From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759549Ab0EMWr1 (ORCPT ); Thu, 13 May 2010 18:47:27 -0400 Received: from crca.org.au ([74.207.252.120]:46088 "EHLO crca.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754075Ab0EMWrY (ORCPT ); Thu, 13 May 2010 18:47:24 -0400 X-Bogosity: Ham, spamicity=0.000000 Message-ID: <4BEC8173.4070500@crca.org.au> Date: Fri, 14 May 2010 08:47:15 +1000 From: Nigel Cunningham User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100423 Thunderbird/3.0.4 MIME-Version: 1.0 To: Matt Reimer CC: Alan Stern , linux-kernel , Jens Axboe , linux-pm , Andrew Morton Subject: Re: [linux-pm] Is it supposed to be ok to call del_gendisk while userspace is frozen? References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi. On 14/05/10 08:20, Matt Reimer wrote: > On Thu, May 13, 2010 at 2:54 PM, Alan Stern wrote: >> On Thu, 13 May 2010, Matt Reimer wrote: >> >>> So how does the attached patch look? >>> >>> Matt >>> >>> >>> From 20d8340471eb05aa54af1349f4ddccecd9c230c6 Mon Sep 17 00:00:00 2001 >>> From: Matt Reimer >>> Date: Thu, 13 May 2010 14:36:54 -0700 >>> Subject: [PATCH] fs: prevent hang on suspend/resume when MMC/SD card present >>> >>> Devices can come and go from the MMC/SD bus during suspend or resume, >>> when the writeback thread is frozen, resulting in a hang. So thaw the >>> writeback thread in del_gendisk() to prevent the hang. >> >> I don't see anything wrong with the patch itself, but I dislike the >> description. Devices can come and go from any hotpluggable bus, not >> just MMC/SD. That just happens to be the first place the problem was >> observed. > > Good point. How about this? > > Matt > >> From 813bd223e5a2fa577b9e64ddf12654a93d0aab8b Mon Sep 17 00:00:00 2001 > From: Matt Reimer > Date: Thu, 13 May 2010 14:36:54 -0700 > Subject: [PATCH] fs: prevent hang on suspend/resume when MMC/SD card present > > Devices can come and go bus during suspend or resume, when the > writeback thread is frozen, resulting in a hang. Prevent the hang > by thawing the writeback thread in del_gendisk(). > > Signed-off-by: Matt Reimer > --- > fs/partitions/check.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/fs/partitions/check.c b/fs/partitions/check.c > index e238ab2..b303919 100644 > --- a/fs/partitions/check.c > +++ b/fs/partitions/check.c > @@ -666,6 +666,8 @@ void del_gendisk(struct gendisk *disk) > struct disk_part_iter piter; > struct hd_struct *part; > > + thaw_process(disk->queue->backing_dev_info.wb.task); > + > /* invalidate stuff */ > disk_part_iter_init(&piter, disk, > DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); > Why not just make it unfreezeable to start with? Regards, Nigel