[5063] in bugtraq
Re: request-route
daemon@ATHENA.MIT.EDU (Kragen Sitaker)
Thu Jul 31 12:55:37 1997
Date: Wed, 30 Jul 1997 23:05:38 -0400
Reply-To: Kragen Sitaker <kragen@dnaco.net>
From: Kragen Sitaker <kragen@DNACO.NET>
X-To: John Macdonald <jmm@ELEGANT.COM>
To: BUGTRAQ@NETSPACE.ORG
In-Reply-To: <m0wtJfz-0003F6C@elegant.com>
On Tue, 29 Jul 1997, John Macdonald wrote:
> Eric Bennett wrote :
> || On Tue, 29 Jul 1997, Zoltan Hidvegi wrote:
> || > lock files in a world-writable directory from a bourne-shell script.
> ||
> || I have done this by creating directories instead of files: only one mkdir
> || will complete.
>
> Nope, you;ve got it backwards. To begin, the same basic problem
> applies to both. If an operation succeeds, but the
> acknowledgement gets lost on the network, then the time-out
> cause a retry which will fail because the target item exists.
I believe that most implementations of NFS maintain a cache of the most
recent few non-idempotent operations (mkdir, rm, rmdir, etc.) and their
results; if the request is retried, the result is resent. Can someone who
has read the code confirm or deny this?
Kragen
