[CRIU] Re: [PATCH 3/6] pstree: Allow to dump and restore session non-leaders if --shell-job passed

[Pavel Emelyanov]

On 10/16/2012 11:27 AM, Cyrill Gorcunov wrote:
> 
> If --shell-job passed we allow to dump and restpre session non-leaders.
> 
> This slightly changes the behaviour or the tool. If previously
> we allowed to dump non-leaders after this commit we refuse to
> do that if not explicitly requested.
> 
> Note that in sake of tty restore (which will be addressed in
> further patches) we do inherit process group for root task.
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
> ---
>  include/pstree.h |    7 ++++
>  pstree.c         |   84 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 89 insertions(+), 2 deletions(-)
> 


> +		 *   PID  GID  SID
> +		 *    2    2    2    shell
> +		 *    3    2    2    `- root-task <-- dump from here
> +		 *    5    2    2      `- task-1
> +		 *    6    6    2      `- task-2
> +		 *
> +		 *   PID  GID  SID
> +		 *    1    1    1    shell
> +		 *    3    1    1    `- root-task <-- restore from here
> +		 *    5    1    1      `- task-1
> +		 *    6    6    1      `- task-2
> +		 *
> +		 * So when we migrate a shell job we need the task-1 to inherit
> +		 * GID from root task, thus we put INHERIT_PGID in the image.
> +		 */
> +		if (item->pgid == origin_sid)
> +			e.pgid = INHERIT_SID;
> +		else if (item->pgid == origin_pgid)
> +			e.pgid = INHERIT_PGID;
> +		else
> +			e.pgid = item->pgid;

In the examples above all the pgid-s will be INHERIT_SID. Show me example when
INHERIT_PGID can happen.