[Devel] [VZ8 PATCH 1/3] ve/cgroup: unmark ve-root cgroups at container stop

[Konstantin Khorenko]

On 01/18/2021 09:08 PM, Valeriy Vdovin wrote:
> fixes: 915a1130c7ee4ffb6de3f69a5bd98c5ee42a723f
>
> Signed-off-by: Valeriy Vdovin <valeriy.vdovin at virtuozzo.com>
> Reviewed-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>
> Cherry-picked from 5dceccf5dd794673ebb1b0e6840d96aa654ec33e)
> Signed-off-by: Valeriy Vdovin <valeriy.vdovin at virtuozzo.com>

Ack, i will drop one redundant copy-paste line during commit, see below.

> ---
>  include/linux/cgroup.h |  1 +
>  kernel/cgroup/cgroup.c | 24 ++++++++++++++++++++++++
>  kernel/ve/ve.c         |  3 +++
>  3 files changed, 28 insertions(+)
>
> diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
> index 4f0dd51338bf..c0a42c3d43fa 100644
> --- a/include/linux/cgroup.h
> +++ b/include/linux/cgroup.h
> @@ -867,6 +867,7 @@ int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
>
>  #ifdef CONFIG_VE
>  extern void cgroup_mark_ve_root(struct ve_struct *ve);
> +void cgroup_unmark_ve_roots(struct ve_struct *ve);
>  #endif
>
>  #else /* !CONFIG_CGROUPS */
> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
> index 0335a07f64e6..4488df184235 100644
> --- a/kernel/cgroup/cgroup.c
> +++ b/kernel/cgroup/cgroup.c
> @@ -1908,6 +1908,30 @@ void cgroup_mark_ve_root(struct ve_struct *ve)
>  	spin_unlock_irq(&css_set_lock);
>  }
>
> +void cgroup_unmark_ve_roots(struct ve_struct *ve)
> +{
> +	struct cgrp_cset_link *link;
> +	struct css_set *cset;
> +	struct cgroup *cgrp;
> +
> +	spin_lock_irq(&css_set_lock);
> +
> +	rcu_read_lock();
> +	cset = rcu_dereference(ve->ve_ns)->cgroup_ns->root_cset;
> +	if (WARN_ON(!cset))
> +		goto unlock;
> +
> +	list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
> +		cgrp = link->cgrp;
> +		clear_bit(CGRP_VE_ROOT, &cgrp->flags);
> +	}
> +	link_ve_root_cpu_cgroup(cset->subsys[cpu_cgrp_id]);

^^^ this line to be dropped.

> +unlock:
> +	rcu_read_unlock();
> +
> +	spin_unlock_irq(&css_set_lock);
> +}
> +
>  struct cgroup *cgroup_get_ve_root1(struct cgroup *cgrp)
>  {
>  	struct cgroup *ve_root = NULL;
> diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
> index 3f53641455ad..b922653acf49 100644
> --- a/kernel/ve/ve.c
> +++ b/kernel/ve/ve.c
> @@ -519,6 +519,9 @@ void ve_exit_ns(struct pid_namespace *pid_ns)
>  	 */
>  	if (!ve_ns || ve_ns->pid_ns_for_children != pid_ns)
>  		goto unlock;
> +
> +	cgroup_unmark_ve_roots(ve);
> +
>  	/*
>  	 * At this point all userspace tasks in container are dead.
>  	 */
>