From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Per-instance devpts Date: Sat, 02 Aug 2008 08:33:59 -0700 Message-ID: <48947E67.9060005@zytor.com> References: <20080412172933.GA19295@us.ibm.com> <1208027215.28187.17.camel@x61.ebiederm.org> <48935205.3090807@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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: Kyle Moffett Cc: Greg KH , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Eric W. Biederman" , Containers , Alan Cox , Pavel Emelyanov List-Id: containers.vger.kernel.org Kyle Moffett wrote: > > Here's my suggestion: > > By default, without any mount options, use the current "legacy" > behavior. The devpts filesystem would point to a "global" instance on > the whole box, controlled by the traditional /dev/ptmx device node. > There would *NOT* be a /dev/pts/ptmx node. > > If the devpts filesystem is mounted with a special option ("permount"? > "noglobal"?), then it will create a new devpts instance associated > with the filesystem. A devpts mounted that way *WILL* have a magic > /dev/pts/ptmx node. > > If the kernel is built with CONFIG_DEVPTS_FORCE_PERMOUNT then the > traditional /dev/ptmx device node will be neutered (IE: always return > -ENODEV) and the "permount" option will be forced for all devpts > mounts. This will also remove the static global devpts instance. > Hm. This might work if we can get the mount behaviour to work right. I'll think about it. It definitely seems like a reasonable way to get from A to B. -hpa