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=-6.8 required=3.0 tests=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 80EA9C433FF for ; Fri, 2 Aug 2019 09:56:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D3372064A for ; Fri, 2 Aug 2019 09:56:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739773; bh=TO/8nnFSSvjptpD6jOWFDtSTYx1GoMZAaSaBFpVcCNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cm5ce0zmCbR44mHvNz2qM5qXOBak9h6CJZ66no3ytXwJXszH5de+QDo8A7+taY7I8 8ECfdm7qXeUCU6mfYlqm+4JWRhxsTXOTCsCdjrWkcndnB2UeQ0rV+0qI/+V8+mPwFk yPgPr+AUVC51idIgoreDP8yIYPc7r/7irQMTaz4k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406694AbfHBJ4M (ORCPT ); Fri, 2 Aug 2019 05:56:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:34896 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406675AbfHBJ4H (ORCPT ); Fri, 2 Aug 2019 05:56:07 -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 822652064A; Fri, 2 Aug 2019 09:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739766; bh=TO/8nnFSSvjptpD6jOWFDtSTYx1GoMZAaSaBFpVcCNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wTbDhJXIC3rs0GVEoV2afWeGRqNS1ikm8GC78GsnS5Bg6EYDmdaFF32kytPDgGZpE Kuz4GVDsNgdYCOekkdXy43JORGbJcce7vbnj7MzM2tIBJaaNFFR5TsWx9vrm11hYo+ x/0VgpeSLhALYluj4Z7QaL4nFqhg8IDx3E0rWL04= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Qian Lu Subject: [PATCH 4.19 05/32] NFSv4: Fix lookup revalidate of regular files Date: Fri, 2 Aug 2019 11:39:39 +0200 Message-Id: <20190802092103.334825109@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190802092101.913646560@linuxfoundation.org> References: <20190802092101.913646560@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: Trond Myklebust commit c7944ebb9ce9461079659e9e6ec5baaf73724b3b upstream. If we're revalidating an existing dentry in order to open a file, we need to ensure that we check the directory has not changed before we optimise away the lookup. Signed-off-by: Trond Myklebust Signed-off-by: Qian Lu Signed-off-by: Greg Kroah-Hartman --- fs/nfs/dir.c | 79 +++++++++++++++++++++++++++++------------------------------ 1 file changed, 39 insertions(+), 40 deletions(-) --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1231,7 +1231,8 @@ out_bad: } static int -nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) +__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags, + int (*reval)(struct inode *, struct dentry *, unsigned int)) { struct dentry *parent; struct inode *dir; @@ -1242,17 +1243,22 @@ nfs_lookup_revalidate(struct dentry *den dir = d_inode_rcu(parent); if (!dir) return -ECHILD; - ret = nfs_do_lookup_revalidate(dir, dentry, flags); + ret = reval(dir, dentry, flags); if (parent != READ_ONCE(dentry->d_parent)) return -ECHILD; } else { parent = dget_parent(dentry); - ret = nfs_do_lookup_revalidate(d_inode(parent), dentry, flags); + ret = reval(d_inode(parent), dentry, flags); dput(parent); } return ret; } +static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) +{ + return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate); +} + /* * A weaker form of d_revalidate for revalidating just the d_inode(dentry) * when we don't really care about the dentry name. This is called when a @@ -1609,62 +1615,55 @@ no_open: } EXPORT_SYMBOL_GPL(nfs_atomic_open); -static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) +static int +nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, + unsigned int flags) { struct inode *inode; - int ret = 0; if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY)) - goto no_open; + goto full_reval; if (d_mountpoint(dentry)) - goto no_open; - if (NFS_SB(dentry->d_sb)->caps & NFS_CAP_ATOMIC_OPEN_V1) - goto no_open; + goto full_reval; inode = d_inode(dentry); /* We can't create new files in nfs_open_revalidate(), so we * optimize away revalidation of negative dentries. */ - if (inode == NULL) { - struct dentry *parent; - struct inode *dir; - - if (flags & LOOKUP_RCU) { - parent = READ_ONCE(dentry->d_parent); - dir = d_inode_rcu(parent); - if (!dir) - return -ECHILD; - } else { - parent = dget_parent(dentry); - dir = d_inode(parent); - } - if (!nfs_neg_need_reval(dir, dentry, flags)) - ret = 1; - else if (flags & LOOKUP_RCU) - ret = -ECHILD; - if (!(flags & LOOKUP_RCU)) - dput(parent); - else if (parent != READ_ONCE(dentry->d_parent)) - return -ECHILD; - goto out; - } + if (inode == NULL) + goto full_reval; + + if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ)) + return nfs_lookup_revalidate_delegated(dir, dentry, inode); /* NFS only supports OPEN on regular files */ if (!S_ISREG(inode->i_mode)) - goto no_open; + goto full_reval; + /* We cannot do exclusive creation on a positive dentry */ - if (flags & LOOKUP_EXCL) - goto no_open; + if (flags & (LOOKUP_EXCL | LOOKUP_REVAL)) + goto reval_dentry; + + /* Check if the directory changed */ + if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) + goto reval_dentry; /* Let f_op->open() actually open (and revalidate) the file */ - ret = 1; + return 1; +reval_dentry: + if (flags & LOOKUP_RCU) + return -ECHILD; + return nfs_lookup_revalidate_dentry(dir, dentry, inode);; -out: - return ret; +full_reval: + return nfs_do_lookup_revalidate(dir, dentry, flags); +} -no_open: - return nfs_lookup_revalidate(dentry, flags); +static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) +{ + return __nfs_lookup_revalidate(dentry, flags, + nfs4_do_lookup_revalidate); } #endif /* CONFIG_NFSV4 */