From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) Subject: [PATCH review 5/6] userns: Allow the userns root to mount ramfs. Date: Fri, 25 Jan 2013 18:26:11 -0800 Message-ID: <87ip6khe7w.fsf@xmission.com> References: <87ehh8it9s.fsf@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87ehh8it9s.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> (Eric W. Biederman's message of "Fri, 25 Jan 2013 18:15:43 -0800") 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: Linux Containers Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: containers.vger.kernel.org There is no backing store to ramfs and file creation rules are the same as for any other filesystem so it is semantically safe to allow unprivileged users to mount it. The memory control group successfully limits how much memory ramfs can consume on any system that cares about a user namespace root using ramfs to exhaust memory the memory control group can be deployed. Signed-off-by: "Eric W. Biederman" --- fs/ramfs/inode.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c index eab8c09..c24f1e1 100644 --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -260,6 +260,7 @@ static struct file_system_type ramfs_fs_type = { .name = "ramfs", .mount = ramfs_mount, .kill_sb = ramfs_kill_sb, + .fs_flags = FS_USERNS_MOUNT, }; static struct file_system_type rootfs_fs_type = { .name = "rootfs", -- 1.7.5.4