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From: John Baldwin <jhb@freebsd.org>
To: freebsd-current@freebsd.org
Subject: Re: How to best overload the fileops ?
Date: Fri, 23 Aug 2013 13:02:32 -0400
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Cc: Yuri <yuri@rawbw.com>, John-Mark Gurney <jmg@funkthat.com>,
 Mateusz Guzik <mjguzik@gmail.com>, Roman Divacky <rdivacky@freebsd.org>,
 current@freebsd.org
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On Wednesday, August 21, 2013 8:30:05 pm Yuri wrote:
> On 08/21/2013 17:10, Mateusz Guzik wrote:
> > Short answer is provide epollops with your own fo_close and the rest as
> > it is currently in kqueueops. All function are static, but this is not a
> > real problem since you have to modify kern_event.c anyway.
> 
> This is exactly what this code I am asking about is doing.
> kqueueops functions are all static. This modification allows to export 
> fileops to child modules.
> Since there is nothing similar in the kernel code, I am asking does this 
> way look ugly or not.

There is something similar: see devfs_ops_f in sys/fs/devfs/devfs_vnops.c.

I don't think we need a generic framework for this, just expose the
relevant fo_ methods for kqueue ops and use them in your epoll_ops.

-- 
John Baldwin