From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valerie Aurora Subject: [PATCH 30/39] union-mount: Implement union-aware link() Date: Mon, 3 May 2010 16:12:29 -0700 Message-ID: <1272928358-20854-31-git-send-email-vaurora@redhat.com> References: <1272928358-20854-1-git-send-email-vaurora@redhat.com> Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Jan Blunck , Valerie Aurora To: Alexander Viro Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34672 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932211Ab0ECXOE (ORCPT ); Mon, 3 May 2010 19:14:04 -0400 In-Reply-To: <1272928358-20854-1-git-send-email-vaurora@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: --- fs/namei.c | 24 ++++++++++++++++++++---- 1 files changed, 20 insertions(+), 4 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 0c52042..d85d7f1 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3029,16 +3029,18 @@ 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; @@ -3046,8 +3048,20 @@ 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_UNIONED_DIR(&old_nd.path) && + (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)) @@ -3070,6 +3084,8 @@ out_release: putname(to); out: path_put(&old_path); + path_put(&old_nd.path); + putname(from); return error; } -- 1.6.3.3