[PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6]

[Jan Engelhardt]

On Thursday 2010-07-15 04:17, David Howells wrote:
> (6) BSD stat compatibility: Including more fields from the BSD stat such as
>     creation time (st_btime) and inode generation number (st_gen) [Jeremy
>     Allison, Bernd Schubert].
>where st_btime is the file creation time, st_gen is the inode generation
>(i_generation), st_data_version is the data version number (i_version),
>st_inode_flags is the flags from FS_IOC_GETFLAGS plus some extras,
>request_mask and st_result_mask are bitmasks of data desired/provided and
>st_extra_results[] is where as-yet undefined fields are appended.

Linux already has a creation time field, it's called otime (there is no "b" in
"creation"), and you will find scattered fragments of that all over the kernel
(foremost, fs/jfs/, now btrfs, and I also notice sysvipc having something with
that name).

>	struct xstat_time {
>		unsigned long long	tv_sec, tv_nsec;
>	};

If it helps getting rid of the ugly suseconds_t in userspace ;-)