DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 50LNcr6n2946938
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 6461D3858D28
MIME-Version: 1.0
Date: Wed, 22 Jan 2025 00:37:57 +0100
Message-ID: <CAKAoaQk4Ftv=VpoW7uDM7Pjo8HhEHO1cMPz+6A0kmz2fWj4o0g@mail.gmail.com>
Subject: Handing filesystems which do not support some timestamp fields in
 |FILE_BASIC_INFO| and Microsoft NFSv3 driver "NfsV3Attributes" EA ...
To: cygwin@cygwin.com
From: Roland Mainz via Cygwin <cygwin@cygwin.com>
Reply-To: Roland Mainz <roland.mainz@nrubsig.org>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie.com@cygwin.com>

Hi!

----

If a Windows filesystem does not support a type of timestamp it sets
the matching timestamp field in |FILE_BASIC_INFO| to |0LL| (e.g. see
Windows-driver-samples/filesys/cdfs/fileinfo.c:
|Buffer->LastAccessTime.QuadPart = 0| ; typically this can affect
|FILE_BASIC_INFO.CreationTime| and/or
|FILE_BASIC_INFO.LastAccessTime|, but formally any combination of
timestamp fields can be unsupported(==|0LL|)), and the Microsoft NFSv3
driver sets the matching
|nfs_timestruc_t.tv_sec|+|nfs_timestruc_t.tv_nsec| to a negative value
(traditional UNIX uses -1, see
https://github.com/gagern/gnulib/blob/master/lib/stat-time.h#L173 -
and this value is then propagated via NFS), but I can't find a place
in Cygwin where this is explicitly handled - is this missing, or is
this code handling this somehow implicitly ?

----

Bye,
Roland
-- 
  __ .  . __
 (o.\ \/ /.o) roland.mainz@nrubsig.org
  \__\/\/__/  MPEG specialist, C&&JAVA&&Sun&&Unix programmer
  /O /==\ O\  TEL +49 641 3992797
 (;O/ \/ \O;)

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple