extern struct file_system_type cgroup_fs_type;
extern struct cgroup_root cgrp_dfl_root;
extern struct css_set init_css_set;
+extern spinlock_t css_set_lock;
#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
#include <linux/cgroup_subsys.h>
* as locks used during the cgroup_subsys::attach() methods.
*/
#ifdef CONFIG_PROVE_RCU
-extern spinlock_t css_set_lock;
#define task_css_set_check(task, __c) \
rcu_dereference_check((task)->cgroups, \
rcu_read_lock_sched_held() || \
#endif /* CONFIG_CGROUP_BPF */
+struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id);
+
#endif /* _LINUX_CGROUP_H */
#define DEFINE_CGROUP_MGCTX(name) \
struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name)
-extern spinlock_t css_set_lock;
extern struct cgroup_subsys *cgroup_subsys[];
extern struct list_head cgroup_roots;
return ret;
}
+/**
+ * task_get_cgroup1 - Acquires the associated cgroup of a task within a
+ * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its
+ * hierarchy ID.
+ * @tsk: The target task
+ * @hierarchy_id: The ID of a cgroup1 hierarchy
+ *
+ * On success, the cgroup is returned. On failure, ERR_PTR is returned.
+ * We limit it to cgroup1 only.
+ */
+struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id)
+{
+ struct cgroup *cgrp = ERR_PTR(-ENOENT);
+ struct cgroup_root *root;
+ unsigned long flags;
+
+ rcu_read_lock();
+ for_each_root(root) {
+ /* cgroup1 only*/
+ if (root == &cgrp_dfl_root)
+ continue;
+ if (root->hierarchy_id != hierarchy_id)
+ continue;
+ spin_lock_irqsave(&css_set_lock, flags);
+ cgrp = task_cgroup_from_root(tsk, root);
+ if (!cgrp || !cgroup_tryget(cgrp))
+ cgrp = ERR_PTR(-ENOENT);
+ spin_unlock_irqrestore(&css_set_lock, flags);
+ break;
+ }
+ rcu_read_unlock();
+ return cgrp;
+}
+
static int __init cgroup1_wq_init(void)
{
/*