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Date: Sat, 8 Dec 2001 22:38:04 -0700
Message-Id: <200112090538.fB95c4G06607@vindaloo.ras.ucalgary.ca>
From: Richard Gooch <rgooch@ras.ucalgary.ca>
To: Alexander Viro <viro@math.psu.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Devfs races with block devices
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[Finally, after other things have stabilised, I'm ready to tackle this
issue]

Alexander Viro writes:
> 	BTW, here's one more devfs rmmod race: check_disk_changed() in
> fs/devfs/base.c.  Calling ->check_media_change() with no protection
> whatsoever.  If rmmod happens at that point...

How about if I do this sequence:
	lock_kernel();
	devfs checks;
	if (bd_op->owner)
		__MOD_INC_USE_COUNT(bd_op->owner);
	revalidate();
	if (bd_op->owner)
		__MOD_DEC_USE_COUNT(bd_op->owner);
	unlock_kernel();

Is there any reason why that won't work?

				Regards,

					Richard....
Permanent: rgooch@atnf.csiro.au
Current:   rgooch@ras.ucalgary.ca
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