From: =?iso-8859-1?Q?Bj=F6rn?= Jacke <bj@SerNet.DE>
Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make
 extended file stats available [ver #6]
Date: Fri, 23 Jul 2010 11:14:53 +0200
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To: Ted Ts'o <tytso@mit.edu>, tridge@samba.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Jeremy Allison <jra@samba.org>, linux-cifs@vger.kernel.org,
	linux-nfs@vger.kernel.org, Volk
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On 2010-07-22 at 21:21 -0400 Ted Ts'o sent off:
> Well, not POSIX, because POSIX doesn't have CreationTime at all.
> BSD's birthtime doesn't allow it to be set, and the question here is
> largely philosophical.

actually, it can (partly :). But the way it can be done is an insane ha=
ck:

<quote "http://ace.delos.com/kirk/">
To provide a sensible birth time for applications that are unaware of t=
he birth
time attribute, we changed the semantics of the "utimes" system call so=
 that if
the birth time was newer than the value of the modification time that i=
t was
setting, it sets the birth time to the same time as the modification ti=
me. An
application that is aware of the birth time attribute can set both the =
birth
time and the modification time by doing two calls to "utimes". First it=
 calls
"utimes" with a modification time equal to the saved birth time, then i=
t calls
"utimes" a second time with a modification time equal to the (presumabl=
y newer)
saved modification time.
</quote>

Thus it can also be only be set more in the past.

Cheers
Bj=F6rn
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