From: Martin Wege <martin.l.wege@gmail.com>
To: cygwin@cygwin.com
Subject: Re: [EXTERNAL] Re: mkfifo: cannot set permissions of 'x.fifo': Not a directory
Date: Thu, 24 Aug 2023 18:40:29 +0200 [thread overview]
Message-ID: <CANH4o6Ozqq7vSqRv+-PLVWcSDToh3WbJ9_E9obm-7R_6WNz5mw@mail.gmail.com> (raw)
In-Reply-To: <14a692f6-7244-4a7e-a69b-d14521fb01e8@secure-endpoints.com>
On Wed, Aug 23, 2023 at 5:44 PM Jeffrey Altman via Cygwin
<cygwin@cygwin.com> wrote:
>
> On 8/22/2023 10:52 AM, Lavrentiev, Anton (NIH/NLM/NCBI) [C] via Cygwin
> wrote:
> >> FIFOs which don't make *any* sense
> >> ... FWIW, a remote NFS fileystem.
> > I got an impression that the OP is trying to deploy something (maybe the entire Cygwin) onto an NFS share. So the named FIFO "file" is also created in there.
> >
> > It's pointless to assume that the FIFO can be used as a communication device between the hosts that can mount the share, but it can be quite feasible to envision a scenario, in which the same host opens the FIFO located on the share from two processes and establish the communication using that special "file" (which is basically a special data-less i-node).
>
> I've been following this thread with quite a bit of curiosity. For those
> who do not know me, I'm the lead developer of the AFS filesystem on
> Windows. There have been requests for more than two decades for AFS
> clients to add support for locally created pipe files because AFS
> volumes are often used as home directories (even on Windows) and so many
> applications allocate a pipe in the home directory as a method of
> inter-process communication or a lock. The problem is that even if the
> intended usage of the file is entirely local, the directory object, the
> directory entry and the allocated inode (or equivalent) is network
> visible.
Who cares? It is up to the user, script or application author to do
'the right thing(tm)'.
>
> What happens when the user executes two copies of an
> application such as PyCharm on two separate machines sharing the same
> home directory? Does the directory entry and inode get reused on startup
> and/or deleted on exit? How does that impact the process instance on the
> other machine? The conclusion I came to long ago is that if pipes are to
> be implemented in a network file system namespace then the pipes must be
> fully functional network pipes. In just about all cases applications can
> be configured to use a non-default paths. In my opinion they should not
> be placed in a shared file system.
Oh my god. Please have this debate at the Austin Group. They do the
POSIX standard. We're here about implementing&using the POSIX
standard.
We only want that mkfifo() works with Cygwin on a NFS filesystem, as
specified in https://pubs.opengroup.org/onlinepubs/009696799/functions/mkfifo.html
My intention was not to invent something new. Just code using mkfifo,
and scripts using /usr/bin/mkfifo, should work on NFS. On UNIX&Linux
this works.
Have a look at https://cygwin.com/pipermail/cygwin/2023-August/254266.html,
sounds like there is a feasible way to implement this.
Thanks,
Martin
next prev parent reply other threads:[~2023-08-24 16:40 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-07 14:42 Martin Wege
2023-08-07 18:26 ` Brian Inglis
2023-08-07 19:14 ` Corinna Vinschen
2023-08-07 21:14 ` Martin Wege
2023-08-08 8:20 ` Corinna Vinschen
2023-08-08 19:38 ` Martin Wege
2023-08-09 8:01 ` Corinna Vinschen
2023-08-09 9:12 ` Martin Wege
2023-08-09 9:56 ` Corinna Vinschen
2023-08-10 12:49 ` Martin Wege
2023-08-18 4:02 ` Martin Wege
2023-08-18 8:34 ` Corinna Vinschen
2023-08-18 13:14 ` Martin Wege
2023-08-21 4:49 ` Cedric Blancher
2023-08-21 8:37 ` Corinna Vinschen
2023-08-22 14:52 ` [EXTERNAL] " Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2023-08-22 23:05 ` How to fix |mkfifo()| failure if |pathname| is on NFS ? / was: " Roland Mainz
2023-08-24 16:45 ` Martin Wege
2023-08-25 4:25 ` Cedric Blancher
2023-08-26 17:58 ` Martin Wege
2023-08-25 12:18 ` Corinna Vinschen
2023-08-25 12:25 ` Corinna Vinschen
2023-08-26 11:26 ` Cedric Blancher
2023-08-26 14:15 ` Corinna Vinschen
2023-08-26 17:40 ` Martin Wege
2023-08-26 19:16 ` Brian Inglis
2023-08-25 15:14 ` Roland Mainz
2023-08-26 11:27 ` Cedric Blancher
2023-08-25 23:21 ` Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2023-08-26 14:28 ` Corinna Vinschen
2023-08-26 14:39 ` Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2023-08-26 17:44 ` Documenting Cygwin on NFS, no longer only exchange-medium! " Martin Wege
2023-08-26 19:16 ` Brian Inglis
2023-08-27 12:35 ` Corinna Vinschen
2023-08-28 5:35 ` Cedric Blancher
2023-08-28 10:02 ` Corinna Vinschen
2023-08-28 11:41 ` Joshuah Hurst
[not found] ` <14a692f6-7244-4a7e-a69b-d14521fb01e8@secure-endpoints.com>
2023-08-23 17:39 ` Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2023-08-24 5:28 ` Cedric Blancher
2023-08-24 16:40 ` Martin Wege [this message]
2023-08-21 12:12 ` Martin Wege
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