%lu", buf.st_ino);
167 }
168
cleanup(void)169 static void cleanup(void)
170 {
171 if (reap_wd && myinotify_rm_watch(fd_notify, wd) < 0) {
172 tst_res(TWARN,
173 "inotify_rm_watch (%d, %d) failed,", fd_notify, wd);
174 }
175
176 if (fd_notify > 0)
177 SAFE_CLOSE(fd_notify);
178 }
179
180 static struct tst_test test = {
181 .needs_root = 1,
182 .mount_device = 1,
183 .needs_overlay = 1,
184 .mntpoint = mntpoint,
185 .setup = setup,
186 .cleanup = cleanup,
187 .test_all = verify_inotify,
188 };
189
190 #else
191 TST_TEST_TCONF("system doesn't have required inotify support");
192 #endif
193