pub const fanotify = struct {
    pub const InitFlags = packed struct(u32) {
        CLOEXEC: bool = false,
        NONBLOCK: bool = false,
        CLASS: enum(u2) {
            NOTIF = 0,
            CONTENT = 1,
            PRE_CONTENT = 2,
        } = .NOTIF,
        UNLIMITED_QUEUE: bool = false,
        UNLIMITED_MARKS: bool = false,
        ENABLE_AUDIT: bool = false,
        REPORT_PIDFD: bool = false,
        REPORT_TID: bool = false,
        REPORT_FID: bool = false,
        REPORT_DIR_FID: bool = false,
        REPORT_NAME: bool = false,
        REPORT_TARGET_FID: bool = false,
        _: u19 = 0,
    };

    pub const MarkFlags = packed struct(u32) {
        ADD: bool = false,
        REMOVE: bool = false,
        DONT_FOLLOW: bool = false,
        ONLYDIR: bool = false,
        MOUNT: bool = false,
        /// Mutually exclusive with `IGNORE`
        IGNORED_MASK: bool = false,
        IGNORED_SURV_MODIFY: bool = false,
        FLUSH: bool = false,
        FILESYSTEM: bool = false,
        EVICTABLE: bool = false,
        /// Mutually exclusive with `IGNORED_MASK`
        IGNORE: bool = false,
        _: u21 = 0,
    };

    pub const MarkMask = packed struct(u64) {
        /// File was accessed
        ACCESS: bool = false,
        /// File was modified
        MODIFY: bool = false,
        /// Metadata changed
        ATTRIB: bool = false,
        /// Writtable file closed
        CLOSE_WRITE: bool = false,
        /// Unwrittable file closed
        CLOSE_NOWRITE: bool = false,
        /// File was opened
        OPEN: bool = false,
        /// File was moved from X
        MOVED_FROM: bool = false,
        /// File was moved to Y
        MOVED_TO: bool = false,

        /// Subfile was created
        CREATE: bool = false,
        /// Subfile was deleted
        DELETE: bool = false,
        /// Self was deleted
        DELETE_SELF: bool = false,
        /// Self was moved
        MOVE_SELF: bool = false,
        /// File was opened for exec
        OPEN_EXEC: bool = false,
        reserved13: u1 = 0,
        /// Event queued overflowed
        Q_OVERFLOW: bool = false,
        /// Filesystem error
        FS_ERROR: bool = false,

        /// File open in perm check
        OPEN_PERM: bool = false,
        /// File accessed in perm check
        ACCESS_PERM: bool = false,
        /// File open/exec in perm check
        OPEN_EXEC_PERM: bool = false,
        reserved19: u8 = 0,
        /// Interested in child events
        EVENT_ON_CHILD: bool = false,
        /// File was renamed
        RENAME: bool = false,
        reserved30: u1 = 0,
        /// Event occurred against dir
        ONDIR: bool = false,
        reserved31: u33 = 0,
    };

    pub const event_metadata = extern struct {
        event_len: u32,
        vers: u8,
        reserved: u8,
        metadata_len: u16,
        mask: MarkMask align(8),
        fd: i32,
        pid: i32,

        pub const VERSION = 3;
    };

    pub const response = extern struct {
        fd: i32,
        response: u32,
    };

    /// Unique file identifier info record.
    ///
    /// This structure is used for records of types `EVENT_INFO_TYPE.FID`.
    /// `EVENT_INFO_TYPE.DFID` and `EVENT_INFO_TYPE.DFID_NAME`.
    ///
    /// For `EVENT_INFO_TYPE.DFID_NAME` there is additionally a null terminated
    /// name immediately after the file handle.
    pub const event_info_fid = extern struct {
        hdr: event_info_header,
        fsid: kernel_fsid_t,
        /// Following is an opaque struct file_handle that can be passed as
        /// an argument to open_by_handle_at(2).
        handle: [0]u8,
    };

    /// Variable length info record following event metadata.
    pub const event_info_header = extern struct {
        info_type: EVENT_INFO_TYPE,
        pad: u8,
        len: u16,
    };

    pub const EVENT_INFO_TYPE = enum(u8) {
        FID = 1,
        DFID_NAME = 2,
        DFID = 3,
        PIDFD = 4,
        ERROR = 5,
        OLD_DFID_NAME = 10,
        OLD_DFID = 11,
        NEW_DFID_NAME = 12,
        NEW_DFID = 13,
    };
}