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 B31CEEB64D7 for ; Wed, 28 Jun 2023 09:01:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232125AbjF1JBt (ORCPT ); Wed, 28 Jun 2023 05:01:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236152AbjF1IpB (ORCPT ); Wed, 28 Jun 2023 04:45:01 -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 B2C374694; Wed, 28 Jun 2023 01:36:58 -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 AC0FC6126B; Wed, 28 Jun 2023 08:36:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F27BBC433C8; Wed, 28 Jun 2023 08:36:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687941376; bh=OIo+iQ1NbQ0Q/3QbREXXSDKg5tSJjXYtebmMPeule1o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qRhjFW5caRw09aD/J+66ROTCSqmKTZzlbW1fyj9VQ6DVlRaIGj9lVOw8OeudEqznx TprARDTLZqJDdjbMvXOlqqaaqh+KQ97Ly9rpSl7EAaYCYYsZ2RGUbDoX31r1mLfzZz Kmm4QWQp5eR7W3S4274x98TxURU19IOD8owD4Twb4dux+RrGjxGyvr/S4x3MydVJcs OpS59BHGH1s6GHGNZE4xZoj0XGlTXFMlv2hneGHzO+pJV1Ym6RNorxkWdpiJjirWsd y5XoiQjl9O9stmv4aMjaKkCCUnQMWZFEOXpuAK/VHMq8I/gDZFXJrR4LJ33/mvY96Q J568AcMf4LTXA== Message-ID: Date: Wed, 28 Jun 2023 16:36:13 +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: [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, linux-f2fs-devel@lists.sourceforge.net, stable@vger.kernel.org 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 2023/6/28 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? 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; >