1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __CGROUP_INTERNAL_H |
3 | #define __CGROUP_INTERNAL_H |
4 | |
5 | #include <linux/cgroup.h> |
6 | #include <linux/kernfs.h> |
7 | #include <linux/workqueue.h> |
8 | #include <linux/list.h> |
9 | #include <linux/refcount.h> |
10 | #include <linux/fs_parser.h> |
11 | |
12 | #define TRACE_CGROUP_PATH_LEN 1024 |
13 | extern spinlock_t trace_cgroup_path_lock; |
14 | extern char trace_cgroup_path[TRACE_CGROUP_PATH_LEN]; |
15 | extern void __init enable_debug_cgroup(void); |
16 | |
17 | /* |
18 | * cgroup_path() takes a spin lock. It is good practice not to take |
19 | * spin locks within trace point handlers, as they are mostly hidden |
20 | * from normal view. As cgroup_path() can take the kernfs_rename_lock |
21 | * spin lock, it is best to not call that function from the trace event |
22 | * handler. |
23 | * |
24 | * Note: trace_cgroup_##type##_enabled() is a static branch that will only |
25 | * be set when the trace event is enabled. |
26 | */ |
27 | #define TRACE_CGROUP_PATH(type, cgrp, ...) \ |
28 | do { \ |
29 | if (trace_cgroup_##type##_enabled()) { \ |
30 | unsigned long flags; \ |
31 | spin_lock_irqsave(&trace_cgroup_path_lock, \ |
32 | flags); \ |
33 | cgroup_path(cgrp, trace_cgroup_path, \ |
34 | TRACE_CGROUP_PATH_LEN); \ |
35 | trace_cgroup_##type(cgrp, trace_cgroup_path, \ |
36 | ##__VA_ARGS__); \ |
37 | spin_unlock_irqrestore(&trace_cgroup_path_lock, \ |
38 | flags); \ |
39 | } \ |
40 | } while (0) |
41 | |
42 | /* |
43 | * The cgroup filesystem superblock creation/mount context. |
44 | */ |
45 | struct cgroup_fs_context { |
46 | struct kernfs_fs_context kfc; |
47 | struct cgroup_root *root; |
48 | struct cgroup_namespace *ns; |
49 | unsigned int flags; /* CGRP_ROOT_* flags */ |
50 | |
51 | /* cgroup1 bits */ |
52 | bool cpuset_clone_children; |
53 | bool none; /* User explicitly requested empty subsystem */ |
54 | bool all_ss; /* Seen 'all' option */ |
55 | u16 subsys_mask; /* Selected subsystems */ |
56 | char *name; /* Hierarchy name */ |
57 | char *release_agent; /* Path for release notifications */ |
58 | }; |
59 | |
60 | static inline struct cgroup_fs_context *cgroup_fc2context(struct fs_context *fc) |
61 | { |
62 | struct kernfs_fs_context *kfc = fc->fs_private; |
63 | |
64 | return container_of(kfc, struct cgroup_fs_context, kfc); |
65 | } |
66 | |
67 | struct cgroup_pidlist; |
68 | |
69 | struct cgroup_file_ctx { |
70 | struct cgroup_namespace *ns; |
71 | |
72 | struct { |
73 | void *trigger; |
74 | } psi; |
75 | |
76 | struct { |
77 | bool started; |
78 | struct css_task_iter iter; |
79 | } procs; |
80 | |
81 | struct { |
82 | struct cgroup_pidlist *pidlist; |
83 | } procs1; |
84 | }; |
85 | |
86 | /* |
87 | * A cgroup can be associated with multiple css_sets as different tasks may |
88 | * belong to different cgroups on different hierarchies. In the other |
89 | * direction, a css_set is naturally associated with multiple cgroups. |
90 | * This M:N relationship is represented by the following link structure |
91 | * which exists for each association and allows traversing the associations |
92 | * from both sides. |
93 | */ |
94 | struct cgrp_cset_link { |
95 | /* the cgroup and css_set this link associates */ |
96 | struct cgroup *cgrp; |
97 | struct css_set *cset; |
98 | |
99 | /* list of cgrp_cset_links anchored at cgrp->cset_links */ |
100 | struct list_head cset_link; |
101 | |
102 | /* list of cgrp_cset_links anchored at css_set->cgrp_links */ |
103 | struct list_head cgrp_link; |
104 | }; |
105 | |
106 | /* used to track tasks and csets during migration */ |
107 | struct cgroup_taskset { |
108 | /* the src and dst cset list running through cset->mg_node */ |
109 | struct list_head src_csets; |
110 | struct list_head dst_csets; |
111 | |
112 | /* the number of tasks in the set */ |
113 | int nr_tasks; |
114 | |
115 | /* the subsys currently being processed */ |
116 | int ssid; |
117 | |
118 | /* |
119 | * Fields for cgroup_taskset_*() iteration. |
120 | * |
121 | * Before migration is committed, the target migration tasks are on |
122 | * ->mg_tasks of the csets on ->src_csets. After, on ->mg_tasks of |
123 | * the csets on ->dst_csets. ->csets point to either ->src_csets |
124 | * or ->dst_csets depending on whether migration is committed. |
125 | * |
126 | * ->cur_csets and ->cur_task point to the current task position |
127 | * during iteration. |
128 | */ |
129 | struct list_head *csets; |
130 | struct css_set *cur_cset; |
131 | struct task_struct *cur_task; |
132 | }; |
133 | |
134 | /* migration context also tracks preloading */ |
135 | struct cgroup_mgctx { |
136 | /* |
137 | * Preloaded source and destination csets. Used to guarantee |
138 | * atomic success or failure on actual migration. |
139 | */ |
140 | struct list_head preloaded_src_csets; |
141 | struct list_head preloaded_dst_csets; |
142 | |
143 | /* tasks and csets to migrate */ |
144 | struct cgroup_taskset tset; |
145 | |
146 | /* subsystems affected by migration */ |
147 | u16 ss_mask; |
148 | }; |
149 | |
150 | #define CGROUP_TASKSET_INIT(tset) \ |
151 | { \ |
152 | .src_csets = LIST_HEAD_INIT(tset.src_csets), \ |
153 | .dst_csets = LIST_HEAD_INIT(tset.dst_csets), \ |
154 | .csets = &tset.src_csets, \ |
155 | } |
156 | |
157 | #define CGROUP_MGCTX_INIT(name) \ |
158 | { \ |
159 | LIST_HEAD_INIT(name.preloaded_src_csets), \ |
160 | LIST_HEAD_INIT(name.preloaded_dst_csets), \ |
161 | CGROUP_TASKSET_INIT(name.tset), \ |
162 | } |
163 | |
164 | #define DEFINE_CGROUP_MGCTX(name) \ |
165 | struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name) |
166 | |
167 | extern spinlock_t css_set_lock; |
168 | extern struct cgroup_subsys *cgroup_subsys[]; |
169 | extern struct list_head cgroup_roots; |
170 | |
171 | /* iterate across the hierarchies */ |
172 | #define for_each_root(root) \ |
173 | list_for_each_entry((root), &cgroup_roots, root_list) |
174 | |
175 | /** |
176 | * for_each_subsys - iterate all enabled cgroup subsystems |
177 | * @ss: the iteration cursor |
178 | * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end |
179 | */ |
180 | #define for_each_subsys(ss, ssid) \ |
181 | for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT && \ |
182 | (((ss) = cgroup_subsys[ssid]) || true); (ssid)++) |
183 | |
184 | static inline bool cgroup_is_dead(const struct cgroup *cgrp) |
185 | { |
186 | return !(cgrp->self.flags & CSS_ONLINE); |
187 | } |
188 | |
189 | static inline bool notify_on_release(const struct cgroup *cgrp) |
190 | { |
191 | return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); |
192 | } |
193 | |
194 | void put_css_set_locked(struct css_set *cset); |
195 | |
196 | static inline void put_css_set(struct css_set *cset) |
197 | { |
198 | unsigned long flags; |
199 | |
200 | /* |
201 | * Ensure that the refcount doesn't hit zero while any readers |
202 | * can see it. Similar to atomic_dec_and_lock(), but for an |
203 | * rwlock |
204 | */ |
205 | if (refcount_dec_not_one(r: &cset->refcount)) |
206 | return; |
207 | |
208 | spin_lock_irqsave(&css_set_lock, flags); |
209 | put_css_set_locked(cset); |
210 | spin_unlock_irqrestore(lock: &css_set_lock, flags); |
211 | } |
212 | |
213 | /* |
214 | * refcounted get/put for css_set objects |
215 | */ |
216 | static inline void get_css_set(struct css_set *cset) |
217 | { |
218 | refcount_inc(r: &cset->refcount); |
219 | } |
220 | |
221 | bool cgroup_ssid_enabled(int ssid); |
222 | bool cgroup_on_dfl(const struct cgroup *cgrp); |
223 | |
224 | struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root); |
225 | struct cgroup *task_cgroup_from_root(struct task_struct *task, |
226 | struct cgroup_root *root); |
227 | struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn, bool drain_offline); |
228 | void cgroup_kn_unlock(struct kernfs_node *kn); |
229 | int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen, |
230 | struct cgroup_namespace *ns); |
231 | |
232 | void cgroup_favor_dynmods(struct cgroup_root *root, bool favor); |
233 | void cgroup_free_root(struct cgroup_root *root); |
234 | void init_cgroup_root(struct cgroup_fs_context *ctx); |
235 | int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask); |
236 | int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask); |
237 | int cgroup_do_get_tree(struct fs_context *fc); |
238 | |
239 | int cgroup_migrate_vet_dst(struct cgroup *dst_cgrp); |
240 | void cgroup_migrate_finish(struct cgroup_mgctx *mgctx); |
241 | void cgroup_migrate_add_src(struct css_set *src_cset, struct cgroup *dst_cgrp, |
242 | struct cgroup_mgctx *mgctx); |
243 | int cgroup_migrate_prepare_dst(struct cgroup_mgctx *mgctx); |
244 | int cgroup_migrate(struct task_struct *leader, bool threadgroup, |
245 | struct cgroup_mgctx *mgctx); |
246 | |
247 | int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader, |
248 | bool threadgroup); |
249 | void cgroup_attach_lock(bool lock_threadgroup); |
250 | void cgroup_attach_unlock(bool lock_threadgroup); |
251 | struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup, |
252 | bool *locked) |
253 | __acquires(&cgroup_threadgroup_rwsem); |
254 | void cgroup_procs_write_finish(struct task_struct *task, bool locked) |
255 | __releases(&cgroup_threadgroup_rwsem); |
256 | |
257 | void cgroup_lock_and_drain_offline(struct cgroup *cgrp); |
258 | |
259 | int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode); |
260 | int cgroup_rmdir(struct kernfs_node *kn); |
261 | int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, |
262 | struct kernfs_root *kf_root); |
263 | |
264 | int __cgroup_task_count(const struct cgroup *cgrp); |
265 | int cgroup_task_count(const struct cgroup *cgrp); |
266 | |
267 | /* |
268 | * rstat.c |
269 | */ |
270 | int cgroup_rstat_init(struct cgroup *cgrp); |
271 | void cgroup_rstat_exit(struct cgroup *cgrp); |
272 | void cgroup_rstat_boot(void); |
273 | void cgroup_base_stat_cputime_show(struct seq_file *seq); |
274 | |
275 | /* |
276 | * namespace.c |
277 | */ |
278 | extern const struct proc_ns_operations cgroupns_operations; |
279 | |
280 | /* |
281 | * cgroup-v1.c |
282 | */ |
283 | extern struct cftype cgroup1_base_files[]; |
284 | extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops; |
285 | extern const struct fs_parameter_spec cgroup1_fs_parameters[]; |
286 | |
287 | int proc_cgroupstats_show(struct seq_file *m, void *v); |
288 | bool cgroup1_ssid_disabled(int ssid); |
289 | void cgroup1_pidlist_destroy_all(struct cgroup *cgrp); |
290 | void cgroup1_release_agent(struct work_struct *work); |
291 | void cgroup1_check_for_release(struct cgroup *cgrp); |
292 | int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param); |
293 | int cgroup1_get_tree(struct fs_context *fc); |
294 | int cgroup1_reconfigure(struct fs_context *ctx); |
295 | |
296 | #endif /* __CGROUP_INTERNAL_H */ |
297 | |