diff options
| -rw-r--r-- | include/linux/cgroup.h | 6 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 26 |
2 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 4f2f79de083e..d2eace88d9d1 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -696,6 +696,7 @@ static inline void cgroup_kthread_ready(void) } void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen); +struct cgroup *cgroup_get_from_id(u64 id); #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -743,6 +744,11 @@ static inline bool task_under_cgroup_hierarchy(struct task_struct *task, static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) {} + +static inline struct cgroup *cgroup_get_from_id(u64 id) +{ + return NULL; +} #endif /* !CONFIG_CGROUPS */ #ifdef CONFIG_CGROUPS diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index e049edd66776..692779d3cdfa 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -577,6 +577,7 @@ out_unlock: rcu_read_unlock(); return css; } +EXPORT_SYMBOL_GPL(cgroup_get_e_css); static void cgroup_get_live(struct cgroup *cgrp) { @@ -5777,6 +5778,31 @@ void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) } /* + * cgroup_get_from_id : get the cgroup associated with cgroup id + * @id: cgroup id + * On success return the cgrp, on failure return NULL + */ +struct cgroup *cgroup_get_from_id(u64 id) +{ + struct kernfs_node *kn; + struct cgroup *cgrp = NULL; + + mutex_lock(&cgroup_mutex); + kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id); + if (!kn) + goto out_unlock; + + cgrp = kn->priv; + if (cgroup_is_dead(cgrp) || !cgroup_tryget(cgrp)) + cgrp = NULL; + kernfs_put(kn); +out_unlock: + mutex_unlock(&cgroup_mutex); + return cgrp; +} +EXPORT_SYMBOL_GPL(cgroup_get_from_id); + +/* * proc_cgroup_show() * - Print task's cgroup paths into seq_file, one line for each hierarchy * - Used for /proc/<pid>/cgroup. |