1 files changed, 327 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
new file mode 100644
index 00000000000..87479328d46
--- /dev/null
+++ b/include/linux/cgroup.h
@@ -0,0 +1,327 @@
+#ifndef _LINUX_CGROUP_H
+#define _LINUX_CGROUP_H
+/*
+ *  cgroup interface
+ *
+ *  Copyright (C) 2003 BULL SA
+ *  Copyright (C) 2004-2006 Silicon Graphics, Inc.
+ *
+ */
+
+#include <linux/sched.h>
+#include <linux/kref.h>
+#include <linux/cpumask.h>
+#include <linux/nodemask.h>
+#include <linux/rcupdate.h>
+#include <linux/cgroupstats.h>
+
+#ifdef CONFIG_CGROUPS
+
+struct cgroupfs_root;
+struct cgroup_subsys;
+struct inode;
+
+extern int cgroup_init_early(void);
+extern int cgroup_init(void);
+extern void cgroup_init_smp(void);
+extern void cgroup_lock(void);
+extern void cgroup_unlock(void);
+extern void cgroup_fork(struct task_struct *p);
+extern void cgroup_fork_callbacks(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 int cgroupstats_build(struct cgroupstats *stats,
+				struct dentry *dentry);
+
+extern struct file_operations proc_cgroup_operations;
+
+/* Define the enumeration of all cgroup subsystems */
+#define SUBSYS(_x) _x ## _subsys_id,
+enum cgroup_subsys_id {
+#include <linux/cgroup_subsys.h>
+	CGROUP_SUBSYS_COUNT
+};
+#undef SUBSYS
+
+/* Per-subsystem/per-cgroup state maintained by the system. */
+struct cgroup_subsys_state {
+	/* The cgroup that this subsystem is attached to. Useful
+	 * for subsystems that want to know about the cgroup
+	 * hierarchy structure */
+	struct cgroup *cgroup;
+
+	/* State maintained by the cgroup system to allow
+	 * subsystems to be "busy". Should be accessed via css_get()
+	 * and css_put() */
+
+	atomic_t refcnt;
+
+	unsigned long flags;
+};
+
+/* bits in struct cgroup_subsys_state flags field */
+enum {
+	CSS_ROOT, /* This CSS is the root of the subsystem */
+};
+
+/*
+ * Call css_get() to hold a reference on the cgroup;
+ *
+ */
+
+static inline void css_get(struct cgroup_subsys_state *css)
+{
+	/* We don't need to reference count the root state */
+	if (!test_bit(CSS_ROOT, &css->flags))
+		atomic_inc(&css->refcnt);
+}
+/*
+ * css_put() should be called to release a reference taken by
+ * css_get()
+ */
+
+extern void __css_put(struct cgroup_subsys_state *css);
+static inline void css_put(struct cgroup_subsys_state *css)
+{
+	if (!test_bit(CSS_ROOT, &css->flags))
+		__css_put(css);
+}
+
+struct cgroup {
+	unsigned long flags;		/* "unsigned long" so bitops work */
+
+	/* count users of this cgroup. >0 means busy, but doesn't
+	 * necessarily indicate the number of tasks in the
+	 * cgroup */
+	atomic_t count;
+
+	/*
+	 * We link our 'sibling' struct into our parent's 'children'.
+	 * Our children link their 'sibling' into our 'children'.
+	 */
+	struct list_head sibling;	/* my parent's children */
+	struct list_head children;	/* my children */
+
+	struct cgroup *parent;	/* my parent */
+	struct dentry *dentry;	  	/* cgroup fs entry */
+
+	/* 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
+	 * tasks in this cgroup. Protected by css_set_lock
+	 */
+	struct list_head css_sets;
+
+	/*
+	 * Linked list running through all cgroups that can
+	 * potentially be reaped by the release agent. Protected by
+	 * release_list_lock
+	 */
+	struct list_head release_list;
+};
+
+/* A css_set is a structure holding pointers to a set of
+ * cgroup_subsys_state objects. This saves space in the task struct
+ * object and speeds up fork()/exit(), since a single inc/dec and a
+ * list_add()/del() can bump the reference count on the entire
+ * cgroup set for a task.
+ */
+
+struct css_set {
+
+	/* Reference count */
+	struct kref ref;
+
+	/*
+	 * List running through all cgroup groups. Protected by
+	 * css_set_lock
+	 */
+	struct list_head list;
+
+	/*
+	 * List running through all tasks using this cgroup
+	 * group. Protected by css_set_lock
+	 */
+	struct list_head tasks;
+
+	/*
+	 * List of cg_cgroup_link objects on link chains from
+	 * cgroups referenced from this css_set. Protected by
+	 * css_set_lock
+	 */
+	struct list_head cg_links;
+
+	/*
+	 * Set of subsystem states, one for each subsystem. This array
+	 * is immutable after creation apart from the init_css_set
+	 * during subsystem registration (at boot time).
+	 */
+	struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
+
+};
+
+/* struct cftype:
+ *
+ * The files in the cgroup filesystem mostly have a very simple read/write
+ * handling, some common function will take care of it. Nevertheless some cases
+ * (read tasks) are special and therefore I define this structure for every
+ * kind of file.
+ *
+ *
+ * When reading/writing to a file:
+ *	- the cgroup to use in file->f_dentry->d_parent->d_fsdata
+ *	- the 'cftype' of the file is file->f_dentry->d_fsdata
+ */
+
+#define MAX_CFTYPE_NAME 64
+struct cftype {
+	/* By convention, the name should begin with the name of the
+	 * subsystem, followed by a period */
+	char name[MAX_CFTYPE_NAME];
+	int private;
+	int (*open) (struct inode *inode, struct file *file);
+	ssize_t (*read) (struct cgroup *cont, struct cftype *cft,
+			 struct file *file,
+			 char __user *buf, size_t nbytes, loff_t *ppos);
+	/*
+	 * read_uint() is a shortcut for the common case of returning a
+	 * single integer. Use it in place of read()
+	 */
+	u64 (*read_uint) (struct cgroup *cont, struct cftype *cft);
+	ssize_t (*write) (struct cgroup *cont, struct cftype *cft,
+			  struct file *file,
+			  const char __user *buf, size_t nbytes, loff_t *ppos);
+
+	/*
+	 * write_uint() is a shortcut for the common case of accepting
+	 * a single integer (as parsed by simple_strtoull) from
+	 * userspace. Use in place of write(); return 0 or error.
+	 */
+	int (*write_uint) (struct cgroup *cont, struct cftype *cft, u64 val);
+
+	int (*release) (struct inode *inode, struct file *file);
+};
+
+/* Add a new file to the given cgroup directory. Should only be
+ * called by subsystems from within a populate() method */
+int cgroup_add_file(struct cgroup *cont, struct cgroup_subsys *subsys,
+		       const struct cftype *cft);
+
+/* Add a set of new files to the given cgroup directory. Should
+ * only be called by subsystems from within a populate() method */
+int cgroup_add_files(struct cgroup *cont,
+			struct cgroup_subsys *subsys,
+			const struct cftype cft[],
+			int count);
+
+int cgroup_is_removed(const struct cgroup *cont);
+
+int cgroup_path(const struct cgroup *cont, char *buf, int buflen);
+
+int cgroup_task_count(const struct cgroup *cont);
+
+/* Return true if the cgroup is a descendant of the current cgroup */
+int cgroup_is_descendant(const struct cgroup *cont);
+
+/* Control Group subsystem type. See Documentation/cgroups.txt for details */
+
+struct cgroup_subsys {
+	struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss,
+						  struct cgroup *cont);
+	void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cont);
+	int (*can_attach)(struct cgroup_subsys *ss,
+			  struct cgroup *cont, struct task_struct *tsk);
+	void (*attach)(struct cgroup_subsys *ss, struct cgroup *cont,
+			struct cgroup *old_cont, struct task_struct *tsk);
+	void (*fork)(struct cgroup_subsys *ss, struct task_struct *task);
+	void (*exit)(struct cgroup_subsys *ss, struct task_struct *task);
+	int (*populate)(struct cgroup_subsys *ss,
+			struct cgroup *cont);
+	void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cont);
+	void (*bind)(struct cgroup_subsys *ss, struct cgroup *root);
+	int subsys_id;
+	int active;
+	int early_init;
+#define MAX_CGROUP_TYPE_NAMELEN 32
+	const char *name;
+
+	/* Protected by RCU */
+	struct cgroupfs_root *root;
+
+	struct list_head sibling;
+
+	void *private;
+};
+
+#define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys;
+#include <linux/cgroup_subsys.h>
+#undef SUBSYS
+
+static inline struct cgroup_subsys_state *cgroup_subsys_state(
+	struct cgroup *cont, int subsys_id)
+{
+	return cont->subsys[subsys_id];
+}
+
+static inline struct cgroup_subsys_state *task_subsys_state(
+	struct task_struct *task, int subsys_id)
+{
+	return rcu_dereference(task->cgroups->subsys[subsys_id]);
+}
+
+static inline struct cgroup* task_cgroup(struct task_struct *task,
+					       int subsys_id)
+{
+	return task_subsys_state(task, subsys_id)->cgroup;
+}
+
+int cgroup_path(const struct cgroup *cont, char *buf, int buflen);
+
+int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *ss);
+
+/* A cgroup_iter should be treated as an opaque object */
+struct cgroup_iter {
+	struct list_head *cg_link;
+	struct list_head *task;
+};
+
+/* To iterate across the tasks in a cgroup:
+ *
+ * 1) call cgroup_iter_start to intialize an iterator
+ *
+ * 2) call cgroup_iter_next() to retrieve member tasks until it
+ *    returns NULL or until you want to end the iteration
+ *
+ * 3) call cgroup_iter_end() to destroy the iterator.
+ */
+void cgroup_iter_start(struct cgroup *cont, struct cgroup_iter *it);
+struct task_struct *cgroup_iter_next(struct cgroup *cont,
+					struct cgroup_iter *it);
+void cgroup_iter_end(struct cgroup *cont, struct cgroup_iter *it);
+
+#else /* !CONFIG_CGROUPS */
+
+static inline int cgroup_init_early(void) { return 0; }
+static inline int cgroup_init(void) { return 0; }
+static inline void cgroup_init_smp(void) {}
+static inline void cgroup_fork(struct task_struct *p) {}
+static inline void cgroup_fork_callbacks(struct task_struct *p) {}
+static inline void cgroup_post_fork(struct task_struct *p) {}
+static inline void cgroup_exit(struct task_struct *p, int callbacks) {}
+
+static inline void cgroup_lock(void) {}
+static inline void cgroup_unlock(void) {}
+static inline int cgroupstats_build(struct cgroupstats *stats,
+					struct dentry *dentry)
+{
+	return -EINVAL;
+}
+
+#endif /* !CONFIG_CGROUPS */
+
+#endif /* _LINUX_CGROUP_H */