Subject: Re: PATCH/FIX for drivers/cdrom/cdrom.c
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Cc: 7eggert@gmx.de, Arjan van de Ven <arjan@infradead.org>,
       Dirk <noisyb@gmx.net>, linux-kernel@vger.kernel.org
In-Reply-To: <20060817132309.GX13639@csclub.uwaterloo.ca>
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	 <1155821951.15195.85.camel@localhost.localdomain>
	 <20060817132309.GX13639@csclub.uwaterloo.ca>
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Date: Thu, 17 Aug 2006 14:48:50 +0100
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Ar Iau, 2006-08-17 am 09:23 -0400, ysgrifennodd Lennart Sorensen:
> Why can't O_EXCL mean that the kernel prevents anyone else from issuing
> ioctl's to the device?  One would think that is the meaning of exlusive.

If you were designing a new OS from scratch you might want to explore
that semantic as a design idea. I wouldn't recommend it because a lot of
apps will be upset if they issue an ioctl and it mysteriously fails or
hangs.

Issues of this nature require high level synchronization and that
(witness email) is generally done in user space which is the only place
that has transaction level visibility.

Alan

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