From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932280Ab0FOSmr (ORCPT ); Tue, 15 Jun 2010 14:42:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21868 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758495Ab0FOSmk (ORCPT ); Tue, 15 Jun 2010 14:42:40 -0400 From: Valerie Aurora To: Alexander Viro Cc: Miklos Szeredi , Jan Blunck , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Valerie Aurora Subject: [PATCH 29/38] union-mount: Implement union-aware link() Date: Tue, 15 Jun 2010 11:39:59 -0700 Message-Id: <1276627208-17242-30-git-send-email-vaurora@redhat.com> In-Reply-To: <1276627208-17242-1-git-send-email-vaurora@redhat.com> References: <1276627208-17242-1-git-send-email-vaurora@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --- fs/namei.c | 24 ++++++++++++++++++++---- 1 files changed, 20 insertions(+), 4 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 505b51d..d2f2618 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2938,16 +2938,18 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, { struct dentry *new_dentry; struct nameidata nd; + struct nameidata old_nd; struct path old_path; int error; char *to; + char *from; if ((flags & ~AT_SYMLINK_FOLLOW) != 0) return -EINVAL; - error = user_path_at(olddfd, oldname, + error = user_path_nd(olddfd, oldname, flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, - &old_path); + &old_nd, &old_path, &from); if (error) return error; @@ -2955,8 +2957,20 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, if (error) goto out; error = -EXDEV; - if (old_path.mnt != nd.path.mnt) - goto out_release; + if (old_path.mnt != nd.path.mnt) { + if (IS_DIR_UNIONED(old_nd.path.dentry) && + (old_nd.path.mnt == nd.path.mnt)) { + error = mnt_want_write(old_nd.path.mnt); + if (error) + goto out_release; + error = union_copyup(&old_nd, &old_path); + mnt_drop_write(old_nd.path.mnt); + if (error) + goto out_release; + } else { + goto out_release; + } + } new_dentry = lookup_create(&nd, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) @@ -2979,6 +2993,8 @@ out_release: putname(to); out: path_put(&old_path); + path_put(&old_nd.path); + putname(from); return error; } -- 1.6.3.3