netcls_cgroup: move config inheritance to ->css_online() and remove .broken_hierarchy...

It turns out that we'll have to live with attributes which are
inherited at cgroup creation time but not affected by further updates
to the parent afterwards - such attributes are already in wide use
e.g. for cpuset.

So, there's nothing to do for netcls_cgroup for hierarchy support.
Its current behavior - inherit only during creation - is good enough.

Move config inheriting from ->css_alloc() to ->css_online() for
consistency, which doesn't change behavior at all, and remove
.broken_hierarchy marking.

Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-and-Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 8cdc18e075fbd09432b0ea7f7f0e3e4725c80702..31f06b633574e8e85acfd288d9d5c574b8941275 100644 (file)
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -41,11 +41,15 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp)
        cs = kzalloc(sizeof(*cs), GFP_KERNEL);
        if (!cs)
                return ERR_PTR(-ENOMEM);
+       return &cs->css;
+}
 
+static int cgrp_css_online(struct cgroup *cgrp)
+{
        if (cgrp->parent)
-               cs->classid = cgrp_cls_state(cgrp->parent)->classid;
-
-       return &cs->css;
+               cgrp_cls_state(cgrp)->classid =
+                       cgrp_cls_state(cgrp->parent)->classid;
+       return 0;
 }
 
 static void cgrp_css_free(struct cgroup *cgrp)
@@ -76,19 +80,11 @@ static struct cftype ss_files[] = {
 struct cgroup_subsys net_cls_subsys = {
        .name           = "net_cls",
        .css_alloc      = cgrp_css_alloc,
+       .css_online     = cgrp_css_online,
        .css_free       = cgrp_css_free,
        .subsys_id      = net_cls_subsys_id,
        .base_cftypes   = ss_files,
        .module         = THIS_MODULE,
-
-       /*
-        * While net_cls cgroup has the rudimentary hierarchy support of
-        * inheriting the parent's classid on cgroup creation, it doesn't
-        * properly propagates config changes in ancestors to their
-        * descendents.  A child should follow the parent's configuration
-        * but be allowed to override it.  Fix it and remove the following.
-        */
-       .broken_hierarchy = true,
 };
 
 struct cls_cgroup_head {