From mboxrd@z Thu Jan 1 00:00:00 1970 From: Serge Hallyn Subject: Re: [PATCH RESEND] userns: enable tmpfs support for user namespace Date: Wed, 16 Jan 2013 08:35:32 -0600 Message-ID: <20130116143532.GA4035@sergelap> References: <1358331945-4106-1-git-send-email-gaofeng@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1358331945-4106-1-git-send-email-gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Gao feng Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org List-Id: containers.vger.kernel.org Quoting Gao feng (gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org): > From: gaofeng > > Since the memory used by tmpfs is under control of > memory cgroup. and the files under the tmpfs will not > be leak to other tmpfs. > > So mounting tmpfs in user namespace does no harm to the > host,we can allow tmpfs to be mounted in user namespace. > > Signed-off-by: gaofeng I've got the same patch in my kernel at http://kernel.ubuntu.com/git?p=serge/quantal-userns.git;a=summary except note that there are two definitions of shmem_fs_type. > --- > mm/shmem.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 5dd56f6..8eff60a 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -2766,6 +2766,7 @@ static struct file_system_type shmem_fs_type = { > .name = "tmpfs", > .mount = shmem_mount, > .kill_sb = kill_litter_super, > + .fs_flags = FS_USERNS_MOUNT, > }; > > int __init shmem_init(void) > -- > 1.7.11.7 >