Merge tag 'fsnotify_for_v6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify fix from Jan Kara:
 "A fix for the recently merged mount notification support"

* tag 'fsnotify_for_v6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  selftests/fs/mount-notify: test also remove/flush of mntns marks
  fanotify: fix flush of mntns marks

Author: torvalds

fs/notify/fanotify/fanotify_user.c

@@ -1961,12 +1961,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 		return -EINVAL;
 
 	if (mark_cmd == FAN_MARK_FLUSH) {
-		if (mark_type == FAN_MARK_MOUNT)
-			fsnotify_clear_vfsmount_marks_by_group(group);
-		else if (mark_type == FAN_MARK_FILESYSTEM)
-			fsnotify_clear_sb_marks_by_group(group);
-		else
-			fsnotify_clear_inode_marks_by_group(group);
+		fsnotify_clear_marks_by_group(group, obj_type);
 		return 0;
 	}
 

include/linux/fsnotify_backend.h

@@ -907,21 +907,6 @@ extern void fsnotify_wait_marks_destroyed(void);
 /* Clear all of the marks of a group attached to a given object type */
 extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
 					  unsigned int obj_type);
-/* run all the marks in a group, and clear all of the vfsmount marks */
-static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
-{
-	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT);
-}
-/* run all the marks in a group, and clear all of the inode marks */
-static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
-{
-	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE);
-}
-/* run all the marks in a group, and clear all of the sn marks */
-static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group)
-{
-	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB);
-}
 extern void fsnotify_get_mark(struct fsnotify_mark *mark);
 extern void fsnotify_put_mark(struct fsnotify_mark *mark);
 extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info);

tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c

@@ -48,8 +48,16 @@ static uint64_t get_mnt_id(struct __test_metadata *const _metadata,
 
 static const char root_mntpoint_templ[] = "/tmp/mount-notify_test_root.XXXXXX";
 
+static const int mark_cmds[] = {
+	FAN_MARK_ADD,
+	FAN_MARK_REMOVE,
+	FAN_MARK_FLUSH
+};
+
+#define NUM_FAN_FDS ARRAY_SIZE(mark_cmds)
+
 FIXTURE(fanotify) {
-	int fan_fd;
+	int fan_fd[NUM_FAN_FDS];
 	char buf[256];
 	unsigned int rem;
 	void *next;
@@ -61,7 +69,7 @@ FIXTURE(fanotify) {
 
 FIXTURE_SETUP(fanotify)
 {
-	int ret;
+	int i, ret;
 
 	ASSERT_EQ(unshare(CLONE_NEWNS), 0);
 
@@ -89,20 +97,34 @@ FIXTURE_SETUP(fanotify)
 	self->root_id = get_mnt_id(_metadata, "/");
 	ASSERT_NE(self->root_id, 0);
 
-	self->fan_fd = fanotify_init(FAN_REPORT_MNT, 0);
-	ASSERT_GE(self->fan_fd, 0);
-
-	ret = fanotify_mark(self->fan_fd, FAN_MARK_ADD | FAN_MARK_MNTNS,
-			    FAN_MNT_ATTACH | FAN_MNT_DETACH, self->ns_fd, NULL);
-	ASSERT_EQ(ret, 0);
+	for (i = 0; i < NUM_FAN_FDS; i++) {
+		self->fan_fd[i] = fanotify_init(FAN_REPORT_MNT | FAN_NONBLOCK,
+						0);
+		ASSERT_GE(self->fan_fd[i], 0);
+		ret = fanotify_mark(self->fan_fd[i], FAN_MARK_ADD |
+				    FAN_MARK_MNTNS,
+				    FAN_MNT_ATTACH | FAN_MNT_DETACH,
+				    self->ns_fd, NULL);
+		ASSERT_EQ(ret, 0);
+		// On fd[0] we do an extra ADD that changes nothing.
+		// On fd[1]/fd[2] we REMOVE/FLUSH which removes the mark.
+		ret = fanotify_mark(self->fan_fd[i], mark_cmds[i] |
+				    FAN_MARK_MNTNS,
+				    FAN_MNT_ATTACH | FAN_MNT_DETACH,
+				    self->ns_fd, NULL);
+		ASSERT_EQ(ret, 0);
+	}
 
 	self->rem = 0;
 }
 
 FIXTURE_TEARDOWN(fanotify)
 {
+	int i;
+
 	ASSERT_EQ(self->rem, 0);
-	close(self->fan_fd);
+	for (i = 0; i < NUM_FAN_FDS; i++)
+		close(self->fan_fd[i]);
 
 	ASSERT_EQ(fchdir(self->orig_root), 0);
 
@@ -123,8 +145,21 @@ static uint64_t expect_notify(struct __test_metadata *const _metadata,
 	unsigned int thislen;
 
 	if (!self->rem) {
-		ssize_t len = read(self->fan_fd, self->buf, sizeof(self->buf));
-		ASSERT_GT(len, 0);
+		ssize_t len;
+		int i;
+
+		for (i = NUM_FAN_FDS - 1; i >= 0; i--) {
+			len = read(self->fan_fd[i], self->buf,
+				   sizeof(self->buf));
+			if (i > 0) {
+				// Groups 1,2 should get EAGAIN
+				ASSERT_EQ(len, -1);
+				ASSERT_EQ(errno, EAGAIN);
+			} else {
+				// Group 0 should get events
+				ASSERT_GT(len, 0);
+			}
+		}
 
 		self->rem = len;
 		self->next = (void *) self->buf;