From patchwork Fri Mar 13 23:53:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 11438055 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A480C14B4 for ; Fri, 13 Mar 2020 23:56:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 866F22074F for ; Fri, 13 Mar 2020 23:56:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbgCMX4A (ORCPT ); Fri, 13 Mar 2020 19:56:00 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:50136 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727806AbgCMXyF (ORCPT ); Fri, 13 Mar 2020 19:54:05 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCu7v-00B6cz-Mo; Fri, 13 Mar 2020 23:54:03 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Linus Torvalds Subject: [RFC][PATCH v4 48/69] follow_dotdot{,_rcu}(): switch to use of step_into() Date: Fri, 13 Mar 2020 23:53:36 +0000 Message-Id: <20200313235357.2646756-48-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200313235357.2646756-1-viro@ZenIV.linux.org.uk> References: <20200313235303.GP23230@ZenIV.linux.org.uk> <20200313235357.2646756-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Al Viro gets the regular mount crossing on result of .. Signed-off-by: Al Viro --- fs/namei.c | 31 +++++++------------------------ 1 file changed, 7 insertions(+), 24 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 1749e435edc7..9c775013368a 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1722,33 +1722,18 @@ static const char *follow_dotdot_rcu(struct nameidata *nd) /* we know that mountpoint was pinned */ nd->path.dentry = mountpoint; nd->path.mnt = &mparent->mnt; - inode = inode2; + inode = nd->inode = inode2; nd->seq = seq; } } if (unlikely(!parent)) { if (unlikely(nd->flags & LOOKUP_BENEATH)) return ERR_PTR(-ECHILD); + return step_into(nd, WALK_NOFOLLOW, + nd->path.dentry, nd->inode, nd->seq); } else { - nd->path.dentry = parent; - nd->seq = seq; + return step_into(nd, WALK_NOFOLLOW, parent, inode, seq); } - while (unlikely(d_mountpoint(nd->path.dentry))) { - struct mount *mounted; - mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry); - if (unlikely(read_seqretry(&mount_lock, nd->m_seq))) - return ERR_PTR(-ECHILD); - if (!mounted) - break; - if (unlikely(nd->flags & LOOKUP_NO_XDEV)) - return ERR_PTR(-ECHILD); - nd->path.mnt = &mounted->mnt; - nd->path.dentry = mounted->mnt.mnt_root; - inode = nd->path.dentry->d_inode; - nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq); - } - nd->inode = inode; - return NULL; } static const char *follow_dotdot(struct nameidata *nd) @@ -1774,13 +1759,11 @@ static const char *follow_dotdot(struct nameidata *nd) if (unlikely(!parent)) { if (unlikely(nd->flags & LOOKUP_BENEATH)) return ERR_PTR(-EXDEV); + return step_into(nd, WALK_NOFOLLOW, + dget(nd->path.dentry), nd->inode, nd->seq); } else { - dput(nd->path.dentry); - nd->path.dentry = parent; + return step_into(nd, WALK_NOFOLLOW, parent, parent->d_inode, 0); } - follow_mount(&nd->path); - nd->inode = nd->path.dentry->d_inode; - return NULL; } static const char *handle_dots(struct nameidata *nd, int type)