From: Andrey Borzenkov <arvidjaar@mail.ru>
To: Jens Axboe <axboe@suse.de>, Olaf Hering <olh@suse.de>
Subject: Re: removable media revalidation - udev vs. devfs or static /dev
Date: Wed, 7 Jan 2004 14:00:46 +0300
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Cc: Andries Brouwer <aebr@win.tue.nl>, Greg KH <greg@kroah.com>,
       linux-hotplug-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
References: <200401012333.04930.arvidjaar@mail.ru> <20040107094321.GC21059@suse.de> <20040107095029.GX3483@suse.de>
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On Wednesday 07 January 2004 12:50, Jens Axboe wrote:
> > > So yeah, poll...
> >
> > Poll how? "kmediachangethread"? Or polling in userland? The latter would
> > (probably) lead to endless IO errors. Not very good.
>
> No need to put it in the kernel, user space fits the bil nicely.

unfortunately opening device in userland effectively locks tray making media 
change impossible. at least given current ->open semantic.

even periodic access is quite annoying for users (tray closing while user 
attempts to insert CD)

we may agree that O_NDELAY does not affect locked state; currently this is not 
consistent across drivers (e.g. cdrom does not lock tray while sd does)


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