From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Christie <michaelc@cs.wisc.edu>
Subject: Re: [Open-FCoE] [RFC PATCH] scsi, fcoe, libfc: drop scsi host_lock
 use from fc_queuecommand
Date: Wed, 01 Sep 2010 20:37:03 -0500
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To: Chris Leech <christopher.leech@intel.com>
Cc: linux-scsi <linux-scsi@vger.kernel.org>, Matthew Wilcox <matthew@wil.cx>, FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>, James Bottomley <James.Bottomley@suse.de>, "devel@open-fcoe.org" <devel@open-fcoe.org>, Christoph Hellwig <hch@lst.de>

On 09/01/2010 06:38 PM, Mike Christie wrote:
> wondering if there could be a problem where one thread completes the IO
> and sets those fields to NULL, but another thread could be completing it
> too and it would see a scsi_cmnd that is not released and reallocated by

There should not be a not in there. So it should be and it would see a 
scsi_cmnd that is released and reallocated by the other thread.

> the other thread. So for example the fc_eh_abort code still grabs the
> host_lock when calling CMD_SP and taking a ref and checking that the fsp
> is not null.