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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5AD1C433EF for ; Wed, 17 Nov 2021 01:58:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA13863222 for ; Wed, 17 Nov 2021 01:58:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232357AbhKQCBJ (ORCPT ); Tue, 16 Nov 2021 21:01:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:41516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229629AbhKQCBJ (ORCPT ); Tue, 16 Nov 2021 21:01:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9F41261507; Wed, 17 Nov 2021 01:58:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637114291; bh=qDteq7fJLGkOPY5wKNBQkh9GOB8n/n6FzEHO09gWBoQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E/sPNuYb2joYmkCGvijBdIXC45JCXl1LpbqwzD82V2BHZRGPxzygETHB/1lrfjxGy zGtOaxuS2882hb3gNiSExIkU88TcnNdeP3lvWyE/P8bMINzflikPWYsrIUFEuVWRn9 Fz2QQdnGL8+9vTgVFgjKRg1ZVpv68fBUDWjdkTdxjgfqzsgbxbdHt6ubD/fPH3WBZT m6gNi33zUujY5obx5+4nCUZ+cwZkcTFxsd9whTFCbNIjIS2v2PDe0Owy5Iv4ZUraiq CzXhoQrBmI7b5LQd4hRSqZPM6HqYQrd05z/euBI+80BAeoDxf52R+27OFz7YhcgMkT v5iXfd6jNxYaw== Date: Tue, 16 Nov 2021 17:58:11 -0800 From: "Darrick J. Wong" To: "xuyang2018.jy@fujitsu.com" Cc: "allison.henderson@oracle.com" , "linux-xfs@vger.kernel.org" , "fstests@vger.kernel.org" Subject: Re: [PATCH v2] xfs: Fix the free logic of state in xfs_attr_node_hasname Message-ID: <20211117015811.GO24282@magnolia> References: <20211029185024.GF24307@magnolia> <1635750020-2275-1-git-send-email-xuyang2018.jy@fujitsu.com> <6184A132.3090901@fujitsu.com> <6191B7A8.9080903@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6191B7A8.9080903@fujitsu.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Nov 15, 2021 at 01:27:28AM +0000, xuyang2018.jy@fujitsu.com wrote: > on 2021/11/5 11:12, xuyang2018.jy@fujitsu.com wrote: > > Hi Darrick, Allison > > > > Any comment? > Ping. FWIW I think it looks fine, but I was kinda wondering if Allison had any input? --D > > > > Best Regards > > Yang Xu > >> 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. > >> > >> 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 > >> --- > >> fs/xfs/libxfs/xfs_attr.c | 17 +++++++---------- > >> 1 file changed, 7 insertions(+), 10 deletions(-) > >> > >> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > >> index fbc9d816882c..23523b802539 100644 > >> --- a/fs/xfs/libxfs/xfs_attr.c > >> +++ b/fs/xfs/libxfs/xfs_attr.c > >> @@ -1077,21 +1077,18 @@ 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; > >> } > >> > >> @@ -1112,7 +1109,7 @@ xfs_attr_node_addname_find_attr( > >> */ > >> retval = xfs_attr_node_hasname(args,&dac->da_state); > >> if (retval != -ENOATTR&& retval != -EEXIST) > >> - return retval; > >> + goto error; > >> > >> if (retval == -ENOATTR&& (args->attr_flags& XATTR_REPLACE)) > >> goto error; > >> @@ -1337,7 +1334,7 @@ int xfs_attr_node_removename_setup( > >> > >> error = xfs_attr_node_hasname(args, state); > >> if (error != -EEXIST) > >> - return error; > >> + goto out; > >> error = 0; > >> > >> ASSERT((*state)->path.blk[(*state)->path.active - 1].bp != NULL); > > > >