From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751786AbaJTQJO (ORCPT <rfc822;w@1wt.eu>);
	Mon, 20 Oct 2014 12:09:14 -0400
Received: from mga11.intel.com ([192.55.52.93]:42357 "EHLO mga11.intel.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751143AbaJTQJN (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Mon, 20 Oct 2014 12:09:13 -0400
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; 
   d="scan'208";a="403026876"
Message-ID: <1413821350.7906.392.camel@sauron.fi.intel.com>
Subject: Re: [PATCH 3/4] UBI: Fastmap: Care about the protection queue
From: Artem Bityutskiy <dedekind1@gmail.com>
Reply-To: dedekind1@gmail.com
To: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Date: Mon, 20 Oct 2014 19:09:10 +0300
In-Reply-To: <54453178.3050903@nod.at>
References: <1412029248-22454-1-git-send-email-richard@nod.at>
							 <1412029248-22454-4-git-send-email-richard@nod.at>
						 <1412346676.3795.62.camel@sauron.fi.intel.com>
		 <542EF3BF.1070401@nod.at>
				 <1413206263.7906.18.camel@sauron.fi.intel.com>
		 <543BE21F.5020504@nod.at>		 <1413213803.7906.45.camel@sauron.fi.intel.com>
		 <543C3E60.4080507@nod.at>	 <1413282203.7906.72.camel@sauron.fi.intel.com>
		 <543F9895.7010502@nod.at> <1413816389.7906.336.camel@sauron.fi.intel.com>
		 <544527A3.7030508@nod.at> <1413819635.7906.369.camel@sauron.fi.intel.com>
	 <54453178.3050903@nod.at>
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20) 
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, 2014-10-20 at 17:59 +0200, Richard Weinberger wrote:
> > Also, say, PEB X is in the work queue waiting for erasure. Fastmap comes
> > along and saves it as "must be erased" in the fastmap. Fastmap finishes
> > its job, PEB X gets erased, and I write my data there, so PEB X is
> > referred to by LEB Y. Now I have power cut. Then I attach the flash
> > again. Surely it is not that fastmap just erases PEB X and I lose the
> > contents of LEB Y?
> 
> This cannot happen. If X is erased you cannot write data do it. I must first go
> thought the pool and the pool is scanned while attaching.

Just noticed from the code that we first add PEBs to the erase list, and
then we go an scan the pools.