rcu_read_unlock();
}
+/**
+ * get_mem_cgroup_from_obj - get a memcg associated with passed kernel object.
+ * @p: pointer to object from which memcg should be extracted. It can be NULL.
+ *
+ * Retrieves the memory group into which the memory of the pointed kernel
+ * object is accounted. If memcg is found, its reference is taken.
+ * If a passed kernel object is uncharged, or if proper memcg cannot be found,
+ * as well as if mem_cgroup is disabled, NULL is returned.
+ *
+ * Return: valid memcg pointer with taken reference or NULL.
+ */
+static inline struct mem_cgroup *get_mem_cgroup_from_obj(void *p)
+{
+ struct mem_cgroup *memcg;
+
+ rcu_read_lock();
+ do {
+ memcg = mem_cgroup_from_obj(p);
+ } while (memcg && !css_tryget(&memcg->css));
+ rcu_read_unlock();
+ return memcg;
+}
+
+/**
+ * mem_cgroup_or_root - always returns a pointer to a valid memory cgroup.
+ * @memcg: pointer to a valid memory cgroup or NULL.
+ *
+ * If passed argument is not NULL, returns it without any additional checks
+ * and changes. Otherwise, root_mem_cgroup is returned.
+ *
+ * NOTE: root_mem_cgroup can be NULL during early boot.
+ */
+static inline struct mem_cgroup *mem_cgroup_or_root(struct mem_cgroup *memcg)
+{
+ return memcg ? memcg : root_mem_cgroup;
+}
#else
static inline bool mem_cgroup_kmem_disabled(void)
{
static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
{
- return NULL;
+ return NULL;
}
static inline struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
{
}
+static inline struct mem_cgroup *get_mem_cgroup_from_obj(void *p)
+{
+ return NULL;
+}
+
+static inline struct mem_cgroup *mem_cgroup_or_root(struct mem_cgroup *memcg)
+{
+ return NULL;
+}
#endif /* CONFIG_MEMCG_KMEM */
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
#include <linux/user_namespace.h>
#include <linux/net_namespace.h>
#include <linux/sched/task.h>
+#include <linux/sched/mm.h>
#include <linux/uidgid.h>
#include <linux/cookie.h>
* setup_net() and cleanup_net() are not possible.
*/
for_each_net(net) {
+ struct mem_cgroup *old, *memcg;
+
+ memcg = mem_cgroup_or_root(get_mem_cgroup_from_obj(net));
+ old = set_active_memcg(memcg);
error = ops_init(ops, net);
+ set_active_memcg(old);
+ mem_cgroup_put(memcg);
if (error)
goto out_undo;
list_add_tail(&net->exit_list, &net_exit_list);