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[2620:137:e000::1:20]) by mx.google.com with ESMTP id e4-20020a17090301c400b001b84f9263e7si515378plh.325.2023.07.17.14.50.48; Mon, 17 Jul 2023 14:51:04 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@mit.edu header.s=outgoing header.b=AhYp6FG0; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=mit.edu Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229601AbjGQVeu (ORCPT + 99 others); Mon, 17 Jul 2023 17:34:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229539AbjGQVet (ORCPT ); Mon, 17 Jul 2023 17:34:49 -0400 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E318134 for ; Mon, 17 Jul 2023 14:34:48 -0700 (PDT) Received: from cwcc.thunk.org (pool-173-48-116-181.bstnma.fios.verizon.net [173.48.116.181]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 36HLYOe4023106 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 17 Jul 2023 17:34:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1689629668; bh=AIJ7eQlGnPTeVEA7EYFHb4RQbDLObtg4FWLQb0yKeA0=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=AhYp6FG0XJz9UMdyC87+MA7F7E0+jqJEAN9UIBRE/YiWHYr7aES6PPKEIOwFeUmyx etZXfRnpfgavY+1dnsZmq6ey06zngeSKKYCUXfV3KHc49kBmgHU2zJT5LBD2WD5ZZZ AlTszUt4smZI1XFRhjiB8T7q1QepJ83222jdYOJsZk6umyUYQvVDQRtc32b2P3QonV IXKs7gUjMpbjdbpdx0y/tnHYMpERKfD0qBl8LBDTNW4wpiofms4HJqy9y2wmu3Z4+C ZKJi54xm2h8bE++9tWGmppPwIVElkGSNyHp166KSRlNXytYHG+9h4HIQDCmF/ov2DS lGV8oz6wVf/QA== Received: by cwcc.thunk.org (Postfix, from userid 15806) id 809FC15C026A; Mon, 17 Jul 2023 17:34:24 -0400 (EDT) Date: Mon, 17 Jul 2023 17:34:24 -0400 From: "Theodore Ts'o" To: Ritesh Harjani Cc: Naresh Kamboju , open list , linux-mm , lkft-triage@lists.linaro.org, linux-ext4 , LTP List , Andrew Morton , Arnd Bergmann , Dan Carpenter , Andreas Dilger , Ojaswin Mujoo Subject: Re: next: kernel BUG at fs/ext4/mballoc.c:4369! Message-ID: <20230717213424.GB3842864@mit.edu> References: <87o7kbnle9.fsf@doe.com> <87jzuyobch.fsf@doe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87jzuyobch.fsf@doe.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon, Jul 17, 2023 at 08:04:54PM +0530, Ritesh Harjani wrote: > > These can basically trigger in extremely low memory space and only when > such ranges exist in the PA rbtree. Hence, I guess it is a little hard > to tigger race. Ritesh, thanks for looking into this! Naresh, how easy is it for you to trigger the BUG when using LTP? I did two xfstests runs using "gce-xfstests -c ext2/default -g auto", one on the ext4 dev branch, and one on linux-next 20230717, and I wasn't able to trigger the BUG. If you can trivially trigger it using LTP (perhaps with a low memory configuration in your test setup?), that would be useful to know. Cheers, - Ted