[no subject]
From: Tejun Heo
Date: Wed May 13 2015 - 15:37:01 EST
This patch separates out cgroup-defs.h from cgroup.h which has grown a
lot of dependencies. cgroup-defs.h currently only contains constant
and type definitions and can be used to break circular include
dependency. While moving, definitions are reordered so that
cgroup-defs.h has consistent logical structure.
This patch is pure reorganization.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
cgroup-defs.h will be used by a following patchset.
Thanks.
include/linux/cgroup-defs.h | 464 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/cgroup.h | 455 +------------------------------------------
2 files changed, 466 insertions(+), 453 deletions(-)
create mode 100644 include/linux/cgroup-defs.h
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
new file mode 100644
index 0000000..55f3120
--- /dev/null
+++ b/include/linux/cgroup-defs.h
@@ -0,0 +1,464 @@
+/*
+ * linux/cgroup-defs.h - basic definitions for cgroup
+ *
+ * This file provides basic type and interface. Include this file directly
+ * only if necessary to avoid cyclic dependencies.
+ */
+#ifndef _LINUX_CGROUP_DEFS_H
+#define _LINUX_CGROUP_DEFS_H
+
+#include <linux/limits.h>
+#include <linux/list.h>
+#include <linux/idr.h>
+#include <linux/wait.h>
+#include <linux/mutex.h>
+#include <linux/rcupdate.h>
+#include <linux/percpu-refcount.h>
+#include <linux/workqueue.h>
+
+#ifdef CONFIG_CGROUPS
+
+struct cgroup;
+struct cgroup_root;
+struct cgroup_subsys;
+struct cgroup_taskset;
+struct kernfs_node;
+struct kernfs_ops;
+struct kernfs_open_file;
+
+#define MAX_CGROUP_TYPE_NAMELEN 32
+#define MAX_CGROUP_ROOT_NAMELEN 64
+#define MAX_CFTYPE_NAME 64
+
+/* define the enumeration of all cgroup subsystems */
+#define SUBSYS(_x) _x ## _cgrp_id,
+enum cgroup_subsys_id {
+#include <linux/cgroup_subsys.h>
+ CGROUP_SUBSYS_COUNT,
+};
+#undef SUBSYS
+
+/* bits in struct cgroup_subsys_state flags field */
+enum {
+ CSS_NO_REF = (1 << 0), /* no reference counting for this css */
+ CSS_ONLINE = (1 << 1), /* between ->css_online() and ->css_offline() */
+ CSS_RELEASED = (1 << 2), /* refcnt reached zero, released */
+};
+
+/* bits in struct cgroup flags field */
+enum {
+ /* Control Group requires release notifications to userspace */
+ CGRP_NOTIFY_ON_RELEASE,
+ /*
+ * Clone the parent's configuration when creating a new child
+ * cpuset cgroup. For historical reasons, this option can be
+ * specified at mount time and thus is implemented here.
+ */
+ CGRP_CPUSET_CLONE_CHILDREN,
+};
+
+/* cgroup_root->flags */
+enum {
+ CGRP_ROOT_SANE_BEHAVIOR = (1 << 0), /* __DEVEL__sane_behavior specified */
+ CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
+ CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
+};
+
+/* cftype->flags */
+enum {
+ CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
+ CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
+ CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
+
+ /* internal flags, do not use outside cgroup core proper */
+ __CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
+ __CFTYPE_NOT_ON_DFL = (1 << 17), /* not on default hierarchy */
+};
+
+/*
+ * Per-subsystem/per-cgroup state maintained by the system. This is the
+ * fundamental structural building block that controllers deal with.
+ *
+ * Fields marked with "PI:" are public and immutable and may be accessed
+ * directly without synchronization.
+ */
+struct cgroup_subsys_state {
+ /* PI: the cgroup that this css is attached to */
+ struct cgroup *cgroup;
+
+ /* PI: the cgroup subsystem that this css is attached to */
+ struct cgroup_subsys *ss;
+
+ /* reference count - access via css_[try]get() and css_put() */
+ struct percpu_ref refcnt;
+
+ /* PI: the parent css */
+ struct cgroup_subsys_state *parent;
+
+ /* siblings list anchored at the parent's ->children */
+ struct list_head sibling;
+ struct list_head children;
+
+ /*
+ * PI: Subsys-unique ID. 0 is unused and root is always 1. The
+ * matching css can be looked up using css_from_id().
+ */
+ int id;
+
+ unsigned int flags;
+
+ /*
+ * Monotonically increasing unique serial number which defines a
+ * uniform order among all csses. It's guaranteed that all
+ * ->children lists are in the ascending order of ->serial_nr and
+ * used to allow interrupting and resuming iterations.
+ */
+ u64 serial_nr;
+
+ /* percpu_ref killing and RCU release */
+ struct rcu_head rcu_head;
+ struct work_struct destroy_work;
+};
+
+/*
+ * 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 */
+ atomic_t refcount;
+
+ /*
+ * List running through all cgroup groups in the same hash
+ * slot. Protected by css_set_lock
+ */
+ struct hlist_node hlist;
+
+ /*
+ * 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
+ * css_set. Protected by css_set_lock.
+ */
+ struct list_head cgrp_links;
+
+ /* the default cgroup associated with this css_set */
+ struct cgroup *dfl_cgrp;
+
+ /*
+ * 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];
+
+ /*
+ * 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;
+
+ /*
+ * On the default hierarhcy, ->subsys[ssid] may point to a css
+ * attached to an ancestor instead of the cgroup this css_set is
+ * associated with. The following node is anchored at
+ * ->subsys[ssid]->cgroup->e_csets[ssid] and provides a way to
+ * iterate through all css's attached to a given cgroup.
+ */
+ struct list_head e_cset_node[CGROUP_SUBSYS_COUNT];
+
+ /* For RCU-protected deletion */
+ struct rcu_head rcu_head;
+};
+
+struct cgroup {
+ /* self css with NULL ->ss, points back to this cgroup */
+ struct cgroup_subsys_state self;
+
+ unsigned long flags; /* "unsigned long" so bitops work */
+
+ /*
+ * idr allocated in-hierarchy ID.
+ *
+ * ID 0 is not used, the ID of the root cgroup is always 1, and a
+ * new cgroup will be assigned with a smallest available ID.
+ *
+ * Allocating/Removing ID must be protected by cgroup_mutex.
+ */
+ int id;
+
+ /*
+ * If this cgroup contains any tasks, it contributes one to
+ * populated_cnt. All children with non-zero popuplated_cnt of
+ * their own contribute one. The count is zero iff there's no task
+ * in this cgroup or its subtree.
+ */
+ int populated_cnt;
+
+ struct kernfs_node *kn; /* cgroup kernfs entry */
+ struct kernfs_node *populated_kn; /* kn for "cgroup.subtree_populated" */
+
+ /*
+ * The bitmask of subsystems enabled on the child cgroups.
+ * ->subtree_control is the one configured through
+ * "cgroup.subtree_control" while ->child_subsys_mask is the
+ * effective one which may have more subsystems enabled.
+ * Controller knobs are made available iff it's enabled in
+ * ->subtree_control.
+ */
+ unsigned int subtree_control;
+ unsigned int child_subsys_mask;
+
+ /* Private pointers for each registered subsystem */
+ struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT];
+
+ struct cgroup_root *root;
+
+ /*
+ * List of cgrp_cset_links pointing at css_sets with tasks in this
+ * cgroup. Protected by css_set_lock.
+ */
+ struct list_head cset_links;
+
+ /*
+ * On the default hierarchy, a css_set for a cgroup with some
+ * susbsys disabled will point to css's which are associated with
+ * the closest ancestor which has the subsys enabled. The
+ * following lists all css_sets which point to this cgroup's css
+ * for the given subsystem.
+ */
+ struct list_head e_csets[CGROUP_SUBSYS_COUNT];
+
+ /*
+ * list of pidlists, up to two for each namespace (one for procs, one
+ * for tasks); created on demand.
+ */
+ struct list_head pidlists;
+ struct mutex pidlist_mutex;
+
+ /* used to wait for offlining of csses */
+ wait_queue_head_t offline_waitq;
+
+ /* used to schedule release agent */
+ struct work_struct release_agent_work;
+};
+
+/*
+ * 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 cgroup_root {
+ struct kernfs_root *kf_root;
+
+ /* The bitmask of subsystems attached to this hierarchy */
+ unsigned int subsys_mask;
+
+ /* Unique id for this hierarchy. */
+ int hierarchy_id;
+
+ /* The root cgroup. Root is destroyed on its release. */
+ struct cgroup cgrp;
+
+ /* Number of cgroups in the hierarchy, used only for /proc/cgroups */
+ atomic_t nr_cgrps;
+
+ /* A list running through the active hierarchies */
+ struct list_head root_list;
+
+ /* Hierarchy-specific flags */
+ unsigned int flags;
+
+ /* IDs for cgroups in this hierarchy */
+ struct idr cgroup_idr;
+
+ /* 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];
+};
+
+/*
+ * struct cftype: handler definitions for cgroup control files
+ *
+ * When reading/writing to a file:
+ * - the cgroup to use is file->f_path.dentry->d_parent->d_fsdata
+ * - the 'cftype' of the file is file->f_path.dentry->d_fsdata
+ */
+struct cftype {
+ /*
+ * By convention, the name should begin with the name of the
+ * subsystem, followed by a period. Zero length string indicates
+ * end of cftype array.
+ */
+ char name[MAX_CFTYPE_NAME];
+ int private;
+ /*
+ * If not 0, file mode is set to this value, otherwise it will
+ * be figured out automatically
+ */
+ umode_t mode;
+
+ /*
+ * The maximum length of string, excluding trailing nul, that can
+ * be passed to write. If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
+ */
+ size_t max_write_len;
+
+ /* CFTYPE_* flags */
+ unsigned int flags;
+
+ /*
+ * Fields used for internal bookkeeping. Initialized automatically
+ * during registration.
+ */
+ struct cgroup_subsys *ss; /* NULL for cgroup core files */
+ struct list_head node; /* anchored at ss->cfts */
+ struct kernfs_ops *kf_ops;
+
+ /*
+ * read_u64() is a shortcut for the common case of returning a
+ * single integer. Use it in place of read()
+ */
+ u64 (*read_u64)(struct cgroup_subsys_state *css, struct cftype *cft);
+ /*
+ * read_s64() is a signed version of read_u64()
+ */
+ s64 (*read_s64)(struct cgroup_subsys_state *css, struct cftype *cft);
+
+ /* generic seq_file read interface */
+ int (*seq_show)(struct seq_file *sf, void *v);
+
+ /* optional ops, implement all or none */
+ void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
+ void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
+ void (*seq_stop)(struct seq_file *sf, void *v);
+
+ /*
+ * write_u64() 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_u64)(struct cgroup_subsys_state *css, struct cftype *cft,
+ u64 val);
+ /*
+ * write_s64() is a signed version of write_u64()
+ */
+ int (*write_s64)(struct cgroup_subsys_state *css, struct cftype *cft,
+ s64 val);
+
+ /*
+ * write() is the generic write callback which maps directly to
+ * kernfs write operation and overrides all other operations.
+ * Maximum write size is determined by ->max_write_len. Use
+ * of_css/cft() to access the associated css and cft.
+ */
+ ssize_t (*write)(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lock_class_key lockdep_key;
+#endif
+};
+
+/*
+ * Control Group subsystem type.
+ * See Documentation/cgroups/cgroups.txt for details
+ */
+struct cgroup_subsys {
+ struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css);
+ int (*css_online)(struct cgroup_subsys_state *css);
+ void (*css_offline)(struct cgroup_subsys_state *css);
+ void (*css_released)(struct cgroup_subsys_state *css);
+ void (*css_free)(struct cgroup_subsys_state *css);
+ void (*css_reset)(struct cgroup_subsys_state *css);
+ void (*css_e_css_changed)(struct cgroup_subsys_state *css);
+
+ int (*can_attach)(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset);
+ void (*cancel_attach)(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset);
+ void (*attach)(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset);
+ void (*fork)(struct task_struct *task);
+ void (*exit)(struct cgroup_subsys_state *css,
+ struct cgroup_subsys_state *old_css,
+ struct task_struct *task);
+ void (*bind)(struct cgroup_subsys_state *root_css);
+
+ int disabled;
+ int early_init;
+
+ /*
+ * If %false, this subsystem is properly hierarchical -
+ * configuration, resource accounting and restriction on a parent
+ * cgroup cover those of its children. If %true, hierarchy support
+ * is broken in some ways - some subsystems ignore hierarchy
+ * completely while others are only implemented half-way.
+ *
+ * It's now disallowed to create nested cgroups if the subsystem is
+ * broken and cgroup core will emit a warning message on such
+ * cases. Eventually, all subsystems will be made properly
+ * hierarchical and this will go away.
+ */
+ bool broken_hierarchy;
+ bool warned_broken_hierarchy;
+
+ /* the following two fields are initialized automtically during boot */
+ int id;
+ const char *name;
+
+ /* link to parent, protected by cgroup_lock() */
+ struct cgroup_root *root;
+
+ /* idr for css->id */
+ struct idr css_idr;
+
+ /*
+ * List of cftypes. Each entry is the first entry of an array
+ * terminated by zero length name.
+ */
+ struct list_head cfts;
+
+ /*
+ * Base cftypes which are automatically registered. The two can
+ * point to the same array.
+ */
+ struct cftype *dfl_cftypes; /* for the default hierarchy */
+ struct cftype *legacy_cftypes; /* for the legacy hierarchies */
+
+ /*
+ * A subsystem may depend on other subsystems. When such subsystem
+ * is enabled on a cgroup, the depended-upon subsystems are enabled
+ * together if available. Subsystems enabled due to dependency are
+ * not visible to userland until explicitly enabled. The following
+ * specifies the mask of subsystems that this one depends on.
+ */
+ unsigned int depends_on;
+};
+
+#endif /* CONFIG_CGROUPS */
+#endif /* _LINUX_CGROUP_DEFS_H */
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b9cb94c..96a2ecd 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -11,23 +11,16 @@
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
-#include <linux/rcupdate.h>
#include <linux/rculist.h>
#include <linux/cgroupstats.h>
#include <linux/rwsem.h>
-#include <linux/idr.h>
-#include <linux/workqueue.h>
#include <linux/fs.h>
-#include <linux/percpu-refcount.h>
#include <linux/seq_file.h>
#include <linux/kernfs.h>
-#include <linux/wait.h>
-#ifdef CONFIG_CGROUPS
+#include <linux/cgroup-defs.h>
-struct cgroup_root;
-struct cgroup_subsys;
-struct cgroup;
+#ifdef CONFIG_CGROUPS
extern int cgroup_init_early(void);
extern int cgroup_init(void);
@@ -40,66 +33,6 @@ extern int cgroupstats_build(struct cgroupstats *stats,
extern int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk);
-/* define the enumeration of all cgroup subsystems */
-#define SUBSYS(_x) _x ## _cgrp_id,
-enum cgroup_subsys_id {
-#include <linux/cgroup_subsys.h>
- CGROUP_SUBSYS_COUNT,
-};
-#undef SUBSYS
-
-/*
- * Per-subsystem/per-cgroup state maintained by the system. This is the
- * fundamental structural building block that controllers deal with.
- *
- * Fields marked with "PI:" are public and immutable and may be accessed
- * directly without synchronization.
- */
-struct cgroup_subsys_state {
- /* PI: the cgroup that this css is attached to */
- struct cgroup *cgroup;
-
- /* PI: the cgroup subsystem that this css is attached to */
- struct cgroup_subsys *ss;
-
- /* reference count - access via css_[try]get() and css_put() */
- struct percpu_ref refcnt;
-
- /* PI: the parent css */
- struct cgroup_subsys_state *parent;
-
- /* siblings list anchored at the parent's ->children */
- struct list_head sibling;
- struct list_head children;
-
- /*
- * PI: Subsys-unique ID. 0 is unused and root is always 1. The
- * matching css can be looked up using css_from_id().
- */
- int id;
-
- unsigned int flags;
-
- /*
- * Monotonically increasing unique serial number which defines a
- * uniform order among all csses. It's guaranteed that all
- * ->children lists are in the ascending order of ->serial_nr and
- * used to allow interrupting and resuming iterations.
- */
- u64 serial_nr;
-
- /* percpu_ref killing and RCU release */
- struct rcu_head rcu_head;
- struct work_struct destroy_work;
-};
-
-/* bits in struct cgroup_subsys_state flags field */
-enum {
- CSS_NO_REF = (1 << 0), /* no reference counting for this css */
- CSS_ONLINE = (1 << 1), /* between ->css_online() and ->css_offline() */
- CSS_RELEASED = (1 << 2), /* refcnt reached zero, released */
-};
-
/**
* css_get - obtain a reference on the specified css
* @css: target css
@@ -185,307 +118,6 @@ static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
percpu_ref_put_many(&css->refcnt, n);
}
-/* bits in struct cgroup flags field */
-enum {
- /* Control Group requires release notifications to userspace */
- CGRP_NOTIFY_ON_RELEASE,
- /*
- * Clone the parent's configuration when creating a new child
- * cpuset cgroup. For historical reasons, this option can be
- * specified at mount time and thus is implemented here.
- */
- CGRP_CPUSET_CLONE_CHILDREN,
-};
-
-struct cgroup {
- /* self css with NULL ->ss, points back to this cgroup */
- struct cgroup_subsys_state self;
-
- unsigned long flags; /* "unsigned long" so bitops work */
-
- /*
- * idr allocated in-hierarchy ID.
- *
- * ID 0 is not used, the ID of the root cgroup is always 1, and a
- * new cgroup will be assigned with a smallest available ID.
- *
- * Allocating/Removing ID must be protected by cgroup_mutex.
- */
- int id;
-
- /*
- * If this cgroup contains any tasks, it contributes one to
- * populated_cnt. All children with non-zero popuplated_cnt of
- * their own contribute one. The count is zero iff there's no task
- * in this cgroup or its subtree.
- */
- int populated_cnt;
-
- struct kernfs_node *kn; /* cgroup kernfs entry */
- struct kernfs_node *populated_kn; /* kn for "cgroup.subtree_populated" */
-
- /*
- * The bitmask of subsystems enabled on the child cgroups.
- * ->subtree_control is the one configured through
- * "cgroup.subtree_control" while ->child_subsys_mask is the
- * effective one which may have more subsystems enabled.
- * Controller knobs are made available iff it's enabled in
- * ->subtree_control.
- */
- unsigned int subtree_control;
- unsigned int child_subsys_mask;
-
- /* Private pointers for each registered subsystem */
- struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT];
-
- struct cgroup_root *root;
-
- /*
- * List of cgrp_cset_links pointing at css_sets with tasks in this
- * cgroup. Protected by css_set_lock.
- */
- struct list_head cset_links;
-
- /*
- * On the default hierarchy, a css_set for a cgroup with some
- * susbsys disabled will point to css's which are associated with
- * the closest ancestor which has the subsys enabled. The
- * following lists all css_sets which point to this cgroup's css
- * for the given subsystem.
- */
- struct list_head e_csets[CGROUP_SUBSYS_COUNT];
-
- /*
- * list of pidlists, up to two for each namespace (one for procs, one
- * for tasks); created on demand.
- */
- struct list_head pidlists;
- struct mutex pidlist_mutex;
-
- /* used to wait for offlining of csses */
- wait_queue_head_t offline_waitq;
-
- /* used to schedule release agent */
- struct work_struct release_agent_work;
-};
-
-#define MAX_CGROUP_ROOT_NAMELEN 64
-
-/* cgroup_root->flags */
-enum {
- CGRP_ROOT_SANE_BEHAVIOR = (1 << 0), /* __DEVEL__sane_behavior specified */
- CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
- CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
-};
-
-/*
- * 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 cgroup_root {
- struct kernfs_root *kf_root;
-
- /* The bitmask of subsystems attached to this hierarchy */
- unsigned int subsys_mask;
-
- /* Unique id for this hierarchy. */
- int hierarchy_id;
-
- /* The root cgroup. Root is destroyed on its release. */
- struct cgroup cgrp;
-
- /* Number of cgroups in the hierarchy, used only for /proc/cgroups */
- atomic_t nr_cgrps;
-
- /* A list running through the active hierarchies */
- struct list_head root_list;
-
- /* Hierarchy-specific flags */
- unsigned int flags;
-
- /* IDs for cgroups in this hierarchy */
- struct idr cgroup_idr;
-
- /* 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
- * 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 */
- atomic_t refcount;
-
- /*
- * List running through all cgroup groups in the same hash
- * slot. Protected by css_set_lock
- */
- struct hlist_node hlist;
-
- /*
- * 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
- * css_set. Protected by css_set_lock.
- */
- struct list_head cgrp_links;
-
- /* the default cgroup associated with this css_set */
- struct cgroup *dfl_cgrp;
-
- /*
- * 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];
-
- /*
- * 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;
-
- /*
- * On the default hierarhcy, ->subsys[ssid] may point to a css
- * attached to an ancestor instead of the cgroup this css_set is
- * associated with. The following node is anchored at
- * ->subsys[ssid]->cgroup->e_csets[ssid] and provides a way to
- * iterate through all css's attached to a given cgroup.
- */
- struct list_head e_cset_node[CGROUP_SUBSYS_COUNT];
-
- /* For RCU-protected deletion */
- struct rcu_head rcu_head;
-};
-
-/*
- * struct cftype: handler definitions for cgroup control files
- *
- * When reading/writing to a file:
- * - the cgroup to use is file->f_path.dentry->d_parent->d_fsdata
- * - the 'cftype' of the file is file->f_path.dentry->d_fsdata
- */
-
-/* cftype->flags */
-enum {
- CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
- CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
- CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
-
- /* internal flags, do not use outside cgroup core proper */
- __CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
- __CFTYPE_NOT_ON_DFL = (1 << 17), /* not on default hierarchy */
-};
-
-#define MAX_CFTYPE_NAME 64
-
-struct cftype {
- /*
- * By convention, the name should begin with the name of the
- * subsystem, followed by a period. Zero length string indicates
- * end of cftype array.
- */
- char name[MAX_CFTYPE_NAME];
- int private;
- /*
- * If not 0, file mode is set to this value, otherwise it will
- * be figured out automatically
- */
- umode_t mode;
-
- /*
- * The maximum length of string, excluding trailing nul, that can
- * be passed to write. If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
- */
- size_t max_write_len;
-
- /* CFTYPE_* flags */
- unsigned int flags;
-
- /*
- * Fields used for internal bookkeeping. Initialized automatically
- * during registration.
- */
- struct cgroup_subsys *ss; /* NULL for cgroup core files */
- struct list_head node; /* anchored at ss->cfts */
- struct kernfs_ops *kf_ops;
-
- /*
- * read_u64() is a shortcut for the common case of returning a
- * single integer. Use it in place of read()
- */
- u64 (*read_u64)(struct cgroup_subsys_state *css, struct cftype *cft);
- /*
- * read_s64() is a signed version of read_u64()
- */
- s64 (*read_s64)(struct cgroup_subsys_state *css, struct cftype *cft);
-
- /* generic seq_file read interface */
- int (*seq_show)(struct seq_file *sf, void *v);
-
- /* optional ops, implement all or none */
- void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
- void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
- void (*seq_stop)(struct seq_file *sf, void *v);
-
- /*
- * write_u64() 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_u64)(struct cgroup_subsys_state *css, struct cftype *cft,
- u64 val);
- /*
- * write_s64() is a signed version of write_u64()
- */
- int (*write_s64)(struct cgroup_subsys_state *css, struct cftype *cft,
- s64 val);
-
- /*
- * write() is the generic write callback which maps directly to
- * kernfs write operation and overrides all other operations.
- * Maximum write size is determined by ->max_write_len. Use
- * of_css/cft() to access the associated css and cft.
- */
- ssize_t (*write)(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lock_class_key lockdep_key;
-#endif
-};
-
extern struct cgroup_root cgrp_dfl_root;
extern struct css_set init_css_set;
@@ -612,11 +244,6 @@ int cgroup_rm_cftypes(struct cftype *cfts);
bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor);
-/*
- * Control Group taskset, used to pass around set of tasks to cgroup_subsys
- * methods.
- */
-struct cgroup_taskset;
struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset);
struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
@@ -629,84 +256,6 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
for ((task) = cgroup_taskset_first((tset)); (task); \
(task) = cgroup_taskset_next((tset)))
-/*
- * Control Group subsystem type.
- * See Documentation/cgroups/cgroups.txt for details
- */
-
-struct cgroup_subsys {
- struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css);
- int (*css_online)(struct cgroup_subsys_state *css);
- void (*css_offline)(struct cgroup_subsys_state *css);
- void (*css_released)(struct cgroup_subsys_state *css);
- void (*css_free)(struct cgroup_subsys_state *css);
- void (*css_reset)(struct cgroup_subsys_state *css);
- void (*css_e_css_changed)(struct cgroup_subsys_state *css);
-
- int (*can_attach)(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset);
- void (*cancel_attach)(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset);
- void (*attach)(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset);
- void (*fork)(struct task_struct *task);
- void (*exit)(struct cgroup_subsys_state *css,
- struct cgroup_subsys_state *old_css,
- struct task_struct *task);
- void (*bind)(struct cgroup_subsys_state *root_css);
-
- int disabled;
- int early_init;
-
- /*
- * If %false, this subsystem is properly hierarchical -
- * configuration, resource accounting and restriction on a parent
- * cgroup cover those of its children. If %true, hierarchy support
- * is broken in some ways - some subsystems ignore hierarchy
- * completely while others are only implemented half-way.
- *
- * It's now disallowed to create nested cgroups if the subsystem is
- * broken and cgroup core will emit a warning message on such
- * cases. Eventually, all subsystems will be made properly
- * hierarchical and this will go away.
- */
- bool broken_hierarchy;
- bool warned_broken_hierarchy;
-
- /* the following two fields are initialized automtically during boot */
- int id;
-#define MAX_CGROUP_TYPE_NAMELEN 32
- const char *name;
-
- /* link to parent, protected by cgroup_lock() */
- struct cgroup_root *root;
-
- /* idr for css->id */
- struct idr css_idr;
-
- /*
- * List of cftypes. Each entry is the first entry of an array
- * terminated by zero length name.
- */
- struct list_head cfts;
-
- /*
- * Base cftypes which are automatically registered. The two can
- * point to the same array.
- */
- struct cftype *dfl_cftypes; /* for the default hierarchy */
- struct cftype *legacy_cftypes; /* for the legacy hierarchies */
-
- /*
- * A subsystem may depend on other subsystems. When such subsystem
- * is enabled on a cgroup, the depended-upon subsystems are enabled
- * together if available. Subsystems enabled due to dependency are
- * not visible to userland until explicitly enabled. The following
- * specifies the mask of subsystems that this one depends on.
- */
- unsigned int depends_on;
-};
-
#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
#include <linux/cgroup_subsys.h>
#undef SUBSYS
--
2.1.0
--
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