From patchwork Thu Aug 20 09:20:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 265513 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=-9.8 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 025B8C433E3 for ; Thu, 20 Aug 2020 11:57:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D273B214F1 for ; Thu, 20 Aug 2020 11:57:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597924659; bh=YZnMjO/6zwXyl+KT3ibEE6f9gUR4An819JMKRFtDwDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=e60tstaB4nO7MbG6KsCpjBBXSPPmut89zKN0vhCiqwtphF9kA7+t+Rui+BghsUp8H U9mNHEVwVShl2IQoupCjrcwTcdaRW0CvywlhTjk+SIujDiLfNCpIDp2+i2DIMrPDxK fGIssOJXNVe11bh2ThrqppYrAiah+DKLXEsDeeXc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730386AbgHTKAt (ORCPT ); Thu, 20 Aug 2020 06:00:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:48806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730472AbgHTKAd (ORCPT ); Thu, 20 Aug 2020 06:00:33 -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 678B520724; Thu, 20 Aug 2020 10:00:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917632; bh=YZnMjO/6zwXyl+KT3ibEE6f9gUR4An819JMKRFtDwDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UmlDL0CJqxVrA341MRzBt4f1da9kq1YX358lMOe1O8hM9CHgwCmD+57pA1iYOtxgc BJIbzlDlQpstBztbSuFkewTQwaqFwNmWp3UBtk+BMfjjxS1RJju2HVQH1UQCKF0T0d XoqINVGvavpudlgKy9e2vJ9WFyfhJgMVYEtpNXXI= 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 4.9 070/212] xattr: break delegations in {set,remove}xattr Date: Thu, 20 Aug 2020 11:20:43 +0200 Message-Id: <20200820091605.901394859@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091602.251285210@linuxfoundation.org> References: <20200820091602.251285210@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -203,10 +203,22 @@ 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; @@ -215,15 +227,40 @@ 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); @@ -379,8 +416,18 @@ __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; @@ -389,11 +436,14 @@ 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) { @@ -402,12 +452,32 @@ 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 @@ -51,8 +51,10 @@ 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);