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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 ECA35C433E0 for ; Thu, 25 Jun 2020 20:40:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4A922072E for ; Thu, 25 Jun 2020 20:40:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="CXN9+h4C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390270AbgFYUkA (ORCPT ); Thu, 25 Jun 2020 16:40:00 -0400 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:54348 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389406AbgFYUj7 (ORCPT ); Thu, 25 Jun 2020 16:39:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1593117598; x=1624653598; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=neO0Khu3ookV42J7AkH6cW5PnC831pEliyuAac+ozhA=; b=CXN9+h4CGKCzwVoxSxk5zaZ6qPFSlcKn2jv6Kf3HpT99/S2OGQxvik2Y kVkRkzhGnqQI4u+ixKJ3JcHg9byf2ZqoaBNlXuMwKzEmepxKY5PSLgf5x nuKCGcn7PepUAlE8Oua8tjZgThSvapbuaLpPKzMQiYhIXzfvDvmx+A0Ub s=; IronPort-SDR: M1hdDHUlSHPLYMwSVx4SRigmbyqufWzyTurJm+ERQfybqKkc7HA1ySEc3scOy82R/w7K2vlmdo NixkL1CnhtHQ== X-IronPort-AV: E=Sophos;i="5.75,280,1589241600"; d="scan'208";a="38479086" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-37fd6b3d.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 25 Jun 2020 20:39:57 +0000 Received: from EX13MTAUEE002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-37fd6b3d.us-east-1.amazon.com (Postfix) with ESMTPS id 8AAC5283BE7; Thu, 25 Jun 2020 20:39:55 +0000 (UTC) Received: from EX13D23UEE002.ant.amazon.com (10.43.62.97) by EX13MTAUEE002.ant.amazon.com (10.43.62.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 25 Jun 2020 20:39:54 +0000 Received: from EX13MTAUEE002.ant.amazon.com (10.43.62.24) by EX13D23UEE002.ant.amazon.com (10.43.62.97) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 25 Jun 2020 20:39:54 +0000 Received: from dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com (172.23.141.97) by mail-relay.amazon.com (10.43.62.224) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 25 Jun 2020 20:39:54 +0000 Received: by dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com (Postfix, from userid 6262777) id 34F33C3318; Thu, 25 Jun 2020 20:39:54 +0000 (UTC) Date: Thu, 25 Jun 2020 20:39:54 +0000 From: Frank van der Linden To: , , Al Viro CC: Subject: Re: [PATCH v3 01/10] xattr: break delegations in {set,remove}xattr Message-ID: <20200625203954.GA10231@dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com> References: <20200623223927.31795-1-fllinden@amazon.com> <20200623223927.31795-2-fllinden@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20200623223927.31795-2-fllinden@amazon.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Al, Do you have any comments / concerns about this patch? It's part of nfs server side user xattr support, full series here: https://lore.kernel.org/linux-nfs/20200623223927.31795-1-fllinden@amazon.com/ I copied this one to linux-fsdevel and you, just giving you an extra ping. Bruce/Chuck are OK with the rest of the series, so I just need your ACK on this one, and the next one (will send the ping separately). Thanks, - Frank On Tue, Jun 23, 2020 at 10:39:18PM +0000, Frank van der Linden wrote: > 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. > > Additonally, 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 > Cc: linux-fsdevel@vger.kernel.org > Cc: Al Viro > Signed-off-by: Frank van der Linden > --- > fs/xattr.c | 84 +++++++++++++++++++++++++++++++++++++++---- > include/linux/xattr.h | 2 ++ > 2 files changed, 79 insertions(+), 7 deletions(-) > > diff --git a/fs/xattr.c b/fs/xattr.c > index 91608d9bfc6a..95f38f57347f 100644 > --- a/fs/xattr.c > +++ b/fs/xattr.c > @@ -204,10 +204,22 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name, > 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, const char *name, const void *value, > 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, const char *name) > } > 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, const char *name) > 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, const char *name) > } > > 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 > */ > diff --git a/include/linux/xattr.h b/include/linux/xattr.h > index 47eaa34f8761..a2f3cd02653c 100644 > --- a/include/linux/xattr.h > +++ b/include/linux/xattr.h > @@ -51,8 +51,10 @@ ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t); > 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); > -- > 2.17.2 >