[Devel] [PATCH rh7 0/3] Zap Unix98 pty virtualization

[Vladimir Davydov]

There is a problem with this patch set - it makes ptmx device
system-wide while its class, tty_class, is still virtualized. Since it's
now system-wide, we have to add its sysfs entry to
ve.default_sysfs_permissions, but since its class is virtualized, we
won't be able to do it (see sysfs_perms_set -> sysfs_find_dirent).

As a result, if the container relies on sysfs while creating devnodes,
it will not find ptmx and therefore fallback to legacy ptys, which we
are going to drop. We either need a follow-up quick fix for this issue,
or we could probably drop tty_class virtualization altogether (not sure
if the latter is possible, because we still need vzconsole, which
depends on it AFAICS).

Anyway, please postpone this patch set. Since "[PATCH rh7 0/6] zap
sb->s_ns + fix memleak in binfmt_misc" won't work w/o it, postpone it
too.

On Thu, Jul 23, 2015 at 06:54:34PM +0300, Vladimir Davydov wrote:
> Dunno why it was done in the first place - Unix98 ptys are already
> virtualized on the VFS layer, nothing needs to be done on the driver's
> side. We don't even have this in PCS6.
> 
> Vladimir Davydov (3):
>   Revert "ve/pty: containerize Unix98 pty drivers"
>   Revert "ve/pty: containerize Unix98 driver"
>   Revert "pty: split Unix98 init routines"
> 
>  drivers/tty/pty.c   | 160 ++++++++++------------------------------------------
>  include/linux/tty.h |   6 +-
>  include/linux/ve.h  |   6 --
>  kernel/ve/ve.c      |   7 ---
>  4 files changed, 33 insertions(+), 146 deletions(-)
> 
> -- 
> 2.1.4
>