#include <linux/idr.h>
#include <linux/workqueue.h>
#include <linux/xattr.h>
+#include <linux/fs.h>
#ifdef CONFIG_CGROUPS
extern int cgroup_init_early(void);
extern int cgroup_init(void);
-extern void cgroup_lock(void);
-extern int cgroup_lock_is_held(void);
-extern bool cgroup_lock_live_group(struct cgroup *cgrp);
-extern void cgroup_unlock(void);
extern void cgroup_fork(struct task_struct *p);
extern void cgroup_post_fork(struct task_struct *p);
extern void cgroup_exit(struct task_struct *p, int run_callbacks);
extern const struct file_operations proc_cgroup_operations;
-/* Define the enumeration of all builtin cgroup subsystems */
+/*
+ * Define the enumeration of all cgroup subsystems.
+ *
+ * We define ids for builtin subsystems and then modular ones.
+ */
#define SUBSYS(_x) _x ## _subsys_id,
-#define IS_SUBSYS_ENABLED(option) IS_ENABLED(option)
enum cgroup_subsys_id {
+#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
#include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
+ CGROUP_BUILTIN_SUBSYS_COUNT,
+
+ __CGROUP_SUBSYS_TEMP_PLACEHOLDER = CGROUP_BUILTIN_SUBSYS_COUNT - 1,
+
+#define IS_SUBSYS_ENABLED(option) IS_MODULE(option)
+#include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
CGROUP_SUBSYS_COUNT,
};
-#undef IS_SUBSYS_ENABLED
#undef SUBSYS
/* Per-subsystem/per-cgroup state maintained by the system. */
* specified at mount time and thus is implemented here.
*/
CGRP_CPUSET_CLONE_CHILDREN,
+ /* see the comment above CGRP_ROOT_SANE_BEHAVIOR for details */
+ CGRP_SANE_BEHAVIOR,
+};
+
+struct cgroup_name {
+ struct rcu_head rcu_head;
+ char name[];
};
struct cgroup {
struct cgroup *parent; /* my parent */
struct dentry *dentry; /* cgroup fs entry, RCU protected */
+ /*
+ * This is a copy of dentry->d_name, and it's needed because
+ * we can't use dentry->d_name in cgroup_path().
+ *
+ * You must acquire rcu_read_lock() to access cgrp->name, and
+ * the only place that can change it is rename(), which is
+ * protected by parent dir's i_mutex.
+ *
+ * Normally you should use cgroup_name() wrapper rather than
+ * access it directly.
+ */
+ struct cgroup_name __rcu *name;
+
/* Private pointers for each registered subsystem */
struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
struct cgroupfs_root *root;
- struct cgroup *top_cgroup;
/*
* List of cg_cgroup_links pointing at css_sets with
struct simple_xattrs xattrs;
};
+#define MAX_CGROUP_ROOT_NAMELEN 64
+
+/* cgroupfs_root->flags */
+enum {
+ /*
+ * Unfortunately, cgroup core and various controllers are riddled
+ * with idiosyncrasies and pointless options. The following flag,
+ * when set, will force sane behavior - some options are forced on,
+ * others are disallowed, and some controllers will change their
+ * hierarchical or other behaviors.
+ *
+ * The set of behaviors affected by this flag are still being
+ * determined and developed and the mount option for this flag is
+ * prefixed with __DEVEL__. The prefix will be dropped once we
+ * reach the point where all behaviors are compatible with the
+ * planned unified hierarchy, which will automatically turn on this
+ * flag.
+ *
+ * The followings are the behaviors currently affected this flag.
+ *
+ * - Mount options "noprefix" and "clone_children" are disallowed.
+ * Also, cgroupfs file cgroup.clone_children is not created.
+ *
+ * - When mounting an existing superblock, mount options should
+ * match.
+ *
+ * - Remount is disallowed.
+ *
+ * - memcg: use_hierarchy is on by default and the cgroup file for
+ * the flag is not created.
+ *
+ * The followings are planned changes.
+ *
+ * - release_agent will be disallowed once replacement notification
+ * mechanism is implemented.
+ */
+ CGRP_ROOT_SANE_BEHAVIOR = (1 << 0),
+
+ CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
+ CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
+};
+
+/*
+ * A cgroupfs_root represents the root of a cgroup hierarchy, and may be
+ * associated with a superblock to form an active hierarchy. This is
+ * internal to cgroup core. Don't access directly from controllers.
+ */
+struct cgroupfs_root {
+ struct super_block *sb;
+
+ /*
+ * The bitmask of subsystems intended to be attached to this
+ * hierarchy
+ */
+ unsigned long subsys_mask;
+
+ /* Unique id for this hierarchy. */
+ int hierarchy_id;
+
+ /* The bitmask of subsystems currently attached to this hierarchy */
+ unsigned long actual_subsys_mask;
+
+ /* A list running through the attached subsystems */
+ struct list_head subsys_list;
+
+ /* The root cgroup for this hierarchy */
+ struct cgroup top_cgroup;
+
+ /* Tracks how many cgroups are currently defined in hierarchy.*/
+ int number_of_cgroups;
+
+ /* A list running through the active hierarchies */
+ struct list_head root_list;
+
+ /* All cgroups on this root, cgroup_mutex protected */
+ struct list_head allcg_list;
+
+ /* Hierarchy-specific flags */
+ unsigned long flags;
+
+ /* IDs for cgroups in this hierarchy */
+ struct ida cgroup_ida;
+
+ /* The path to use for release notifications. */
+ char release_agent_path[PATH_MAX];
+
+ /* The name for this hierarchy - may be empty */
+ char name[MAX_CGROUP_ROOT_NAMELEN];
+};
+
/*
* A css_set is a structure holding pointers to a set of
* cgroup_subsys_state objects. This saves space in the task struct
/* cftype->flags */
#define CFTYPE_ONLY_ON_ROOT (1U << 0) /* only create on root cg */
#define CFTYPE_NOT_ON_ROOT (1U << 1) /* don't create on root cg */
+#define CFTYPE_INSANE (1U << 2) /* don't create if sane_behavior */
#define MAX_CFTYPE_NAME 64
/* CFTYPE_* flags */
unsigned int flags;
- /* file xattrs */
- struct simple_xattrs xattrs;
-
int (*open)(struct inode *inode, struct file *file);
ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft,
struct file *file,
void *data;
};
+/*
+ * See the comment above CGRP_ROOT_SANE_BEHAVIOR for details. This
+ * function can be called as long as @cgrp is accessible.
+ */
+static inline bool cgroup_sane_behavior(const struct cgroup *cgrp)
+{
+ return cgrp->root->flags & CGRP_ROOT_SANE_BEHAVIOR;
+}
+
+/* Caller should hold rcu_read_lock() */
+static inline const char *cgroup_name(const struct cgroup *cgrp)
+{
+ return rcu_dereference(cgrp->name)->name;
+}
+
int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_rm_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_is_removed(const struct cgroup *cgrp);
+bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor);
int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen);
int cgroup_task_count(const struct cgroup *cgrp);
-/* Return true if cgrp is a descendant of the task's cgroup */
-int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task);
-
/*
* Control Group taskset, used to pass around set of tasks to cgroup_subsys
* methods.
* rcu_dereference_check() conditions, such as locks used during the
* cgroup_subsys::attach() methods.
*/
+#ifdef CONFIG_PROVE_RCU
+extern struct mutex cgroup_mutex;
#define task_subsys_state_check(task, subsys_id, __c) \
- rcu_dereference_check(task->cgroups->subsys[subsys_id], \
- lockdep_is_held(&task->alloc_lock) || \
- cgroup_lock_is_held() || (__c))
+ rcu_dereference_check((task)->cgroups->subsys[(subsys_id)], \
+ lockdep_is_held(&(task)->alloc_lock) || \
+ lockdep_is_held(&cgroup_mutex) || (__c))
+#else
+#define task_subsys_state_check(task, subsys_id, __c) \
+ rcu_dereference((task)->cgroups->subsys[(subsys_id)])
+#endif
static inline struct cgroup_subsys_state *
task_subsys_state(struct task_struct *task, int subsys_id)
struct cgroup_iter *it);
void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it);
int cgroup_scan_tasks(struct cgroup_scanner *scan);
-int cgroup_attach_task(struct cgroup *, struct task_struct *);
int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
+int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
/*
* CSS ID is ID for cgroup_subsys_state structs under subsys. This only works
struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id);
-/*
- * Get a cgroup whose id is greater than or equal to id under tree of root.
- * Returning a cgroup_subsys_state or NULL.
- */
-struct cgroup_subsys_state *css_get_next(struct cgroup_subsys *ss, int id,
- struct cgroup_subsys_state *root, int *foundid);
-
/* Returns true if root is ancestor of cg */
bool css_is_ancestor(struct cgroup_subsys_state *cg,
const struct cgroup_subsys_state *root);
projects / karo-tx-linux.git / blobdiff