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 <amir73il@gmail.com>
6 * based on reproducer from Ivan Delalande <colona@arista.com>
7 */
8
9 /*\
10 * [Description]
11 * Test opening files after receiving IN_DELETE.
12 *
13 * Kernel v5.13 has a regression allowing files to be open after IN_DELETE.
14 *
15 * The problem has been fixed by commit:
16 * a37d9a17f099 "fsnotify: invalidate dcache before IN_DELETE event".
17 */
18
19 #include "config.h"
20
21 #include <stdio.h>
22 #include <unistd.h>
23 #include <fcntl.h>
24 #include <signal.h>
25 #include <sys/wait.h>
26
27 #include "tst_test.h"
28 #include "tst_safe_macros.h"
29 #include "inotify.h"
30
31 #if defined(HAVE_SYS_INOTIFY_H)
32 #include <sys/inotify.h>
33
34 /* Number of files to test */
35 #define CHURN_FILES 9999
36
37 #define EVENT_MAX 32
38 /* Size of the event structure, not including the name */
39 #define EVENT_SIZE (sizeof(struct inotify_event))
40 #define EVENT_BUF_LEN (EVENT_MAX * (EVENT_SIZE + 16))
41
42 static pid_t pid;
43
44 static char event_buf[EVENT_BUF_LEN];
45
churn(void)46 static void churn(void)
47 {
48 char path[10];
49 int i;
50
51 for (i = 0; i <= CHURN_FILES; ++i) {
52 snprintf(path, sizeof(path), "%d", i);
53 SAFE_FILE_PRINTF(path, "1");
54 SAFE_UNLINK(path);
55 }
56 }
57
verify_inotify(void)58 static void verify_inotify(void)
59 {
60 int nevents = 0, opened = 0;
61 struct inotify_event *event;
62 int inotify_fd;
63
64 inotify_fd = SAFE_MYINOTIFY_INIT();
65 SAFE_MYINOTIFY_ADD_WATCH(inotify_fd, ".", IN_DELETE);
66
67 pid = SAFE_FORK();
68 if (pid == 0) {
69 SAFE_CLOSE(inotify_fd);
70 churn();
71 return;
72 }
73
74 while (!opened && nevents < CHURN_FILES) {
75 int i, fd, len;
76
77 len = SAFE_READ(0, inotify_fd, event_buf, EVENT_BUF_LEN);
78
79 for (i = 0; i < len; i += EVENT_SIZE + event->len) {
80 event = (struct inotify_event *)&event_buf[i];
81
82 if (!(event->mask & IN_DELETE))
83 continue;
84
85 nevents++;
86
87 /* Open file after IN_DELETE should fail */
88 fd = open(event->name, O_RDONLY);
89 if (fd < 0)
90 continue;
91
92 tst_res(TFAIL, "File %s opened after IN_DELETE", event->name);
93 SAFE_CLOSE(fd);
94 opened = 1;
95 break;
96 }
97 }
98
99 SAFE_CLOSE(inotify_fd);
100
101 if (!nevents)
102 tst_res(TFAIL, "Didn't get any IN_DELETE events");
103 else if (!opened)
104 tst_res(TPASS, "Got %d IN_DELETE events", nevents);
105
106 /* Kill the child creating / deleting files and wait for it */
107 SAFE_KILL(pid, SIGKILL);
108 pid = 0;
109 SAFE_WAIT(NULL);
110 }
111
cleanup(void)112 static void cleanup(void)
113 {
114 if (pid) {
115 SAFE_KILL(pid, SIGKILL);
116 SAFE_WAIT(NULL);
117 }
118 }
119
120 static struct tst_test test = {
121 .needs_tmpdir = 1,
122 .forks_child = 1,
123 .cleanup = cleanup,
124 .test_all = verify_inotify,
125 .tags = (const struct tst_tag[]) {
126 {"linux-git", "a37d9a17f099"},
127 {}
128 }
129 };
130
131 #else
132 TST_TEST_TCONF("system doesn't have required inotify support");
133 #endif
134