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From: Arnd Bergmann <arnd@arndb.de>
To: Jeff Garzik <jeff@garzik.org>
Subject: Re: [PATCH] net/core: split dev_ifsioc() according to locking
Date: Sun, 7 Oct 2007 02:17:08 +0200
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On Saturday 06 October 2007, Jeff Garzik wrote:
> 
> This always bugged me:  dev_ioctl() called dev_ifsioc() either inside
> read_lock(dev_base_lock) or rtnl_lock(), depending on the ioctl being
> executed.
> 
> This change moves the ioctls executed inside dev_base_lock to a new
> function, dev_ifsioc_locked().  Now the locking context is completely
> clear to the reader.
> 
> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Great idea!

I've been experimenting with a new compat_dev_ioctl() function along
the lines of what I just posted for the blkdev ioctls. For that, it
would be perfect to streamline dev_ioctl further:

* move the dev_load() and locking into dev_ifsioc{,_locked}
* move the copy_to_user step to a single place at the end of dev_ioctl

After that, we could have very simple dev_ioctl and compat_dev_ioctl
functions calling the same dev_ifsioc{,_locked} functions.

	Arnd <><