From mboxrd@z Thu Jan  1 00:00:00 1970
From: keith.busch@intel.com (Keith Busch)
Date: Mon, 8 Feb 2016 15:01:33 +0000
Subject: [PATCH] NVMe: do not touch sq door bell if nvmeq has been
 suspended
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On Sat, Feb 06, 2016@02:32:24PM +0000, Wenbo Wang wrote:
> Keith,
> 
> Is the following solution OK?
> synchronize_rcu guarantee that no queue_rq is running concurrently with device disable code. Together with your another patch (adding blk_sync_queue), both sync/async path shall be handled correctly.
> 
> Do you think synchronize_rcu shall be added to blk_sync_queue?

I was nearly going to suggest the same last week, but it feels wrong since
no one takes rcu_read_lock in the path we're trying to sychronoize. Is
this safe if the task is interrupted?