From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED4F2C43334 for ; Wed, 22 Jun 2022 16:32:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359088AbiFVQcN (ORCPT ); Wed, 22 Jun 2022 12:32:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237555AbiFVQcM (ORCPT ); Wed, 22 Jun 2022 12:32:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44DC93150E; Wed, 22 Jun 2022 09:32:11 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D239461AA0; Wed, 22 Jun 2022 16:32:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 372D0C34114; Wed, 22 Jun 2022 16:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1655915530; bh=oZ/HMwEEpMmlxsE2fXgdNXqxu7e4J0wswI5GmTqQnI8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XKpEegHqdgwIxpcMmHEvWml4KlhLr/+RSQARZDOeTI1GkrTWYNQlsYxV+aTPQCG1M wviDrGXyfCLFNuYpYf8BHiXuIyvdbSJqGyqu6SKQGwbx5BNL6noorAzfufT2EdkSkk Rfx6tx0MRKPPLp7uohze9F4JPYm0+OHphfD0K0mcBxOBUoNzLVB9BwUmPxNB/CX7VE eHHYTMISEywEAXU4es6NWQa6AjlPvIZ3Knn2rJdt9x5AdI7aUm0fKCNcOQkH3mun62 tUjUXrI+jteEGBAH4Th7wvlPJdJ2rHhacDKJ7JZVsuRFPRsMFh+RZSWxPcbUVAKniR RfQ7hRloBP4/g== Date: Wed, 22 Jun 2022 09:32:09 -0700 From: "Darrick J. Wong" To: Amir Goldstein Cc: Leah Rumancik , Luis Chamberlain , Dave Chinner , Christoph Hellwig , Christian Brauner , linux-xfs@vger.kernel.org, fstests@vger.kernel.org, Yang Xu Subject: Re: [PATCH 5.10 CANDIDATE 03/11] xfs: Fix the free logic of state in xfs_attr_node_hasname Message-ID: References: <20220617100641.1653164-1-amir73il@gmail.com> <20220617100641.1653164-4-amir73il@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220617100641.1653164-4-amir73il@gmail.com> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Fri, Jun 17, 2022 at 01:06:33PM +0300, Amir Goldstein wrote: > From: Yang Xu > > commit a1de97fe296c52eafc6590a3506f4bbd44ecb19a upstream. > > When testing xfstests xfs/126 on lastest upstream kernel, it will hang on some machine. > Adding a getxattr operation after xattr corrupted, I can reproduce it 100%. > > The deadlock as below: > [983.923403] task:setfattr state:D stack: 0 pid:17639 ppid: 14687 flags:0x00000080 > [ 983.923405] Call Trace: > [ 983.923410] __schedule+0x2c4/0x700 > [ 983.923412] schedule+0x37/0xa0 > [ 983.923414] schedule_timeout+0x274/0x300 > [ 983.923416] __down+0x9b/0xf0 > [ 983.923451] ? xfs_buf_find.isra.29+0x3c8/0x5f0 [xfs] > [ 983.923453] down+0x3b/0x50 > [ 983.923471] xfs_buf_lock+0x33/0xf0 [xfs] > [ 983.923490] xfs_buf_find.isra.29+0x3c8/0x5f0 [xfs] > [ 983.923508] xfs_buf_get_map+0x4c/0x320 [xfs] > [ 983.923525] xfs_buf_read_map+0x53/0x310 [xfs] > [ 983.923541] ? xfs_da_read_buf+0xcf/0x120 [xfs] > [ 983.923560] xfs_trans_read_buf_map+0x1cf/0x360 [xfs] > [ 983.923575] ? xfs_da_read_buf+0xcf/0x120 [xfs] > [ 983.923590] xfs_da_read_buf+0xcf/0x120 [xfs] > [ 983.923606] xfs_da3_node_read+0x1f/0x40 [xfs] > [ 983.923621] xfs_da3_node_lookup_int+0x69/0x4a0 [xfs] > [ 983.923624] ? kmem_cache_alloc+0x12e/0x270 > [ 983.923637] xfs_attr_node_hasname+0x6e/0xa0 [xfs] > [ 983.923651] xfs_has_attr+0x6e/0xd0 [xfs] > [ 983.923664] xfs_attr_set+0x273/0x320 [xfs] > [ 983.923683] xfs_xattr_set+0x87/0xd0 [xfs] > [ 983.923686] __vfs_removexattr+0x4d/0x60 > [ 983.923688] __vfs_removexattr_locked+0xac/0x130 > [ 983.923689] vfs_removexattr+0x4e/0xf0 > [ 983.923690] removexattr+0x4d/0x80 > [ 983.923693] ? __check_object_size+0xa8/0x16b > [ 983.923695] ? strncpy_from_user+0x47/0x1a0 > [ 983.923696] ? getname_flags+0x6a/0x1e0 > [ 983.923697] ? _cond_resched+0x15/0x30 > [ 983.923699] ? __sb_start_write+0x1e/0x70 > [ 983.923700] ? mnt_want_write+0x28/0x50 > [ 983.923701] path_removexattr+0x9b/0xb0 > [ 983.923702] __x64_sys_removexattr+0x17/0x20 > [ 983.923704] do_syscall_64+0x5b/0x1a0 > [ 983.923705] entry_SYSCALL_64_after_hwframe+0x65/0xca > [ 983.923707] RIP: 0033:0x7f080f10ee1b > > When getxattr calls xfs_attr_node_get function, xfs_da3_node_lookup_int fails with EFSCORRUPTED in > xfs_attr_node_hasname because we have use blocktrash to random it in xfs/126. So it > free state in internal and xfs_attr_node_get doesn't do xfs_buf_trans release job. > > Then subsequent removexattr will hang because of it. > > This bug was introduced by kernel commit 07120f1abdff ("xfs: Add xfs_has_attr and subroutines"). > It adds xfs_attr_node_hasname helper and said caller will be responsible for freeing the state > in this case. But xfs_attr_node_hasname will free state itself instead of caller if > xfs_da3_node_lookup_int fails. > > Fix this bug by moving the step of free state into caller. > > [amir: this text from original commit is not relevant for 5.10 backport: > Also, use "goto error/out" instead of returning error directly in xfs_attr_node_addname_find_attr and > xfs_attr_node_removename_setup function because we should free state ourselves. > ] > > Fixes: 07120f1abdff ("xfs: Add xfs_has_attr and subroutines") > Signed-off-by: Yang Xu > Reviewed-by: Darrick J. Wong > Signed-off-by: Darrick J. Wong > Signed-off-by: Amir Goldstein > --- > fs/xfs/libxfs/xfs_attr.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > index 96ac7e562b87..fcca36bbd997 100644 > --- a/fs/xfs/libxfs/xfs_attr.c > +++ b/fs/xfs/libxfs/xfs_attr.c > @@ -876,21 +876,18 @@ xfs_attr_node_hasname( > > state = xfs_da_state_alloc(args); > if (statep != NULL) > - *statep = NULL; > + *statep = state; > > /* > * Search to see if name exists, and get back a pointer to it. > */ > error = xfs_da3_node_lookup_int(state, &retval); > - if (error) { > - xfs_da_state_free(state); > - return error; > - } > + if (error) > + retval = error; > > - if (statep != NULL) > - *statep = state; > - else > + if (!statep) > xfs_da_state_free(state); > + > return retval; > } > > -- Curious -- the conversion of the _node_hasname callers isn't in this patch. Looking at 5.10.124, I see that most of the callers already clean up the passed-out statep, but do the callers of xfs_has_attr free it too? --D > 2.25.1 >