1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2022 CTERA Networks. All Rights Reserved.
4 *
5 * Started by Amir Goldstein <[email protected]>
6 * based on reproducer from Ivan Delalande <[email protected]>
7 */
8
9 /*\
10 * [Description]
11 *
12 * Test opening files after receiving IN_DELETE.
13 *
14 * Kernel v5.13 has a regression allowing files to be open after IN_DELETE.
15 *
16 * The problem has been fixed by commit:
17 * a37d9a17f099 ("fsnotify: invalidate dcache before IN_DELETE event").
18 */
19
20 #include "config.h"
21
22 #include <stdio.h>
23 #include <unistd.h>
24 #include <fcntl.h>
25 #include <signal.h>
26 #include <sys/wait.h>
27
28 #include "tst_test.h"
29 #include "tst_safe_macros.h"
30 #include "inotify.h"
31
32 #if defined(HAVE_SYS_INOTIFY_H)
33 #include <sys/inotify.h>
34
35 /* Number of files to test */
36 #define CHURN_FILES 9999
37
38 #define EVENT_MAX 32
39 /* Size of the event structure, not including the name */
40 #define EVENT_SIZE (sizeof(struct inotify_event))
41 #define EVENT_BUF_LEN (EVENT_MAX * (EVENT_SIZE + 16))
42
43 static pid_t pid;
44
45 static char event_buf[EVENT_BUF_LEN];
46
churn(void)47 static void churn(void)
48 {
49 char path[10];
50 int i;
51
52 for (i = 0; i <= CHURN_FILES; ++i) {
53 snprintf(path, sizeof(path), "%d", i);
54 SAFE_FILE_PRINTF(path, "1");
55 SAFE_UNLINK(path);
56 }
57 }
58
verify_inotify(void)59 static void verify_inotify(void)
60 {
61 int nevents = 0, opened = 0;
62 struct inotify_event *event;
63 int inotify_fd;
64
65 inotify_fd = SAFE_MYINOTIFY_INIT();
66 SAFE_MYINOTIFY_ADD_WATCH(inotify_fd, ".", IN_DELETE);
67
68 pid = SAFE_FORK();
69 if (pid == 0) {
70 SAFE_CLOSE(inotify_fd);
71 churn();
72 return;
73 }
74
75 while (!opened && nevents < CHURN_FILES) {
76 int i, fd, len;
77
78 len = SAFE_READ(0, inotify_fd, event_buf, EVENT_BUF_LEN);
79
80 for (i = 0; i < len; i += EVENT_SIZE + event->len) {
81 event = (struct inotify_event *)&event_buf[i];
82
83 if (!(event->mask & IN_DELETE))
84 continue;
85
86 nevents++;
87
88 /* Open file after IN_DELETE should fail */
89 fd = open(event->name, O_RDONLY);
90 if (fd < 0)
91 continue;
92
93 tst_res(TFAIL, "File %s opened after IN_DELETE", event->name);
94 SAFE_CLOSE(fd);
95 opened = 1;
96 break;
97 }
98 }
99
100 SAFE_CLOSE(inotify_fd);
101
102 if (!nevents)
103 tst_res(TFAIL, "Didn't get any IN_DELETE events");
104 else if (!opened)
105 tst_res(TPASS, "Got %d IN_DELETE events", nevents);
106
107 /* Kill the child creating / deleting files and wait for it */
108 SAFE_KILL(pid, SIGKILL);
109 pid = 0;
110 SAFE_WAIT(NULL);
111 }
112
cleanup(void)113 static void cleanup(void)
114 {
115 if (pid) {
116 SAFE_KILL(pid, SIGKILL);
117 SAFE_WAIT(NULL);
118 }
119 }
120
121 static struct tst_test test = {
122 .needs_tmpdir = 1,
123 .forks_child = 1,
124 .cleanup = cleanup,
125 .test_all = verify_inotify,
126 .tags = (const struct tst_tag[]) {
127 {"linux-git", "a37d9a17f099"},
128 {}
129 }
130 };
131
132 #else
133 TST_TEST_TCONF("system doesn't have required inotify support");
134 #endif
135