1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2014 SUSE Linux.  All Rights Reserved.
4 * Author: Jan Kara <jack@suse.cz>
5 *
6 * DESCRIPTION
7 *     Check that inotify overflow event is properly generated
8 *
9 * ALGORITHM
10 *     Generate enough events without reading them and check that overflow
11 *     event is generated.
12 */
13#include "config.h"
14
15#include <stdio.h>
16#include <sys/stat.h>
17#include <sys/types.h>
18#include <fcntl.h>
19#include <errno.h>
20#include <string.h>
21#include <sys/syscall.h>
22#include "tst_test.h"
23#include "inotify.h"
24
25#if defined(HAVE_SYS_INOTIFY_H)
26#include <sys/inotify.h>
27
28/* size of the event structure, not counting name */
29#define EVENT_SIZE  (sizeof(struct inotify_event))
30#define EVENT_BUF_LEN (EVENT_SIZE * 16)
31
32#define BUF_SIZE 256
33static char fname[BUF_SIZE];
34static char buf[BUF_SIZE];
35static int fd, fd_notify;
36static int wd;
37static int max_events;
38
39static char event_buf[EVENT_BUF_LEN];
40
41void verify_inotify(void)
42{
43	int i;
44	int len, stop;
45
46	/*
47	 * generate events
48	 */
49	fd = SAFE_OPEN(fname, O_RDWR);
50
51	for (i = 0; i < max_events; i++) {
52		SAFE_LSEEK(fd, 0, SEEK_SET);
53		SAFE_READ(1, fd, buf, BUF_SIZE);
54		SAFE_LSEEK(fd, 0, SEEK_SET);
55		SAFE_WRITE(SAFE_WRITE_ALL, fd, buf, BUF_SIZE);
56	}
57
58	SAFE_CLOSE(fd);
59
60	stop = 0;
61	while (!stop) {
62		/*
63		 * get list on events
64		 */
65		len = read(fd_notify, event_buf, EVENT_BUF_LEN);
66		if (len < 0) {
67			tst_brk(TBROK | TERRNO,
68				"read(%d, buf, %zu) failed",
69				fd_notify, EVENT_BUF_LEN);
70		}
71
72		/*
73		 * check events
74		 */
75		i = 0;
76		while (i < len) {
77			struct inotify_event *event;
78
79			event = (struct inotify_event *)&event_buf[i];
80			if (event->mask != IN_ACCESS &&
81					event->mask != IN_MODIFY &&
82					event->mask != IN_OPEN &&
83					event->mask != IN_Q_OVERFLOW) {
84				tst_res(TFAIL,
85					"get event: wd=%d mask=%x "
86					"cookie=%u (expected 0) len=%u",
87					event->wd, event->mask,
88					event->cookie, event->len);
89				stop = 1;
90				break;
91			}
92			if (event->mask == IN_Q_OVERFLOW) {
93				if (event->len != 0 ||
94						event->cookie != 0 ||
95						event->wd != -1) {
96					tst_res(TFAIL,
97						"invalid overflow event: "
98						"wd=%d mask=%x "
99						"cookie=%u len=%u",
100						event->wd, event->mask,
101						event->cookie,
102						event->len);
103					stop = 1;
104					break;
105				}
106				if ((int)(i + EVENT_SIZE) != len) {
107					tst_res(TFAIL,
108						"overflow event is not last");
109					stop = 1;
110					break;
111				}
112				tst_res(TPASS, "get event: wd=%d "
113					"mask=%x cookie=%u len=%u",
114					event->wd, event->mask,
115					event->cookie, event->len);
116				stop = 1;
117				break;
118			}
119			i += EVENT_SIZE + event->len;
120		}
121	}
122}
123
124static void setup(void)
125{
126	sprintf(fname, "tfile_%d", getpid());
127	fd = SAFE_OPEN(fname, O_RDWR | O_CREAT, 0700);
128	SAFE_WRITE(SAFE_WRITE_ALL, fd, buf, BUF_SIZE);
129	SAFE_CLOSE(fd);
130
131	fd_notify = SAFE_MYINOTIFY_INIT1(O_NONBLOCK);
132
133	wd = SAFE_MYINOTIFY_ADD_WATCH(fd_notify, fname, IN_ALL_EVENTS);
134
135	SAFE_FILE_SCANF("/proc/sys/fs/inotify/max_queued_events",
136			"%d", &max_events);
137}
138
139static void cleanup(void)
140{
141	if (fd_notify > 0 && myinotify_rm_watch(fd_notify, wd) == -1) {
142		tst_res(TWARN | TERRNO, "inotify_rm_watch (%d, %d) failed",
143			fd_notify, wd);
144	}
145
146	if (fd_notify > 0)
147		SAFE_CLOSE(fd_notify);
148}
149
150static struct tst_test test = {
151	.needs_tmpdir = 1,
152	.setup = setup,
153	.cleanup = cleanup,
154	.test_all = verify_inotify,
155};
156
157#else
158	TST_TEST_TCONF("system doesn't have required inotify support");
159#endif
160