Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261856AbVEPTyB (ORCPT ); Mon, 16 May 2005 15:54:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261847AbVEPTxv (ORCPT ); Mon, 16 May 2005 15:53:51 -0400 Received: from rev.193.226.232.93.euroweb.hu ([193.226.232.93]:52233 "EHLO dorka.pomaz.szeredi.hu") by vger.kernel.org with ESMTP id S261836AbVEPTv5 (ORCPT ); Mon, 16 May 2005 15:51:57 -0400 To: akpm@osdl.org, viro@parcelfarce.linux.theplanet.co.uk CC: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH] namespace.c: fix bind mount from foreign namespace Message-Id: From: Miklos Szeredi Date: Mon, 16 May 2005 21:51:14 +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1839 Lines: 46 I'm resending this patch, because I still believe it's the correct fix. Tested before/after applying the patch with a test application available from: http://www.inf.bme.hu/~mszeredi/nstest.c Bind mount from a foreign namespace results in an un-removable mount. The reason is that mnt->mnt_namespace is copied from the old mount in clone_mnt(). Because of this check_mnt() in sys_umount() will fail. The solution is to set mnt->mnt_namespace to current->namespace in clone_mnt(). clone_mnt() is either called from do_loopback() or copy_tree(). copy_tree() is called from do_loopback() or copy_namespace(). When called (directly or indirectly) from do_loopback(), always current->namspace is being modified: check_mnt(nd->mnt). So setting mnt->mnt_namespace to current->namspace is the right thing to do. When called from copy_namespace(), the setting of mnt_namespace is irrelevant, since mnt_namespace is reset later in that function for all copied mounts. Signed-off-by: Miklos Szeredi Index: linux/fs/namespace.c =================================================================== --- linux.orig/fs/namespace.c 2005-05-13 12:22:52.000000000 +0200 +++ linux/fs/namespace.c 2005-05-13 12:32:36.000000000 +0200 @@ -160,7 +160,7 @@ clone_mnt(struct vfsmount *old, struct d mnt->mnt_root = dget(root); mnt->mnt_mountpoint = mnt->mnt_root; mnt->mnt_parent = mnt; - mnt->mnt_namespace = old->mnt_namespace; + mnt->mnt_namespace = current->namespace; /* stick the duplicate mount on the same expiry list * as the original if that was on one */ - 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/