From patchwork Wed May 13 22:26:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 6400811 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BC233BEEE1 for ; Wed, 13 May 2015 22:28:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B64C320411 for ; Wed, 13 May 2015 22:28:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E38E203EB for ; Wed, 13 May 2015 22:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965176AbbEMW2U (ORCPT ); Wed, 13 May 2015 18:28:20 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:44952 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965612AbbEMW0p (ORCPT ); Wed, 13 May 2015 18:26:45 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.76 #1 (Red Hat Linux)) id 1Ysf6W-0006ma-Fl; Wed, 13 May 2015 22:26:16 +0000 From: Al Viro To: Linus Torvalds Cc: Neil Brown , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 12/21] namei: shift nameidata down into filename_parentat() Date: Wed, 13 May 2015 23:26:06 +0100 Message-Id: <1431555975-25997-12-git-send-email-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <20150513222533.GA24192@ZenIV.linux.org.uk> References: <20150513222533.GA24192@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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: Al Viro Signed-off-by: Al Viro --- fs/namei.c | 84 ++++++++++++++++++++++++++++++++------------------------------ 1 file changed, 43 insertions(+), 41 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 6607a05..dbd1a34 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2144,7 +2144,8 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags, /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ static int path_parentat(int dfd, const struct filename *name, - unsigned int flags, struct nameidata *nd) + unsigned int flags, struct nameidata *nd, + struct path *parent) { const char *s = path_init(dfd, name, flags, nd); int err; @@ -2153,26 +2154,34 @@ static int path_parentat(int dfd, const struct filename *name, err = link_path_walk(s, nd); if (!err) err = complete_walk(nd); - if (err) - terminate_walk(nd); + if (!err) { + *parent = nd->path; + nd->path.mnt = NULL; + nd->path.dentry = NULL; + } + terminate_walk(nd); path_cleanup(nd); return err; } static int filename_parentat(int dfd, struct filename *name, - unsigned int flags, struct nameidata *nd) + unsigned int flags, struct path *parent, + struct qstr *last, int *type) { int retval; - struct nameidata *saved_nd = set_nameidata(nd); + struct nameidata nd, *saved_nd = set_nameidata(&nd); - retval = path_parentat(dfd, name, flags | LOOKUP_RCU, nd); + retval = path_parentat(dfd, name, flags | LOOKUP_RCU, &nd, parent); if (unlikely(retval == -ECHILD)) - retval = path_parentat(dfd, name, flags, nd); + retval = path_parentat(dfd, name, flags, &nd, parent); if (unlikely(retval == -ESTALE)) - retval = path_parentat(dfd, name, flags | LOOKUP_REVAL, nd); - - if (likely(!retval)) - audit_inode(name, nd->path.dentry, LOOKUP_PARENT); + retval = path_parentat(dfd, name, flags | LOOKUP_REVAL, + &nd, parent); + if (likely(!retval)) { + *last = nd.last; + *type = nd.last_type; + audit_inode(name, parent->dentry, LOOKUP_PARENT); + } restore_nameidata(saved_nd); return retval; } @@ -2181,31 +2190,30 @@ static int filename_parentat(int dfd, struct filename *name, struct dentry *kern_path_locked(const char *name, struct path *path) { struct filename *filename = getname_kernel(name); - struct nameidata nd; + struct qstr last; + int type; struct dentry *d; int err; if (IS_ERR(filename)) return ERR_CAST(filename); - err = filename_parentat(AT_FDCWD, filename, 0, &nd); + err = filename_parentat(AT_FDCWD, filename, 0, path, &last, &type); if (err) { d = ERR_PTR(err); goto out; } - if (nd.last_type != LAST_NORM) { - path_put(&nd.path); + if (type != LAST_NORM) { + path_put(path); d = ERR_PTR(-EINVAL); goto out; } - mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); - d = __lookup_hash(&nd.last, nd.path.dentry, 0); + mutex_lock_nested(&path->dentry->d_inode->i_mutex, I_MUTEX_PARENT); + d = __lookup_hash(&last, path->dentry, 0); if (IS_ERR(d)) { - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - path_put(&nd.path); - goto out; + mutex_unlock(&path->dentry->d_inode->i_mutex); + path_put(path); } - *path = nd.path; out: putname(filename); return d; @@ -2315,7 +2323,6 @@ user_path_parent(int dfd, const char __user *path, int *type, unsigned int flags) { - struct nameidata nd; struct filename *s = getname(path); int error; @@ -2325,15 +2332,11 @@ user_path_parent(int dfd, const char __user *path, if (IS_ERR(s)) return s; - error = filename_parentat(dfd, s, flags, &nd); + error = filename_parentat(dfd, s, flags, parent, last, type); if (error) { putname(s); - return ERR_PTR(error); + s = ERR_PTR(error); } - *parent = nd.path; - *last = nd.last; - *type = nd.last_type; - return s; } @@ -3392,7 +3395,8 @@ static struct dentry *filename_create(int dfd, struct filename *name, struct path *path, unsigned int lookup_flags) { struct dentry *dentry = ERR_PTR(-EEXIST); - struct nameidata nd; + struct qstr last; + int type; int err2; int error; bool is_dir = (lookup_flags & LOOKUP_DIRECTORY); @@ -3403,7 +3407,7 @@ static struct dentry *filename_create(int dfd, struct filename *name, */ lookup_flags &= LOOKUP_REVAL; - error = filename_parentat(dfd, name, lookup_flags, &nd); + error = filename_parentat(dfd, name, lookup_flags, path, &last, &type); if (error) return ERR_PTR(error); @@ -3411,18 +3415,17 @@ static struct dentry *filename_create(int dfd, struct filename *name, * Yucky last component or no last component at all? * (foo/., foo/.., /////) */ - if (nd.last_type != LAST_NORM) + if (type != LAST_NORM) goto out; - nd.flags &= ~LOOKUP_PARENT; - nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL; /* don't fail immediately if it's r/o, at least try to report other errors */ - err2 = mnt_want_write(nd.path.mnt); + err2 = mnt_want_write(path->mnt); /* * Do the final lookup. */ - mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); - dentry = __lookup_hash(&nd.last, nd.path.dentry, nd.flags); + lookup_flags |= LOOKUP_CREATE | LOOKUP_EXCL; + mutex_lock_nested(&path->dentry->d_inode->i_mutex, I_MUTEX_PARENT); + dentry = __lookup_hash(&last, path->dentry, lookup_flags); if (IS_ERR(dentry)) goto unlock; @@ -3436,7 +3439,7 @@ static struct dentry *filename_create(int dfd, struct filename *name, * all is fine. Let's be bastards - you had / on the end, you've * been asking for (non-existent) directory. -ENOENT for you. */ - if (unlikely(!is_dir && nd.last.name[nd.last.len])) { + if (unlikely(!is_dir && last.name[last.len])) { error = -ENOENT; goto fail; } @@ -3444,17 +3447,16 @@ static struct dentry *filename_create(int dfd, struct filename *name, error = err2; goto fail; } - *path = nd.path; return dentry; fail: dput(dentry); dentry = ERR_PTR(error); unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); + mutex_unlock(&path->dentry->d_inode->i_mutex); if (!err2) - mnt_drop_write(nd.path.mnt); + mnt_drop_write(path->mnt); out: - path_put(&nd.path); + path_put(path); return dentry; }