From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755409AbcH3PCx (ORCPT ); Tue, 30 Aug 2016 11:02:53 -0400 Received: from mail-oi0-f42.google.com ([209.85.218.42]:34505 "EHLO mail-oi0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753595AbcH3PCv (ORCPT ); Tue, 30 Aug 2016 11:02:51 -0400 Date: Tue, 30 Aug 2016 10:02:49 -0500 From: Seth Forshee To: Juergen Gross Cc: "Eric W. Biederman" , Boris Ostrovsky , David Vrabel , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] xenbus: Use proc_create_mount_point() to create /proc/xen Message-ID: <20160830150249.GA55509@ubuntu-hedt> References: <1472483029-135090-1-git-send-email-seth.forshee@canonical.com> <7389d1f8-7d61-fbcc-7e62-3f7e7b6f7e50@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7389d1f8-7d61-fbcc-7e62-3f7e7b6f7e50@suse.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 30, 2016 at 04:48:08PM +0200, Juergen Gross wrote: > On 29/08/16 17:03, Seth Forshee wrote: > > Mounting proc in user namespace containers fails if the xenbus > > filesystem is mounted on /proc/xen because this directory fails > > the "permanently empty" test. proc_create_mount_point() exists > > specifically to create such mountpoints in proc but is currently > > proc-internal. Export this interface to modules, then use it in > > xenbus when creating /proc/xen. > > > > Signed-off-by: Seth Forshee > > --- > > drivers/xen/xenbus/xenbus_probe.c | 2 +- > > fs/proc/generic.c | 1 + > > fs/proc/internal.h | 1 - > > include/linux/proc_fs.h | 2 ++ > > 4 files changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c > > index 33a31cfef55d..b5c1dec4a7c2 100644 > > --- a/drivers/xen/xenbus/xenbus_probe.c > > +++ b/drivers/xen/xenbus/xenbus_probe.c > > @@ -826,7 +826,7 @@ static int __init xenbus_init(void) > > * Create xenfs mountpoint in /proc for compatibility with > > * utilities that expect to find "xenbus" under "/proc/xen". > > */ > > - proc_mkdir("xen", NULL); > > + proc_create_mount_point("xen"); > > #endif > > > > out_error: > > diff --git a/fs/proc/generic.c b/fs/proc/generic.c > > index c633476616e0..be014c544d50 100644 > > --- a/fs/proc/generic.c > > +++ b/fs/proc/generic.c > > @@ -477,6 +477,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name) > > } > > return ent; > > } > > +EXPORT_SYMBOL(proc_create_mount_point); > > EXPORT_SYMBOL_GPL()? Other similar sorts of calls in proc (proc_mkdir in particular) are EXPORT_SYMBOL, so I guessed this one should follow suit. But if it should be EXPORT_SYMOBL_GPL then that's fine too. Thanks, Seth