Message-ID: <48B6EC83.1070207@kernel.org>
Date: Thu, 28 Aug 2008 11:20:51 -0700
From: "H. Peter Anvin" <hpa@kernel.org>
Organization: Linux Kernel Organization, Inc.
User-Agent: Thunderbird 2.0.0.14 (X11/20080501)
MIME-Version: 1.0
To: Tejun Heo <tj@kernel.org>
CC: fuse-devel@lists.sourceforge.net, miklos@szeredi.hu, greg@kroah.com,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/7] FUSE: implement ioctl support
References: <1219945263-21074-1-git-send-email-tj@kernel.org> <1219945263-21074-6-git-send-email-tj@kernel.org>
In-Reply-To: <1219945263-21074-6-git-send-email-tj@kernel.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 875
Lines: 19

Tejun Heo wrote:
> ioctl support is tricky to implement because only the ioctl
> implementation itself knows which memory regions need to be read
> and/or written.  To support this, fuse client can request retry of
> ioctl specifying memory regions to read and write.  Deep copying
> (nested pointers) can be implemented by retrying multiple times
> resolving one depth of dereference at a time.

Okay, I'm going to say it... wouldn't it be better to have some kind of 
data structure description language which the userspace can register 
with the kernel to linearize the data on a per-ioctl basis (kind of like 
rpcgen)?

	-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/