Messages in this thread | | | Date | Sat, 12 Apr 2008 12:24:32 -0700 | From | "H. Peter Anvin" <> | Subject | Re: Multiple instances of devpts |
| |
Eric W. Biederman wrote: >> >> /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. > > Agreed. That is another legitimate path. And if all you care about is > isolation and not dealing with the general class of problems with the > global device number to device mapping that is sane. I know we have > several other virtual devices that we tend to care about but ptys are > the real world pain point. >
Thinking about it further, allowing this restriction would also allow a whole lot of cleanups inside the pty setup, since it would eliminate the need to do a separate lookup to find the corresponding devpts entry in pty_open(). The benefit here comes from the closer coupling between the pty and the devpts filesystem and isn't at all related to namespaces, but it's a very nice side benefit.
-hpa
| |