Drivers that handle processes on a per-cgroup basis need to be able to lookup the cgroup that a process belongs to. Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: cgroups@xxxxxxxxxxxxxxx Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> --- include/linux/cgroup.h | 5 ++++- kernel/cgroup/cgroup-internal.h | 3 --- kernel/cgroup/cgroup.c | 8 +++++--- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 1c1758ac1a97..1b93fb018bfc 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -103,6 +103,8 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, struct cgroup *cgroup_get_from_path(const char *path); struct cgroup *cgroup_get_from_fd(int fd); +struct cgroup *task_cgroup_from_root(struct task_struct *task, + struct cgroup_root *root); int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); @@ -432,7 +434,6 @@ static inline void cgroup_put(struct cgroup *cgrp) * as locks used during the cgroup_subsys::attach() methods. */ #ifdef CONFIG_PROVE_RCU -extern struct mutex cgroup_mutex; extern spinlock_t css_set_lock; #define task_css_set_check(task, __c) \ rcu_dereference_check((task)->cgroups, \ @@ -444,6 +445,8 @@ extern spinlock_t css_set_lock; rcu_dereference((task)->cgroups) #endif +extern struct mutex cgroup_mutex; + /** * task_css_check - obtain css for (task, subsys) w/ extra access conds * @task: the target task diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 7338083ee3bc..5471f8fe8c2d 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -99,7 +99,6 @@ struct cgroup_sb_opts { bool none; }; -extern struct mutex cgroup_mutex; extern spinlock_t css_set_lock; extern struct cgroup_subsys *cgroup_subsys[]; extern struct list_head cgroup_roots; @@ -160,8 +159,6 @@ bool cgroup_is_thread_root(struct cgroup *cgrp); bool cgroup_is_threaded(struct cgroup *cgrp); struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root); -struct cgroup *task_cgroup_from_root(struct task_struct *task, - struct cgroup_root *root); struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn, bool drain_offline); void cgroup_kn_unlock(struct kernfs_node *kn); int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen, diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 6069191653f8..0a0093a36a7f 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -69,8 +69,9 @@ * css_set_lock protects task->cgroups pointer, the list of css_set * objects, and the chain of tasks off each css_set. * - * These locks are exported if CONFIG_PROVE_RCU so that accessors in - * cgroup.h can use them for lockdep annotations. + * cgroup_mutex is always exported so that it may be taken by non-controller + * drivers. css_set_lock is exported if CONFIG_PROVE_RCU so that accessors in + * cgroup.h can use it for lockdep annotations. */ DEFINE_MUTEX(cgroup_mutex); DEFINE_SPINLOCK(css_set_lock); @@ -84,8 +85,8 @@ DEFINE_SPINLOCK(css_set_lock); BLOCKING_NOTIFIER_HEAD(cgroup_destroy_notifier_list); EXPORT_SYMBOL_GPL(cgroup_destroy_notifier_list); -#ifdef CONFIG_PROVE_RCU EXPORT_SYMBOL_GPL(cgroup_mutex); +#ifdef CONFIG_PROVE_RCU EXPORT_SYMBOL_GPL(css_set_lock); #endif @@ -1367,6 +1368,7 @@ struct cgroup *task_cgroup_from_root(struct task_struct *task, */ return cset_cgroup_from_root(task_css_set(task), root); } +EXPORT_SYMBOL(task_cgroup_from_root); /* * A task must hold cgroup_mutex to modify cgroups. -- 2.14.3 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html