#ifdef CONFIG_CGROUPS
-struct cgroupfs_root;
+struct cgroup_root;
struct cgroup_subsys;
struct inode;
struct cgroup;
*/
u64 serial_nr;
+ /* The bitmask of subsystems attached to this cgroup */
+ unsigned long subsys_mask;
+
/* Private pointers for each registered subsystem */
struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT];
- struct cgroupfs_root *root;
+ struct cgroup_root *root;
/*
* List of cgrp_cset_links pointing at css_sets with tasks in this
#define MAX_CGROUP_ROOT_NAMELEN 64
-/* cgroupfs_root->flags */
+/* cgroup_root->flags */
enum {
/*
* Unfortunately, cgroup core and various controllers are riddled
*
* - "cgroup.clone_children" is removed.
*
+ * - If mount is requested with sane_behavior but without any
+ * subsystem, the default unified hierarchy is mounted.
+ *
* - cpuset: tasks will be kept in empty cpusets when hotplug happens
* and take masks of ancestors with non-empty cpus/mems, instead of
* being moved to an ancestor.
};
/*
- * A cgroupfs_root represents the root of a cgroup hierarchy, and may be
+ * A cgroup_root represents the root of a cgroup hierarchy, and may be
* associated with a kernfs_root to form an active hierarchy. This is
* internal to cgroup core. Don't access directly from controllers.
*/
-struct cgroupfs_root {
+struct cgroup_root {
struct kernfs_root *kf_root;
- /* The bitmask of subsystems attached to this hierarchy */
- unsigned long subsys_mask;
-
/* Unique id for this hierarchy. */
int hierarchy_id;
/* The root cgroup. Root is destroyed on its release. */
- struct cgroup top_cgroup;
+ struct cgroup cgrp;
/* Number of cgroups in the hierarchy, used only for /proc/cgroups */
atomic_t nr_cgrps;
struct hlist_node hlist;
/*
- * List running through all tasks using this cgroup
- * group. Protected by css_set_lock
+ * Lists running through all tasks using this cgroup group.
+ * mg_tasks lists tasks which belong to this cset but are in the
+ * process of being migrated out or in. Protected by
+ * css_set_rwsem, but, during migration, once tasks are moved to
+ * mg_tasks, it can be read safely while holding cgroup_mutex.
*/
struct list_head tasks;
+ struct list_head mg_tasks;
/*
* List of cgrp_cset_links pointing at cgroups referenced from this
*/
struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
+ /*
+ * List of csets participating in the on-going migration either as
+ * source or destination. Protected by cgroup_mutex.
+ */
+ struct list_head mg_preload_node;
+ struct list_head mg_node;
+
+ /*
+ * If this cset is acting as the source of migration the following
+ * two fields are set. mg_src_cgrp is the source cgroup of the
+ * on-going migration and mg_dst_cset is the destination cset the
+ * target tasks on this cset should be migrated to. Protected by
+ * cgroup_mutex.
+ */
+ struct cgroup *mg_src_cgrp;
+ struct css_set *mg_dst_cset;
+
/* For RCU-protected deletion */
struct rcu_head rcu_head;
};
CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
CFTYPE_INSANE = (1 << 2), /* don't create if sane_behavior */
CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
+ CFTYPE_ONLY_ON_DFL = (1 << 4), /* only on default hierarchy */
};
#define MAX_CFTYPE_NAME 64
* Returns 0 or -ve error code.
*/
int (*write_string)(struct cgroup_subsys_state *css, struct cftype *cft,
- const char *buffer);
+ char *buffer);
/*
* trigger() callback can be used to get some kick from the
* userspace, when the actual string written is not important
#endif
};
+extern struct cgroup_root cgrp_dfl_root;
+
+static inline bool cgroup_on_dfl(const struct cgroup *cgrp)
+{
+ return cgrp->root == &cgrp_dfl_root;
+}
+
/*
* See the comment above CGRP_ROOT_SANE_BEHAVIOR for details. This
* function can be called as long as @cgrp is accessible.
static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
{
- /* dummy_top doesn't have a kn associated */
- if (cgrp->kn)
- return kernfs_name(cgrp->kn, buf, buflen);
- else
- return strlcpy(buf, "/", buflen);
+ return kernfs_name(cgrp->kn, buf, buflen);
}
static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf,
size_t buflen)
{
- /* dummy_top doesn't have a kn associated */
- if (cgrp->kn)
- return kernfs_path(cgrp->kn, buf, buflen);
- strlcpy(buf, "/", buflen);
- return (buflen <= 2) ? NULL : buf;
+ return kernfs_path(cgrp->kn, buf, buflen);
}
static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
{
- /* dummy_top doesn't have a kn associated */
- if (cgrp->kn)
- pr_cont_kernfs_name(cgrp->kn);
- else
- pr_cont("/");
+ pr_cont_kernfs_name(cgrp->kn);
}
static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
{
- /* dummy_top doesn't have a kn associated */
- if (cgrp->kn)
- pr_cont_kernfs_path(cgrp->kn);
- else
- pr_cont("/");
+ pr_cont_kernfs_path(cgrp->kn);
}
char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
const char *name;
/* link to parent, protected by cgroup_lock() */
- struct cgroupfs_root *root;
+ struct cgroup_root *root;
/*
* List of cftypes. Each entry is the first entry of an array
*/
#ifdef CONFIG_PROVE_RCU
extern struct mutex cgroup_mutex;
+extern struct rw_semaphore css_set_rwsem;
#define task_css_set_check(task, __c) \
rcu_dereference_check((task)->cgroups, \
- lockdep_is_held(&(task)->alloc_lock) || \
- lockdep_is_held(&cgroup_mutex) || (__c))
+ lockdep_is_held(&cgroup_mutex) || \
+ lockdep_is_held(&css_set_rwsem) || \
+ ((task)->flags & PF_EXITING) || (__c))
#else
#define task_css_set_check(task, __c) \
rcu_dereference((task)->cgroups)
projects / firefly-linux-kernel-4.4.55.git / blobdiff