As Pavel proposed we can refine fanotify image objects
squeezing common part in separate entry. Finally the objects
are grouped as

enum mark_type {
	INODE	= 1;
	MOUNT	= 2;
}

message fanotify_inode_mark_entry {
	required uint64		i_ino		= 1;
	required fh_entry	f_handle	= 2;
}

message fanotify_mount_mark_entry {
	required uint32		mnt_id		= 1;
}

message fanotify_mark_entry {
	required uint32		id		= 1;
	required mark_type	type		= 2;

	required uint32		mflags		= 3;
	required uint32		mask		= 4;
	required uint32		ignored_mask	= 5;
	required uint32		s_dev		= 6;

	optional fanotify_inode_mark_entry ie	= 7;
	optional fanotify_mount_mark_entry me	= 8;
}

This required some tuning in fdinfo parsing and
fsnotify code itself, but result looks good to me.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>