[mirror_ubuntu-eoan-kernel.git] / kernel / bpf / local_storage.c

//SPDX-License-Identifier: GPL-2.0
#include <linux/bpf-cgroup.h>
#include <linux/bpf.h>
#include <linux/bug.h>
#include <linux/filter.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
#include <linux/slab.h>

DEFINE_PER_CPU(struct bpf_cgroup_storage*,
	       bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);

#ifdef CONFIG_CGROUP_BPF

#define LOCAL_STORAGE_CREATE_FLAG_MASK					\
	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)

struct bpf_cgroup_storage_map {
	struct bpf_map map;

	spinlock_t lock;
	struct bpf_prog *prog;
	struct rb_root root;
	struct list_head list;
};

static struct bpf_cgroup_storage_map *map_to_storage(struct bpf_map *map)
{
	return container_of(map, struct bpf_cgroup_storage_map, map);
}

static int bpf_cgroup_storage_key_cmp(
	const struct bpf_cgroup_storage_key *key1,
	const struct bpf_cgroup_storage_key *key2)
{
	if (key1->cgroup_inode_id < key2->cgroup_inode_id)
		return -1;
	else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
		return 1;
	else if (key1->attach_type < key2->attach_type)
		return -1;
	else if (key1->attach_type > key2->attach_type)
		return 1;
	return 0;
}

static struct bpf_cgroup_storage *cgroup_storage_lookup(
	struct bpf_cgroup_storage_map *map, struct bpf_cgroup_storage_key *key,
	bool locked)
{
	struct rb_root *root = &map->root;
	struct rb_node *node;

	if (!locked)
		spin_lock_bh(&map->lock);

	node = root->rb_node;
	while (node) {
		struct bpf_cgroup_storage *storage;

		storage = container_of(node, struct bpf_cgroup_storage, node);

		switch (bpf_cgroup_storage_key_cmp(key, &storage->key)) {
		case -1:
			node = node->rb_left;
			break;
		case 1:
			node = node->rb_right;
			break;
		default:
			if (!locked)
				spin_unlock_bh(&map->lock);
			return storage;
		}
	}

	if (!locked)
		spin_unlock_bh(&map->lock);

	return NULL;
}

static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
				 struct bpf_cgroup_storage *storage)
{
	struct rb_root *root = &map->root;
	struct rb_node **new = &(root->rb_node), *parent = NULL;

	while (*new) {
		struct bpf_cgroup_storage *this;

		this = container_of(*new, struct bpf_cgroup_storage, node);

		parent = *new;
		switch (bpf_cgroup_storage_key_cmp(&storage->key, &this->key)) {
		case -1:
			new = &((*new)->rb_left);
			break;
		case 1:
			new = &((*new)->rb_right);
			break;
		default:
			return -EEXIST;
		}
	}

	rb_link_node(&storage->node, parent, new);
	rb_insert_color(&storage->node, root);

	return 0;
}

static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *_key)
{
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	struct bpf_cgroup_storage_key *key = _key;
	struct bpf_cgroup_storage *storage;

	storage = cgroup_storage_lookup(map, key, false);
	if (!storage)
		return NULL;

	return &READ_ONCE(storage->buf)->data[0];
}

static int cgroup_storage_update_elem(struct bpf_map *map, void *_key,
				      void *value, u64 flags)
{
	struct bpf_cgroup_storage_key *key = _key;
	struct bpf_cgroup_storage *storage;
	struct bpf_storage_buffer *new;

	if (flags & BPF_NOEXIST)
		return -EINVAL;

	storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
					key, false);
	if (!storage)
		return -ENOENT;

	new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
			   map->value_size, __GFP_ZERO | GFP_USER,
			   map->numa_node);
	if (!new)
		return -ENOMEM;

	memcpy(&new->data[0], value, map->value_size);

	new = xchg(&storage->buf, new);
	kfree_rcu(new, rcu);

	return 0;
}

static int cgroup_storage_get_next_key(struct bpf_map *_map, void *_key,
				       void *_next_key)
{
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	struct bpf_cgroup_storage_key *key = _key;
	struct bpf_cgroup_storage_key *next = _next_key;
	struct bpf_cgroup_storage *storage;

	spin_lock_bh(&map->lock);

	if (list_empty(&map->list))
		goto enoent;

	if (key) {
		storage = cgroup_storage_lookup(map, key, true);
		if (!storage)
			goto enoent;

		storage = list_next_entry(storage, list);
		if (!storage)
			goto enoent;
	} else {
		storage = list_first_entry(&map->list,
					 struct bpf_cgroup_storage, list);
	}

	spin_unlock_bh(&map->lock);
	next->attach_type = storage->key.attach_type;
	next->cgroup_inode_id = storage->key.cgroup_inode_id;
	return 0;

enoent:
	spin_unlock_bh(&map->lock);
	return -ENOENT;
}

static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
{
	int numa_node = bpf_map_attr_numa_node(attr);
	struct bpf_cgroup_storage_map *map;

	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
		return ERR_PTR(-EINVAL);

	if (attr->value_size > PAGE_SIZE)
		return ERR_PTR(-E2BIG);

	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK)
		/* reserved bits should not be used */
		return ERR_PTR(-EINVAL);

	if (attr->max_entries)
		/* max_entries is not used and enforced to be 0 */
		return ERR_PTR(-EINVAL);

	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
			   __GFP_ZERO | GFP_USER, numa_node);
	if (!map)
		return ERR_PTR(-ENOMEM);

	map->map.pages = round_up(sizeof(struct bpf_cgroup_storage_map),
				  PAGE_SIZE) >> PAGE_SHIFT;

	/* copy mandatory map attributes */
	bpf_map_init_from_attr(&map->map, attr);

	spin_lock_init(&map->lock);
	map->root = RB_ROOT;
	INIT_LIST_HEAD(&map->list);

	return &map->map;
}

static void cgroup_storage_map_free(struct bpf_map *_map)
{
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);

	WARN_ON(!RB_EMPTY_ROOT(&map->root));
	WARN_ON(!list_empty(&map->list));

	kfree(map);
}

static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)
{
	return -EINVAL;
}

const struct bpf_map_ops cgroup_storage_map_ops = {
	.map_alloc = cgroup_storage_map_alloc,
	.map_free = cgroup_storage_map_free,
	.map_get_next_key = cgroup_storage_get_next_key,
	.map_lookup_elem = cgroup_storage_lookup_elem,
	.map_update_elem = cgroup_storage_update_elem,
	.map_delete_elem = cgroup_storage_delete_elem,
	.map_check_btf = map_check_no_btf,
};

int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *_map)
{
	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	int ret = -EBUSY;

	spin_lock_bh(&map->lock);

	if (map->prog && map->prog != prog)
		goto unlock;
	if (prog->aux->cgroup_storage[stype] &&
	    prog->aux->cgroup_storage[stype] != _map)
		goto unlock;

	map->prog = prog;
	prog->aux->cgroup_storage[stype] = _map;
	ret = 0;
unlock:
	spin_unlock_bh(&map->lock);

	return ret;
}

void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *_map)
{
	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);

	spin_lock_bh(&map->lock);
	if (map->prog == prog) {
		WARN_ON(prog->aux->cgroup_storage[stype] != _map);
		map->prog = NULL;
		prog->aux->cgroup_storage[stype] = NULL;
	}
	spin_unlock_bh(&map->lock);
}

struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
					enum bpf_cgroup_storage_type stype)
{
	struct bpf_cgroup_storage *storage;
	struct bpf_map *map;
	u32 pages;

	map = prog->aux->cgroup_storage[stype];
	if (!map)
		return NULL;

	pages = round_up(sizeof(struct bpf_cgroup_storage) +
			 sizeof(struct bpf_storage_buffer) +
			 map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
	if (bpf_map_charge_memlock(map, pages))
		return ERR_PTR(-EPERM);

	storage = kmalloc_node(sizeof(struct bpf_cgroup_storage),
			       __GFP_ZERO | GFP_USER, map->numa_node);
	if (!storage) {
		bpf_map_uncharge_memlock(map, pages);
		return ERR_PTR(-ENOMEM);
	}

	storage->buf = kmalloc_node(sizeof(struct bpf_storage_buffer) +
				    map->value_size, __GFP_ZERO | GFP_USER,
				    map->numa_node);
	if (!storage->buf) {
		bpf_map_uncharge_memlock(map, pages);
		kfree(storage);
		return ERR_PTR(-ENOMEM);
	}

	storage->map = (struct bpf_cgroup_storage_map *)map;

	return storage;
}

void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
{
	u32 pages;
	struct bpf_map *map;

	if (!storage)
		return;

	map = &storage->map->map;
	pages = round_up(sizeof(struct bpf_cgroup_storage) +
			 sizeof(struct bpf_storage_buffer) +
			 map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
	bpf_map_uncharge_memlock(map, pages);

	kfree_rcu(storage->buf, rcu);
	kfree_rcu(storage, rcu);
}

void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
			     struct cgroup *cgroup,
			     enum bpf_attach_type type)
{
	struct bpf_cgroup_storage_map *map;

	if (!storage)
		return;

	storage->key.attach_type = type;
	storage->key.cgroup_inode_id = cgroup->kn->id.id;

	map = storage->map;

	spin_lock_bh(&map->lock);
	WARN_ON(cgroup_storage_insert(map, storage));
	list_add(&storage->list, &map->list);
	spin_unlock_bh(&map->lock);
}

void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
{
	struct bpf_cgroup_storage_map *map;
	struct rb_root *root;

	if (!storage)
		return;

	map = storage->map;

	spin_lock_bh(&map->lock);
	root = &map->root;
	rb_erase(&storage->node, root);

	list_del(&storage->list);
	spin_unlock_bh(&map->lock);
}

#endif
Commit	Line	Data
de9cbbaa RG	1	//SPDX-License-Identifier: GPL-2.0
	2	#include <linux/bpf-cgroup.h>
	3	#include <linux/bpf.h>
	4	#include <linux/bug.h>
	5	#include <linux/filter.h>
	6	#include <linux/mm.h>
	7	#include <linux/rbtree.h>
	8	#include <linux/slab.h>
	9
f294b37e RG	10	DEFINE_PER_CPU(struct bpf_cgroup_storage*,
f294b37e RG	11	bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
aa0ad5b0	12
de9cbbaa RG	13	#ifdef CONFIG_CGROUP_BPF
	14
	15	#define LOCAL_STORAGE_CREATE_FLAG_MASK \
	16	(BPF_F_NUMA_NODE \| BPF_F_RDONLY \| BPF_F_WRONLY)
	17
	18	struct bpf_cgroup_storage_map {
	19	struct bpf_map map;
	20
	21	spinlock_t lock;
	22	struct bpf_prog *prog;
	23	struct rb_root root;
	24	struct list_head list;
	25	};
	26
	27	static struct bpf_cgroup_storage_map map_to_storage(struct bpf_map map)
	28	{
	29	return container_of(map, struct bpf_cgroup_storage_map, map);
	30	}
	31
	32	static int bpf_cgroup_storage_key_cmp(
	33	const struct bpf_cgroup_storage_key *key1,
	34	const struct bpf_cgroup_storage_key *key2)
	35	{
	36	if (key1->cgroup_inode_id < key2->cgroup_inode_id)
	37	return -1;
	38	else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
	39	return 1;
	40	else if (key1->attach_type < key2->attach_type)
	41	return -1;
	42	else if (key1->attach_type > key2->attach_type)
	43	return 1;
	44	return 0;
	45	}
	46
	47	static struct bpf_cgroup_storage *cgroup_storage_lookup(
	48	struct bpf_cgroup_storage_map map, struct bpf_cgroup_storage_key key,
	49	bool locked)
	50	{
	51	struct rb_root *root = &map->root;
	52	struct rb_node *node;
	53
	54	if (!locked)
	55	spin_lock_bh(&map->lock);
	56
	57	node = root->rb_node;
	58	while (node) {
	59	struct bpf_cgroup_storage *storage;
	60
	61	storage = container_of(node, struct bpf_cgroup_storage, node);
	62
	63	switch (bpf_cgroup_storage_key_cmp(key, &storage->key)) {
	64	case -1:
	65	node = node->rb_left;
	66	break;
	67	case 1:
	68	node = node->rb_right;
	69	break;
	70	default:
	71	if (!locked)
	72	spin_unlock_bh(&map->lock);
	73	return storage;
	74	}
	75	}
	76
77	if (!locked)
78	spin_unlock_bh(&map->lock);
79
80	return NULL;
81	}
82
83	static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
84	struct bpf_cgroup_storage *storage)
85	{
86	struct rb_root *root = &map->root;
87	struct rb_node *new = &(root->rb_node), parent = NULL;
88
89	while (*new) {
90	struct bpf_cgroup_storage *this;
91
92	this = container_of(*new, struct bpf_cgroup_storage, node);
93
94	parent = *new;
95	switch (bpf_cgroup_storage_key_cmp(&storage->key, &this->key)) {
96	case -1:
97	new = &((*new)->rb_left);
98	break;
99	case 1:
100	new = &((*new)->rb_right);
101	break;
102	default:
103	return -EEXIST;
104	}
105	}
106
107	rb_link_node(&storage->node, parent, new);
108	rb_insert_color(&storage->node, root);
109
110	return 0;
111	}
112
113	static void cgroup_storage_lookup_elem(struct bpf_map _map, void *_key)
114	{
115	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
116	struct bpf_cgroup_storage_key *key = _key;
117	struct bpf_cgroup_storage *storage;
118
119	storage = cgroup_storage_lookup(map, key, false);
120	if (!storage)
121	return NULL;
122
123	return &READ_ONCE(storage->buf)->data[0];
124	}
125
126	static int cgroup_storage_update_elem(struct bpf_map map, void _key,
127	void *value, u64 flags)
128	{
129	struct bpf_cgroup_storage_key *key = _key;
130	struct bpf_cgroup_storage *storage;
131	struct bpf_storage_buffer *new;
132
133	if (flags & BPF_NOEXIST)
134	return -EINVAL;
135
136	storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
137	key, false);
138	if (!storage)
139	return -ENOENT;
140
141	new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
142	map->value_size, __GFP_ZERO \| GFP_USER,
143	map->numa_node);
144	if (!new)
145	return -ENOMEM;
146
147	memcpy(&new->data[0], value, map->value_size);
148
149	new = xchg(&storage->buf, new);
150	kfree_rcu(new, rcu);
151
152	return 0;
153	}
154
155	static int cgroup_storage_get_next_key(struct bpf_map _map, void _key,
156	void *_next_key)
157	{
158	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
159	struct bpf_cgroup_storage_key *key = _key;
160	struct bpf_cgroup_storage_key *next = _next_key;
161	struct bpf_cgroup_storage *storage;
162
163	spin_lock_bh(&map->lock);
164
165	if (list_empty(&map->list))
166	goto enoent;
167
168	if (key) {
169	storage = cgroup_storage_lookup(map, key, true);
170	if (!storage)
171	goto enoent;
172
173	storage = list_next_entry(storage, list);
174	if (!storage)
175	goto enoent;
176	} else {
177	storage = list_first_entry(&map->list,
178	struct bpf_cgroup_storage, list);
179	}
180
181	spin_unlock_bh(&map->lock);
182	next->attach_type = storage->key.attach_type;
183	next->cgroup_inode_id = storage->key.cgroup_inode_id;
184	return 0;
185
186	enoent:
187	spin_unlock_bh(&map->lock);
188	return -ENOENT;
189	}
190
191	static struct bpf_map cgroup_storage_map_alloc(union bpf_attr attr)
192	{
193	int numa_node = bpf_map_attr_numa_node(attr);
194	struct bpf_cgroup_storage_map *map;
195
196	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
197	return ERR_PTR(-EINVAL);
198
199	if (attr->value_size > PAGE_SIZE)
200	return ERR_PTR(-E2BIG);
201
202	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK)
203	/* reserved bits should not be used */
204	return ERR_PTR(-EINVAL);
205
206	if (attr->max_entries)
207	/* max_entries is not used and enforced to be 0 */
208	return ERR_PTR(-EINVAL);
209
210	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
211	__GFP_ZERO \| GFP_USER, numa_node);
212	if (!map)
213	return ERR_PTR(-ENOMEM);
214
215	map->map.pages = round_up(sizeof(struct bpf_cgroup_storage_map),
216	PAGE_SIZE) >> PAGE_SHIFT;
217
218	/* copy mandatory map attributes */
219	bpf_map_init_from_attr(&map->map, attr);
220
221	spin_lock_init(&map->lock);
222	map->root = RB_ROOT;
223	INIT_LIST_HEAD(&map->list);
224
225	return &map->map;
226	}
227
228	static void cgroup_storage_map_free(struct bpf_map *_map)
229	{
230	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
231
232	WARN_ON(!RB_EMPTY_ROOT(&map->root));
233	WARN_ON(!list_empty(&map->list));
234
235	kfree(map);
236	}
237
238	static int cgroup_storage_delete_elem(struct bpf_map map, void key)
239	{
240	return -EINVAL;
241	}
242
243	const struct bpf_map_ops cgroup_storage_map_ops = {
244	.map_alloc = cgroup_storage_map_alloc,
245	.map_free = cgroup_storage_map_free,
246	.map_get_next_key = cgroup_storage_get_next_key,
247	.map_lookup_elem = cgroup_storage_lookup_elem,
248	.map_update_elem = cgroup_storage_update_elem,
249	.map_delete_elem = cgroup_storage_delete_elem,
e8d2bec0	250	.map_check_btf = map_check_no_btf,
de9cbbaa RG	251	};
	252
	253	int bpf_cgroup_storage_assign(struct bpf_prog prog, struct bpf_map _map)
	254	{
8bad74f9	255	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
de9cbbaa RG	256	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	257	int ret = -EBUSY;
	258
	259	spin_lock_bh(&map->lock);
	260
	261	if (map->prog && map->prog != prog)
	262	goto unlock;
8bad74f9 RG	263	if (prog->aux->cgroup_storage[stype] &&
8bad74f9 RG	264	prog->aux->cgroup_storage[stype] != _map)
de9cbbaa RG	265	goto unlock;
	266
	267	map->prog = prog;
8bad74f9	268	prog->aux->cgroup_storage[stype] = _map;
de9cbbaa RG	269	ret = 0;
	270	unlock:
	271	spin_unlock_bh(&map->lock);
	272
	273	return ret;
	274	}
	275
	276	void bpf_cgroup_storage_release(struct bpf_prog prog, struct bpf_map _map)
	277	{
8bad74f9	278	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
de9cbbaa RG	279	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	280
	281	spin_lock_bh(&map->lock);
	282	if (map->prog == prog) {
8bad74f9	283	WARN_ON(prog->aux->cgroup_storage[stype] != _map);
de9cbbaa	284	map->prog = NULL;
8bad74f9	285	prog->aux->cgroup_storage[stype] = NULL;
de9cbbaa RG	286	}
	287	spin_unlock_bh(&map->lock);
	288	}
	289
8bad74f9 RG	290	struct bpf_cgroup_storage bpf_cgroup_storage_alloc(struct bpf_prog prog,
8bad74f9 RG	291	enum bpf_cgroup_storage_type stype)
de9cbbaa RG	292	{
	293	struct bpf_cgroup_storage *storage;
	294	struct bpf_map *map;
	295	u32 pages;
	296
8bad74f9	297	map = prog->aux->cgroup_storage[stype];
de9cbbaa RG	298	if (!map)
	299	return NULL;
	300
	301	pages = round_up(sizeof(struct bpf_cgroup_storage) +
	302	sizeof(struct bpf_storage_buffer) +
	303	map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
	304	if (bpf_map_charge_memlock(map, pages))
	305	return ERR_PTR(-EPERM);
	306
	307	storage = kmalloc_node(sizeof(struct bpf_cgroup_storage),
	308	__GFP_ZERO \| GFP_USER, map->numa_node);
	309	if (!storage) {
	310	bpf_map_uncharge_memlock(map, pages);
	311	return ERR_PTR(-ENOMEM);
	312	}
	313
	314	storage->buf = kmalloc_node(sizeof(struct bpf_storage_buffer) +
	315	map->value_size, __GFP_ZERO \| GFP_USER,
	316	map->numa_node);
	317	if (!storage->buf) {
	318	bpf_map_uncharge_memlock(map, pages);
	319	kfree(storage);
	320	return ERR_PTR(-ENOMEM);
	321	}
	322
	323	storage->map = (struct bpf_cgroup_storage_map *)map;
	324
	325	return storage;
	326	}
	327
	328	void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
	329	{
	330	u32 pages;
	331	struct bpf_map *map;
	332
	333	if (!storage)
	334	return;
	335
	336	map = &storage->map->map;
	337	pages = round_up(sizeof(struct bpf_cgroup_storage) +
	338	sizeof(struct bpf_storage_buffer) +
	339	map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
	340	bpf_map_uncharge_memlock(map, pages);
	341
	342	kfree_rcu(storage->buf, rcu);
	343	kfree_rcu(storage, rcu);
	344	}
	345
	346	void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
	347	struct cgroup *cgroup,
	348	enum bpf_attach_type type)
	349	{
	350	struct bpf_cgroup_storage_map *map;
	351
	352	if (!storage)
	353	return;
	354
	355	storage->key.attach_type = type;
	356	storage->key.cgroup_inode_id = cgroup->kn->id.id;
	357
	358	map = storage->map;
	359
	360	spin_lock_bh(&map->lock);
	361	WARN_ON(cgroup_storage_insert(map, storage));
362	list_add(&storage->list, &map->list);
363	spin_unlock_bh(&map->lock);
364	}
365
366	void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
367	{
368	struct bpf_cgroup_storage_map *map;
369	struct rb_root *root;
370
371	if (!storage)
372	return;
373
374	map = storage->map;
375
376	spin_lock_bh(&map->lock);
377	root = &map->root;
378	rb_erase(&storage->node, root);
379
380	list_del(&storage->list);
381	spin_unlock_bh(&map->lock);
382	}
383
384	#endif