From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [BUG] Oops in inode_to_bdi() Date: Wed, 21 Jan 2015 13:04:04 -0700 Message-ID: <54C00634.1080106@fb.com> References: <20150121191707.GA27823@kernel.dk> <20150121192949.GA24787@infradead.org> <54BFFEF3.1070809@fb.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Cc: To: Christoph Hellwig Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:25745 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484AbbAUUEb (ORCPT ); Wed, 21 Jan 2015 15:04:31 -0500 In-Reply-To: <54BFFEF3.1070809@fb.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 01/21/2015 12:33 PM, Jens Axboe wrote: > On 01/21/2015 12:29 PM, Christoph Hellwig wrote: >> On Wed, Jan 21, 2015 at 12:17:07PM -0700, Jens Axboe wrote: >>> Christoph, >>> >>> Ran into this one while testing. Looks like mapping->host is NULL, off >>> the shmem_writepage(). >> >> Hmm. Not sure how this can happen, but for a NULL inode we can >> always just return noop_backing_dev_info safely, I'll cook up a patch. > > I got 8 of them in a row. Current kernel is running with the attached, > just to see if I can reproduce it. Works fine with the debug patch. Added a page dump for when we hit this: page:ffffea0001afa680 count:2 mapcount:0 mapping: (null) index:0x0 flags: 0x40000000000d0009(locked|uptodate|swapcache|reclaim|swapbacked) I'll commit the NULL inode work-around. -- Jens Axboe