[112] in arla-drinkers
Re: flock and fcntl(F_SETLK)
daemon@ATHENA.MIT.EDU (Alan Cox)
Sun Jul 19 19:01:46 1998
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From: alan@lxorguk.ukuu.org.uk (Alan Cox)
Subject: Re: flock and fcntl(F_SETLK)
To: map@stacken.kth.se (Magnus Ahltorp)
Date: Mon, 20 Jul 1998 00:01:30 +0100 (BST)
Cc: linux-kernel@vger.rutgers.edu, arla-drinkers@stacken.kth.se
In-Reply-To: <lv14swdy14u.fsf@yakko.stacken.kth.se> from "Magnus Ahltorp" at Jul 19, 98 11:36:01 pm
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> fcntl(F_SETLK) uses the f_op->lock(), so why doesn't flock() have a
> similar hook in the file system?
>
> This inconsistency makes flock() broken when using network file
> systems that have proper locking (like AFS). How is this supposed to
> be implemented in network file systems?
The semantics of flock not locking on network file systems go back to
SunOS and make some sense. flock() gives you a locking scheme that is
local and fast, lockf/fcntl locks give you slow but networked NFS locks.
Alan
