Re: cp -p : timestamp NOT preserved (coreutils 6.9, Linux)

[Jim Meyering]

"Graf, Peter" <address@hidden> wrote:

> Additional info to my former mail:
>
> 1) My former mail contained a small inconsistency (after anonymizing
> the user name).  The following messages   show the problem in a
> consistent way (username, home-directory name):
>
> ...
> prompt%  cp -p ~/.cshrc ~/tmp/.cshrc
> prompt%  ls -l ~/.cshrc ~/tmp/.cshrc
> -rwxr-x--- 1 pg mygroup 2180 Jan 19  2007 /home/pg/.cshrc
> -rwxr-x--- 1 pg mygroup 2180 Oct 31 14:46 /home/pg/tmp/.cshrc
> Timestamp was NOT preserved.
>
> 2) I did NOT see this bug on a solaris machine with gnu
> copy-coreutils-6.9, acting on the same NFS directory /home/pg/tmp/.
>
> 3) Maybe this bug is similar to bug #340236 ,  that was reported for
> an earlier  corutils version. I saw this too
> late. 
> http://lists.gnu.org/archive/cgi-bin/namazu.cgi?query=340236&submit=Search%21&idxname=bug-coreutils&max=20&result=normal&sort=score

Thanks for the strace details.
That confirms utimes is operating on /proc/fd/... and succeeding,
yet not changing time stamps.
You might want to try the latest snapshot, just in case it helps,
but I doubt it will:

  http://meyering.net/cu/coreutils-6.9-ss.tar.gz
  http://meyering.net/cu/coreutils-6.9-ss.tar.gz.sig

In any case, please try rebuilding with -DHAVE_BUGGY_NFS_TIME_STAMPS.
Your NFS client's kernel (linux-2.6.9-34.0.1.ELsmp, you said) may be at fault.
[from lib/utimens.c]

  /* Some Linux-based NFS clients are buggy, and mishandle time stamps
     of files in NFS file systems in some cases.  We have no
     configure-time test for this, but please see
     <http://bugs.gentoo.org/show_bug.cgi?id=132673> for references to
     some of the problems with Linux 2.6.16.  If this affects you,
     compile with -DHAVE_BUGGY_NFS_TIME_STAMPS; this is reported to
     help in some cases, albeit at a cost in performance.  But you
     really should upgrade your kernel to a fixed version, since the
     problem affects many applications.  */