[LTP] [PATCH 5/5] syscalls/fanotify09: Add test case for events with filename info

[Amir Goldstein <amir73il@gmail.com>]

Kernel v5.9 has a bug when there is a mark on filesystem or mount
interested in events with filename AND there is an additional
mark on a parent watching children.

In some situations the event is reported to filesystem or mount mark
without the filename info.

This bug is fixed by kernel commit 7372e79c9eb9:
  fanotify: fix logic of reporting name info with watched parent

The test case requires a blockdev filesystem.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 .../kernel/syscalls/fanotify/fanotify09.c     | 49 ++++++++++++++++---
 1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/testcases/kernel/syscalls/fanotify/fanotify09.c b/testcases/kernel/syscalls/fanotify/fanotify09.c
index 0f1923981..25b6b8be1 100644
--- a/testcases/kernel/syscalls/fanotify/fanotify09.c
+++ b/testcases/kernel/syscalls/fanotify/fanotify09.c
@@ -19,6 +19,10 @@
  * Test case #2 is a regression test for commit 55bf882c7f13:
  *
  *      fanotify: fix merging marks masks with FAN_ONDIR
+ *
+ * Test case #5 is a regression test for commit 7372e79c9eb9:
+ *
+ *      fanotify: fix logic of reporting name info with watched parent
  */
 #define _GNU_SOURCE
 #include "config.h"
@@ -53,15 +57,19 @@ static int fd_notify[NUM_GROUPS];
 
 static char event_buf[EVENT_BUF_LEN];
 
+#define MOUNT_PATH "fs_mnt"
 #define MOUNT_NAME "mntpoint"
 #define DIR_NAME "testdir"
 #define FILE2_NAME "testfile"
 static int mount_created;
 
+static int fan_report_dfid_unsupported;
+
 static struct tcase {
 	const char *tname;
 	struct fanotify_mark_type mark;
 	unsigned int ondir;
+	unsigned int report_name;
 	const char *close_nowrite;
 	int nevents;
 } tcases[] = {
@@ -69,6 +77,7 @@ static struct tcase {
 		"Events on non-dir child with both parent and mount marks",
 		INIT_FANOTIFY_MARK_TYPE(MOUNT),
 		0,
+		0,
 		DIR_NAME,
 		1,
 	},
@@ -76,6 +85,7 @@ static struct tcase {
 		"Events on non-dir child and subdir with both parent and mount marks",
 		INIT_FANOTIFY_MARK_TYPE(MOUNT),
 		FAN_ONDIR,
+		0,
 		DIR_NAME,
 		2,
 	},
@@ -83,6 +93,7 @@ static struct tcase {
 		"Events on non-dir child and parent with both parent and mount marks",
 		INIT_FANOTIFY_MARK_TYPE(MOUNT),
 		FAN_ONDIR,
+		0,
 		".",
 		2,
 	},
@@ -90,6 +101,7 @@ static struct tcase {
 		"Events on non-dir child and subdir with both parent and subdir marks",
 		INIT_FANOTIFY_MARK_TYPE(INODE),
 		FAN_ONDIR,
+		0,
 		DIR_NAME,
 		2,
 	},
@@ -97,6 +109,15 @@ static struct tcase {
 		"Events on non-dir children with both parent and mount marks",
 		INIT_FANOTIFY_MARK_TYPE(MOUNT),
 		0,
+		0,
+		FILE2_NAME,
+		2,
+	},
+	{
+		"Events on non-dir child with both parent and mount marks and filename info",
+		INIT_FANOTIFY_MARK_TYPE(MOUNT),
+		0,
+		FAN_REPORT_DFID_NAME,
 		FILE2_NAME,
 		2,
 	},
@@ -105,12 +126,15 @@ static struct tcase {
 static void create_fanotify_groups(struct tcase *tc)
 {
 	struct fanotify_mark_type *mark = &tc->mark;
-	unsigned int i, onchild, ondir = tc->ondir;
+	unsigned int i, onchild, report_name, ondir = tc->ondir;
 
 	for (i = 0; i < NUM_GROUPS; i++) {
-		fd_notify[i] = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF |
-						  FAN_NONBLOCK,
-						  O_RDONLY);
+		/*
+		 * The first group may request events with filename info.
+		 */
+		report_name = (i == 0) ? tc->report_name : 0;
+		fd_notify[i] = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF | report_name |
+						  FAN_NONBLOCK, O_RDONLY);
 
 		/*
 		 * Add subdir or mount mark for each group with CLOSE event,
@@ -217,6 +241,11 @@ static void test_fanotify(unsigned int n)
 
 	tst_res(TINFO, "Test #%d: %s", n, tc->tname);
 
+	if (fan_report_dfid_unsupported && tc->report_name) {
+		FANOTIFY_INIT_FLAGS_ERR_MSG(FAN_REPORT_DFID_NAME, fan_report_dfid_unsupported);
+		return;
+	}
+
 	create_fanotify_groups(tc);
 
 	/*
@@ -249,10 +278,11 @@ static void test_fanotify(unsigned int n)
 			ret, tc->nevents * (int)FAN_EVENT_METADATA_LEN);
 	}
 	event = (struct fanotify_event_metadata *)event_buf;
-	verify_event(0, event, FAN_MODIFY, "");
+	verify_event(0, event, FAN_MODIFY, tc->report_name ? fname : "");
 	event = FAN_EVENT_NEXT(event, ret);
 	if (tc->nevents > 1) {
-		verify_event(0, event, FAN_CLOSE_NOWRITE, "");
+		verify_event(0, event, FAN_CLOSE_NOWRITE,
+			     tc->report_name ? (tc->ondir ? "." : tc->close_nowrite) : "");
 		event = FAN_EVENT_NEXT(event, ret);
 	}
 	if (ret > 0) {
@@ -304,8 +334,11 @@ static void test_fanotify(unsigned int n)
 
 static void setup(void)
 {
+	fan_report_dfid_unsupported = fanotify_init_flags_supported_on_fs(FAN_REPORT_DFID_NAME,
+									  MOUNT_PATH);
+
 	SAFE_MKDIR(MOUNT_NAME, 0755);
-	SAFE_MOUNT(MOUNT_NAME, MOUNT_NAME, "none", MS_BIND, NULL);
+	SAFE_MOUNT(MOUNT_PATH, MOUNT_NAME, "none", MS_BIND, NULL);
 	mount_created = 1;
 	SAFE_CHDIR(MOUNT_NAME);
 	SAFE_MKDIR(DIR_NAME, 0755);
@@ -330,6 +363,8 @@ static struct tst_test test = {
 	.tcnt = ARRAY_SIZE(tcases),
 	.setup = setup,
 	.cleanup = cleanup,
+	.mount_device = 1,
+	.mntpoint = MOUNT_PATH,
 	.needs_tmpdir = 1,
 	.needs_root = 1,
 	.tags = (const struct tst_tag[]) {
-- 
2.25.1