From patchwork Wed Feb 26 19:54:08 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shirish Pargaonkar X-Patchwork-Id: 3728311 Return-Path: X-Original-To: patchwork-cifs-client@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1F9139F2ED for ; Wed, 26 Feb 2014 19:54:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3100D201DD for ; Wed, 26 Feb 2014 19:54:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48456201CD for ; Wed, 26 Feb 2014 19:54:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751989AbaBZTyS (ORCPT ); Wed, 26 Feb 2014 14:54:18 -0500 Received: from mail-ob0-f177.google.com ([209.85.214.177]:58191 "EHLO mail-ob0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbaBZTyS (ORCPT ); Wed, 26 Feb 2014 14:54:18 -0500 Received: by mail-ob0-f177.google.com with SMTP id uy5so1274151obc.36 for ; Wed, 26 Feb 2014 11:54:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=kUwXsq8YKBHRKHjRJ4gba1QiU02UjxAEnQJXSoS2jkk=; b=ot4QvLdYyrfCX/K+3M/HisJGELCTJA1EC/dehCGyfQs/UCbS3ZSwLqTuN/UCuzl40w hTsjGbacWDycaFtiTQ/mm9UTBeHTXNDHOfgEAHsRqkGaZLZpvjNZpUF2Q/+CFdyRDR0B M+OexX8ciMyRgH/K2LS0kPPJU6QHKgTLTShUMEGK2talgRa5MBD3f1Argitwj8YGPbwm 8rB9Jq6+KpVVqtZxLnBb7el4NMVJOkcR2xwA9kz4bwpgli2ZvmUTcX+F2rcJclC9Kxcw QtbhDDMv/nQTHFKd1fAfWHUBOwVqm623XmqPnhGKjDoSigJ8Lj51N6CpD3Ps7lJUsucq SVzA== X-Received: by 10.183.3.102 with SMTP id bv6mr4487931obd.18.1393444457609; Wed, 26 Feb 2014 11:54:17 -0800 (PST) Received: from shirish-ThinkPad-T400.gns.novell.com (75-13-85-90.lightspeed.austtx.sbcglobal.net. [75.13.85.90]) by mx.google.com with ESMTPSA id m7sm4333221obo.7.2014.02.26.11.54.15 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 26 Feb 2014 11:54:16 -0800 (PST) From: shirishpargaonkar@gmail.com To: smfrench@gmail.com Cc: linux-cifs@vger.kernel.org, Shirish Pargaonkar Subject: [PATCH] cifs: Allow mounts with restricted intermediate paths (try #2) Date: Wed, 26 Feb 2014 13:54:08 -0600 Message-Id: <1393444448-10428-1-git-send-email-spargaonkar@suse.com> X-Mailer: git-send-email 1.8.3.2 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Shirish Pargaonkar Allow mounts with intermediate paths without access. Create an anonymous root dentry for a vfsmount with an inode obtained via path info if any of the intermediate path entries are not accessible with EACCES error. If this dentry becomes accessible via other mounts, splice this anonymous root dentry (and the subtree under it) at the appropriate place in that mount. Reference: Samba bugzilla 6950 Signed-off-by: Shirish Pargaonkar --- fs/cifs/cifsfs.c | 25 +++++++++++++++++++++++-- fs/cifs/dir.c | 18 ++++++++++++++---- fs/cifs/inode.c | 6 ++++-- 3 files changed, 41 insertions(+), 8 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 849f613..35a7a80 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -584,9 +584,12 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) char *full_path = NULL; char *s, *p; char sep; + int rc; + unsigned int xid; + struct inode *rinode = NULL; + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); - full_path = cifs_build_path_to_root(vol, cifs_sb, - cifs_sb_master_tcon(cifs_sb)); + full_path = cifs_build_path_to_root(vol, cifs_sb, tcon); if (full_path == NULL) return ERR_PTR(-ENOMEM); @@ -627,6 +630,24 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) dput(dentry); dentry = child; } while (!IS_ERR(dentry)); + if (IS_ERR(dentry) && (PTR_ERR(dentry) == -EACCES) && *s) { + xid = get_xid(); + if (tcon->unix_ext) { + rc = cifs_get_inode_info_unix(&rinode, full_path, + sb, xid); + } else { + rc = cifs_get_inode_info(&rinode, full_path, NULL, + sb, xid, NULL); + } + free_xid(xid); + + if ((rc == 0) && (rinode != NULL)) { + dentry = d_obtain_alias(rinode); + if (IS_ERR(dentry)) + iput(rinode); + } + } + kfree(full_path); return dentry; } diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 3db0c5f..7eb8ccc 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -702,6 +702,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct cifs_tcon *pTcon; struct inode *newInode = NULL; char *full_path = NULL; + struct dentry *ret = NULL; xid = get_xid(); @@ -748,11 +749,19 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, } if ((rc == 0) && (newInode != NULL)) { - d_add(direntry, newInode); /* since paths are not looked up by component - the parent directories are presumed to be good here */ - renew_parental_timestamps(direntry); - + ret = d_splice_alias(newInode, direntry); + if (!ret) + renew_parental_timestamps(direntry); + else { + if (!IS_ERR(ret)) { + renew_parental_timestamps(direntry); + dput(ret); + goto lookup_out; + } else + rc = PTR_ERR(ret); + } } else if (rc == -ENOENT) { rc = 0; direntry->d_time = jiffies; @@ -764,12 +773,13 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, /* We special case check for Access Denied - since that is a common return code */ } + ret = ERR_PTR(rc); lookup_out: kfree(full_path); cifs_put_tlink(tlink); free_xid(xid); - return ERR_PTR(rc); + return ret; } static int diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index aadc2b6..00006ab 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -885,8 +885,10 @@ inode_has_hashed_dentries(struct inode *inode) spin_lock(&inode->i_lock); hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) { if (!d_unhashed(dentry) || IS_ROOT(dentry)) { - spin_unlock(&inode->i_lock); - return true; + if (!(dentry->d_flags & DCACHE_DISCONNECTED)) { + spin_unlock(&inode->i_lock); + return true; + } } } spin_unlock(&inode->i_lock);