From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Multiple instances of devpts Date: Sat, 12 Apr 2008 11:54:59 -0700 Message-ID: <48010583.3020403@zytor.com> References: <20080412172933.GA19295@us.ibm.com> <20080412183514.GO9785@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080412183514.GO9785@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org To: Al Viro Cc: sukadev@us.ibm.com, Andrew Morton , serue@us.ibm.com, matthltc@us.ibm.com, "Eric W. Biederman" , Pavel Emelyanov , Containers , linux-kernel@vger.kernel.org, Linus Torvalds List-Id: containers.vger.kernel.org Al Viro wrote: > > *boggle* > > Care to explain how that "namespace" is different from devpts instance? > IOW, why the devil do you guys ignore Occam's Razor? > > Frankly, this nonsense has gone far enough; I can buy the need to compensate > for shitty APIs (sockets, non-fs-based-IPC, etc.), but devpts *is* *a* > *fucking* *filesystem*. Already. And as such it's already present in > normal, real, we-really-shouldn't-have-any-other-if-not-for-ancient-stupidity > namespace. > > Why not simply allow independent instances of devpts and be done with that? In particular: /dev/ptmx can be a symlink ptmx -> pts/ptmx, and we add a ptmx instance inside the devpts filesystem. Each devpts filesystem is responsible for its own pool of ptys, with own numbering, etc. This does mean that entries in /dev/pts are more than just plain device nodes, which they are now (you can cp -a a device node from /dev/pts into another filesystem and it will still "just work"), but I doubt this actually matters to anyone. If anyone cares, now I guess would be a good time to speak up. -hpa