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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4AA2BC433DF for ; Mon, 10 Aug 2020 15:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22B7421775 for ; Mon, 10 Aug 2020 15:24:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597073071; bh=ced6ACKeiVQz70N1jpmr7sSe/5mq+5lAuhok2wNXuMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ui2tHHG5dWXKKB3NXC4BWyS5ZvUVYGB9etolvR9l3tgXoDir4d4UGX8Pv5LHOoVuj q9N8j2qHPhhmQBJKiuGOwdFSNMny6XWudOjQhdKpDnloZpjxcMJ6/9ryh1Kj6yFkkM 3wcSie3jM+ZsbriXDlusmXnw8pVupu0DIMNkuds0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728427AbgHJPY3 (ORCPT ); Mon, 10 Aug 2020 11:24:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:57252 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728416AbgHJPYS (ORCPT ); Mon, 10 Aug 2020 11:24:18 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ADC1220825; Mon, 10 Aug 2020 15:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597073057; bh=ced6ACKeiVQz70N1jpmr7sSe/5mq+5lAuhok2wNXuMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S+VSdgIbmC8PDS4q7jLZ50SM4QFATseNzOP50DMHcUiXxJZHxS+xHrf9j5kVNnSRu 6mqIPH+Z6V1YWfNdltR2lXJDbgRPIXhC2auJCYsUePjrasdPds5y/8Oa36L2g5j6SC YHqVQ4GjzTOYDMH2BnhnwWgJjhRXt+mBkvrbOJX4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, linux-fsdevel@vger.kernel.org, Al Viro , Frank van der Linden , Chuck Lever Subject: [PATCH 5.7 52/79] xattr: break delegations in {set,remove}xattr Date: Mon, 10 Aug 2020 17:21:11 +0200 Message-Id: <20200810151814.820572804@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200810151812.114485777@linuxfoundation.org> References: <20200810151812.114485777@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Frank van der Linden commit 08b5d5014a27e717826999ad20e394a8811aae92 upstream. set/removexattr on an exported filesystem should break NFS delegations. This is true in general, but also for the upcoming support for RFC 8726 (NFSv4 extended attribute support). Make sure that they do. Additionally, they need to grow a _locked variant, since callers might call this with i_rwsem held (like the NFS server code). Cc: stable@vger.kernel.org # v4.9+ Cc: linux-fsdevel@vger.kernel.org Cc: Al Viro Signed-off-by: Frank van der Linden Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/xattr.c | 84 +++++++++++++++++++++++++++++++++++++++++++++----- include/linux/xattr.h | 2 + 2 files changed, 79 insertions(+), 7 deletions(-) --- a/fs/xattr.c +++ b/fs/xattr.c @@ -204,10 +204,22 @@ int __vfs_setxattr_noperm(struct dentry return error; } - +/** + * __vfs_setxattr_locked: set an extended attribute while holding the inode + * lock + * + * @dentry - object to perform setxattr on + * @name - xattr name to set + * @value - value to set @name to + * @size - size of @value + * @flags - flags to pass into filesystem operations + * @delegated_inode - on return, will contain an inode pointer that + * a delegation was broken on, NULL if none. + */ int -vfs_setxattr(struct dentry *dentry, const char *name, const void *value, - size_t size, int flags) +__vfs_setxattr_locked(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags, + struct inode **delegated_inode) { struct inode *inode = dentry->d_inode; int error; @@ -216,15 +228,40 @@ vfs_setxattr(struct dentry *dentry, cons if (error) return error; - inode_lock(inode); error = security_inode_setxattr(dentry, name, value, size, flags); if (error) goto out; + error = try_break_deleg(inode, delegated_inode); + if (error) + goto out; + error = __vfs_setxattr_noperm(dentry, name, value, size, flags); out: + return error; +} +EXPORT_SYMBOL_GPL(__vfs_setxattr_locked); + +int +vfs_setxattr(struct dentry *dentry, const char *name, const void *value, + size_t size, int flags) +{ + struct inode *inode = dentry->d_inode; + struct inode *delegated_inode = NULL; + int error; + +retry_deleg: + inode_lock(inode); + error = __vfs_setxattr_locked(dentry, name, value, size, flags, + &delegated_inode); inode_unlock(inode); + + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } return error; } EXPORT_SYMBOL_GPL(vfs_setxattr); @@ -378,8 +415,18 @@ __vfs_removexattr(struct dentry *dentry, } EXPORT_SYMBOL(__vfs_removexattr); +/** + * __vfs_removexattr_locked: set an extended attribute while holding the inode + * lock + * + * @dentry - object to perform setxattr on + * @name - name of xattr to remove + * @delegated_inode - on return, will contain an inode pointer that + * a delegation was broken on, NULL if none. + */ int -vfs_removexattr(struct dentry *dentry, const char *name) +__vfs_removexattr_locked(struct dentry *dentry, const char *name, + struct inode **delegated_inode) { struct inode *inode = dentry->d_inode; int error; @@ -388,11 +435,14 @@ vfs_removexattr(struct dentry *dentry, c if (error) return error; - inode_lock(inode); error = security_inode_removexattr(dentry, name); if (error) goto out; + error = try_break_deleg(inode, delegated_inode); + if (error) + goto out; + error = __vfs_removexattr(dentry, name); if (!error) { @@ -401,12 +451,32 @@ vfs_removexattr(struct dentry *dentry, c } out: + return error; +} +EXPORT_SYMBOL_GPL(__vfs_removexattr_locked); + +int +vfs_removexattr(struct dentry *dentry, const char *name) +{ + struct inode *inode = dentry->d_inode; + struct inode *delegated_inode = NULL; + int error; + +retry_deleg: + inode_lock(inode); + error = __vfs_removexattr_locked(dentry, name, &delegated_inode); inode_unlock(inode); + + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } + return error; } EXPORT_SYMBOL_GPL(vfs_removexattr); - /* * Extended attribute SET operations */ --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -52,8 +52,10 @@ ssize_t vfs_getxattr(struct dentry *, co ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int); int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int); +int __vfs_setxattr_locked(struct dentry *, const char *, const void *, size_t, int, struct inode **); int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int); int __vfs_removexattr(struct dentry *, const char *); +int __vfs_removexattr_locked(struct dentry *, const char *, struct inode **); int vfs_removexattr(struct dentry *, const char *); ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);