From mboxrd@z Thu Jan  1 00:00:00 1970
From: Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PULL REQUEST] md bug fixes and minor improvements
Date: Fri, 1 Aug 2008 11:18:45 -0700 (PDT)
Message-ID: <alpine.LFD.1.10.0808011115050.3277@nehalem.linux-foundation.org>
References: <18578.31924.259887.735206@notabene.brown> <alpine.LFD.1.10.0808011007240.3277@nehalem.linux-foundation.org> <20080801172231.GF20055@kernel.dk>
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To: Jens Axboe <jens.axboe@oracle.com>
Cc: Neil Brown <neilb@suse.de>, Arthur Jones <ajones@riverbed.com>, Dan Williams <dan.j.williams@intel.com>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, linux-raid@vger.kernel.org, "Rafael J. Wysocki" <rjw@sisk.pl>
List-Id: linux-raid.ids



On Fri, 1 Aug 2008, Jens Axboe wrote:
> +			spin_lock_irq(&bitmap->mddev->queue->queue_lock);
>  			blk_plug_device(bitmap->mddev->queue);
> +			spin_unlock_irq(&bitmap->mddev->queue->queue_lock);

Can we please not have a chain of three dereferences in a row like that? 
That's an almost certain sign that we should either have a helper function 
or just a variable, and do it as

	queue = bitmap->mddev->queue;

	spin_lock_irq(&queue->queue_lock);
	blk_plug_device(queue);
	spin_unlock_irq(&queue->queue_lock);

Hmm? Perhaps the helper function is cleaner, ie

	static inline blk_plug_device_unlocked(struct request_queue * queue)
	{..

instead. That, of course, would have to use spin_lock_irqsave().

			Linus