1 /* SPDX-License-Identifier: GPL-2.0 */
3 * linux/cgroup-defs.h - basic definitions for cgroup
5 * This file provides basic type and interface. Include this file directly
6 * only if necessary to avoid cyclic dependencies.
8 #ifndef _LINUX_CGROUP_DEFS_H
9 #define _LINUX_CGROUP_DEFS_H
11 #include <linux/limits.h>
12 #include <linux/list.h>
13 #include <linux/idr.h>
14 #include <linux/wait.h>
15 #include <linux/mutex.h>
16 #include <linux/rcupdate.h>
17 #include <linux/refcount.h>
18 #include <linux/percpu-refcount.h>
19 #include <linux/percpu-rwsem.h>
20 #include <linux/u64_stats_sync.h>
21 #include <linux/workqueue.h>
22 #include <linux/bpf-cgroup.h>
29 struct cgroup_taskset;
32 struct kernfs_open_file;
35 #define MAX_CGROUP_TYPE_NAMELEN 32
36 #define MAX_CGROUP_ROOT_NAMELEN 64
37 #define MAX_CFTYPE_NAME 64
39 /* define the enumeration of all cgroup subsystems */
40 #define SUBSYS(_x) _x ## _cgrp_id,
41 enum cgroup_subsys_id {
42 #include <linux/cgroup_subsys.h>
47 /* bits in struct cgroup_subsys_state flags field */
49 CSS_NO_REF = (1 << 0), /* no reference counting for this css */
50 CSS_ONLINE = (1 << 1), /* between ->css_online() and ->css_offline() */
51 CSS_RELEASED = (1 << 2), /* refcnt reached zero, released */
52 CSS_VISIBLE = (1 << 3), /* css is visible to userland */
53 CSS_DYING = (1 << 4), /* css is dying */
56 /* bits in struct cgroup flags field */
58 /* Control Group requires release notifications to userspace */
59 CGRP_NOTIFY_ON_RELEASE,
61 * Clone the parent's configuration when creating a new child
62 * cpuset cgroup. For historical reasons, this option can be
63 * specified at mount time and thus is implemented here.
65 CGRP_CPUSET_CLONE_CHILDREN,
68 /* cgroup_root->flags */
70 CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
71 CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
74 * Consider namespaces as delegation boundaries. If this flag is
75 * set, controller specific interface files in a namespace root
76 * aren't writeable from inside the namespace.
78 CGRP_ROOT_NS_DELEGATE = (1 << 3),
81 * Enable cpuset controller in v1 cgroup to use v2 behavior.
83 CGRP_ROOT_CPUSET_V2_MODE = (1 << 4),
88 CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
89 CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
90 CFTYPE_NS_DELEGATABLE = (1 << 2), /* writeable beyond delegation boundaries */
92 CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
93 CFTYPE_WORLD_WRITABLE = (1 << 4), /* (DON'T USE FOR NEW FILES) S_IWUGO */
95 /* internal flags, do not use outside cgroup core proper */
96 __CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
97 __CFTYPE_NOT_ON_DFL = (1 << 17), /* not on default hierarchy */
101 * cgroup_file is the handle for a file instance created in a cgroup which
102 * is used, for example, to generate file changed notifications. This can
103 * be obtained by setting cftype->file_offset.
106 /* do not access any fields from outside cgroup core */
107 struct kernfs_node *kn;
108 unsigned long notified_at;
109 struct timer_list notify_timer;
113 * Per-subsystem/per-cgroup state maintained by the system. This is the
114 * fundamental structural building block that controllers deal with.
116 * Fields marked with "PI:" are public and immutable and may be accessed
117 * directly without synchronization.
119 struct cgroup_subsys_state {
120 /* PI: the cgroup that this css is attached to */
121 struct cgroup *cgroup;
123 /* PI: the cgroup subsystem that this css is attached to */
124 struct cgroup_subsys *ss;
126 /* reference count - access via css_[try]get() and css_put() */
127 struct percpu_ref refcnt;
129 /* siblings list anchored at the parent's ->children */
130 struct list_head sibling;
131 struct list_head children;
133 /* flush target list anchored at cgrp->rstat_css_list */
134 struct list_head rstat_css_node;
137 * PI: Subsys-unique ID. 0 is unused and root is always 1. The
138 * matching css can be looked up using css_from_id().
145 * Monotonically increasing unique serial number which defines a
146 * uniform order among all csses. It's guaranteed that all
147 * ->children lists are in the ascending order of ->serial_nr and
148 * used to allow interrupting and resuming iterations.
153 * Incremented by online self and children. Used to guarantee that
154 * parents are not offlined before their children.
158 /* percpu_ref killing and RCU release */
159 struct work_struct destroy_work;
160 struct rcu_work destroy_rwork;
163 * PI: the parent css. Placed here for cache proximity to following
164 * fields of the containing structure.
166 struct cgroup_subsys_state *parent;
170 * A css_set is a structure holding pointers to a set of
171 * cgroup_subsys_state objects. This saves space in the task struct
172 * object and speeds up fork()/exit(), since a single inc/dec and a
173 * list_add()/del() can bump the reference count on the entire cgroup
178 * Set of subsystem states, one for each subsystem. This array is
179 * immutable after creation apart from the init_css_set during
180 * subsystem registration (at boot time).
182 struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
184 /* reference count */
188 * For a domain cgroup, the following points to self. If threaded,
189 * to the matching cset of the nearest domain ancestor. The
190 * dom_cset provides access to the domain cgroup and its csses to
191 * which domain level resource consumptions should be charged.
193 struct css_set *dom_cset;
195 /* the default cgroup associated with this css_set */
196 struct cgroup *dfl_cgrp;
198 /* internal task count, protected by css_set_lock */
202 * Lists running through all tasks using this cgroup group.
203 * mg_tasks lists tasks which belong to this cset but are in the
204 * process of being migrated out or in. Protected by
205 * css_set_rwsem, but, during migration, once tasks are moved to
206 * mg_tasks, it can be read safely while holding cgroup_mutex.
208 struct list_head tasks;
209 struct list_head mg_tasks;
211 /* all css_task_iters currently walking this cset */
212 struct list_head task_iters;
215 * On the default hierarhcy, ->subsys[ssid] may point to a css
216 * attached to an ancestor instead of the cgroup this css_set is
217 * associated with. The following node is anchored at
218 * ->subsys[ssid]->cgroup->e_csets[ssid] and provides a way to
219 * iterate through all css's attached to a given cgroup.
221 struct list_head e_cset_node[CGROUP_SUBSYS_COUNT];
223 /* all threaded csets whose ->dom_cset points to this cset */
224 struct list_head threaded_csets;
225 struct list_head threaded_csets_node;
228 * List running through all cgroup groups in the same hash
229 * slot. Protected by css_set_lock
231 struct hlist_node hlist;
234 * List of cgrp_cset_links pointing at cgroups referenced from this
235 * css_set. Protected by css_set_lock.
237 struct list_head cgrp_links;
240 * List of csets participating in the on-going migration either as
241 * source or destination. Protected by cgroup_mutex.
243 struct list_head mg_preload_node;
244 struct list_head mg_node;
247 * If this cset is acting as the source of migration the following
248 * two fields are set. mg_src_cgrp and mg_dst_cgrp are
249 * respectively the source and destination cgroups of the on-going
250 * migration. mg_dst_cset is the destination cset the target tasks
251 * on this cset should be migrated to. Protected by cgroup_mutex.
253 struct cgroup *mg_src_cgrp;
254 struct cgroup *mg_dst_cgrp;
255 struct css_set *mg_dst_cset;
257 /* dead and being drained, ignore for migration */
260 /* For RCU-protected deletion */
261 struct rcu_head rcu_head;
264 struct cgroup_base_stat {
265 struct task_cputime cputime;
269 * rstat - cgroup scalable recursive statistics. Accounting is done
270 * per-cpu in cgroup_rstat_cpu which is then lazily propagated up the
271 * hierarchy on reads.
273 * When a stat gets updated, the cgroup_rstat_cpu and its ancestors are
274 * linked into the updated tree. On the following read, propagation only
275 * considers and consumes the updated tree. This makes reading O(the
276 * number of descendants which have been active since last read) instead of
277 * O(the total number of descendants).
279 * This is important because there can be a lot of (draining) cgroups which
280 * aren't active and stat may be read frequently. The combination can
281 * become very expensive. By propagating selectively, increasing reading
282 * frequency decreases the cost of each read.
284 * This struct hosts both the fields which implement the above -
285 * updated_children and updated_next - and the fields which track basic
286 * resource statistics on top of it - bsync, bstat and last_bstat.
288 struct cgroup_rstat_cpu {
290 * ->bsync protects ->bstat. These are the only fields which get
291 * updated in the hot path.
293 struct u64_stats_sync bsync;
294 struct cgroup_base_stat bstat;
297 * Snapshots at the last reading. These are used to calculate the
298 * deltas to propagate to the global counters.
300 struct cgroup_base_stat last_bstat;
303 * Child cgroups with stat updates on this cpu since the last read
304 * are linked on the parent's ->updated_children through
307 * In addition to being more compact, singly-linked list pointing
308 * to the cgroup makes it unnecessary for each per-cpu struct to
309 * point back to the associated cgroup.
311 * Protected by per-cpu cgroup_rstat_cpu_lock.
313 struct cgroup *updated_children; /* terminated by self cgroup */
314 struct cgroup *updated_next; /* NULL iff not on the list */
318 /* self css with NULL ->ss, points back to this cgroup */
319 struct cgroup_subsys_state self;
321 unsigned long flags; /* "unsigned long" so bitops work */
324 * idr allocated in-hierarchy ID.
326 * ID 0 is not used, the ID of the root cgroup is always 1, and a
327 * new cgroup will be assigned with a smallest available ID.
329 * Allocating/Removing ID must be protected by cgroup_mutex.
334 * The depth this cgroup is at. The root is at depth zero and each
335 * step down the hierarchy increments the level. This along with
336 * ancestor_ids[] can determine whether a given cgroup is a
337 * descendant of another without traversing the hierarchy.
341 /* Maximum allowed descent tree depth */
345 * Keep track of total numbers of visible and dying descent cgroups.
346 * Dying cgroups are cgroups which were deleted by a user,
347 * but are still existing because someone else is holding a reference.
348 * max_descendants is a maximum allowed number of descent cgroups.
351 int nr_dying_descendants;
355 * Each non-empty css_set associated with this cgroup contributes
356 * one to nr_populated_csets. The counter is zero iff this cgroup
357 * doesn't have any tasks.
359 * All children which have non-zero nr_populated_csets and/or
360 * nr_populated_children of their own contribute one to either
361 * nr_populated_domain_children or nr_populated_threaded_children
362 * depending on their type. Each counter is zero iff all cgroups
363 * of the type in the subtree proper don't have any tasks.
365 int nr_populated_csets;
366 int nr_populated_domain_children;
367 int nr_populated_threaded_children;
369 int nr_threaded_children; /* # of live threaded child cgroups */
371 struct kernfs_node *kn; /* cgroup kernfs entry */
372 struct cgroup_file procs_file; /* handle for "cgroup.procs" */
373 struct cgroup_file events_file; /* handle for "cgroup.events" */
376 * The bitmask of subsystems enabled on the child cgroups.
377 * ->subtree_control is the one configured through
378 * "cgroup.subtree_control" while ->child_ss_mask is the effective
379 * one which may have more subsystems enabled. Controller knobs
380 * are made available iff it's enabled in ->subtree_control.
384 u16 old_subtree_control;
385 u16 old_subtree_ss_mask;
387 /* Private pointers for each registered subsystem */
388 struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT];
390 struct cgroup_root *root;
393 * List of cgrp_cset_links pointing at css_sets with tasks in this
394 * cgroup. Protected by css_set_lock.
396 struct list_head cset_links;
399 * On the default hierarchy, a css_set for a cgroup with some
400 * susbsys disabled will point to css's which are associated with
401 * the closest ancestor which has the subsys enabled. The
402 * following lists all css_sets which point to this cgroup's css
403 * for the given subsystem.
405 struct list_head e_csets[CGROUP_SUBSYS_COUNT];
408 * If !threaded, self. If threaded, it points to the nearest
409 * domain ancestor. Inside a threaded subtree, cgroups are exempt
410 * from process granularity and no-internal-task constraint.
411 * Domain level resource consumptions which aren't tied to a
412 * specific task are charged to the dom_cgrp.
414 struct cgroup *dom_cgrp;
416 /* per-cpu recursive resource statistics */
417 struct cgroup_rstat_cpu __percpu *rstat_cpu;
418 struct list_head rstat_css_list;
420 /* cgroup basic resource statistics */
421 struct cgroup_base_stat pending_bstat; /* pending from children */
422 struct cgroup_base_stat bstat;
423 struct prev_cputime prev_cputime; /* for printing out cputime */
426 * list of pidlists, up to two for each namespace (one for procs, one
427 * for tasks); created on demand.
429 struct list_head pidlists;
430 struct mutex pidlist_mutex;
432 /* used to wait for offlining of csses */
433 wait_queue_head_t offline_waitq;
435 /* used to schedule release agent */
436 struct work_struct release_agent_work;
438 /* used to store eBPF programs */
439 struct cgroup_bpf bpf;
441 /* ids of the ancestors at each level including self */
446 * A cgroup_root represents the root of a cgroup hierarchy, and may be
447 * associated with a kernfs_root to form an active hierarchy. This is
448 * internal to cgroup core. Don't access directly from controllers.
451 struct kernfs_root *kf_root;
453 /* The bitmask of subsystems attached to this hierarchy */
454 unsigned int subsys_mask;
456 /* Unique id for this hierarchy. */
459 /* The root cgroup. Root is destroyed on its release. */
462 /* for cgrp->ancestor_ids[0] */
463 int cgrp_ancestor_id_storage;
465 /* Number of cgroups in the hierarchy, used only for /proc/cgroups */
468 /* A list running through the active hierarchies */
469 struct list_head root_list;
471 /* Hierarchy-specific flags */
474 /* IDs for cgroups in this hierarchy */
475 struct idr cgroup_idr;
477 /* The path to use for release notifications. */
478 char release_agent_path[PATH_MAX];
480 /* The name for this hierarchy - may be empty */
481 char name[MAX_CGROUP_ROOT_NAMELEN];
485 * struct cftype: handler definitions for cgroup control files
487 * When reading/writing to a file:
488 * - the cgroup to use is file->f_path.dentry->d_parent->d_fsdata
489 * - the 'cftype' of the file is file->f_path.dentry->d_fsdata
493 * By convention, the name should begin with the name of the
494 * subsystem, followed by a period. Zero length string indicates
495 * end of cftype array.
497 char name[MAX_CFTYPE_NAME];
498 unsigned long private;
501 * The maximum length of string, excluding trailing nul, that can
502 * be passed to write. If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
504 size_t max_write_len;
510 * If non-zero, should contain the offset from the start of css to
511 * a struct cgroup_file field. cgroup will record the handle of
512 * the created file into it. The recorded handle can be used as
513 * long as the containing css remains accessible.
515 unsigned int file_offset;
518 * Fields used for internal bookkeeping. Initialized automatically
519 * during registration.
521 struct cgroup_subsys *ss; /* NULL for cgroup core files */
522 struct list_head node; /* anchored at ss->cfts */
523 struct kernfs_ops *kf_ops;
525 int (*open)(struct kernfs_open_file *of);
526 void (*release)(struct kernfs_open_file *of);
529 * read_u64() is a shortcut for the common case of returning a
530 * single integer. Use it in place of read()
532 u64 (*read_u64)(struct cgroup_subsys_state *css, struct cftype *cft);
534 * read_s64() is a signed version of read_u64()
536 s64 (*read_s64)(struct cgroup_subsys_state *css, struct cftype *cft);
538 /* generic seq_file read interface */
539 int (*seq_show)(struct seq_file *sf, void *v);
541 /* optional ops, implement all or none */
542 void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
543 void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
544 void (*seq_stop)(struct seq_file *sf, void *v);
547 * write_u64() is a shortcut for the common case of accepting
548 * a single integer (as parsed by simple_strtoull) from
549 * userspace. Use in place of write(); return 0 or error.
551 int (*write_u64)(struct cgroup_subsys_state *css, struct cftype *cft,
554 * write_s64() is a signed version of write_u64()
556 int (*write_s64)(struct cgroup_subsys_state *css, struct cftype *cft,
560 * write() is the generic write callback which maps directly to
561 * kernfs write operation and overrides all other operations.
562 * Maximum write size is determined by ->max_write_len. Use
563 * of_css/cft() to access the associated css and cft.
565 ssize_t (*write)(struct kernfs_open_file *of,
566 char *buf, size_t nbytes, loff_t off);
568 #ifdef CONFIG_DEBUG_LOCK_ALLOC
569 struct lock_class_key lockdep_key;
574 * Control Group subsystem type.
575 * See Documentation/cgroup-v1/cgroups.txt for details
577 struct cgroup_subsys {
578 struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css);
579 int (*css_online)(struct cgroup_subsys_state *css);
580 void (*css_offline)(struct cgroup_subsys_state *css);
581 void (*css_released)(struct cgroup_subsys_state *css);
582 void (*css_free)(struct cgroup_subsys_state *css);
583 void (*css_reset)(struct cgroup_subsys_state *css);
584 void (*css_rstat_flush)(struct cgroup_subsys_state *css, int cpu);
585 int (*css_extra_stat_show)(struct seq_file *seq,
586 struct cgroup_subsys_state *css);
588 int (*can_attach)(struct cgroup_taskset *tset);
589 void (*cancel_attach)(struct cgroup_taskset *tset);
590 void (*attach)(struct cgroup_taskset *tset);
591 void (*post_attach)(void);
592 int (*can_fork)(struct task_struct *task);
593 void (*cancel_fork)(struct task_struct *task);
594 void (*fork)(struct task_struct *task);
595 void (*exit)(struct task_struct *task);
596 void (*free)(struct task_struct *task);
597 void (*bind)(struct cgroup_subsys_state *root_css);
602 * If %true, the controller, on the default hierarchy, doesn't show
603 * up in "cgroup.controllers" or "cgroup.subtree_control", is
604 * implicitly enabled on all cgroups on the default hierarchy, and
605 * bypasses the "no internal process" constraint. This is for
606 * utility type controllers which is transparent to userland.
608 * An implicit controller can be stolen from the default hierarchy
609 * anytime and thus must be okay with offline csses from previous
610 * hierarchies coexisting with csses for the current one.
612 bool implicit_on_dfl:1;
615 * If %true, the controller, supports threaded mode on the default
616 * hierarchy. In a threaded subtree, both process granularity and
617 * no-internal-process constraint are ignored and a threaded
618 * controllers should be able to handle that.
620 * Note that as an implicit controller is automatically enabled on
621 * all cgroups on the default hierarchy, it should also be
622 * threaded. implicit && !threaded is not supported.
627 * If %false, this subsystem is properly hierarchical -
628 * configuration, resource accounting and restriction on a parent
629 * cgroup cover those of its children. If %true, hierarchy support
630 * is broken in some ways - some subsystems ignore hierarchy
631 * completely while others are only implemented half-way.
633 * It's now disallowed to create nested cgroups if the subsystem is
634 * broken and cgroup core will emit a warning message on such
635 * cases. Eventually, all subsystems will be made properly
636 * hierarchical and this will go away.
638 bool broken_hierarchy:1;
639 bool warned_broken_hierarchy:1;
641 /* the following two fields are initialized automtically during boot */
645 /* optional, initialized automatically during boot if not set */
646 const char *legacy_name;
648 /* link to parent, protected by cgroup_lock() */
649 struct cgroup_root *root;
651 /* idr for css->id */
655 * List of cftypes. Each entry is the first entry of an array
656 * terminated by zero length name.
658 struct list_head cfts;
661 * Base cftypes which are automatically registered. The two can
662 * point to the same array.
664 struct cftype *dfl_cftypes; /* for the default hierarchy */
665 struct cftype *legacy_cftypes; /* for the legacy hierarchies */
668 * A subsystem may depend on other subsystems. When such subsystem
669 * is enabled on a cgroup, the depended-upon subsystems are enabled
670 * together if available. Subsystems enabled due to dependency are
671 * not visible to userland until explicitly enabled. The following
672 * specifies the mask of subsystems that this one depends on.
674 unsigned int depends_on;
677 extern struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
680 * cgroup_threadgroup_change_begin - threadgroup exclusion for cgroups
683 * Allows cgroup operations to synchronize against threadgroup changes
684 * using a percpu_rw_semaphore.
686 static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk)
688 percpu_down_read(&cgroup_threadgroup_rwsem);
692 * cgroup_threadgroup_change_end - threadgroup exclusion for cgroups
695 * Counterpart of cgroup_threadcgroup_change_begin().
697 static inline void cgroup_threadgroup_change_end(struct task_struct *tsk)
699 percpu_up_read(&cgroup_threadgroup_rwsem);
702 #else /* CONFIG_CGROUPS */
704 #define CGROUP_SUBSYS_COUNT 0
706 static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk)
711 static inline void cgroup_threadgroup_change_end(struct task_struct *tsk) {}
713 #endif /* CONFIG_CGROUPS */
715 #ifdef CONFIG_SOCK_CGROUP_DATA
718 * sock_cgroup_data is embedded at sock->sk_cgrp_data and contains
719 * per-socket cgroup information except for memcg association.
721 * On legacy hierarchies, net_prio and net_cls controllers directly set
722 * attributes on each sock which can then be tested by the network layer.
723 * On the default hierarchy, each sock is associated with the cgroup it was
724 * created in and the networking layer can match the cgroup directly.
726 * To avoid carrying all three cgroup related fields separately in sock,
727 * sock_cgroup_data overloads (prioidx, classid) and the cgroup pointer.
728 * On boot, sock_cgroup_data records the cgroup that the sock was created
729 * in so that cgroup2 matches can be made; however, once either net_prio or
730 * net_cls starts being used, the area is overriden to carry prioidx and/or
731 * classid. The two modes are distinguished by whether the lowest bit is
732 * set. Clear bit indicates cgroup pointer while set bit prioidx and
735 * While userland may start using net_prio or net_cls at any time, once
736 * either is used, cgroup2 matching no longer works. There is no reason to
737 * mix the two and this is in line with how legacy and v2 compatibility is
738 * handled. On mode switch, cgroup references which are already being
739 * pointed to by socks may be leaked. While this can be remedied by adding
740 * synchronization around sock_cgroup_data, given that the number of leaked
741 * cgroups is bound and highly unlikely to be high, this seems to be the
744 struct sock_cgroup_data {
746 #ifdef __LITTLE_ENDIAN
766 * There's a theoretical window where the following accessors race with
767 * updaters and return part of the previous pointer as the prioidx or
768 * classid. Such races are short-lived and the result isn't critical.
770 static inline u16 sock_cgroup_prioidx(const struct sock_cgroup_data *skcd)
772 /* fallback to 1 which is always the ID of the root cgroup */
773 return (skcd->is_data & 1) ? skcd->prioidx : 1;
776 static inline u32 sock_cgroup_classid(const struct sock_cgroup_data *skcd)
778 /* fallback to 0 which is the unconfigured default classid */
779 return (skcd->is_data & 1) ? skcd->classid : 0;
783 * If invoked concurrently, the updaters may clobber each other. The
784 * caller is responsible for synchronization.
786 static inline void sock_cgroup_set_prioidx(struct sock_cgroup_data *skcd,
789 struct sock_cgroup_data skcd_buf = {{ .val = READ_ONCE(skcd->val) }};
791 if (sock_cgroup_prioidx(&skcd_buf) == prioidx)
794 if (!(skcd_buf.is_data & 1)) {
796 skcd_buf.is_data = 1;
799 skcd_buf.prioidx = prioidx;
800 WRITE_ONCE(skcd->val, skcd_buf.val); /* see sock_cgroup_ptr() */
803 static inline void sock_cgroup_set_classid(struct sock_cgroup_data *skcd,
806 struct sock_cgroup_data skcd_buf = {{ .val = READ_ONCE(skcd->val) }};
808 if (sock_cgroup_classid(&skcd_buf) == classid)
811 if (!(skcd_buf.is_data & 1)) {
813 skcd_buf.is_data = 1;
816 skcd_buf.classid = classid;
817 WRITE_ONCE(skcd->val, skcd_buf.val); /* see sock_cgroup_ptr() */
820 #else /* CONFIG_SOCK_CGROUP_DATA */
822 struct sock_cgroup_data {
825 #endif /* CONFIG_SOCK_CGROUP_DATA */
827 #endif /* _LINUX_CGROUP_DEFS_H */