diff options
| -rw-r--r-- | kernel/cgroup.c | 72 |
1 files changed, 43 insertions, 29 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 5d452e7fcb4f..4178e45becb4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -222,8 +222,8 @@ static struct cftype cgroup_legacy_base_files[]; static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask); static void css_task_iter_advance(struct css_task_iter *it); static int cgroup_destroy_locked(struct cgroup *cgrp); -static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss, - bool visible); +static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, + struct cgroup_subsys *ss); static void css_release(struct percpu_ref *ref); static void kill_css(struct cgroup_subsys_state *css); static int cgroup_addrm_files(struct cgroup_subsys_state *css, @@ -3082,14 +3082,26 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, */ do_each_subsys_mask(ss, ssid, enable) { cgroup_for_each_live_child(child, cgrp) { - if (css_enable & (1 << ssid)) - ret = create_css(child, ss, - cgrp->subtree_control & (1 << ssid)); - else + if (css_enable & (1 << ssid)) { + struct cgroup_subsys_state *css; + + css = css_create(child, ss); + if (IS_ERR(css)) { + ret = PTR_ERR(css); + goto err_undo_css; + } + + if (cgrp->subtree_control & (1 << ssid)) { + ret = css_populate_dir(css, NULL); + if (ret) + goto err_undo_css; + } + } else { ret = css_populate_dir(cgroup_css(child, ss), NULL); - if (ret) - goto err_undo_css; + if (ret) + goto err_undo_css; + } } } while_each_subsys_mask(); @@ -4717,7 +4729,9 @@ static void css_release_work_fn(struct work_struct *work) * Those are supported by RCU protecting clearing of * cgrp->kn->priv backpointer. */ - RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL); + if (cgrp->kn) + RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, + NULL); } mutex_unlock(&cgroup_mutex); @@ -4801,17 +4815,16 @@ static void offline_css(struct cgroup_subsys_state *css) } /** - * create_css - create a cgroup_subsys_state + * css_create - create a cgroup_subsys_state * @cgrp: the cgroup new css will be associated with * @ss: the subsys of new css - * @visible: whether to create control knobs for the new css or not * * Create a new css associated with @cgrp - @ss pair. On success, the new - * css is online and installed in @cgrp with all interface files created if - * @visible. Returns 0 on success, -errno on failure. + * css is online and installed in @cgrp. This function doesn't create the + * interface files. Returns 0 on success, -errno on failure. */ -static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss, - bool visible) +static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, + struct cgroup_subsys *ss) { struct cgroup *parent = cgroup_parent(cgrp); struct cgroup_subsys_state *parent_css = cgroup_css(parent, ss); @@ -4822,7 +4835,7 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss, css = ss->css_alloc(parent_css); if (IS_ERR(css)) - return PTR_ERR(css); + return css; init_and_link_css(css, ss, cgrp); @@ -4835,12 +4848,6 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss, goto err_free_percpu_ref; css->id = err; - if (visible) { - err = css_populate_dir(css, NULL); - if (err) - goto err_free_id; - } - /* @css is ready to be brought online now, make it visible */ list_add_tail_rcu(&css->sibling, &parent_css->children); cgroup_idr_replace(&ss->css_idr, css, css->id); @@ -4858,18 +4865,16 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss, ss->warned_broken_hierarchy = true; } - return 0; + return css; err_list_del: list_del_rcu(&css->sibling); - css_clear_dir(css, NULL); -err_free_id: cgroup_idr_remove(&ss->css_idr, css->id); err_free_percpu_ref: percpu_ref_exit(&css->refcnt); err_free_css: call_rcu(&css->rcu_head, css_free_rcu_fn); - return err; + return ERR_PTR(err); } static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, @@ -4966,10 +4971,19 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, /* let's create and online css's */ do_each_subsys_mask(ss, ssid, parent->subtree_ss_mask) { - ret = create_css(cgrp, ss, - parent->subtree_control & (1 << ssid)); - if (ret) + struct cgroup_subsys_state *css; + + css = css_create(cgrp, ss); + if (IS_ERR(css)) { + ret = PTR_ERR(css); goto out_destroy; + } + + if (parent->subtree_control & (1 << ssid)) { + ret = css_populate_dir(css, NULL); + if (ret) + goto out_destroy; + } } while_each_subsys_mask(); /* |