From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CA281E98E6 for ; Thu, 24 Jul 2025 04:56:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=18.9.28.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753332989; cv=none; b=XGlDelIP185UjCHBtoST0x1RlBEm3NSHMepVyY/jnrW60xw1joZrdAxZvOT4LgYZOb2cB0npuLbv5FrwwITv0c1vXGnif7ya4tSXLn5zB/ASNFyG9nFVkLd7ftnfp3MJPPysr8WYVZWo57ufFAHx2YG9LTBu8qd63rK4KjcsqK4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753332989; c=relaxed/simple; bh=fP6kX1LMGmOTclonzU54n3N9v2G92MN3VZq19VXBsgs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LRlguGmTtCF7BenY8YAX49lc5pZInL8IRdJjdLz0vJa+keZLI9q9eCYkcAORNd7TJSU8IROYlv7RI4dOgR/LcJEIbQDiNAdGrJWPFrfwC94WQiGHiLqfEuohM/+gKNXXgLD7oymce6yJmm/nSnPYj3jFo/e6lDYDW9lCQAHoHho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu; spf=pass smtp.mailfrom=mit.edu; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b=Q9eu57+x; arc=none smtp.client-ip=18.9.28.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mit.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b="Q9eu57+x" Received: from trampoline.thunk.org (pool-173-48-112-231.bstnma.fios.verizon.net [173.48.112.231]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 56O4suTs029451 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 24 Jul 2025 00:54:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1753332901; bh=1TXGdBZR9RlN4AvgbzOvBSB5nCw6F2aas8EVLPSRxe4=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=Q9eu57+xuy3qN3Iwbp/+OHTKDS/A1hIvgruYiiuKEWAEqUK+X9CZSu3cz0EQThwtL 5a1tv5ioqGrp8Rsu5OGMrTIs9WQz3iYVPlnYR6+Ia8vPVJtdMTA/v4+HP8Xo6fA5qf 4OU1O4rRrNrekBNJrEwzaN7F+zaLnhe7FvJdSgzSfgK2HRT5an51HQOzRzxJQ7wrbi X/FAKjkSX8ZMPqzTtDod5e+T13qZLhhOodzrcTdfCsR96TqRhCGyZsiBwr5glXsKvc utIRh6bYPDmWRWNm65+v6W7U4xdSwUsf+QreeCxTecVq7lPWEWOKNhA8mnvnwQMZWO cF2EMzz2CFIeA== Received: by trampoline.thunk.org (Postfix, from userid 15806) id 6A76E2E00D5; Thu, 24 Jul 2025 00:54:56 -0400 (EDT) Date: Thu, 24 Jul 2025 00:54:56 -0400 From: "Theodore Ts'o" To: Guenter Roeck Cc: Baokun Li , linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca, jack@suse.cz, linux-kernel@vger.kernel.org, ojaswin@linux.ibm.com, julia.lawall@inria.fr, yi.zhang@huawei.com, yangerkun@huawei.com, libaokun@huaweicloud.com Subject: Re: [PATCH v3 15/17] ext4: convert free groups order lists to xarrays Message-ID: <20250724045456.GA80823@mit.edu> References: <20250714130327.1830534-1-libaokun1@huawei.com> <20250714130327.1830534-16-libaokun1@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 23, 2025 at 08:55:14PM -0700, Guenter Roeck wrote: > Hi, > > On Mon, Jul 14, 2025 at 09:03:25PM +0800, Baokun Li wrote: > > While traversing the list, holding a spin_lock prevents load_buddy, making > > direct use of ext4_try_lock_group impossible. This can lead to a bouncing > > scenario where spin_is_locked(grp_A) succeeds, but ext4_try_lock_group() > > fails, forcing the list traversal to repeatedly restart from grp_A. > > > > This patch causes crashes for pretty much every architecture when > running unit tests as part of booting. I'm assuming that you're using a randconfig that happened to enable CONFIG_EXT4_KUNIT_TESTS=y. A simpler reprducer is to have a .kunitconfig containing: CONFIG_KUNIT=y CONFIG_KUNIT_TEST=y CONFIG_KUNIT_EXAMPLE_TEST=y CONFIG_EXT4_KUNIT_TESTS=y ... and then run :./tools/testing/kunit/kunit.py run". The first failure is actually with [11/17] ext4: fix largest free orders lists corruption on mb_optimize_scan switch, which triggers a failure of test_mb_mark_used. Baokun, can you take a look please? Many thanks! - Ted