Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932266AbZJUTVu (ORCPT ); Wed, 21 Oct 2009 15:21:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755399AbZJUTVt (ORCPT ); Wed, 21 Oct 2009 15:21:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11042 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755258AbZJUTVl (ORCPT ); Wed, 21 Oct 2009 15:21:41 -0400 From: Valerie Aurora To: Jan Blunck , Alexander Viro , Christoph Hellwig , Andy Whitcroft , Scott James Remnant , Sandu Popa Marius , Jan Rekorajski , "J. R. Okajima" , Arnd Bergmann , Vladimir Dronnikov , Felix Fietkau Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 38/41] union-mount: Make pivot_root work with union mounts Date: Wed, 21 Oct 2009 12:19:36 -0700 Message-Id: <1256152779-10054-39-git-send-email-vaurora@redhat.com> In-Reply-To: <1256152779-10054-38-git-send-email-vaurora@redhat.com> References: <1256152779-10054-1-git-send-email-vaurora@redhat.com> <1256152779-10054-2-git-send-email-vaurora@redhat.com> <1256152779-10054-3-git-send-email-vaurora@redhat.com> <1256152779-10054-4-git-send-email-vaurora@redhat.com> <1256152779-10054-5-git-send-email-vaurora@redhat.com> <1256152779-10054-6-git-send-email-vaurora@redhat.com> <1256152779-10054-7-git-send-email-vaurora@redhat.com> <1256152779-10054-8-git-send-email-vaurora@redhat.com> <1256152779-10054-9-git-send-email-vaurora@redhat.com> <1256152779-10054-10-git-send-email-vaurora@redhat.com> <1256152779-10054-11-git-send-email-vaurora@redhat.com> <1256152779-10054-12-git-send-email-vaurora@redhat.com> <1256152779-10054-13-git-send-email-vaurora@redhat.com> <1256152779-10054-14-git-send-email-vaurora@redhat.com> <1256152779-10054-15-git-send-email-vaurora@redhat.com> <1256152779-10054-16-git-send-email-vaurora@redhat.com> <1256152779-10054-17-git-send-email-vaurora@redhat.com> <1256152779-10054-18-git-send-email-vaurora@redhat.com> <1256152779-10054-19-git-send-email-vaurora@redhat.com> <1256152779-10054-20-git-send-email-vaurora@redhat.com> <1256152779-10054-21-git-send-email-vaurora@redhat.com> <1256152779-10054-22-git-send-email-vaurora@redhat.com> <1256152779-10054-23-git-send-email-vaurora@redhat.com> <1256152779-10054-24-git-send-email-vaurora@redhat.com> <1256152779-10054-25-git-send-email-vaurora@redhat.com> <1256152779-10054-26-git-send-email-vaurora@redhat.com> <1256152779-10054-27-git-send-email-vaurora@redhat.com> <1256152779-10054-28-git-send-email-vaurora@redhat.com> <1256152779-10054-29-git-send-email-vaurora@redhat.com> <1256152779-10054-30-git-send-email-vaurora@redhat.com> <1256152779-10054-31-git-send-email-vaurora@redhat.com> <1256152779-10054-32-git-send-email-vaurora@redhat.com> <1256152779-10054-33-git-send-email-vaurora@redhat.com> <1256152779-10054-34-git-send-email-vaurora@redhat.com> <1256152779-10054-35-git-send-email-vaurora@redhat.com> <1256152779-10054-36-git-send-email-vaurora@redhat.com> <1256152779-10054-37-git-send-email-vaurora@redhat.com> <1256152779-10054-38-git-send-email-vaurora@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1240 Lines: 36 When moving a union mount, follow it down to the bottom layer and move that instead of just the top layer. Signed-off-by: Valerie Aurora --- fs/namespace.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 9b71743..6ac5fc1 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2282,6 +2282,15 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, if (d_unlinked(old.dentry)) goto out2; error = -EBUSY; + /* + * follow_union_down() only goes one layer down. We want the + * bottom-most layer here - if we move that around, all the + * layers on top move with it. But if we ever allow more than + * two layers, the below two will both need to be in while() + * loops. + */ + follow_union_down(&new.mnt, &new.dentry); + follow_union_down(&root.mnt, &root.dentry); if (new.mnt == root.mnt || old.mnt == root.mnt) goto out2; /* loop, on the same file system */ -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/