[linux.git] / net / core / dst.c

/*
 * net/core/dst.c	Protocol independent destination cache.
 *
 * Authors:		Alexey Kuznetsov, <[email protected]>
 *
 */

#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/types.h>
#include <net/net_namespace.h>
#include <linux/sched.h>
#include <linux/prefetch.h>
#include <net/lwtunnel.h>
#include <net/xfrm.h>

#include <net/dst.h>
#include <net/dst_metadata.h>

/*
 * Theory of operations:
 * 1) We use a list, protected by a spinlock, to add
 *    new entries from both BH and non-BH context.
 * 2) In order to keep spinlock held for a small delay,
 *    we use a second list where are stored long lived
 *    entries, that are handled by the garbage collect thread
 *    fired by a workqueue.
 * 3) This list is guarded by a mutex,
 *    so that the gc_task and dst_dev_event() can be synchronized.
 */

/*
 * We want to keep lock & list close together
 * to dirty as few cache lines as possible in __dst_free().
 * As this is not a very strong hint, we dont force an alignment on SMP.
 */
int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	kfree_skb(skb);
	return 0;
}
EXPORT_SYMBOL(dst_discard_out);

const struct dst_metrics dst_default_metrics = {
	/* This initializer is needed to force linker to place this variable
	 * into const section. Otherwise it might end into bss section.
	 * We really want to avoid false sharing on this variable, and catch
	 * any writes on it.
	 */
	.refcnt = REFCOUNT_INIT(1),
};
EXPORT_SYMBOL(dst_default_metrics);

void dst_init(struct dst_entry *dst, struct dst_ops *ops,
	      struct net_device *dev, int initial_ref, int initial_obsolete,
	      unsigned short flags)
{
	dst->dev = dev;
	if (dev)
		dev_hold(dev);
	dst->ops = ops;
	dst_init_metrics(dst, dst_default_metrics.metrics, true);
	dst->expires = 0UL;
#ifdef CONFIG_XFRM
	dst->xfrm = NULL;
#endif
	dst->input = dst_discard;
	dst->output = dst_discard_out;
	dst->error = 0;
	dst->obsolete = initial_obsolete;
	dst->header_len = 0;
	dst->trailer_len = 0;
#ifdef CONFIG_IP_ROUTE_CLASSID
	dst->tclassid = 0;
#endif
	dst->lwtstate = NULL;
	atomic_set(&dst->__refcnt, initial_ref);
	dst->__use = 0;
	dst->lastuse = jiffies;
	dst->flags = flags;
	if (!(flags & DST_NOCOUNT))
		dst_entries_add(ops, 1);
}
EXPORT_SYMBOL(dst_init);

void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
		int initial_ref, int initial_obsolete, unsigned short flags)
{
	struct dst_entry *dst;

	if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) {
		if (ops->gc(ops))
			return NULL;
	}

	dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC);
	if (!dst)
		return NULL;

	dst_init(dst, ops, dev, initial_ref, initial_obsolete, flags);

	return dst;
}
EXPORT_SYMBOL(dst_alloc);

struct dst_entry *dst_destroy(struct dst_entry * dst)
{
	struct dst_entry *child = NULL;

	smp_rmb();

#ifdef CONFIG_XFRM
	if (dst->xfrm) {
		struct xfrm_dst *xdst = (struct xfrm_dst *) dst;

		child = xdst->child;
	}
#endif
	if (!(dst->flags & DST_NOCOUNT))
		dst_entries_add(dst->ops, -1);

	if (dst->ops->destroy)
		dst->ops->destroy(dst);
	if (dst->dev)
		dev_put(dst->dev);

	lwtstate_put(dst->lwtstate);

	if (dst->flags & DST_METADATA)
		metadata_dst_free((struct metadata_dst *)dst);
	else
		kmem_cache_free(dst->ops->kmem_cachep, dst);

	dst = child;
	if (dst)
		dst_release_immediate(dst);
	return NULL;
}
EXPORT_SYMBOL(dst_destroy);

static void dst_destroy_rcu(struct rcu_head *head)
{
	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);

	dst = dst_destroy(dst);
}

/* Operations to mark dst as DEAD and clean up the net device referenced
 * by dst:
 * 1. put the dst under loopback interface and discard all tx/rx packets
 *    on this route.
 * 2. release the net_device
 * This function should be called when removing routes from the fib tree
 * in preparation for a NETDEV_DOWN/NETDEV_UNREGISTER event and also to
 * make the next dst_ops->check() fail.
 */
void dst_dev_put(struct dst_entry *dst)
{
	struct net_device *dev = dst->dev;

	dst->obsolete = DST_OBSOLETE_DEAD;
	if (dst->ops->ifdown)
		dst->ops->ifdown(dst, dev, true);
	dst->input = dst_discard;
	dst->output = dst_discard_out;
	dst->dev = dev_net(dst->dev)->loopback_dev;
	dev_hold(dst->dev);
	dev_put(dev);
}
EXPORT_SYMBOL(dst_dev_put);

void dst_release(struct dst_entry *dst)
{
	if (dst) {
		int newrefcnt;

		newrefcnt = atomic_dec_return(&dst->__refcnt);
		if (unlikely(newrefcnt < 0))
			net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
					     __func__, dst, newrefcnt);
		if (!newrefcnt)
			call_rcu(&dst->rcu_head, dst_destroy_rcu);
	}
}
EXPORT_SYMBOL(dst_release);

void dst_release_immediate(struct dst_entry *dst)
{
	if (dst) {
		int newrefcnt;

		newrefcnt = atomic_dec_return(&dst->__refcnt);
		if (unlikely(newrefcnt < 0))
			net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
					     __func__, dst, newrefcnt);
		if (!newrefcnt)
			dst_destroy(dst);
	}
}
EXPORT_SYMBOL(dst_release_immediate);

u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old)
{
	struct dst_metrics *p = kmalloc(sizeof(*p), GFP_ATOMIC);

	if (p) {
		struct dst_metrics *old_p = (struct dst_metrics *)__DST_METRICS_PTR(old);
		unsigned long prev, new;

		refcount_set(&p->refcnt, 1);
		memcpy(p->metrics, old_p->metrics, sizeof(p->metrics));

		new = (unsigned long) p;
		prev = cmpxchg(&dst->_metrics, old, new);

		if (prev != old) {
			kfree(p);
			p = (struct dst_metrics *)__DST_METRICS_PTR(prev);
			if (prev & DST_METRICS_READ_ONLY)
				p = NULL;
		} else if (prev & DST_METRICS_REFCOUNTED) {
			if (refcount_dec_and_test(&old_p->refcnt))
				kfree(old_p);
		}
	}
	BUILD_BUG_ON(offsetof(struct dst_metrics, metrics) != 0);
	return (u32 *)p;
}
EXPORT_SYMBOL(dst_cow_metrics_generic);

/* Caller asserts that dst_metrics_read_only(dst) is false.  */
void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
{
	unsigned long prev, new;

	new = ((unsigned long) &dst_default_metrics) | DST_METRICS_READ_ONLY;
	prev = cmpxchg(&dst->_metrics, old, new);
	if (prev == old)
		kfree(__DST_METRICS_PTR(old));
}
EXPORT_SYMBOL(__dst_destroy_metrics_generic);

static struct dst_ops md_dst_ops = {
	.family =		AF_UNSPEC,
};

static int dst_md_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	WARN_ONCE(1, "Attempting to call output on metadata dst\n");
	kfree_skb(skb);
	return 0;
}

static int dst_md_discard(struct sk_buff *skb)
{
	WARN_ONCE(1, "Attempting to call input on metadata dst\n");
	kfree_skb(skb);
	return 0;
}

static void __metadata_dst_init(struct metadata_dst *md_dst,
				enum metadata_type type, u8 optslen)

{
	struct dst_entry *dst;

	dst = &md_dst->dst;
	dst_init(dst, &md_dst_ops, NULL, 1, DST_OBSOLETE_NONE,
		 DST_METADATA | DST_NOCOUNT);

	dst->input = dst_md_discard;
	dst->output = dst_md_discard_out;

	memset(dst + 1, 0, sizeof(*md_dst) + optslen - sizeof(*dst));
	md_dst->type = type;
}

struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
					gfp_t flags)
{
	struct metadata_dst *md_dst;

	md_dst = kmalloc(sizeof(*md_dst) + optslen, flags);
	if (!md_dst)
		return NULL;

	__metadata_dst_init(md_dst, type, optslen);

	return md_dst;
}
EXPORT_SYMBOL_GPL(metadata_dst_alloc);

void metadata_dst_free(struct metadata_dst *md_dst)
{
#ifdef CONFIG_DST_CACHE
	if (md_dst->type == METADATA_IP_TUNNEL)
		dst_cache_destroy(&md_dst->u.tun_info.dst_cache);
#endif
	kfree(md_dst);
}
EXPORT_SYMBOL_GPL(metadata_dst_free);

struct metadata_dst __percpu *
metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags)
{
	int cpu;
	struct metadata_dst __percpu *md_dst;

	md_dst = __alloc_percpu_gfp(sizeof(struct metadata_dst) + optslen,
				    __alignof__(struct metadata_dst), flags);
	if (!md_dst)
		return NULL;

	for_each_possible_cpu(cpu)
		__metadata_dst_init(per_cpu_ptr(md_dst, cpu), type, optslen);

	return md_dst;
}
EXPORT_SYMBOL_GPL(metadata_dst_alloc_percpu);

void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst)
{
#ifdef CONFIG_DST_CACHE
	int cpu;

	for_each_possible_cpu(cpu) {
		struct metadata_dst *one_md_dst = per_cpu_ptr(md_dst, cpu);

		if (one_md_dst->type == METADATA_IP_TUNNEL)
			dst_cache_destroy(&one_md_dst->u.tun_info.dst_cache);
	}
#endif
	free_percpu(md_dst);
}
EXPORT_SYMBOL_GPL(metadata_dst_free_percpu);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/core/dst.c Protocol independent destination cache.
	3	*
	4	* Authors: Alexey Kuznetsov, <[email protected]>
	5	*
	6	*/
	7
	8	#include <linux/bitops.h>
	9	#include <linux/errno.h>
	10	#include <linux/init.h>
	11	#include <linux/kernel.h>
86bba269	12	#include <linux/workqueue.h>
1da177e4 LT	13	#include <linux/mm.h>
1da177e4 LT	14	#include <linux/module.h>
5a0e3ad6	15	#include <linux/slab.h>
1da177e4	16	#include <linux/netdevice.h>
1da177e4 LT	17	#include <linux/skbuff.h>
	18	#include <linux/string.h>
	19	#include <linux/types.h>
e9dc8653	20	#include <net/net_namespace.h>
2fc1b5dd	21	#include <linux/sched.h>
268bb0ce	22	#include <linux/prefetch.h>
61adedf3	23	#include <net/lwtunnel.h>
b6ca8bd5	24	#include <net/xfrm.h>
1da177e4 LT	25
1da177e4 LT	26	#include <net/dst.h>
f38a9eb1	27	#include <net/dst_metadata.h>
1da177e4	28
86bba269 ED	29	/*
	30	* Theory of operations:
	31	* 1) We use a list, protected by a spinlock, to add
	32	* new entries from both BH and non-BH context.
	33	* 2) In order to keep spinlock held for a small delay,
	34	* we use a second list where are stored long lived
	35	* entries, that are handled by the garbage collect thread
	36	* fired by a workqueue.
	37	* 3) This list is guarded by a mutex,
	38	* so that the gc_task and dst_dev_event() can be synchronized.
1da177e4	39	*/
1da177e4	40
86bba269 ED	41	/*
	42	* We want to keep lock & list close together
	43	* to dirty as few cache lines as possible in __dst_free().
	44	* As this is not a very strong hint, we dont force an alignment on SMP.
	45	*/
ede2059d	46	int dst_discard_out(struct net net, struct sock sk, struct sk_buff *skb)
1da177e4 LT	47	{
	48	kfree_skb(skb);
	49	return 0;
	50	}
ede2059d	51	EXPORT_SYMBOL(dst_discard_out);
1da177e4	52
3fb07daf	53	const struct dst_metrics dst_default_metrics = {
a37e6e34 ED	54	/* This initializer is needed to force linker to place this variable
	55	* into const section. Otherwise it might end into bss section.
	56	* We really want to avoid false sharing on this variable, and catch
	57	* any writes on it.
	58	*/
9620fef2	59	.refcnt = REFCOUNT_INIT(1),
a37e6e34	60	};
d4ead6b3	61	EXPORT_SYMBOL(dst_default_metrics);
a37e6e34	62
f38a9eb1 TG	63	void dst_init(struct dst_entry dst, struct dst_ops ops,
	64	struct net_device *dev, int initial_ref, int initial_obsolete,
	65	unsigned short flags)
1da177e4	66	{
5c1e6aa3 DM	67	dst->dev = dev;
	68	if (dev)
	69	dev_hold(dev);
1da177e4	70	dst->ops = ops;
3fb07daf	71	dst_init_metrics(dst, dst_default_metrics.metrics, true);
cf911662	72	dst->expires = 0UL;
cf911662 DM	73	#ifdef CONFIG_XFRM
	74	dst->xfrm = NULL;
	75	#endif
5c1e6aa3	76	dst->input = dst_discard;
ede2059d	77	dst->output = dst_discard_out;
cf911662	78	dst->error = 0;
5c1e6aa3	79	dst->obsolete = initial_obsolete;
cf911662 DM	80	dst->header_len = 0;
	81	dst->trailer_len = 0;
	82	#ifdef CONFIG_IP_ROUTE_CLASSID
	83	dst->tclassid = 0;
1da177e4	84	#endif
61adedf3	85	dst->lwtstate = NULL;
5c1e6aa3	86	atomic_set(&dst->__refcnt, initial_ref);
cf911662	87	dst->__use = 0;
5c1e6aa3 DM	88	dst->lastuse = jiffies;
5c1e6aa3 DM	89	dst->flags = flags;
957c665f DM	90	if (!(flags & DST_NOCOUNT))
957c665f DM	91	dst_entries_add(ops, 1);
f38a9eb1 TG	92	}
	93	EXPORT_SYMBOL(dst_init);
	94
	95	void dst_alloc(struct dst_ops ops, struct net_device *dev,
	96	int initial_ref, int initial_obsolete, unsigned short flags)
	97	{
	98	struct dst_entry *dst;
	99
	100	if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) {
	101	if (ops->gc(ops))
	102	return NULL;
	103	}
	104
	105	dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC);
	106	if (!dst)
	107	return NULL;
	108
	109	dst_init(dst, ops, dev, initial_ref, initial_obsolete, flags);
	110
1da177e4 LT	111	return dst;
1da177e4 LT	112	}
598ed936	113	EXPORT_SYMBOL(dst_alloc);
1da177e4	114
1da177e4 LT	115	struct dst_entry dst_destroy(struct dst_entry dst)
1da177e4 LT	116	{
b92cf4aa	117	struct dst_entry *child = NULL;
1da177e4 LT	118
	119	smp_rmb();
	120
b92cf4aa	121	#ifdef CONFIG_XFRM
b6ca8bd5 DM	122	if (dst->xfrm) {
	123	struct xfrm_dst xdst = (struct xfrm_dst ) dst;
	124
	125	child = xdst->child;
	126	}
b92cf4aa	127	#endif
957c665f DM	128	if (!(dst->flags & DST_NOCOUNT))
957c665f DM	129	dst_entries_add(dst->ops, -1);
1da177e4 LT	130
	131	if (dst->ops->destroy)
	132	dst->ops->destroy(dst);
	133	if (dst->dev)
	134	dev_put(dst->dev);
f38a9eb1	135
e252b3d1 WC	136	lwtstate_put(dst->lwtstate);
e252b3d1 WC	137
f38a9eb1	138	if (dst->flags & DST_METADATA)
d71785ff	139	metadata_dst_free((struct metadata_dst *)dst);
f38a9eb1 TG	140	else
f38a9eb1 TG	141	kmem_cache_free(dst->ops->kmem_cachep, dst);
1da177e4 LT	142
1da177e4 LT	143	dst = child;
52df157f WW	144	if (dst)
52df157f WW	145	dst_release_immediate(dst);
1da177e4 LT	146	return NULL;
1da177e4 LT	147	}
598ed936	148	EXPORT_SYMBOL(dst_destroy);
1da177e4	149
f8864972 ED	150	static void dst_destroy_rcu(struct rcu_head *head)
	151	{
	152	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	153
	154	dst = dst_destroy(dst);
f8864972 ED	155	}
f8864972 ED	156
4a6ce2b6 WW	157	/* Operations to mark dst as DEAD and clean up the net device referenced
	158	* by dst:
	159	* 1. put the dst under loopback interface and discard all tx/rx packets
	160	* on this route.
	161	* 2. release the net_device
	162	* This function should be called when removing routes from the fib tree
	163	* in preparation for a NETDEV_DOWN/NETDEV_UNREGISTER event and also to
	164	* make the next dst_ops->check() fail.
	165	*/
	166	void dst_dev_put(struct dst_entry *dst)
	167	{
	168	struct net_device *dev = dst->dev;
	169
	170	dst->obsolete = DST_OBSOLETE_DEAD;
	171	if (dst->ops->ifdown)
	172	dst->ops->ifdown(dst, dev, true);
	173	dst->input = dst_discard;
	174	dst->output = dst_discard_out;
	175	dst->dev = dev_net(dst->dev)->loopback_dev;
	176	dev_hold(dst->dev);
	177	dev_put(dev);
	178	}
	179	EXPORT_SYMBOL(dst_dev_put);
	180
8d330868 IJ	181	void dst_release(struct dst_entry *dst)
	182	{
	183	if (dst) {
598ed936	184	int newrefcnt;
ef711cf1	185
598ed936	186	newrefcnt = atomic_dec_return(&dst->__refcnt);
8bf4ada2 KK	187	if (unlikely(newrefcnt < 0))
	188	net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
	189	__func__, dst, newrefcnt);
b2a9c0ed	190	if (!newrefcnt)
f8864972	191	call_rcu(&dst->rcu_head, dst_destroy_rcu);
8d330868 IJ	192	}
	193	}
	194	EXPORT_SYMBOL(dst_release);
	195
5f56f409 WW	196	void dst_release_immediate(struct dst_entry *dst)
	197	{
	198	if (dst) {
	199	int newrefcnt;
	200
	201	newrefcnt = atomic_dec_return(&dst->__refcnt);
	202	if (unlikely(newrefcnt < 0))
	203	net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
	204	__func__, dst, newrefcnt);
	205	if (!newrefcnt)
	206	dst_destroy(dst);
	207	}
	208	}
	209	EXPORT_SYMBOL(dst_release_immediate);
	210
62fa8a84 DM	211	u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old)
62fa8a84 DM	212	{
3fb07daf	213	struct dst_metrics p = kmalloc(sizeof(p), GFP_ATOMIC);
62fa8a84 DM	214
62fa8a84 DM	215	if (p) {
3fb07daf	216	struct dst_metrics old_p = (struct dst_metrics )__DST_METRICS_PTR(old);
62fa8a84 DM	217	unsigned long prev, new;
62fa8a84 DM	218
9620fef2	219	refcount_set(&p->refcnt, 1);
3fb07daf	220	memcpy(p->metrics, old_p->metrics, sizeof(p->metrics));
62fa8a84 DM	221
	222	new = (unsigned long) p;
	223	prev = cmpxchg(&dst->_metrics, old, new);
	224
	225	if (prev != old) {
	226	kfree(p);
3fb07daf	227	p = (struct dst_metrics *)__DST_METRICS_PTR(prev);
62fa8a84 DM	228	if (prev & DST_METRICS_READ_ONLY)
62fa8a84 DM	229	p = NULL;
3fb07daf	230	} else if (prev & DST_METRICS_REFCOUNTED) {
9620fef2	231	if (refcount_dec_and_test(&old_p->refcnt))
3fb07daf	232	kfree(old_p);
62fa8a84 DM	233	}
62fa8a84 DM	234	}
3fb07daf ED	235	BUILD_BUG_ON(offsetof(struct dst_metrics, metrics) != 0);
3fb07daf ED	236	return (u32 *)p;
62fa8a84 DM	237	}
	238	EXPORT_SYMBOL(dst_cow_metrics_generic);
	239
	240	/* Caller asserts that dst_metrics_read_only(dst) is false. */
	241	void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
	242	{
	243	unsigned long prev, new;
	244
3fb07daf	245	new = ((unsigned long) &dst_default_metrics) \| DST_METRICS_READ_ONLY;
62fa8a84 DM	246	prev = cmpxchg(&dst->_metrics, old, new);
	247	if (prev == old)
	248	kfree(__DST_METRICS_PTR(old));
	249	}
	250	EXPORT_SYMBOL(__dst_destroy_metrics_generic);
	251
f38a9eb1 TG	252	static struct dst_ops md_dst_ops = {
	253	.family = AF_UNSPEC,
	254	};
	255
ede2059d	256	static int dst_md_discard_out(struct net net, struct sock sk, struct sk_buff *skb)
f38a9eb1 TG	257	{
	258	WARN_ONCE(1, "Attempting to call output on metadata dst\n");
	259	kfree_skb(skb);
	260	return 0;
	261	}
	262
	263	static int dst_md_discard(struct sk_buff *skb)
	264	{
	265	WARN_ONCE(1, "Attempting to call input on metadata dst\n");
	266	kfree_skb(skb);
	267	return 0;
	268	}
	269
3fcece12 JK	270	static void __metadata_dst_init(struct metadata_dst *md_dst,
	271	enum metadata_type type, u8 optslen)
	272
f38a9eb1	273	{
f38a9eb1 TG	274	struct dst_entry *dst;
f38a9eb1 TG	275
f38a9eb1 TG	276	dst = &md_dst->dst;
f38a9eb1 TG	277	dst_init(dst, &md_dst_ops, NULL, 1, DST_OBSOLETE_NONE,
a4c2fd7f	278	DST_METADATA \| DST_NOCOUNT);
f38a9eb1 TG	279
f38a9eb1 TG	280	dst->input = dst_md_discard;
ede2059d	281	dst->output = dst_md_discard_out;
f38a9eb1 TG	282
f38a9eb1 TG	283	memset(dst + 1, 0, sizeof(md_dst) + optslen - sizeof(dst));
3fcece12	284	md_dst->type = type;
d3aa45ce AS	285	}
d3aa45ce AS	286
3fcece12 JK	287	struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
3fcece12 JK	288	gfp_t flags)
d3aa45ce AS	289	{
	290	struct metadata_dst *md_dst;
	291
	292	md_dst = kmalloc(sizeof(*md_dst) + optslen, flags);
	293	if (!md_dst)
	294	return NULL;
	295
3fcece12	296	__metadata_dst_init(md_dst, type, optslen);
f38a9eb1 TG	297
	298	return md_dst;
	299	}
	300	EXPORT_SYMBOL_GPL(metadata_dst_alloc);
	301
d71785ff PA	302	void metadata_dst_free(struct metadata_dst *md_dst)
	303	{
	304	#ifdef CONFIG_DST_CACHE
e65a4955 DL	305	if (md_dst->type == METADATA_IP_TUNNEL)
e65a4955 DL	306	dst_cache_destroy(&md_dst->u.tun_info.dst_cache);
d71785ff PA	307	#endif
	308	kfree(md_dst);
	309	}
af308b94	310	EXPORT_SYMBOL_GPL(metadata_dst_free);
d71785ff	311
3fcece12 JK	312	struct metadata_dst __percpu *
3fcece12 JK	313	metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags)
d3aa45ce AS	314	{
	315	int cpu;
	316	struct metadata_dst __percpu *md_dst;
	317
	318	md_dst = __alloc_percpu_gfp(sizeof(struct metadata_dst) + optslen,
	319	__alignof__(struct metadata_dst), flags);
	320	if (!md_dst)
	321	return NULL;
	322
	323	for_each_possible_cpu(cpu)
3fcece12	324	__metadata_dst_init(per_cpu_ptr(md_dst, cpu), type, optslen);
d3aa45ce AS	325
	326	return md_dst;
	327	}
	328	EXPORT_SYMBOL_GPL(metadata_dst_alloc_percpu);
d66f2b91 JK	329
	330	void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst)
	331	{
833e0e2f	332	#ifdef CONFIG_DST_CACHE
d66f2b91 JK	333	int cpu;
d66f2b91 JK	334
d66f2b91 JK	335	for_each_possible_cpu(cpu) {
	336	struct metadata_dst *one_md_dst = per_cpu_ptr(md_dst, cpu);
	337
	338	if (one_md_dst->type == METADATA_IP_TUNNEL)
	339	dst_cache_destroy(&one_md_dst->u.tun_info.dst_cache);
	340	}
	341	#endif
	342	free_percpu(md_dst);
	343	}
	344	EXPORT_SYMBOL_GPL(metadata_dst_free_percpu);