| 1 | #ifndef _LINUX_CGROUP_H
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| 2 | #define _LINUX_CGROUP_H
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| 3 | |
| 4 | * cgroup interface
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| 5 | *
|
| 6 | * Copyright (C) 2003 BULL SA
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| 7 | * Copyright (C) 2004-2006 Silicon Graphics, Inc.
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| 8 | *
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| 9 |
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| 10 |
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| 11 | #include <linux/sched.h>
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| 12 | #include <linux/cpumask.h>
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| 13 | #include <linux/nodemask.h>
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| 14 | #include <linux/rculist.h>
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| 15 | #include <linux/cgroupstats.h>
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| 16 | #include <linux/fs.h>
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| 17 | #include <linux/seq_file.h>
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| 18 | #include <linux/kernfs.h>
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| 19 | #include <linux/jump_label.h>
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| 20 | #include <linux/nsproxy.h>
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| 21 | #include <linux/types.h>
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| 22 | #include <linux/ns_common.h>
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| 23 | #include <linux/nsproxy.h>
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| 24 | #include <linux/user_namespace.h>
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| 25 |
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| 26 | #include <linux/cgroup-defs.h>
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| 27 |
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| 28 | #ifdef CONFIG_CGROUPS
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| 29 |
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| 30 | |
| 31 | * All weight knobs on the default hierarhcy should use the following min,
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| 32 | * default and max values. The default value is the logarithmic center of
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| 33 | * MIN and MAX and allows 100x to be expressed in both directions.
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| 34 |
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| 35 | #define CGROUP_WEIGHT_MIN 1
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| 36 | #define CGROUP_WEIGHT_DFL 100
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| 37 | #define CGROUP_WEIGHT_MAX 10000
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| 38 |
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| 39 |
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| 40 | struct css_task_iter {
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| 41 | struct cgroup_subsys *ss;
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| 42 |
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| 43 | struct list_head *cset_pos;
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| 44 | struct list_head *cset_head;
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| 45 |
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| 46 | struct list_head *task_pos;
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| 47 | struct list_head *tasks_head;
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| 48 | struct list_head *mg_tasks_head;
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| 49 |
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| 50 | struct css_set *cur_cset;
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| 51 | struct task_struct *cur_task;
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| 52 | struct list_head iters_node;
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| 53 | };
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| 54 |
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| 55 | extern struct cgroup_root cgrp_dfl_root;
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| 56 | extern struct css_set init_css_set;
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| 57 |
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| 58 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
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| 59 | #include <linux/cgroup_subsys.h>
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| 60 | #undef SUBSYS
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| 61 |
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| 62 | #define SUBSYS(_x) \
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| 63 | extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \
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| 64 | extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
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| 65 | #include <linux/cgroup_subsys.h>
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| 66 | #undef SUBSYS
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| 67 |
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| 68 | |
| 69 | * cgroup_subsys_enabled - fast test on whether a subsys is enabled
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| 70 | * @ss: subsystem in question
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| 71 |
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| 72 | #define cgroup_subsys_enabled(ss) \
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| 73 | static_branch_likely(&ss ## _enabled_key)
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| 74 |
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| 75 | |
| 76 | * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
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| 77 | * @ss: subsystem in question
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| 78 |
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| 79 | #define cgroup_subsys_on_dfl(ss) \
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| 80 | static_branch_likely(&ss ## _on_dfl_key)
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| 81 |
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| 82 | bool css_has_online_children(struct cgroup_subsys_state *css);
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| 83 | struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss);
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| 84 | struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup,
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| 85 | struct cgroup_subsys *ss);
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| 86 | struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
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| 87 | struct cgroup_subsys *ss);
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| 88 |
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| 89 | struct cgroup *cgroup_get_from_path(const char *path);
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| 90 | struct cgroup *cgroup_get_from_fd(int fd);
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| 91 |
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| 92 | int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
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| 93 | int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
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| 94 |
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| 95 | int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
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| 96 | int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
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| 97 | int cgroup_rm_cftypes(struct cftype *cfts);
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| 98 | void cgroup_file_notify(struct cgroup_file *cfile);
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| 99 |
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| 100 | char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
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| 101 | int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
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| 102 | int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
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| 103 | struct pid *pid, struct task_struct *tsk);
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| 104 |
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| 105 | void cgroup_fork(struct task_struct *p);
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| 106 | extern int cgroup_can_fork(struct task_struct *p);
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| 107 | extern void cgroup_cancel_fork(struct task_struct *p);
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| 108 | extern void cgroup_post_fork(struct task_struct *p);
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| 109 | void cgroup_exit(struct task_struct *p);
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| 110 | void cgroup_free(struct task_struct *p);
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| 111 |
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| 112 | int cgroup_init_early(void);
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| 113 | int cgroup_init(void);
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| 114 |
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| 115 | |
| 116 | * Iteration helpers and macros.
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| 117 |
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| 118 |
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| 119 | struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
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| 120 | struct cgroup_subsys_state *parent);
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| 121 | struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos,
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| 122 | struct cgroup_subsys_state *css);
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| 123 | struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos);
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| 124 | struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
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| 125 | struct cgroup_subsys_state *css);
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| 126 |
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| 127 | struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
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| 128 | struct cgroup_subsys_state **dst_cssp);
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| 129 | struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
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| 130 | struct cgroup_subsys_state **dst_cssp);
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| 131 |
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| 132 | void css_task_iter_start(struct cgroup_subsys_state *css,
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| 133 | struct css_task_iter *it);
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| 134 | struct task_struct *css_task_iter_next(struct css_task_iter *it);
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| 135 | void css_task_iter_end(struct css_task_iter *it);
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| 136 |
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| 137 | |
| 138 | * css_for_each_child - iterate through children of a css
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| 139 | * @pos: the css * to use as the loop cursor
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| 140 | * @parent: css whose children to walk
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| 141 | *
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| 142 | * Walk @parent's children. Must be called under rcu_read_lock().
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| 143 | *
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| 144 | * If a subsystem synchronizes ->css_online() and the start of iteration, a
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| 145 | * css which finished ->css_online() is guaranteed to be visible in the
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| 146 | * future iterations and will stay visible until the last reference is put.
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| 147 | * A css which hasn't finished ->css_online() or already finished
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| 148 | * ->css_offline() may show up during traversal. It's each subsystem's
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| 149 | * responsibility to synchronize against on/offlining.
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| 150 | *
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| 151 | * It is allowed to temporarily drop RCU read lock during iteration. The
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| 152 | * caller is responsible for ensuring that @pos remains accessible until
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| 153 | * the start of the next iteration by, for example, bumping the css refcnt.
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| 154 |
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| 155 | #define css_for_each_child(pos, parent) \
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| 156 | for ((pos) = css_next_child(NULL, (parent)); (pos); \
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| 157 | (pos) = css_next_child((pos), (parent)))
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| 158 |
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| 159 | |
| 160 | * css_for_each_descendant_pre - pre-order walk of a css's descendants
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| 161 | * @pos: the css * to use as the loop cursor
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| 162 | * @root: css whose descendants to walk
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| 163 | *
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| 164 | * Walk @root's descendants. @root is included in the iteration and the
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| 165 | * first node to be visited. Must be called under rcu_read_lock().
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| 166 | *
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| 167 | * If a subsystem synchronizes ->css_online() and the start of iteration, a
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| 168 | * css which finished ->css_online() is guaranteed to be visible in the
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| 169 | * future iterations and will stay visible until the last reference is put.
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| 170 | * A css which hasn't finished ->css_online() or already finished
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| 171 | * ->css_offline() may show up during traversal. It's each subsystem's
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| 172 | * responsibility to synchronize against on/offlining.
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| 173 | *
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| 174 | * For example, the following guarantees that a descendant can't escape
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| 175 | * state updates of its ancestors.
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| 176 | *
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| 177 | * my_online(@css)
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| 178 | * {
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| 179 | * Lock @css's parent and @css;
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| 180 | * Inherit state from the parent;
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| 181 | * Unlock both.
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| 182 | * }
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| 183 | *
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| 184 | * my_update_state(@css)
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| 185 | * {
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| 186 | * css_for_each_descendant_pre(@pos, @css) {
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| 187 | * Lock @pos;
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| 188 | * if (@pos == @css)
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| 189 | * Update @css's state;
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| 190 | * else
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| 191 | * Verify @pos is alive and inherit state from its parent;
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| 192 | * Unlock @pos;
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| 193 | * }
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| 194 | * }
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| 195 | *
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| 196 | * As long as the inheriting step, including checking the parent state, is
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| 197 | * enclosed inside @pos locking, double-locking the parent isn't necessary
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| 198 | * while inheriting. The state update to the parent is guaranteed to be
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| 199 | * visible by walking order and, as long as inheriting operations to the
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| 200 | * same @pos are atomic to each other, multiple updates racing each other
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| 201 | * still result in the correct state. It's guaranateed that at least one
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| 202 | * inheritance happens for any css after the latest update to its parent.
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| 203 | *
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| 204 | * If checking parent's state requires locking the parent, each inheriting
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| 205 | * iteration should lock and unlock both @pos->parent and @pos.
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| 206 | *
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| 207 | * Alternatively, a subsystem may choose to use a single global lock to
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| 208 | * synchronize ->css_online() and ->css_offline() against tree-walking
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| 209 | * operations.
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| 210 | *
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| 211 | * It is allowed to temporarily drop RCU read lock during iteration. The
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| 212 | * caller is responsible for ensuring that @pos remains accessible until
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| 213 | * the start of the next iteration by, for example, bumping the css refcnt.
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| 214 |
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| 215 | #define css_for_each_descendant_pre(pos, css) \
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| 216 | for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \
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| 217 | (pos) = css_next_descendant_pre((pos), (css)))
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| 218 |
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| 219 | |
| 220 | * css_for_each_descendant_post - post-order walk of a css's descendants
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| 221 | * @pos: the css * to use as the loop cursor
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| 222 | * @css: css whose descendants to walk
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| 223 | *
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| 224 | * Similar to css_for_each_descendant_pre() but performs post-order
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| 225 | * traversal instead. @root is included in the iteration and the last
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| 226 | * node to be visited.
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| 227 | *
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| 228 | * If a subsystem synchronizes ->css_online() and the start of iteration, a
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| 229 | * css which finished ->css_online() is guaranteed to be visible in the
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| 230 | * future iterations and will stay visible until the last reference is put.
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| 231 | * A css which hasn't finished ->css_online() or already finished
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| 232 | * ->css_offline() may show up during traversal. It's each subsystem's
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| 233 | * responsibility to synchronize against on/offlining.
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| 234 | *
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| 235 | * Note that the walk visibility guarantee example described in pre-order
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| 236 | * walk doesn't apply the same to post-order walks.
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| 237 |
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| 238 | #define css_for_each_descendant_post(pos, css) \
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| 239 | for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \
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| 240 | (pos) = css_next_descendant_post((pos), (css)))
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| 241 |
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| 242 | |
| 243 | * cgroup_taskset_for_each - iterate cgroup_taskset
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| 244 | * @task: the loop cursor
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| 245 | * @dst_css: the destination css
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| 246 | * @tset: taskset to iterate
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| 247 | *
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| 248 | * @tset may contain multiple tasks and they may belong to multiple
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| 249 | * processes.
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| 250 | *
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| 251 | * On the v2 hierarchy, there may be tasks from multiple processes and they
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| 252 | * may not share the source or destination csses.
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| 253 | *
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| 254 | * On traditional hierarchies, when there are multiple tasks in @tset, if a
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| 255 | * task of a process is in @tset, all tasks of the process are in @tset.
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| 256 | * Also, all are guaranteed to share the same source and destination csses.
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| 257 | *
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| 258 | * Iteration is not in any specific order.
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| 259 |
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| 260 | #define cgroup_taskset_for_each(task, dst_css, tset) \
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| 261 | for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
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| 262 | (task); \
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| 263 | (task) = cgroup_taskset_next((tset), &(dst_css)))
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| 264 |
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| 265 | |
| 266 | * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
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| 267 | * @leader: the loop cursor
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| 268 | * @dst_css: the destination css
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| 269 | * @tset: takset to iterate
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| 270 | *
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| 271 | * Iterate threadgroup leaders of @tset. For single-task migrations, @tset
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| 272 | * may not contain any.
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| 273 |
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| 274 | #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
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| 275 | for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
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| 276 | (leader); \
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| 277 | (leader) = cgroup_taskset_next((tset), &(dst_css))) \
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| 278 | if ((leader) != (leader)->group_leader) \
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| 279 | ; \
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| 280 | else
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| 281 |
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| 282 | |
| 283 | * Inline functions.
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| 284 |
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| 285 |
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| 286 | |
| 287 | * css_get - obtain a reference on the specified css
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| 288 | * @css: target css
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| 289 | *
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| 290 | * The caller must already have a reference.
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| 291 |
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| 292 | static inline void css_get(struct cgroup_subsys_state *css)
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| 293 | {
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| 294 | if (!(css->flags & CSS_NO_REF))
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| 295 | percpu_ref_get(&css->refcnt);
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| 296 | }
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| 297 |
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| 298 | |
| 299 | * css_get_many - obtain references on the specified css
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| 300 | * @css: target css
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| 301 | * @n: number of references to get
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| 302 | *
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| 303 | * The caller must already have a reference.
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| 304 |
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| 305 | static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n)
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| 306 | {
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| 307 | if (!(css->flags & CSS_NO_REF))
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| 308 | percpu_ref_get_many(&css->refcnt, n);
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| 309 | }
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| 310 |
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| 311 | |
| 312 | * css_tryget - try to obtain a reference on the specified css
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| 313 | * @css: target css
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| 314 | *
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| 315 | * Obtain a reference on @css unless it already has reached zero and is
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| 316 | * being released. This function doesn't care whether @css is on or
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| 317 | * offline. The caller naturally needs to ensure that @css is accessible
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| 318 | * but doesn't have to be holding a reference on it - IOW, RCU protected
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| 319 | * access is good enough for this function. Returns %true if a reference
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| 320 | * count was successfully obtained; %false otherwise.
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| 321 |
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| 322 | static inline bool css_tryget(struct cgroup_subsys_state *css)
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| 323 | {
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| 324 | if (!(css->flags & CSS_NO_REF))
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| 325 | return percpu_ref_tryget(&css->refcnt);
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| 326 | return true;
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| 327 | }
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| 328 |
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| 329 | |
| 330 | * css_tryget_online - try to obtain a reference on the specified css if online
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| 331 | * @css: target css
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| 332 | *
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| 333 | * Obtain a reference on @css if it's online. The caller naturally needs
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| 334 | * to ensure that @css is accessible but doesn't have to be holding a
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| 335 | * reference on it - IOW, RCU protected access is good enough for this
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| 336 | * function. Returns %true if a reference count was successfully obtained;
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| 337 | * %false otherwise.
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| 338 |
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| 339 | static inline bool css_tryget_online(struct cgroup_subsys_state *css)
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| 340 | {
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| 341 | if (!(css->flags & CSS_NO_REF))
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| 342 | return percpu_ref_tryget_live(&css->refcnt);
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| 343 | return true;
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| 344 | }
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| 345 |
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| 346 | |
| 347 | * css_put - put a css reference
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| 348 | * @css: target css
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| 349 | *
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| 350 | * Put a reference obtained via css_get() and css_tryget_online().
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| 351 |
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| 352 | static inline void css_put(struct cgroup_subsys_state *css)
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| 353 | {
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| 354 | if (!(css->flags & CSS_NO_REF))
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| 355 | percpu_ref_put(&css->refcnt);
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| 356 | }
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| 357 |
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| 358 | |
| 359 | * css_put_many - put css references
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| 360 | * @css: target css
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| 361 | * @n: number of references to put
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| 362 | *
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| 363 | * Put references obtained via css_get() and css_tryget_online().
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| 364 |
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| 365 | static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
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| 366 | {
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| 367 | if (!(css->flags & CSS_NO_REF))
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| 368 | percpu_ref_put_many(&css->refcnt, n);
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| 369 | }
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| 370 |
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| 371 | static inline void cgroup_put(struct cgroup *cgrp)
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| 372 | {
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| 373 | css_put(&cgrp->self);
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| 374 | }
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| 375 |
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| 376 | |
| 377 | * task_css_set_check - obtain a task's css_set with extra access conditions
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| 378 | * @task: the task to obtain css_set for
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| 379 | * @__c: extra condition expression to be passed to rcu_dereference_check()
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| 380 | *
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| 381 | * A task's css_set is RCU protected, initialized and exited while holding
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| 382 | * task_lock(), and can only be modified while holding both cgroup_mutex
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| 383 | * and task_lock() while the task is alive. This macro verifies that the
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| 384 | * caller is inside proper critical section and returns @task's css_set.
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| 385 | *
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| 386 | * The caller can also specify additional allowed conditions via @__c, such
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| 387 | * as locks used during the cgroup_subsys::attach() methods.
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| 388 |
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| 389 | #ifdef CONFIG_PROVE_RCU
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| 390 | extern struct mutex cgroup_mutex;
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| 391 | extern spinlock_t css_set_lock;
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| 392 | #define task_css_set_check(task, __c) \
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| 393 | rcu_dereference_check((task)->cgroups, \
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| 394 | lockdep_is_held(&cgroup_mutex) || \
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| 395 | lockdep_is_held(&css_set_lock) || \
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| 396 | ((task)->flags & PF_EXITING) || (__c))
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| 397 | #else
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| 398 | #define task_css_set_check(task, __c) \
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| 399 | rcu_dereference((task)->cgroups)
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| 400 | #endif
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| 401 |
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| 402 | |
| 403 | * task_css_check - obtain css for (task, subsys) w/ extra access conds
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| 404 | * @task: the target task
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| 405 | * @subsys_id: the target subsystem ID
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| 406 | * @__c: extra condition expression to be passed to rcu_dereference_check()
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| 407 | *
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| 408 | * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
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| 409 | * synchronization rules are the same as task_css_set_check().
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| 410 |
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| 411 | #define task_css_check(task, subsys_id, __c) \
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| 412 | task_css_set_check((task), (__c))->subsys[(subsys_id)]
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| 413 |
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| 414 | |
| 415 | * task_css_set - obtain a task's css_set
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| 416 | * @task: the task to obtain css_set for
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| 417 | *
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| 418 | * See task_css_set_check().
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| 419 |
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| 420 | static inline struct css_set *task_css_set(struct task_struct *task)
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| 421 | {
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| 422 | return task_css_set_check(task, false);
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| 423 | }
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| 424 |
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| 425 | |
| 426 | * task_css - obtain css for (task, subsys)
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| 427 | * @task: the target task
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| 428 | * @subsys_id: the target subsystem ID
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| 429 | *
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| 430 | * See task_css_check().
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| 431 |
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| 432 | static inline struct cgroup_subsys_state *task_css(struct task_struct *task,
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| 433 | int subsys_id)
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| 434 | {
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| 435 | return task_css_check(task, subsys_id, false);
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| 436 | }
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| 437 |
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| 438 | |
| 439 | * task_get_css - find and get the css for (task, subsys)
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| 440 | * @task: the target task
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| 441 | * @subsys_id: the target subsystem ID
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| 442 | *
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| 443 | * Find the css for the (@task, @subsys_id) combination, increment a
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| 444 | * reference on and return it. This function is guaranteed to return a
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| 445 | * valid css.
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| 446 |
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| 447 | static inline struct cgroup_subsys_state *
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| 448 | task_get_css(struct task_struct *task, int subsys_id)
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| 449 | {
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| 450 | struct cgroup_subsys_state *css;
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| 451 |
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| 452 | rcu_read_lock();
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| 453 | while (true) {
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| 454 | css = task_css(task, subsys_id);
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| 455 | if (likely(css_tryget_online(css)))
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| 456 | break;
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| 457 | cpu_relax();
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| 458 | }
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| 459 | rcu_read_unlock();
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| 460 | return css;
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| 461 | }
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| 462 |
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| 463 | |
| 464 | * task_css_is_root - test whether a task belongs to the root css
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| 465 | * @task: the target task
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| 466 | * @subsys_id: the target subsystem ID
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| 467 | *
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| 468 | * Test whether @task belongs to the root css on the specified subsystem.
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| 469 | * May be invoked in any context.
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| 470 |
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| 471 | static inline bool task_css_is_root(struct task_struct *task, int subsys_id)
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| 472 | {
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| 473 | return task_css_check(task, subsys_id, true) ==
|
| 474 | init_css_set.subsys[subsys_id];
|
| 475 | }
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| 476 |
|
| 477 | static inline struct cgroup *task_cgroup(struct task_struct *task,
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| 478 | int subsys_id)
|
| 479 | {
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| 480 | return task_css(task, subsys_id)->cgroup;
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| 481 | }
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| 482 |
|
| 483 | |
| 484 | * cgroup_is_descendant - test ancestry
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| 485 | * @cgrp: the cgroup to be tested
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| 486 | * @ancestor: possible ancestor of @cgrp
|
| 487 | *
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| 488 | * Test whether @cgrp is a descendant of @ancestor. It also returns %true
|
| 489 | * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
|
| 490 | * and @ancestor are accessible.
|
| 491 |
|
| 492 | static inline bool cgroup_is_descendant(struct cgroup *cgrp,
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| 493 | struct cgroup *ancestor)
|
| 494 | {
|
| 495 | if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
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| 496 | return false;
|
| 497 | return cgrp->ancestor_ids[ancestor->level] == ancestor->id;
|
| 498 | }
|
| 499 |
|
| 500 |
|
| 501 | static inline bool cgroup_is_populated(struct cgroup *cgrp)
|
| 502 | {
|
| 503 | return cgrp->populated_cnt;
|
| 504 | }
|
| 505 |
|
| 506 |
|
| 507 | static inline ino_t cgroup_ino(struct cgroup *cgrp)
|
| 508 | {
|
| 509 | return cgrp->kn->ino;
|
| 510 | }
|
| 511 |
|
| 512 |
|
| 513 | static inline struct cftype *of_cft(struct kernfs_open_file *of)
|
| 514 | {
|
| 515 | return of->kn->priv;
|
| 516 | }
|
| 517 |
|
| 518 | struct cgroup_subsys_state *of_css(struct kernfs_open_file *of);
|
| 519 |
|
| 520 |
|
| 521 | static inline struct cftype *seq_cft(struct seq_file *seq)
|
| 522 | {
|
| 523 | return of_cft(seq->private);
|
| 524 | }
|
| 525 |
|
| 526 | static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
|
| 527 | {
|
| 528 | return of_css(seq->private);
|
| 529 | }
|
| 530 |
|
| 531 | |
| 532 | * Name / path handling functions. All are thin wrappers around the kernfs
|
| 533 | * counterparts and can be called under any context.
|
| 534 |
|
| 535 |
|
| 536 | static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
|
| 537 | {
|
| 538 | return kernfs_name(cgrp->kn, buf, buflen);
|
| 539 | }
|
| 540 |
|
| 541 | static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf,
|
| 542 | size_t buflen)
|
| 543 | {
|
| 544 | return kernfs_path(cgrp->kn, buf, buflen);
|
| 545 | }
|
| 546 |
|
| 547 | static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
|
| 548 | {
|
| 549 | pr_cont_kernfs_name(cgrp->kn);
|
| 550 | }
|
| 551 |
|
| 552 | static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
|
| 553 | {
|
| 554 | pr_cont_kernfs_path(cgrp->kn);
|
| 555 | }
|
| 556 |
|
| 557 | #else
|
| 558 |
|
| 559 | struct cgroup_subsys_state;
|
| 560 |
|
| 561 | static inline void css_put(struct cgroup_subsys_state *css) {}
|
| 562 | static inline int cgroup_attach_task_all(struct task_struct *from,
|
| 563 | struct task_struct *t) { return 0; }
|
| 564 | static inline int cgroupstats_build(struct cgroupstats *stats,
|
| 565 | struct dentry *dentry) { return -EINVAL; }
|
| 566 |
|
| 567 | static inline void cgroup_fork(struct task_struct *p) {}
|
| 568 | static inline int cgroup_can_fork(struct task_struct *p) { return 0; }
|
| 569 | static inline void cgroup_cancel_fork(struct task_struct *p) {}
|
| 570 | static inline void cgroup_post_fork(struct task_struct *p) {}
|
| 571 | static inline void cgroup_exit(struct task_struct *p) {}
|
| 572 | static inline void cgroup_free(struct task_struct *p) {}
|
| 573 |
|
| 574 | static inline int cgroup_init_early(void) { return 0; }
|
| 575 | static inline int cgroup_init(void) { return 0; }
|
| 576 |
|
| 577 | #endif
|
| 578 |
|
| 579 | |
| 580 | * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
|
| 581 | * definition in cgroup-defs.h.
|
| 582 |
|
| 583 | #ifdef CONFIG_SOCK_CGROUP_DATA
|
| 584 |
|
| 585 | #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
|
| 586 | extern spinlock_t cgroup_sk_update_lock;
|
| 587 | #endif
|
| 588 |
|
| 589 | void cgroup_sk_alloc_disable(void);
|
| 590 | void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
|
| 591 | void cgroup_sk_free(struct sock_cgroup_data *skcd);
|
| 592 |
|
| 593 | static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
|
| 594 | {
|
| 595 | #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
|
| 596 | unsigned long v;
|
| 597 |
|
| 598 | |
| 599 | * @skcd->val is 64bit but the following is safe on 32bit too as we
|
| 600 | * just need the lower ulong to be written and read atomically.
|
| 601 |
|
| 602 | v = READ_ONCE(skcd->val);
|
| 603 |
|
| 604 | if (v & 1)
|
| 605 | return &cgrp_dfl_root.cgrp;
|
| 606 |
|
| 607 | return (struct cgroup *)(unsigned long)v ?: &cgrp_dfl_root.cgrp;
|
| 608 | #else
|
| 609 | return (struct cgroup *)(unsigned long)skcd->val;
|
| 610 | #endif
|
| 611 | }
|
| 612 |
|
| 613 | #else
|
| 614 |
|
| 615 | static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
|
| 616 | static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
|
| 617 |
|
| 618 | #endif
|
| 619 |
|
| 620 | struct cgroup_namespace {
|
| 621 | atomic_t count;
|
| 622 | struct ns_common ns;
|
| 623 | struct user_namespace *user_ns;
|
| 624 | struct css_set *root_cset;
|
| 625 | };
|
| 626 |
|
| 627 | extern struct cgroup_namespace init_cgroup_ns;
|
| 628 |
|
| 629 | #ifdef CONFIG_CGROUPS
|
| 630 |
|
| 631 | void free_cgroup_ns(struct cgroup_namespace *ns);
|
| 632 |
|
| 633 | struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
|
| 634 | struct user_namespace *user_ns,
|
| 635 | struct cgroup_namespace *old_ns);
|
| 636 |
|
| 637 | char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
|
| 638 | struct cgroup_namespace *ns);
|
| 639 |
|
| 640 | #else
|
| 641 |
|
| 642 | static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
|
| 643 | static inline struct cgroup_namespace *
|
| 644 | copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns,
|
| 645 | struct cgroup_namespace *old_ns)
|
| 646 | {
|
| 647 | return old_ns;
|
| 648 | }
|
| 649 |
|
| 650 | #endif
|
| 651 |
|
| 652 | static inline void get_cgroup_ns(struct cgroup_namespace *ns)
|
| 653 | {
|
| 654 | if (ns)
|
| 655 | atomic_inc(&ns->count);
|
| 656 | }
|
| 657 |
|
| 658 | static inline void put_cgroup_ns(struct cgroup_namespace *ns)
|
| 659 | {
|
| 660 | if (ns && atomic_dec_and_test(&ns->count))
|
| 661 | free_cgroup_ns(ns);
|
| 662 | }
|
| 663 |
|
| 664 | #endif
|