[LTP] [PATCH 1/5] syscalls/inotify12: Introduce test for inotify mask flags

[Amir Goldstein]

Test behavior of IN_ONESHOT and IN_EXCL_UNLINK.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 runtest/syscalls                              |   1 +
 testcases/kernel/syscalls/inotify/.gitignore  |   1 +
 testcases/kernel/syscalls/inotify/inotify12.c | 168 ++++++++++++++++++
 3 files changed, 170 insertions(+)
 create mode 100644 testcases/kernel/syscalls/inotify/inotify12.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 3b26d19e6..1259e41f1 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -588,6 +588,7 @@ inotify08 inotify08
 inotify09 inotify09
 inotify10 inotify10
 inotify11 inotify11
+inotify12 inotify12
 
 fanotify01 fanotify01
 fanotify02 fanotify02
diff --git a/testcases/kernel/syscalls/inotify/.gitignore b/testcases/kernel/syscalls/inotify/.gitignore
index 593cf6c04..f6e5c546a 100644
--- a/testcases/kernel/syscalls/inotify/.gitignore
+++ b/testcases/kernel/syscalls/inotify/.gitignore
@@ -9,3 +9,4 @@
 /inotify09
 /inotify10
 /inotify11
+/inotify12
diff --git a/testcases/kernel/syscalls/inotify/inotify12.c b/testcases/kernel/syscalls/inotify/inotify12.c
new file mode 100644
index 000000000..fe72771c5
--- /dev/null
+++ b/testcases/kernel/syscalls/inotify/inotify12.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 CTERA Networks. All Rights Reserved.
+ *
+ * Author: Amir Goldstein <amir73il@gmail.com>
+ */
+
+/*\
+ * [Description]
+ * Test special inotify mask flags.
+ *
+ * Regression test for kernel commit a32e697cda27:
+ *
+ *     inotify: show inotify mask flags in proc fdinfo
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include "tst_test.h"
+#include "tst_safe_macros.h"
+#include "inotify.h"
+
+#if defined(HAVE_SYS_INOTIFY_H)
+#include <sys/inotify.h>
+
+#define EVENT_MAX 32
+/* Size of the event structure, not including the name */
+#define EVENT_SIZE	(sizeof(struct inotify_event))
+#define EVENT_BUF_LEN	(EVENT_MAX * (EVENT_SIZE + 16))
+
+#define	TEST_FILE	"test_file"
+
+static char event_buf[EVENT_BUF_LEN];
+
+static struct tcase {
+	const char *tname;
+	unsigned int mask;
+	int expect_events;
+} tcases[] = {
+	{
+		"Watch for multi events",
+		IN_MODIFY,
+		2,
+	},
+	{
+		"Watch for single event",
+		IN_MODIFY | IN_ONESHOT,
+		1,
+	},
+	{
+		"Watch for events on linked file",
+		IN_MODIFY | IN_EXCL_UNLINK,
+		1,
+	},
+};
+
+int fd_notify;
+
+static void verify_inotify(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+	int fd, len;
+	unsigned int tmpmask;
+	char procfdinfo[100];
+	struct inotify_event *event = (struct inotify_event *)event_buf;
+
+	tst_res(TINFO, "Test #%d: %s", n, tc->tname);
+
+	fd_notify = SAFE_MYINOTIFY_INIT1(O_NONBLOCK);
+
+	SAFE_FILE_PRINTF(TEST_FILE, "1");
+
+	SAFE_MYINOTIFY_ADD_WATCH(fd_notify, ".", tc->mask);
+
+	sprintf(procfdinfo, "/proc/%d/fdinfo/%d", (int)getpid(), fd_notify);
+	if (FILE_LINES_SCANF(procfdinfo, "inotify wd:%*d ino:%*x sdev:%*x mask:%x",
+			     &tmpmask)) {
+		tst_res(TFAIL, "Could not parse inotify fdinfo");
+	} else if (tmpmask != tc->mask) {
+		tst_res(TFAIL, "Incorrect mask %x in inotify fdinfo (expected %x)",
+			tmpmask, tc->mask);
+	} else {
+		tst_res(TPASS, "Correct mask in inotify fdinfo");
+	}
+
+	fd = SAFE_OPEN(TEST_FILE, O_RDWR);
+	SAFE_WRITE(1, fd, "2", 1);
+
+	/*
+	 * Read the 1st IN_MODIFY event
+	 */
+	len = SAFE_READ(0, fd_notify, event_buf, EVENT_BUF_LEN);
+
+	if (len < (int)sizeof(*event)) {
+		tst_res(TFAIL, "Got no events");
+	} else if (event->mask == IN_MODIFY) {
+		tst_res(TPASS, "Got 1st event as expected");
+	} else {
+		tst_res(TFAIL, "Got event 0x%x (expected 0x%x)",
+				event->mask, IN_MODIFY);
+	}
+
+	/*
+	 * Unlink file so IN_EXCL_UNLINK won't get IN_ACCESS event.
+	 * IN_ONESHOT won't get IN_ACCESS event because IN_MODIFY
+	 * was already generated.
+	 */
+	SAFE_UNLINK(TEST_FILE);
+	SAFE_WRITE(1, fd, "3", 1);
+	SAFE_CLOSE(fd);
+
+	/*
+	 * Possibly read the 2nd IN_MODIFY event
+	 */
+	errno = 0;
+	len = read(fd_notify, event_buf, EVENT_BUF_LEN);
+	SAFE_CLOSE(fd_notify);
+	if (len < 0 && errno == EAGAIN) {
+		/* Treat no event same as we treat IN_IGNORED */
+		event->mask = IN_IGNORED;
+	} else if (len < (int)sizeof(*event)) {
+		tst_res(TFAIL | TERRNO, "Failed to read events");
+		return;
+	}
+
+	if (event->mask == IN_MODIFY) {
+		if (tc->expect_events > 1)
+			tst_res(TPASS, "Got 2nd event as expected");
+		else
+			tst_res(TFAIL, "Got unexpected 2nd event");
+	} else if (event->mask == IN_IGNORED) {
+		if (tc->expect_events == 1)
+			tst_res(TPASS, "Got no more events as expected");
+		else
+			tst_res(TFAIL, "Got only one event (expected %d)",
+					tc->expect_events);
+	} else {
+		tst_res(TFAIL, "Got unexpected event 0x%x",
+				event->mask);
+	}
+}
+
+static void cleanup(void)
+{
+	if (fd_notify > 0)
+		SAFE_CLOSE(fd_notify);
+}
+
+static struct tst_test test = {
+	.timeout = 10,
+	.needs_tmpdir = 1,
+	.cleanup = cleanup,
+	.test = verify_inotify,
+	.tcnt = ARRAY_SIZE(tcases),
+	.tags = (const struct tst_tag[]) {
+		{"linux-git", "a32e697cda27"},
+		{}
+};
+
+#else
+	TST_TEST_TCONF("system doesn't have required inotify support");
+#endif
-- 
2.25.1