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 A10B1EB64DD for ; Fri, 30 Jun 2023 23:36:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231844AbjF3Xg2 (ORCPT ); Fri, 30 Jun 2023 19:36:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbjF3XgZ (ORCPT ); Fri, 30 Jun 2023 19:36:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBED12683; Fri, 30 Jun 2023 16:36:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 70EFF61807; Fri, 30 Jun 2023 23:36:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFF1FC433C7; Fri, 30 Jun 2023 23:36:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688168183; bh=aK6yYJgscyZwWj5dtSV65RXKY0BEz1UX2yJwu5X1aZ8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=MoIiIYi0ETQup2yAMpWWZEQCL1KgbttW38aGQd9oj+soN2lWps5H2gS+e10zrOeST bTYKG04zuQ/1RY/buL8tObEzyG5DsCX+jwcOIuKgCwJO5MDC2QzCT7OkGEWGJXjUy5 GfdV59i3bUnftyi704U/xTI9rRpXMwBsrgxNKlws2o2SjCiK9GRp/EV8ZV6bs1gChd id2amycXugMhySZcMTI/9KHDXzTEzD9s6OvocDP8wmPuSUnvZa1RukVnsPvAOw2faJ YPebe6SIx7l1pbsjb1GBRjhXOAo4r6lGELCl7fHFeCVYXUX9neYzHGixjio2Vfvnp3 mSGzs+zqKYv0g== Message-ID: <44777f8c-6f2e-a9bd-6923-b12d0326d3cb@kernel.org> Date: Sat, 1 Jul 2023 07:36:20 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [f2fs-dev] [PATCH v2] f2fs: fix deadlock in i_xattr_sem and inode page lock and fix the original issue Content-Language: en-US To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net References: <20230613233940.3643362-1-jaegeuk@kernel.org> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/7/1 5:59, Jaegeuk Kim wrote: > On 06/28, Jaegeuk Kim wrote: >> On 06/28, Chao Yu wrote: >>> On 2023/6/28 16:08, Jaegeuk Kim wrote: >>>> Thread #1: >>>> >>>> [122554.641906][ T92] f2fs_getxattr+0xd4/0x5fc >>>> -> waiting for f2fs_down_read(&F2FS_I(inode)->i_xattr_sem); >>>> >>>> [122554.641927][ T92] __f2fs_get_acl+0x50/0x284 >>>> [122554.641948][ T92] f2fs_init_acl+0x84/0x54c >>>> [122554.641969][ T92] f2fs_init_inode_metadata+0x460/0x5f0 >>>> [122554.641990][ T92] f2fs_add_inline_entry+0x11c/0x350 >>>> -> Locked dir->inode_page by f2fs_get_node_page() >>>> >>>> [122554.642009][ T92] f2fs_do_add_link+0x100/0x1e4 >>>> [122554.642025][ T92] f2fs_create+0xf4/0x22c >>>> [122554.642047][ T92] vfs_create+0x130/0x1f4 >>>> >>>> Thread #2: >>>> >>>> [123996.386358][ T92] __get_node_page+0x8c/0x504 >>>> -> waiting for dir->inode_page lock >>>> >>>> [123996.386383][ T92] read_all_xattrs+0x11c/0x1f4 >>>> [123996.386405][ T92] __f2fs_setxattr+0xcc/0x528 >>>> [123996.386424][ T92] f2fs_setxattr+0x158/0x1f4 >>>> -> f2fs_down_write(&F2FS_I(inode)->i_xattr_sem); >>>> >>>> [123996.386443][ T92] __f2fs_set_acl+0x328/0x430 >>>> [123996.386618][ T92] f2fs_set_acl+0x38/0x50 >>>> [123996.386642][ T92] posix_acl_chmod+0xc8/0x1c8 >>>> [123996.386669][ T92] f2fs_setattr+0x5e0/0x6bc >>>> [123996.386689][ T92] notify_change+0x4d8/0x580 >>>> [123996.386717][ T92] chmod_common+0xd8/0x184 >>>> [123996.386748][ T92] do_fchmodat+0x60/0x124 >>>> [123996.386766][ T92] __arm64_sys_fchmodat+0x28/0x3c >>> >>> Back to the race condition, my question is why we can chmod on inode before >>> it has been created? >> >> This is touching the directory. > > Chao, > > Do you have other concern? Otherwise, I'll include this into the next pull > request. Jaegeuk, Sorry for late reply, I was misled by "dir->inode_page" and "inode" words in commit message, it should be "dir->inode_page" and "dir_inode". Anyway, the patch looks good to me. Reviewed-by: Chao Yu Thanks, > > Thanks, > >> >>> >>> Thanks, >>> >>>> >>>> Fixes: 27161f13e3c3 "f2fs: avoid race in between read xattr & write xattr" >>>> Cc: >>>> Signed-off-by: Jaegeuk Kim >>>> --- >>>> fs/f2fs/dir.c | 9 ++++++++- >>>> fs/f2fs/xattr.c | 6 ++++-- >>>> 2 files changed, 12 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c >>>> index 887e55988450..d635c58cf5a3 100644 >>>> --- a/fs/f2fs/dir.c >>>> +++ b/fs/f2fs/dir.c >>>> @@ -775,8 +775,15 @@ int f2fs_add_dentry(struct inode *dir, const struct f2fs_filename *fname, >>>> { >>>> int err = -EAGAIN; >>>> - if (f2fs_has_inline_dentry(dir)) >>>> + if (f2fs_has_inline_dentry(dir)) { >>>> + /* >>>> + * Should get i_xattr_sem to keep the lock order: >>>> + * i_xattr_sem -> inode_page lock used by f2fs_setxattr. >>>> + */ >>>> + f2fs_down_read(&F2FS_I(dir)->i_xattr_sem); >>>> err = f2fs_add_inline_entry(dir, fname, inode, ino, mode); >>>> + f2fs_up_read(&F2FS_I(dir)->i_xattr_sem); >>>> + } >>>> if (err == -EAGAIN) >>>> err = f2fs_add_regular_entry(dir, fname, inode, ino, mode); >>>> diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c >>>> index 213805d3592c..476b186b90a6 100644 >>>> --- a/fs/f2fs/xattr.c >>>> +++ b/fs/f2fs/xattr.c >>>> @@ -528,10 +528,12 @@ int f2fs_getxattr(struct inode *inode, int index, const char *name, >>>> if (len > F2FS_NAME_LEN) >>>> return -ERANGE; >>>> - f2fs_down_read(&F2FS_I(inode)->i_xattr_sem); >>>> + if (!ipage) >>>> + f2fs_down_read(&F2FS_I(inode)->i_xattr_sem); >>>> error = lookup_all_xattrs(inode, ipage, index, len, name, >>>> &entry, &base_addr, &base_size, &is_inline); >>>> - f2fs_up_read(&F2FS_I(inode)->i_xattr_sem); >>>> + if (!ipage) >>>> + f2fs_up_read(&F2FS_I(inode)->i_xattr_sem); >>>> if (error) >>>> return error; >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel