Re: [EXIM] Linux - Solaris file locking

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Author: Chris Thompson
Date:  
To: exim-users
Subject: Re: [EXIM] Linux - Solaris file locking
Vadim Vygonets <vadik@???> wrote:
[...]
> Usually, you can't do flock(2)/fcntl(2) via NFS (unless lockd (or
> something) runs).


Well, one might well describe an implementation of NFS without NLM
as defective ...

Unless things go seriously wrong, NFS v4 will have built-in locking
primitives and such implementations will be a thing of the past. We
only have to wait another decade or so.

On a technical nit: "can't do flock(2)/fcntl(2) [...] unless lockd
runs" is true only for modern Unixes that implement flock(3) in
terms of fcntl(F_SETLK). For the older implementations flock(2)
works perfectly well against NFS filing systems, but of course only
interlocks against other processes on the host it was issued on.

Exim doesn't use flock anyway, of course, so this is MOTA.

Chris Thompson               Cambridge University Computing Service,
Email: cet1@???    New Museums Site, Cambridge CB2 3QG,
Phone: +44 1223 334715       United Kingdom.


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