Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751818AbaDRD47 (ORCPT ); Thu, 17 Apr 2014 23:56:59 -0400 Received: from mail-ig0-f171.google.com ([209.85.213.171]:42182 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751609AbaDRD4p (ORCPT ); Thu, 17 Apr 2014 23:56:45 -0400 MIME-Version: 1.0 In-Reply-To: References: <000c01cf1b47$ce280170$6a780450$%yang@samsung.com> <20140203153628.5e186b0e4e81400773faa7ac@linux-foundation.org> Date: Fri, 18 Apr 2014 11:56:45 +0800 Message-ID: Subject: Re: [PATCH 3/8] mm/swap: prevent concurrent swapon on the same S_ISBLK blockdev From: Weijie Yang To: Hugh Dickins Cc: Andrew Morton , Weijie Yang , Minchan Kim , shli@kernel.org, Bob Liu , Seth Jennings , Heesub Shin , mquzik@redhat.com, Linux-MM , linux-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 4, 2014 at 12:20 PM, Hugh Dickins wrote: > On Mon, 3 Feb 2014, Andrew Morton wrote: >> On Mon, 27 Jan 2014 18:03:04 +0800 Weijie Yang wrote: >> >> > When swapon the same S_ISBLK blockdev concurrent, the allocated two >> > swap_info could hold the same block_device, because claim_swapfile() >> > allow the same holder(here, it is sys_swapon function). >> > >> > To prevent this situation, This patch adds swap_lock protect to ensure >> > we can find this situation and return -EBUSY for one swapon call. >> > >> > As for S_ISREG swapfile, claim_swapfile() already prevent this scenario >> > by holding inode->i_mutex. >> > >> > This patch is just for a rare scenario, aim to correct of code. >> > >> >> hm, OK. Would it be saner to pass a unique `holder' to >> claim_swapfile()? Say, `p'? >> >> Truly, I am fed up with silly swapon/swapoff races. How often does >> anyone call these things? Let's slap a huge lock around the whole >> thing and be done with it? > > That answer makes me sad: we can't be bothered to get it right, > even when Weijie goes to the trouble of presenting a series to do so. > But I sure don't deserve a vote until I've actually looked through it. > Hi, This is a ping email. Could I get some options about these patch series? Thanks. > Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/