From mboxrd@z Thu Jan  1 00:00:00 1970
From: hch@infradead.org (Christoph Hellwig)
Date: Mon, 14 May 2018 07:17:34 -0700
Subject: [PATCH] nvme: block ioctls if controller not in a live state
In-Reply-To: <06b65874-8bc8-b532-ad98-44e64b8440b8@broadcom.com>
References: <20180507225558.5009-1-jsmart2021@gmail.com>
 <20180509051156.GB28673@infradead.org>
 <06b65874-8bc8-b532-ad98-44e64b8440b8@broadcom.com>
Message-ID: <20180514141734.GA26302@infradead.org>

On Wed, May 09, 2018@09:29:13AM -0700, James Smart wrote:
> 
> That is the exact intent.? I do want the app to trigger off -EAGAIN in those
> two states and try again after a delay./? Perhaps I should change from !LIVE
> to NEW || RESETTING || CONNECTING to be more explicit.? I assumed !LIVE was
> sufficient as the other states should transition to LIVE or the delete path
> is taken which would remove the fd all together.

The problem is that userspace reasonably expects to be able to call
poll/select when used on a character device and it gets -EAGAIN.

Maybe the right solution here is to just do a wait_event_interruptible to
wait for the controller being live.