blob: 7f540f7f588d8c8461af975a5ebd21a08e6cf14b [file] [log] [blame]
Tejun Heob4a04ab2015-05-13 15:38:40 -04001/*
2 * linux/cgroup-defs.h - basic definitions for cgroup
3 *
4 * This file provides basic type and interface. Include this file directly
5 * only if necessary to avoid cyclic dependencies.
6 */
7#ifndef _LINUX_CGROUP_DEFS_H
8#define _LINUX_CGROUP_DEFS_H
9
10#include <linux/limits.h>
11#include <linux/list.h>
12#include <linux/idr.h>
13#include <linux/wait.h>
14#include <linux/mutex.h>
15#include <linux/rcupdate.h>
16#include <linux/percpu-refcount.h>
Tejun Heo7d7efec2015-05-13 16:35:16 -040017#include <linux/percpu-rwsem.h>
Tejun Heob4a04ab2015-05-13 15:38:40 -040018#include <linux/workqueue.h>
19
20#ifdef CONFIG_CGROUPS
21
22struct cgroup;
23struct cgroup_root;
24struct cgroup_subsys;
25struct cgroup_taskset;
26struct kernfs_node;
27struct kernfs_ops;
28struct kernfs_open_file;
Arnd Bergmannc80ef9e2015-05-29 10:52:59 +020029struct seq_file;
Tejun Heob4a04ab2015-05-13 15:38:40 -040030
31#define MAX_CGROUP_TYPE_NAMELEN 32
32#define MAX_CGROUP_ROOT_NAMELEN 64
33#define MAX_CFTYPE_NAME 64
34
35/* define the enumeration of all cgroup subsystems */
36#define SUBSYS(_x) _x ## _cgrp_id,
37enum cgroup_subsys_id {
38#include <linux/cgroup_subsys.h>
39 CGROUP_SUBSYS_COUNT,
40};
41#undef SUBSYS
42
43/* bits in struct cgroup_subsys_state flags field */
44enum {
45 CSS_NO_REF = (1 << 0), /* no reference counting for this css */
46 CSS_ONLINE = (1 << 1), /* between ->css_online() and ->css_offline() */
47 CSS_RELEASED = (1 << 2), /* refcnt reached zero, released */
48};
49
50/* bits in struct cgroup flags field */
51enum {
52 /* Control Group requires release notifications to userspace */
53 CGRP_NOTIFY_ON_RELEASE,
54 /*
55 * Clone the parent's configuration when creating a new child
56 * cpuset cgroup. For historical reasons, this option can be
57 * specified at mount time and thus is implemented here.
58 */
59 CGRP_CPUSET_CLONE_CHILDREN,
60};
61
62/* cgroup_root->flags */
63enum {
Tejun Heob4a04ab2015-05-13 15:38:40 -040064 CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
65 CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
66};
67
68/* cftype->flags */
69enum {
70 CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
71 CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
72 CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
Tejun Heo7dbdb192015-09-18 17:54:23 -040073 CFTYPE_WORLD_WRITABLE = (1 << 4), /* (DON'T USE FOR NEW FILES) S_IWUGO */
Tejun Heob4a04ab2015-05-13 15:38:40 -040074
75 /* internal flags, do not use outside cgroup core proper */
76 __CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
77 __CFTYPE_NOT_ON_DFL = (1 << 17), /* not on default hierarchy */
78};
79
80/*
Tejun Heo6f60ead2015-09-18 17:54:23 -040081 * cgroup_file is the handle for a file instance created in a cgroup which
82 * is used, for example, to generate file changed notifications. This can
83 * be obtained by setting cftype->file_offset.
84 */
85struct cgroup_file {
86 /* do not access any fields from outside cgroup core */
Tejun Heo6f60ead2015-09-18 17:54:23 -040087 struct kernfs_node *kn;
88};
89
90/*
Tejun Heob4a04ab2015-05-13 15:38:40 -040091 * Per-subsystem/per-cgroup state maintained by the system. This is the
92 * fundamental structural building block that controllers deal with.
93 *
94 * Fields marked with "PI:" are public and immutable and may be accessed
95 * directly without synchronization.
96 */
97struct cgroup_subsys_state {
98 /* PI: the cgroup that this css is attached to */
99 struct cgroup *cgroup;
100
101 /* PI: the cgroup subsystem that this css is attached to */
102 struct cgroup_subsys *ss;
103
104 /* reference count - access via css_[try]get() and css_put() */
105 struct percpu_ref refcnt;
106
107 /* PI: the parent css */
108 struct cgroup_subsys_state *parent;
109
110 /* siblings list anchored at the parent's ->children */
111 struct list_head sibling;
112 struct list_head children;
113
114 /*
115 * PI: Subsys-unique ID. 0 is unused and root is always 1. The
116 * matching css can be looked up using css_from_id().
117 */
118 int id;
119
120 unsigned int flags;
121
122 /*
123 * Monotonically increasing unique serial number which defines a
124 * uniform order among all csses. It's guaranteed that all
125 * ->children lists are in the ascending order of ->serial_nr and
126 * used to allow interrupting and resuming iterations.
127 */
128 u64 serial_nr;
129
130 /* percpu_ref killing and RCU release */
131 struct rcu_head rcu_head;
132 struct work_struct destroy_work;
133};
134
135/*
136 * A css_set is a structure holding pointers to a set of
137 * cgroup_subsys_state objects. This saves space in the task struct
138 * object and speeds up fork()/exit(), since a single inc/dec and a
139 * list_add()/del() can bump the reference count on the entire cgroup
140 * set for a task.
141 */
142struct css_set {
143 /* Reference count */
144 atomic_t refcount;
145
146 /*
147 * List running through all cgroup groups in the same hash
148 * slot. Protected by css_set_lock
149 */
150 struct hlist_node hlist;
151
152 /*
153 * Lists running through all tasks using this cgroup group.
154 * mg_tasks lists tasks which belong to this cset but are in the
155 * process of being migrated out or in. Protected by
156 * css_set_rwsem, but, during migration, once tasks are moved to
157 * mg_tasks, it can be read safely while holding cgroup_mutex.
158 */
159 struct list_head tasks;
160 struct list_head mg_tasks;
161
162 /*
163 * List of cgrp_cset_links pointing at cgroups referenced from this
164 * css_set. Protected by css_set_lock.
165 */
166 struct list_head cgrp_links;
167
168 /* the default cgroup associated with this css_set */
169 struct cgroup *dfl_cgrp;
170
171 /*
172 * Set of subsystem states, one for each subsystem. This array is
173 * immutable after creation apart from the init_css_set during
174 * subsystem registration (at boot time).
175 */
176 struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
177
178 /*
179 * List of csets participating in the on-going migration either as
180 * source or destination. Protected by cgroup_mutex.
181 */
182 struct list_head mg_preload_node;
183 struct list_head mg_node;
184
185 /*
186 * If this cset is acting as the source of migration the following
187 * two fields are set. mg_src_cgrp is the source cgroup of the
188 * on-going migration and mg_dst_cset is the destination cset the
189 * target tasks on this cset should be migrated to. Protected by
190 * cgroup_mutex.
191 */
192 struct cgroup *mg_src_cgrp;
193 struct css_set *mg_dst_cset;
194
195 /*
196 * On the default hierarhcy, ->subsys[ssid] may point to a css
197 * attached to an ancestor instead of the cgroup this css_set is
198 * associated with. The following node is anchored at
199 * ->subsys[ssid]->cgroup->e_csets[ssid] and provides a way to
200 * iterate through all css's attached to a given cgroup.
201 */
202 struct list_head e_cset_node[CGROUP_SUBSYS_COUNT];
203
Tejun Heoed27b9f2015-10-15 16:41:52 -0400204 /* all css_task_iters currently walking this cset */
205 struct list_head task_iters;
206
Tejun Heob4a04ab2015-05-13 15:38:40 -0400207 /* For RCU-protected deletion */
208 struct rcu_head rcu_head;
209};
210
211struct cgroup {
212 /* self css with NULL ->ss, points back to this cgroup */
213 struct cgroup_subsys_state self;
214
215 unsigned long flags; /* "unsigned long" so bitops work */
216
217 /*
218 * idr allocated in-hierarchy ID.
219 *
220 * ID 0 is not used, the ID of the root cgroup is always 1, and a
221 * new cgroup will be assigned with a smallest available ID.
222 *
223 * Allocating/Removing ID must be protected by cgroup_mutex.
224 */
225 int id;
226
227 /*
Tejun Heob11cfb52015-11-20 15:55:52 -0500228 * The depth this cgroup is at. The root is at depth zero and each
229 * step down the hierarchy increments the level. This along with
230 * ancestor_ids[] can determine whether a given cgroup is a
231 * descendant of another without traversing the hierarchy.
232 */
233 int level;
234
235 /*
Tejun Heo0de09422015-10-15 16:41:49 -0400236 * Each non-empty css_set associated with this cgroup contributes
237 * one to populated_cnt. All children with non-zero popuplated_cnt
238 * of their own contribute one. The count is zero iff there's no
239 * task in this cgroup or its subtree.
Tejun Heob4a04ab2015-05-13 15:38:40 -0400240 */
241 int populated_cnt;
242
243 struct kernfs_node *kn; /* cgroup kernfs entry */
Tejun Heo6f60ead2015-09-18 17:54:23 -0400244 struct cgroup_file procs_file; /* handle for "cgroup.procs" */
245 struct cgroup_file events_file; /* handle for "cgroup.events" */
Tejun Heob4a04ab2015-05-13 15:38:40 -0400246
247 /*
248 * The bitmask of subsystems enabled on the child cgroups.
249 * ->subtree_control is the one configured through
250 * "cgroup.subtree_control" while ->child_subsys_mask is the
251 * effective one which may have more subsystems enabled.
252 * Controller knobs are made available iff it's enabled in
253 * ->subtree_control.
254 */
255 unsigned int subtree_control;
256 unsigned int child_subsys_mask;
257
258 /* Private pointers for each registered subsystem */
259 struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT];
260
261 struct cgroup_root *root;
262
263 /*
264 * List of cgrp_cset_links pointing at css_sets with tasks in this
265 * cgroup. Protected by css_set_lock.
266 */
267 struct list_head cset_links;
268
269 /*
270 * On the default hierarchy, a css_set for a cgroup with some
271 * susbsys disabled will point to css's which are associated with
272 * the closest ancestor which has the subsys enabled. The
273 * following lists all css_sets which point to this cgroup's css
274 * for the given subsystem.
275 */
276 struct list_head e_csets[CGROUP_SUBSYS_COUNT];
277
278 /*
279 * list of pidlists, up to two for each namespace (one for procs, one
280 * for tasks); created on demand.
281 */
282 struct list_head pidlists;
283 struct mutex pidlist_mutex;
284
285 /* used to wait for offlining of csses */
286 wait_queue_head_t offline_waitq;
287
288 /* used to schedule release agent */
289 struct work_struct release_agent_work;
Tejun Heob11cfb52015-11-20 15:55:52 -0500290
291 /* ids of the ancestors at each level including self */
292 int ancestor_ids[];
Tejun Heob4a04ab2015-05-13 15:38:40 -0400293};
294
295/*
296 * A cgroup_root represents the root of a cgroup hierarchy, and may be
297 * associated with a kernfs_root to form an active hierarchy. This is
298 * internal to cgroup core. Don't access directly from controllers.
299 */
300struct cgroup_root {
301 struct kernfs_root *kf_root;
302
303 /* The bitmask of subsystems attached to this hierarchy */
304 unsigned int subsys_mask;
305
306 /* Unique id for this hierarchy. */
307 int hierarchy_id;
308
309 /* The root cgroup. Root is destroyed on its release. */
310 struct cgroup cgrp;
311
Tejun Heob11cfb52015-11-20 15:55:52 -0500312 /* for cgrp->ancestor_ids[0] */
313 int cgrp_ancestor_id_storage;
314
Tejun Heob4a04ab2015-05-13 15:38:40 -0400315 /* Number of cgroups in the hierarchy, used only for /proc/cgroups */
316 atomic_t nr_cgrps;
317
318 /* A list running through the active hierarchies */
319 struct list_head root_list;
320
321 /* Hierarchy-specific flags */
322 unsigned int flags;
323
324 /* IDs for cgroups in this hierarchy */
325 struct idr cgroup_idr;
326
327 /* The path to use for release notifications. */
328 char release_agent_path[PATH_MAX];
329
330 /* The name for this hierarchy - may be empty */
331 char name[MAX_CGROUP_ROOT_NAMELEN];
332};
333
334/*
335 * struct cftype: handler definitions for cgroup control files
336 *
337 * When reading/writing to a file:
338 * - the cgroup to use is file->f_path.dentry->d_parent->d_fsdata
339 * - the 'cftype' of the file is file->f_path.dentry->d_fsdata
340 */
341struct cftype {
342 /*
343 * By convention, the name should begin with the name of the
344 * subsystem, followed by a period. Zero length string indicates
345 * end of cftype array.
346 */
347 char name[MAX_CFTYPE_NAME];
Tejun Heo731a9812015-08-11 13:35:42 -0400348 unsigned long private;
Tejun Heob4a04ab2015-05-13 15:38:40 -0400349
350 /*
351 * The maximum length of string, excluding trailing nul, that can
352 * be passed to write. If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
353 */
354 size_t max_write_len;
355
356 /* CFTYPE_* flags */
357 unsigned int flags;
358
359 /*
Tejun Heo6f60ead2015-09-18 17:54:23 -0400360 * If non-zero, should contain the offset from the start of css to
361 * a struct cgroup_file field. cgroup will record the handle of
362 * the created file into it. The recorded handle can be used as
363 * long as the containing css remains accessible.
364 */
365 unsigned int file_offset;
366
367 /*
Tejun Heob4a04ab2015-05-13 15:38:40 -0400368 * Fields used for internal bookkeeping. Initialized automatically
369 * during registration.
370 */
371 struct cgroup_subsys *ss; /* NULL for cgroup core files */
372 struct list_head node; /* anchored at ss->cfts */
373 struct kernfs_ops *kf_ops;
374
375 /*
376 * read_u64() is a shortcut for the common case of returning a
377 * single integer. Use it in place of read()
378 */
379 u64 (*read_u64)(struct cgroup_subsys_state *css, struct cftype *cft);
380 /*
381 * read_s64() is a signed version of read_u64()
382 */
383 s64 (*read_s64)(struct cgroup_subsys_state *css, struct cftype *cft);
384
385 /* generic seq_file read interface */
386 int (*seq_show)(struct seq_file *sf, void *v);
387
388 /* optional ops, implement all or none */
389 void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
390 void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
391 void (*seq_stop)(struct seq_file *sf, void *v);
392
393 /*
394 * write_u64() is a shortcut for the common case of accepting
395 * a single integer (as parsed by simple_strtoull) from
396 * userspace. Use in place of write(); return 0 or error.
397 */
398 int (*write_u64)(struct cgroup_subsys_state *css, struct cftype *cft,
399 u64 val);
400 /*
401 * write_s64() is a signed version of write_u64()
402 */
403 int (*write_s64)(struct cgroup_subsys_state *css, struct cftype *cft,
404 s64 val);
405
406 /*
407 * write() is the generic write callback which maps directly to
408 * kernfs write operation and overrides all other operations.
409 * Maximum write size is determined by ->max_write_len. Use
410 * of_css/cft() to access the associated css and cft.
411 */
412 ssize_t (*write)(struct kernfs_open_file *of,
413 char *buf, size_t nbytes, loff_t off);
414
415#ifdef CONFIG_DEBUG_LOCK_ALLOC
416 struct lock_class_key lockdep_key;
417#endif
418};
419
420/*
421 * Control Group subsystem type.
422 * See Documentation/cgroups/cgroups.txt for details
423 */
424struct cgroup_subsys {
425 struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css);
426 int (*css_online)(struct cgroup_subsys_state *css);
427 void (*css_offline)(struct cgroup_subsys_state *css);
428 void (*css_released)(struct cgroup_subsys_state *css);
429 void (*css_free)(struct cgroup_subsys_state *css);
430 void (*css_reset)(struct cgroup_subsys_state *css);
431 void (*css_e_css_changed)(struct cgroup_subsys_state *css);
432
Tejun Heo1f7dd3e52015-12-03 10:18:21 -0500433 int (*can_attach)(struct cgroup_taskset *tset);
434 void (*cancel_attach)(struct cgroup_taskset *tset);
435 void (*attach)(struct cgroup_taskset *tset);
Oleg Nesterovb53202e2015-12-03 10:24:08 -0500436 int (*can_fork)(struct task_struct *task);
437 void (*cancel_fork)(struct task_struct *task);
438 void (*fork)(struct task_struct *task);
Tejun Heo2e91fa72015-10-15 16:41:53 -0400439 void (*exit)(struct task_struct *task);
Tejun Heoafcf6c82015-10-15 16:41:53 -0400440 void (*free)(struct task_struct *task);
Tejun Heob4a04ab2015-05-13 15:38:40 -0400441 void (*bind)(struct cgroup_subsys_state *root_css);
442
Tejun Heob4a04ab2015-05-13 15:38:40 -0400443 int early_init;
444
445 /*
446 * If %false, this subsystem is properly hierarchical -
447 * configuration, resource accounting and restriction on a parent
448 * cgroup cover those of its children. If %true, hierarchy support
449 * is broken in some ways - some subsystems ignore hierarchy
450 * completely while others are only implemented half-way.
451 *
452 * It's now disallowed to create nested cgroups if the subsystem is
453 * broken and cgroup core will emit a warning message on such
454 * cases. Eventually, all subsystems will be made properly
455 * hierarchical and this will go away.
456 */
457 bool broken_hierarchy;
458 bool warned_broken_hierarchy;
459
460 /* the following two fields are initialized automtically during boot */
461 int id;
462 const char *name;
463
Tejun Heo3e1d2ee2015-08-18 13:58:16 -0700464 /* optional, initialized automatically during boot if not set */
465 const char *legacy_name;
466
Tejun Heob4a04ab2015-05-13 15:38:40 -0400467 /* link to parent, protected by cgroup_lock() */
468 struct cgroup_root *root;
469
470 /* idr for css->id */
471 struct idr css_idr;
472
473 /*
474 * List of cftypes. Each entry is the first entry of an array
475 * terminated by zero length name.
476 */
477 struct list_head cfts;
478
479 /*
480 * Base cftypes which are automatically registered. The two can
481 * point to the same array.
482 */
483 struct cftype *dfl_cftypes; /* for the default hierarchy */
484 struct cftype *legacy_cftypes; /* for the legacy hierarchies */
485
486 /*
487 * A subsystem may depend on other subsystems. When such subsystem
488 * is enabled on a cgroup, the depended-upon subsystems are enabled
489 * together if available. Subsystems enabled due to dependency are
490 * not visible to userland until explicitly enabled. The following
491 * specifies the mask of subsystems that this one depends on.
492 */
493 unsigned int depends_on;
494};
495
Tejun Heo1ed13282015-09-16 12:53:17 -0400496extern struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
497
498/**
499 * cgroup_threadgroup_change_begin - threadgroup exclusion for cgroups
500 * @tsk: target task
501 *
502 * Called from threadgroup_change_begin() and allows cgroup operations to
503 * synchronize against threadgroup changes using a percpu_rw_semaphore.
504 */
505static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk)
506{
507 percpu_down_read(&cgroup_threadgroup_rwsem);
508}
509
510/**
511 * cgroup_threadgroup_change_end - threadgroup exclusion for cgroups
512 * @tsk: target task
513 *
514 * Called from threadgroup_change_end(). Counterpart of
515 * cgroup_threadcgroup_change_begin().
516 */
517static inline void cgroup_threadgroup_change_end(struct task_struct *tsk)
518{
519 percpu_up_read(&cgroup_threadgroup_rwsem);
520}
Tejun Heo7d7efec2015-05-13 16:35:16 -0400521
522#else /* CONFIG_CGROUPS */
523
Aleksa Saraicb4a3162015-06-06 10:02:14 +1000524#define CGROUP_SUBSYS_COUNT 0
525
Tejun Heo7d7efec2015-05-13 16:35:16 -0400526static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk) {}
527static inline void cgroup_threadgroup_change_end(struct task_struct *tsk) {}
528
Tejun Heob4a04ab2015-05-13 15:38:40 -0400529#endif /* CONFIG_CGROUPS */
Tejun Heo7d7efec2015-05-13 16:35:16 -0400530
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500531#ifdef CONFIG_SOCK_CGROUP_DATA
532
Tejun Heobd1060a2015-12-07 17:38:53 -0500533/*
534 * sock_cgroup_data is embedded at sock->sk_cgrp_data and contains
535 * per-socket cgroup information except for memcg association.
536 *
537 * On legacy hierarchies, net_prio and net_cls controllers directly set
538 * attributes on each sock which can then be tested by the network layer.
539 * On the default hierarchy, each sock is associated with the cgroup it was
540 * created in and the networking layer can match the cgroup directly.
541 *
542 * To avoid carrying all three cgroup related fields separately in sock,
543 * sock_cgroup_data overloads (prioidx, classid) and the cgroup pointer.
544 * On boot, sock_cgroup_data records the cgroup that the sock was created
545 * in so that cgroup2 matches can be made; however, once either net_prio or
546 * net_cls starts being used, the area is overriden to carry prioidx and/or
547 * classid. The two modes are distinguished by whether the lowest bit is
548 * set. Clear bit indicates cgroup pointer while set bit prioidx and
549 * classid.
550 *
551 * While userland may start using net_prio or net_cls at any time, once
552 * either is used, cgroup2 matching no longer works. There is no reason to
553 * mix the two and this is in line with how legacy and v2 compatibility is
554 * handled. On mode switch, cgroup references which are already being
555 * pointed to by socks may be leaked. While this can be remedied by adding
556 * synchronization around sock_cgroup_data, given that the number of leaked
557 * cgroups is bound and highly unlikely to be high, this seems to be the
558 * better trade-off.
559 */
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500560struct sock_cgroup_data {
Tejun Heobd1060a2015-12-07 17:38:53 -0500561 union {
562#ifdef __LITTLE_ENDIAN
563 struct {
564 u8 is_data;
565 u8 padding;
566 u16 prioidx;
567 u32 classid;
568 } __packed;
569#else
570 struct {
571 u32 classid;
572 u16 prioidx;
573 u8 padding;
574 u8 is_data;
575 } __packed;
576#endif
577 u64 val;
578 };
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500579};
580
Tejun Heobd1060a2015-12-07 17:38:53 -0500581/*
582 * There's a theoretical window where the following accessors race with
583 * updaters and return part of the previous pointer as the prioidx or
584 * classid. Such races are short-lived and the result isn't critical.
585 */
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500586static inline u16 sock_cgroup_prioidx(struct sock_cgroup_data *skcd)
587{
Tejun Heobd1060a2015-12-07 17:38:53 -0500588 /* fallback to 1 which is always the ID of the root cgroup */
589 return (skcd->is_data & 1) ? skcd->prioidx : 1;
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500590}
591
592static inline u32 sock_cgroup_classid(struct sock_cgroup_data *skcd)
593{
Tejun Heobd1060a2015-12-07 17:38:53 -0500594 /* fallback to 0 which is the unconfigured default classid */
595 return (skcd->is_data & 1) ? skcd->classid : 0;
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500596}
597
Tejun Heobd1060a2015-12-07 17:38:53 -0500598/*
599 * If invoked concurrently, the updaters may clobber each other. The
600 * caller is responsible for synchronization.
601 */
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500602static inline void sock_cgroup_set_prioidx(struct sock_cgroup_data *skcd,
603 u16 prioidx)
604{
Tejun Heoad2c8c72015-12-09 12:30:46 -0500605 struct sock_cgroup_data skcd_buf = {{ .val = READ_ONCE(skcd->val) }};
Tejun Heobd1060a2015-12-07 17:38:53 -0500606
607 if (sock_cgroup_prioidx(&skcd_buf) == prioidx)
608 return;
609
610 if (!(skcd_buf.is_data & 1)) {
611 skcd_buf.val = 0;
612 skcd_buf.is_data = 1;
613 }
614
615 skcd_buf.prioidx = prioidx;
616 WRITE_ONCE(skcd->val, skcd_buf.val); /* see sock_cgroup_ptr() */
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500617}
618
619static inline void sock_cgroup_set_classid(struct sock_cgroup_data *skcd,
620 u32 classid)
621{
Tejun Heoad2c8c72015-12-09 12:30:46 -0500622 struct sock_cgroup_data skcd_buf = {{ .val = READ_ONCE(skcd->val) }};
Tejun Heobd1060a2015-12-07 17:38:53 -0500623
624 if (sock_cgroup_classid(&skcd_buf) == classid)
625 return;
626
627 if (!(skcd_buf.is_data & 1)) {
628 skcd_buf.val = 0;
629 skcd_buf.is_data = 1;
630 }
631
632 skcd_buf.classid = classid;
633 WRITE_ONCE(skcd->val, skcd_buf.val); /* see sock_cgroup_ptr() */
Tejun Heo2a56a1f2015-12-07 17:38:52 -0500634}
635
636#else /* CONFIG_SOCK_CGROUP_DATA */
637
638struct sock_cgroup_data {
639};
640
641#endif /* CONFIG_SOCK_CGROUP_DATA */
642
Tejun Heob4a04ab2015-05-13 15:38:40 -0400643#endif /* _LINUX_CGROUP_DEFS_H */