* Re: - cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch removed from -mm tree
[not found] ` <200812192316.mBJNGxbW012070-AB4EexQrvXRQetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
@ 2009-01-06 1:25 ` Li Zefan
[not found] ` <4962B2EE.9090606-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
0 siblings, 1 reply; 3+ messages in thread
From: Li Zefan @ 2009-01-06 1:25 UTC (permalink / raw)
To: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b
Cc: Linux Containers, Grzegorz Nosek, menage-hpIqsD4AKlfQT0dZR+AlfA,
xemul-GEFAQzZX7r8dnm+yROfE0A
akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org wrote:
> The patch titled
> cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups
> has been removed from the -mm tree. Its filename was
> cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch
>
> This patch was dropped because an updated version will be merged
>
Hi Andrew,
You picked up the right patch, but then dropped it by mistake.
There won't be an updated version. ;)
> The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
>
> ------------------------------------------------------
> Subject: cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups
> From: Grzegorz Nosek <root-AfQBxy1nhrQ00sYp1HPQUA@public.gmane.org>
>
> The ns_proxy cgroup allows moving processes to child cgroups only one
> level deep at a time. This commit relaxes this restriction and makes it
> possible to attach tasks directly to grandchild cgroups, e.g.:
>
> ($pid is in the root cgroup)
> echo $pid > /cgroup/CG1/CG2/tasks
>
> Previously this operation would fail with -EPERM and would have to be
> performed as two steps:
> echo $pid > /cgroup/CG1/tasks
> echo $pid > /cgroup/CG1/CG2/tasks
>
> Signed-off-by: Grzegorz Nosek <root-AfQBxy1nhrQ00sYp1HPQUA@public.gmane.org>
> Reviewed-by: Li Zefan <lizf-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
> Cc: Paul Menage <menage-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
> Cc: Balbir Singh <balbir-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
> Cc: Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
> Signed-off-by: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
> ---
>
> include/linux/cgroup.h | 4 ++--
> kernel/cgroup.c | 12 +++++++-----
> kernel/ns_cgroup.c | 9 +++------
> 3 files changed, 12 insertions(+), 13 deletions(-)
>
> diff -puN include/linux/cgroup.h~cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups include/linux/cgroup.h
> --- a/include/linux/cgroup.h~cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups
> +++ a/include/linux/cgroup.h
> @@ -309,8 +309,8 @@ int cgroup_path(const struct cgroup *cgr
>
> int cgroup_task_count(const struct cgroup *cgrp);
>
> -/* Return true if the cgroup is a descendant of the current cgroup */
> -int cgroup_is_descendant(const struct cgroup *cgrp);
> +/* Return true if cgrp is a descendant of the task's cgroup */
> +int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task);
>
> /* Control Group subsystem type. See Documentation/cgroups.txt for details */
>
> diff -puN kernel/cgroup.c~cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups kernel/cgroup.c
> --- a/kernel/cgroup.c~cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups
> +++ a/kernel/cgroup.c
> @@ -3024,18 +3024,19 @@ int cgroup_clone(struct task_struct *tsk
> }
>
> /**
> - * cgroup_is_descendant - see if @cgrp is a descendant of current task's cgrp
> + * cgroup_is_descendant - see if @cgrp is a descendant of @task's cgrp
> * @cgrp: the cgroup in question
> + * @task: the task in question
> *
> - * See if @cgrp is a descendant of the current task's cgroup in
> - * the appropriate hierarchy.
> + * See if @cgrp is a descendant of @task's cgroup in the appropriate
> + * hierarchy.
> *
> * If we are sending in dummytop, then presumably we are creating
> * the top cgroup in the subsystem.
> *
> * Called only by the ns (nsproxy) cgroup.
> */
> -int cgroup_is_descendant(const struct cgroup *cgrp)
> +int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task)
> {
> int ret;
> struct cgroup *target;
> @@ -3045,7 +3046,8 @@ int cgroup_is_descendant(const struct cg
> return 1;
>
> get_first_subsys(cgrp, NULL, &subsys_id);
> - target = task_cgroup(current, subsys_id);
> + target = task_cgroup(task, subsys_id);
> +
> while (cgrp != target && cgrp!= cgrp->top_cgroup)
> cgrp = cgrp->parent;
> ret = (cgrp == target);
> diff -puN kernel/ns_cgroup.c~cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups kernel/ns_cgroup.c
> --- a/kernel/ns_cgroup.c~cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups
> +++ a/kernel/ns_cgroup.c
> @@ -46,21 +46,18 @@ int ns_cgroup_clone(struct task_struct *
> static int ns_can_attach(struct cgroup_subsys *ss,
> struct cgroup *new_cgroup, struct task_struct *task)
> {
> - struct cgroup *orig;
> -
> if (current != task) {
> if (!capable(CAP_SYS_ADMIN))
> return -EPERM;
>
> - if (!cgroup_is_descendant(new_cgroup))
> + if (!cgroup_is_descendant(new_cgroup, current))
> return -EPERM;
> }
>
> if (atomic_read(&new_cgroup->count) != 0)
> return -EPERM;
>
> - orig = task_cgroup(task, ns_subsys_id);
> - if (orig && orig != new_cgroup->parent)
> + if (!cgroup_is_descendant(new_cgroup, task))
> return -EPERM;
>
> return 0;
> @@ -78,7 +75,7 @@ static struct cgroup_subsys_state *ns_cr
>
> if (!capable(CAP_SYS_ADMIN))
> return ERR_PTR(-EPERM);
> - if (!cgroup_is_descendant(cgroup))
> + if (!cgroup_is_descendant(cgroup, current))
> return ERR_PTR(-EPERM);
>
> ns_cgroup = kzalloc(sizeof(*ns_cgroup), GFP_KERNEL);
> _
>
> Patches currently in -mm which might be from root-AfQBxy1nhrQ00sYp1HPQUA@public.gmane.org are
>
> cgroups-relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch
>
>
>
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