From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:1454 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752419AbcGSMQ1 (ORCPT ); Tue, 19 Jul 2016 08:16:27 -0400 Subject: Re: [PATCH] Fix sysrq emergency thaw To: Charles Gong , Alexander Viro References: <5823da614460b8c40809e6e0a6de172a9c4f4611.1468015143.git.cggong@fb.com> CC: , , , Christoph Hellwig From: Chris Mason Message-ID: Date: Tue, 19 Jul 2016 08:15:45 -0400 MIME-Version: 1.0 In-Reply-To: <5823da614460b8c40809e6e0a6de172a9c4f4611.1468015143.git.cggong@fb.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 07/15/2016 08:38 PM, Charles Gong wrote: > "SYSRQ + J" triggers a call to emergency_thaw_all(). Currently, this is an > infinite loop. Once we trigger it, we'll need to do a hard power-cycle. There > are users reporting this bug from 2012 to 2016, for example, at > https://bugzilla.kernel.org/show_bug.cgi?id=47741. > > This happens because thaw_bdev() fails to return -EINVAL in the non-frozen case, > and I fixed it so that do_one_thaw() can recognize this case and quit from > looping. I checked that none of the other thaw_bdev() callers check the return > value. Hi Charles, Can you please resend this without the hunks that change only whitespace? Looks like your editor was properly killing off trailing whitespace, but that's not related to your fix. Also, please reference the commit where the regression was introduced: commit 4504230a71566785a05d3e6b53fa1ee071b864eb Author: Christoph Hellwig Date: Mon Aug 3 23:28:35 2009 +0200 freeze_bdev: grab active reference to frozen superblocks Then you can add: Reviewed-by: Chris Mason Thanks! -chris