From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stable-owner@vger.kernel.org>
Received: from mail-pf0-f169.google.com ([209.85.192.169]:32809 "EHLO
	mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756879AbcAYNDK (ORCPT
	<rfc822;stable@vger.kernel.org>); Mon, 25 Jan 2016 08:03:10 -0500
Date: Mon, 25 Jan 2016 22:01:20 +0900
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: stable@vger.kernel.org, Minchan Kim <minchan@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Kyeongdon Kim <kyeongdon.kim@lge.com>,
	linux-kernel@vger.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [stable] upstream 3d5fe03a3ea01 -stable backport request
Message-ID: <20160125130120.GD526@swordfish>
References: <20160125124654.GA526@swordfish>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20160125124654.GA526@swordfish>
Sender: stable-owner@vger.kernel.org
List-ID: <stable.vger.kernel.org>

On (01/25/16 21:46), Sergey Senozhatsky wrote:
> 
> Hello,
> 
> Please add upstream 'commit 3d5fe03a3ea01 ("zram/zcomp: use
> GFP_NOIO to allocate streams")' to stable releases.
> 

[v3.15+]

	-ss

> 
> :commit 3d5fe03a3ea013060ebba2a811aeb0f23f56aefa
> :Author: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> :
> :    zram/zcomp: use GFP_NOIO to allocate streams
> :    
> :    We can end up allocating a new compression stream with GFP_KERNEL from
> :    within the IO path, which may result is nested (recursive) IO
> :    operations.  That can introduce problems if the IO path in question is a
> :    reclaimer, holding some locks that will deadlock nested IOs.
> :    
> :    Allocate streams and working memory using GFP_NOIO flag, forbidding
> :    recursive IO and FS operations.
> 
> 
> 	-ss
>