Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 1 | #ifndef _LINUX_CGROUP_H |
| 2 | #define _LINUX_CGROUP_H |
| 3 | /* |
| 4 | * cgroup interface |
| 5 | * |
| 6 | * Copyright (C) 2003 BULL SA |
| 7 | * Copyright (C) 2004-2006 Silicon Graphics, Inc. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/sched.h> |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 12 | #include <linux/cpumask.h> |
| 13 | #include <linux/nodemask.h> |
| 14 | #include <linux/rcupdate.h> |
Balbir Singh | 846c7bb | 2007-10-18 23:39:44 -0700 | [diff] [blame] | 15 | #include <linux/cgroupstats.h> |
Cliff Wickman | 31a7df0 | 2008-02-07 00:14:42 -0800 | [diff] [blame] | 16 | #include <linux/prio_heap.h> |
Paul Menage | cc31edc | 2008-10-18 20:28:04 -0700 | [diff] [blame] | 17 | #include <linux/rwsem.h> |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 18 | |
| 19 | #ifdef CONFIG_CGROUPS |
| 20 | |
| 21 | struct cgroupfs_root; |
| 22 | struct cgroup_subsys; |
| 23 | struct inode; |
Paul Menage | 84eea84 | 2008-07-25 01:47:00 -0700 | [diff] [blame] | 24 | struct cgroup; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 25 | |
| 26 | extern int cgroup_init_early(void); |
| 27 | extern int cgroup_init(void); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 28 | extern void cgroup_lock(void); |
Paul Menage | 84eea84 | 2008-07-25 01:47:00 -0700 | [diff] [blame] | 29 | extern bool cgroup_lock_live_group(struct cgroup *cgrp); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 30 | extern void cgroup_unlock(void); |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 31 | extern void cgroup_fork(struct task_struct *p); |
| 32 | extern void cgroup_fork_callbacks(struct task_struct *p); |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 33 | extern void cgroup_post_fork(struct task_struct *p); |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 34 | extern void cgroup_exit(struct task_struct *p, int run_callbacks); |
Balbir Singh | 846c7bb | 2007-10-18 23:39:44 -0700 | [diff] [blame] | 35 | extern int cgroupstats_build(struct cgroupstats *stats, |
| 36 | struct dentry *dentry); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 37 | |
Paul Menage | a424316 | 2007-10-18 23:39:35 -0700 | [diff] [blame] | 38 | extern struct file_operations proc_cgroup_operations; |
| 39 | |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 40 | /* Define the enumeration of all cgroup subsystems */ |
| 41 | #define SUBSYS(_x) _x ## _subsys_id, |
| 42 | enum cgroup_subsys_id { |
| 43 | #include <linux/cgroup_subsys.h> |
| 44 | CGROUP_SUBSYS_COUNT |
| 45 | }; |
| 46 | #undef SUBSYS |
| 47 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 48 | /* Per-subsystem/per-cgroup state maintained by the system. */ |
| 49 | struct cgroup_subsys_state { |
| 50 | /* The cgroup that this subsystem is attached to. Useful |
| 51 | * for subsystems that want to know about the cgroup |
| 52 | * hierarchy structure */ |
| 53 | struct cgroup *cgroup; |
| 54 | |
Paul Menage | e7c5ec9 | 2009-01-07 18:08:38 -0800 | [diff] [blame] | 55 | /* State maintained by the cgroup system to allow subsystems |
| 56 | * to be "busy". Should be accessed via css_get(), |
| 57 | * css_tryget() and and css_put(). */ |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 58 | |
| 59 | atomic_t refcnt; |
| 60 | |
| 61 | unsigned long flags; |
| 62 | }; |
| 63 | |
| 64 | /* bits in struct cgroup_subsys_state flags field */ |
| 65 | enum { |
| 66 | CSS_ROOT, /* This CSS is the root of the subsystem */ |
Paul Menage | e7c5ec9 | 2009-01-07 18:08:38 -0800 | [diff] [blame] | 67 | CSS_REMOVED, /* This CSS is dead */ |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 68 | }; |
| 69 | |
| 70 | /* |
Paul Menage | e7c5ec9 | 2009-01-07 18:08:38 -0800 | [diff] [blame] | 71 | * Call css_get() to hold a reference on the css; it can be used |
| 72 | * for a reference obtained via: |
| 73 | * - an existing ref-counted reference to the css |
| 74 | * - task->cgroups for a locked task |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 75 | */ |
| 76 | |
| 77 | static inline void css_get(struct cgroup_subsys_state *css) |
| 78 | { |
| 79 | /* We don't need to reference count the root state */ |
| 80 | if (!test_bit(CSS_ROOT, &css->flags)) |
| 81 | atomic_inc(&css->refcnt); |
| 82 | } |
Paul Menage | e7c5ec9 | 2009-01-07 18:08:38 -0800 | [diff] [blame] | 83 | |
| 84 | static inline bool css_is_removed(struct cgroup_subsys_state *css) |
| 85 | { |
| 86 | return test_bit(CSS_REMOVED, &css->flags); |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * Call css_tryget() to take a reference on a css if your existing |
| 91 | * (known-valid) reference isn't already ref-counted. Returns false if |
| 92 | * the css has been destroyed. |
| 93 | */ |
| 94 | |
| 95 | static inline bool css_tryget(struct cgroup_subsys_state *css) |
| 96 | { |
| 97 | if (test_bit(CSS_ROOT, &css->flags)) |
| 98 | return true; |
| 99 | while (!atomic_inc_not_zero(&css->refcnt)) { |
| 100 | if (test_bit(CSS_REMOVED, &css->flags)) |
| 101 | return false; |
| 102 | } |
| 103 | return true; |
| 104 | } |
| 105 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 106 | /* |
| 107 | * css_put() should be called to release a reference taken by |
Paul Menage | e7c5ec9 | 2009-01-07 18:08:38 -0800 | [diff] [blame] | 108 | * css_get() or css_tryget() |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 109 | */ |
| 110 | |
Paul Menage | 81a6a5c | 2007-10-18 23:39:38 -0700 | [diff] [blame] | 111 | extern void __css_put(struct cgroup_subsys_state *css); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 112 | static inline void css_put(struct cgroup_subsys_state *css) |
| 113 | { |
| 114 | if (!test_bit(CSS_ROOT, &css->flags)) |
Paul Menage | 81a6a5c | 2007-10-18 23:39:38 -0700 | [diff] [blame] | 115 | __css_put(css); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 116 | } |
| 117 | |
Paul Menage | 3116f0e | 2008-04-29 01:00:04 -0700 | [diff] [blame] | 118 | /* bits in struct cgroup flags field */ |
| 119 | enum { |
| 120 | /* Control Group is dead */ |
| 121 | CGRP_REMOVED, |
| 122 | /* Control Group has previously had a child cgroup or a task, |
| 123 | * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set) */ |
| 124 | CGRP_RELEASABLE, |
| 125 | /* Control Group requires release notifications to userspace */ |
| 126 | CGRP_NOTIFY_ON_RELEASE, |
| 127 | }; |
| 128 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 129 | struct cgroup { |
| 130 | unsigned long flags; /* "unsigned long" so bitops work */ |
| 131 | |
| 132 | /* count users of this cgroup. >0 means busy, but doesn't |
| 133 | * necessarily indicate the number of tasks in the |
| 134 | * cgroup */ |
| 135 | atomic_t count; |
| 136 | |
| 137 | /* |
| 138 | * We link our 'sibling' struct into our parent's 'children'. |
| 139 | * Our children link their 'sibling' into our 'children'. |
| 140 | */ |
| 141 | struct list_head sibling; /* my parent's children */ |
| 142 | struct list_head children; /* my children */ |
| 143 | |
| 144 | struct cgroup *parent; /* my parent */ |
Paul Menage | a47295e | 2009-01-07 18:07:44 -0800 | [diff] [blame] | 145 | struct dentry *dentry; /* cgroup fs entry, RCU protected */ |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 146 | |
| 147 | /* Private pointers for each registered subsystem */ |
| 148 | struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; |
| 149 | |
| 150 | struct cgroupfs_root *root; |
| 151 | struct cgroup *top_cgroup; |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 152 | |
| 153 | /* |
| 154 | * List of cg_cgroup_links pointing at css_sets with |
| 155 | * tasks in this cgroup. Protected by css_set_lock |
| 156 | */ |
| 157 | struct list_head css_sets; |
Paul Menage | 81a6a5c | 2007-10-18 23:39:38 -0700 | [diff] [blame] | 158 | |
| 159 | /* |
| 160 | * Linked list running through all cgroups that can |
| 161 | * potentially be reaped by the release agent. Protected by |
| 162 | * release_list_lock |
| 163 | */ |
| 164 | struct list_head release_list; |
Paul Menage | cc31edc | 2008-10-18 20:28:04 -0700 | [diff] [blame] | 165 | |
| 166 | /* pids_mutex protects the fields below */ |
| 167 | struct rw_semaphore pids_mutex; |
| 168 | /* Array of process ids in the cgroup */ |
| 169 | pid_t *tasks_pids; |
| 170 | /* How many files are using the current tasks_pids array */ |
| 171 | int pids_use_count; |
| 172 | /* Length of the current tasks_pids array */ |
| 173 | int pids_length; |
Paul Menage | a47295e | 2009-01-07 18:07:44 -0800 | [diff] [blame] | 174 | |
| 175 | /* For RCU-protected deletion */ |
| 176 | struct rcu_head rcu_head; |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 177 | }; |
| 178 | |
| 179 | /* A css_set is a structure holding pointers to a set of |
| 180 | * cgroup_subsys_state objects. This saves space in the task struct |
| 181 | * object and speeds up fork()/exit(), since a single inc/dec and a |
| 182 | * list_add()/del() can bump the reference count on the entire |
| 183 | * cgroup set for a task. |
| 184 | */ |
| 185 | |
| 186 | struct css_set { |
| 187 | |
| 188 | /* Reference count */ |
Lai Jiangshan | 146aa1b | 2008-10-18 20:28:03 -0700 | [diff] [blame] | 189 | atomic_t refcount; |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 190 | |
| 191 | /* |
Li Zefan | 472b105 | 2008-04-29 01:00:11 -0700 | [diff] [blame] | 192 | * List running through all cgroup groups in the same hash |
| 193 | * slot. Protected by css_set_lock |
| 194 | */ |
| 195 | struct hlist_node hlist; |
| 196 | |
| 197 | /* |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 198 | * List running through all tasks using this cgroup |
| 199 | * group. Protected by css_set_lock |
| 200 | */ |
| 201 | struct list_head tasks; |
| 202 | |
| 203 | /* |
| 204 | * List of cg_cgroup_link objects on link chains from |
| 205 | * cgroups referenced from this css_set. Protected by |
| 206 | * css_set_lock |
| 207 | */ |
| 208 | struct list_head cg_links; |
| 209 | |
| 210 | /* |
| 211 | * Set of subsystem states, one for each subsystem. This array |
| 212 | * is immutable after creation apart from the init_css_set |
| 213 | * during subsystem registration (at boot time). |
| 214 | */ |
| 215 | struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 216 | }; |
| 217 | |
Paul Menage | 9179656 | 2008-04-29 01:00:01 -0700 | [diff] [blame] | 218 | /* |
| 219 | * cgroup_map_cb is an abstract callback API for reporting map-valued |
| 220 | * control files |
| 221 | */ |
| 222 | |
| 223 | struct cgroup_map_cb { |
| 224 | int (*fill)(struct cgroup_map_cb *cb, const char *key, u64 value); |
| 225 | void *state; |
| 226 | }; |
| 227 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 228 | /* struct cftype: |
| 229 | * |
| 230 | * The files in the cgroup filesystem mostly have a very simple read/write |
| 231 | * handling, some common function will take care of it. Nevertheless some cases |
| 232 | * (read tasks) are special and therefore I define this structure for every |
| 233 | * kind of file. |
| 234 | * |
| 235 | * |
| 236 | * When reading/writing to a file: |
Li Zefan | a043e3b | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 237 | * - the cgroup to use is file->f_dentry->d_parent->d_fsdata |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 238 | * - the 'cftype' of the file is file->f_dentry->d_fsdata |
| 239 | */ |
| 240 | |
| 241 | #define MAX_CFTYPE_NAME 64 |
| 242 | struct cftype { |
| 243 | /* By convention, the name should begin with the name of the |
| 244 | * subsystem, followed by a period */ |
| 245 | char name[MAX_CFTYPE_NAME]; |
| 246 | int private; |
Paul Menage | db3b149 | 2008-07-25 01:46:58 -0700 | [diff] [blame] | 247 | |
| 248 | /* |
| 249 | * If non-zero, defines the maximum length of string that can |
| 250 | * be passed to write_string; defaults to 64 |
| 251 | */ |
| 252 | size_t max_write_len; |
| 253 | |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 254 | int (*open)(struct inode *inode, struct file *file); |
| 255 | ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft, |
| 256 | struct file *file, |
| 257 | char __user *buf, size_t nbytes, loff_t *ppos); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 258 | /* |
Paul Menage | f4c753b | 2008-04-29 00:59:56 -0700 | [diff] [blame] | 259 | * read_u64() is a shortcut for the common case of returning a |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 260 | * single integer. Use it in place of read() |
| 261 | */ |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 262 | u64 (*read_u64)(struct cgroup *cgrp, struct cftype *cft); |
Paul Menage | 9179656 | 2008-04-29 01:00:01 -0700 | [diff] [blame] | 263 | /* |
Paul Menage | e73d2c6 | 2008-04-29 01:00:06 -0700 | [diff] [blame] | 264 | * read_s64() is a signed version of read_u64() |
| 265 | */ |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 266 | s64 (*read_s64)(struct cgroup *cgrp, struct cftype *cft); |
Paul Menage | e73d2c6 | 2008-04-29 01:00:06 -0700 | [diff] [blame] | 267 | /* |
Paul Menage | 9179656 | 2008-04-29 01:00:01 -0700 | [diff] [blame] | 268 | * read_map() is used for defining a map of key/value |
| 269 | * pairs. It should call cb->fill(cb, key, value) for each |
| 270 | * entry. The key/value pairs (and their ordering) should not |
| 271 | * change between reboots. |
| 272 | */ |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 273 | int (*read_map)(struct cgroup *cont, struct cftype *cft, |
| 274 | struct cgroup_map_cb *cb); |
Serge E. Hallyn | 29486df | 2008-04-29 01:00:14 -0700 | [diff] [blame] | 275 | /* |
| 276 | * read_seq_string() is used for outputting a simple sequence |
| 277 | * using seqfile. |
| 278 | */ |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 279 | int (*read_seq_string)(struct cgroup *cont, struct cftype *cft, |
| 280 | struct seq_file *m); |
Paul Menage | 9179656 | 2008-04-29 01:00:01 -0700 | [diff] [blame] | 281 | |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 282 | ssize_t (*write)(struct cgroup *cgrp, struct cftype *cft, |
| 283 | struct file *file, |
| 284 | const char __user *buf, size_t nbytes, loff_t *ppos); |
Paul Menage | 355e0c4 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 285 | |
| 286 | /* |
Paul Menage | f4c753b | 2008-04-29 00:59:56 -0700 | [diff] [blame] | 287 | * write_u64() is a shortcut for the common case of accepting |
Paul Menage | 355e0c4 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 288 | * a single integer (as parsed by simple_strtoull) from |
| 289 | * userspace. Use in place of write(); return 0 or error. |
| 290 | */ |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 291 | int (*write_u64)(struct cgroup *cgrp, struct cftype *cft, u64 val); |
Paul Menage | e73d2c6 | 2008-04-29 01:00:06 -0700 | [diff] [blame] | 292 | /* |
| 293 | * write_s64() is a signed version of write_u64() |
| 294 | */ |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 295 | int (*write_s64)(struct cgroup *cgrp, struct cftype *cft, s64 val); |
Paul Menage | 355e0c4 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 296 | |
Pavel Emelyanov | d447ea2 | 2008-04-29 01:00:08 -0700 | [diff] [blame] | 297 | /* |
Paul Menage | db3b149 | 2008-07-25 01:46:58 -0700 | [diff] [blame] | 298 | * write_string() is passed a nul-terminated kernelspace |
| 299 | * buffer of maximum length determined by max_write_len. |
| 300 | * Returns 0 or -ve error code. |
| 301 | */ |
| 302 | int (*write_string)(struct cgroup *cgrp, struct cftype *cft, |
| 303 | const char *buffer); |
| 304 | /* |
Pavel Emelyanov | d447ea2 | 2008-04-29 01:00:08 -0700 | [diff] [blame] | 305 | * trigger() callback can be used to get some kick from the |
| 306 | * userspace, when the actual string written is not important |
| 307 | * at all. The private field can be used to determine the |
| 308 | * kick type for multiplexing. |
| 309 | */ |
| 310 | int (*trigger)(struct cgroup *cgrp, unsigned int event); |
| 311 | |
Paul Menage | ce16b49 | 2008-07-25 01:46:57 -0700 | [diff] [blame] | 312 | int (*release)(struct inode *inode, struct file *file); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 313 | }; |
| 314 | |
Cliff Wickman | 31a7df0 | 2008-02-07 00:14:42 -0800 | [diff] [blame] | 315 | struct cgroup_scanner { |
| 316 | struct cgroup *cg; |
| 317 | int (*test_task)(struct task_struct *p, struct cgroup_scanner *scan); |
| 318 | void (*process_task)(struct task_struct *p, |
| 319 | struct cgroup_scanner *scan); |
| 320 | struct ptr_heap *heap; |
| 321 | }; |
| 322 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 323 | /* Add a new file to the given cgroup directory. Should only be |
| 324 | * called by subsystems from within a populate() method */ |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 325 | int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 326 | const struct cftype *cft); |
| 327 | |
| 328 | /* Add a set of new files to the given cgroup directory. Should |
| 329 | * only be called by subsystems from within a populate() method */ |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 330 | int cgroup_add_files(struct cgroup *cgrp, |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 331 | struct cgroup_subsys *subsys, |
| 332 | const struct cftype cft[], |
| 333 | int count); |
| 334 | |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 335 | int cgroup_is_removed(const struct cgroup *cgrp); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 336 | |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 337 | int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 338 | |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 339 | int cgroup_task_count(const struct cgroup *cgrp); |
Paul Menage | bbcb81d | 2007-10-18 23:39:32 -0700 | [diff] [blame] | 340 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 341 | /* Return true if the cgroup is a descendant of the current cgroup */ |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 342 | int cgroup_is_descendant(const struct cgroup *cgrp); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 343 | |
| 344 | /* Control Group subsystem type. See Documentation/cgroups.txt for details */ |
| 345 | |
| 346 | struct cgroup_subsys { |
| 347 | struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss, |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 348 | struct cgroup *cgrp); |
| 349 | void (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp); |
| 350 | void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 351 | int (*can_attach)(struct cgroup_subsys *ss, |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 352 | struct cgroup *cgrp, struct task_struct *tsk); |
| 353 | void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, |
| 354 | struct cgroup *old_cgrp, struct task_struct *tsk); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 355 | void (*fork)(struct cgroup_subsys *ss, struct task_struct *task); |
| 356 | void (*exit)(struct cgroup_subsys *ss, struct task_struct *task); |
| 357 | int (*populate)(struct cgroup_subsys *ss, |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 358 | struct cgroup *cgrp); |
| 359 | void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 360 | void (*bind)(struct cgroup_subsys *ss, struct cgroup *root); |
Hugh Dickins | e599137 | 2009-01-06 14:39:22 -0800 | [diff] [blame] | 361 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 362 | int subsys_id; |
| 363 | int active; |
Paul Menage | 8bab8dd | 2008-04-04 14:29:57 -0700 | [diff] [blame] | 364 | int disabled; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 365 | int early_init; |
| 366 | #define MAX_CGROUP_TYPE_NAMELEN 32 |
| 367 | const char *name; |
| 368 | |
Paul Menage | 999cd8a | 2009-01-07 18:08:36 -0800 | [diff] [blame] | 369 | /* |
| 370 | * Protects sibling/children links of cgroups in this |
| 371 | * hierarchy, plus protects which hierarchy (or none) the |
| 372 | * subsystem is a part of (i.e. root/sibling). To avoid |
| 373 | * potential deadlocks, the following operations should not be |
| 374 | * undertaken while holding any hierarchy_mutex: |
| 375 | * |
| 376 | * - allocating memory |
| 377 | * - initiating hotplug events |
| 378 | */ |
| 379 | struct mutex hierarchy_mutex; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 380 | |
Paul Menage | 999cd8a | 2009-01-07 18:08:36 -0800 | [diff] [blame] | 381 | /* |
| 382 | * Link to parent, and list entry in parent's children. |
| 383 | * Protected by this->hierarchy_mutex and cgroup_lock() |
| 384 | */ |
| 385 | struct cgroupfs_root *root; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 386 | struct list_head sibling; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 387 | }; |
| 388 | |
| 389 | #define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys; |
| 390 | #include <linux/cgroup_subsys.h> |
| 391 | #undef SUBSYS |
| 392 | |
| 393 | static inline struct cgroup_subsys_state *cgroup_subsys_state( |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 394 | struct cgroup *cgrp, int subsys_id) |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 395 | { |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 396 | return cgrp->subsys[subsys_id]; |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 397 | } |
| 398 | |
| 399 | static inline struct cgroup_subsys_state *task_subsys_state( |
| 400 | struct task_struct *task, int subsys_id) |
| 401 | { |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 402 | return rcu_dereference(task->cgroups->subsys[subsys_id]); |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 403 | } |
| 404 | |
| 405 | static inline struct cgroup* task_cgroup(struct task_struct *task, |
| 406 | int subsys_id) |
| 407 | { |
| 408 | return task_subsys_state(task, subsys_id)->cgroup; |
| 409 | } |
| 410 | |
Serge E. Hallyn | e885dcd | 2008-07-25 01:47:06 -0700 | [diff] [blame] | 411 | int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *ss, |
| 412 | char *nodename); |
Paul Menage | 697f416 | 2007-10-18 23:39:34 -0700 | [diff] [blame] | 413 | |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 414 | /* A cgroup_iter should be treated as an opaque object */ |
| 415 | struct cgroup_iter { |
| 416 | struct list_head *cg_link; |
| 417 | struct list_head *task; |
| 418 | }; |
| 419 | |
| 420 | /* To iterate across the tasks in a cgroup: |
| 421 | * |
| 422 | * 1) call cgroup_iter_start to intialize an iterator |
| 423 | * |
| 424 | * 2) call cgroup_iter_next() to retrieve member tasks until it |
| 425 | * returns NULL or until you want to end the iteration |
| 426 | * |
| 427 | * 3) call cgroup_iter_end() to destroy the iterator. |
Cliff Wickman | 31a7df0 | 2008-02-07 00:14:42 -0800 | [diff] [blame] | 428 | * |
| 429 | * Or, call cgroup_scan_tasks() to iterate through every task in a cpuset. |
| 430 | * - cgroup_scan_tasks() holds the css_set_lock when calling the test_task() |
| 431 | * callback, but not while calling the process_task() callback. |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 432 | */ |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 433 | void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it); |
| 434 | struct task_struct *cgroup_iter_next(struct cgroup *cgrp, |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 435 | struct cgroup_iter *it); |
Li Zefan | ffd2d88 | 2008-02-23 15:24:09 -0800 | [diff] [blame] | 436 | void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it); |
Cliff Wickman | 31a7df0 | 2008-02-07 00:14:42 -0800 | [diff] [blame] | 437 | int cgroup_scan_tasks(struct cgroup_scanner *scan); |
Cliff Wickman | 956db3c | 2008-02-07 00:14:43 -0800 | [diff] [blame] | 438 | int cgroup_attach_task(struct cgroup *, struct task_struct *); |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 439 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 440 | #else /* !CONFIG_CGROUPS */ |
| 441 | |
| 442 | static inline int cgroup_init_early(void) { return 0; } |
| 443 | static inline int cgroup_init(void) { return 0; } |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 444 | static inline void cgroup_fork(struct task_struct *p) {} |
| 445 | static inline void cgroup_fork_callbacks(struct task_struct *p) {} |
Paul Menage | 817929e | 2007-10-18 23:39:36 -0700 | [diff] [blame] | 446 | static inline void cgroup_post_fork(struct task_struct *p) {} |
Paul Menage | b4f48b6 | 2007-10-18 23:39:33 -0700 | [diff] [blame] | 447 | static inline void cgroup_exit(struct task_struct *p, int callbacks) {} |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 448 | |
| 449 | static inline void cgroup_lock(void) {} |
| 450 | static inline void cgroup_unlock(void) {} |
Balbir Singh | 846c7bb | 2007-10-18 23:39:44 -0700 | [diff] [blame] | 451 | static inline int cgroupstats_build(struct cgroupstats *stats, |
| 452 | struct dentry *dentry) |
| 453 | { |
| 454 | return -EINVAL; |
| 455 | } |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 456 | |
| 457 | #endif /* !CONFIG_CGROUPS */ |
| 458 | |
Paul Menage | ddbcc7e | 2007-10-18 23:39:30 -0700 | [diff] [blame] | 459 | #endif /* _LINUX_CGROUP_H */ |