From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751679AbeDEKq3 (ORCPT ); Thu, 5 Apr 2018 06:46:29 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:41503 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751251AbeDEKp4 (ORCPT ); Thu, 5 Apr 2018 06:45:56 -0400 X-Google-Smtp-Source: AIpwx49JahAJmmcQ04o26IR6F5HbQEriXrtZZj4zqLzxblezS1Ln1x8hSkYadN5pDrVWYwR2lri2vQ== From: Christian Brauner To: ebiederm@xmission.com, torvalds@linux-foundation.o, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org Cc: Christian Brauner Subject: [PATCH 1/3] namei: add follow_up_bind() Date: Thu, 5 Apr 2018 12:45:47 +0200 Message-Id: <20180405104549.12365-2-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180405104549.12365-1-christian.brauner@ubuntu.com> References: <20180405104549.12365-1-christian.brauner@ubuntu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds a new helper for resolving bind-mounts. Signed-off-by: Christian Brauner --- fs/namei.c | 10 ++++++++++ include/linux/namei.h | 1 + 2 files changed, 11 insertions(+) diff --git a/fs/namei.c b/fs/namei.c index a09419379f5d..4fa56ec78f63 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1085,6 +1085,16 @@ int follow_up(struct path *path) } EXPORT_SYMBOL(follow_up); +/* + * follow_up_bind - Resolve bind-mounts to mountpoint of path's vfsmount + */ +inline void follow_up_bind(struct path *path) +{ + while (path->mnt->mnt_root == path->dentry && follow_up(path)) + ; +} +EXPORT_SYMBOL(follow_up_bind); + /* * Perform an automount * - return -EISDIR to tell follow_managed() to stop and return the path we diff --git a/include/linux/namei.h b/include/linux/namei.h index a982bb7cd480..ea93127be26c 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -87,6 +87,7 @@ extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int extern int follow_down_one(struct path *); extern int follow_down(struct path *); extern int follow_up(struct path *); +extern void follow_up_bind(struct path *path); extern struct dentry *lock_rename(struct dentry *, struct dentry *); extern void unlock_rename(struct dentry *, struct dentry *); -- 2.15.1