forked from Minki/linux
nftables: Convert nft_hash to use generic rhashtable
The sizing of the hash table and the practice of requiring a lookup to retrieve the pprev to be stored in the element cookie before the deletion of an entry is left intact. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Patrick McHardy <kaber@trash.net> Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Graf
David S. Miller
parent
e341694e3e
commit
cfe4a9dda0
@ -15,209 +15,40 @@
|
||||
#include <linux/log2.h>
|
||||
#include <linux/jhash.h>
|
||||
#include <linux/netlink.h>
|
||||
#include <linux/vmalloc.h>
|
||||
#include <linux/rhashtable.h>
|
||||
#include <linux/netfilter.h>
|
||||
#include <linux/netfilter/nf_tables.h>
|
||||
#include <net/netfilter/nf_tables.h>
|
||||
|
||||
#define NFT_HASH_MIN_SIZE 4UL
|
||||
|
||||
struct nft_hash {
|
||||
struct nft_hash_table __rcu *tbl;
|
||||
};
|
||||
|
||||
struct nft_hash_table {
|
||||
unsigned int size;
|
||||
struct nft_hash_elem __rcu *buckets[];
|
||||
};
|
||||
/* We target a hash table size of 4, element hint is 75% of final size */
|
||||
#define NFT_HASH_ELEMENT_HINT 3
|
||||
|
||||
struct nft_hash_elem {
|
||||
struct nft_hash_elem __rcu *next;
|
||||
struct rhash_head node;
|
||||
struct nft_data key;
|
||||
struct nft_data data[];
|
||||
};
|
||||
|
||||
#define nft_hash_for_each_entry(i, head) \
|
||||
for (i = nft_dereference(head); i != NULL; i = nft_dereference(i->next))
|
||||
#define nft_hash_for_each_entry_rcu(i, head) \
|
||||
for (i = rcu_dereference(head); i != NULL; i = rcu_dereference(i->next))
|
||||
|
||||
static u32 nft_hash_rnd __read_mostly;
|
||||
static bool nft_hash_rnd_initted __read_mostly;
|
||||
|
||||
static unsigned int nft_hash_data(const struct nft_data *data,
|
||||
unsigned int hsize, unsigned int len)
|
||||
{
|
||||
unsigned int h;
|
||||
|
||||
h = jhash(data->data, len, nft_hash_rnd);
|
||||
return h & (hsize - 1);
|
||||
}
|
||||
|
||||
static bool nft_hash_lookup(const struct nft_set *set,
|
||||
const struct nft_data *key,
|
||||
struct nft_data *data)
|
||||
{
|
||||
const struct nft_hash *priv = nft_set_priv(set);
|
||||
const struct nft_hash_table *tbl = rcu_dereference(priv->tbl);
|
||||
const struct rhashtable *priv = nft_set_priv(set);
|
||||
const struct nft_hash_elem *he;
|
||||
unsigned int h;
|
||||
|
||||
h = nft_hash_data(key, tbl->size, set->klen);
|
||||
nft_hash_for_each_entry_rcu(he, tbl->buckets[h]) {
|
||||
if (nft_data_cmp(&he->key, key, set->klen))
|
||||
continue;
|
||||
if (set->flags & NFT_SET_MAP)
|
||||
nft_data_copy(data, he->data);
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
he = rhashtable_lookup(priv, key);
|
||||
if (he && set->flags & NFT_SET_MAP)
|
||||
nft_data_copy(data, he->data);
|
||||
|
||||
static void nft_hash_tbl_free(const struct nft_hash_table *tbl)
|
||||
{
|
||||
kvfree(tbl);
|
||||
}
|
||||
|
||||
static unsigned int nft_hash_tbl_size(unsigned int nelem)
|
||||
{
|
||||
return max(roundup_pow_of_two(nelem * 4 / 3), NFT_HASH_MIN_SIZE);
|
||||
}
|
||||
|
||||
static struct nft_hash_table *nft_hash_tbl_alloc(unsigned int nbuckets)
|
||||
{
|
||||
struct nft_hash_table *tbl;
|
||||
size_t size;
|
||||
|
||||
size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
|
||||
tbl = kzalloc(size, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN);
|
||||
if (tbl == NULL)
|
||||
tbl = vzalloc(size);
|
||||
if (tbl == NULL)
|
||||
return NULL;
|
||||
tbl->size = nbuckets;
|
||||
|
||||
return tbl;
|
||||
}
|
||||
|
||||
static void nft_hash_chain_unzip(const struct nft_set *set,
|
||||
const struct nft_hash_table *ntbl,
|
||||
struct nft_hash_table *tbl, unsigned int n)
|
||||
{
|
||||
struct nft_hash_elem *he, *last, *next;
|
||||
unsigned int h;
|
||||
|
||||
he = nft_dereference(tbl->buckets[n]);
|
||||
if (he == NULL)
|
||||
return;
|
||||
h = nft_hash_data(&he->key, ntbl->size, set->klen);
|
||||
|
||||
/* Find last element of first chain hashing to bucket h */
|
||||
last = he;
|
||||
nft_hash_for_each_entry(he, he->next) {
|
||||
if (nft_hash_data(&he->key, ntbl->size, set->klen) != h)
|
||||
break;
|
||||
last = he;
|
||||
}
|
||||
|
||||
/* Unlink first chain from the old table */
|
||||
RCU_INIT_POINTER(tbl->buckets[n], last->next);
|
||||
|
||||
/* If end of chain reached, done */
|
||||
if (he == NULL)
|
||||
return;
|
||||
|
||||
/* Find first element of second chain hashing to bucket h */
|
||||
next = NULL;
|
||||
nft_hash_for_each_entry(he, he->next) {
|
||||
if (nft_hash_data(&he->key, ntbl->size, set->klen) != h)
|
||||
continue;
|
||||
next = he;
|
||||
break;
|
||||
}
|
||||
|
||||
/* Link the two chains */
|
||||
RCU_INIT_POINTER(last->next, next);
|
||||
}
|
||||
|
||||
static int nft_hash_tbl_expand(const struct nft_set *set, struct nft_hash *priv)
|
||||
{
|
||||
struct nft_hash_table *tbl = nft_dereference(priv->tbl), *ntbl;
|
||||
struct nft_hash_elem *he;
|
||||
unsigned int i, h;
|
||||
bool complete;
|
||||
|
||||
ntbl = nft_hash_tbl_alloc(tbl->size * 2);
|
||||
if (ntbl == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
/* Link new table's buckets to first element in the old table
|
||||
* hashing to the new bucket.
|
||||
*/
|
||||
for (i = 0; i < ntbl->size; i++) {
|
||||
h = i < tbl->size ? i : i - tbl->size;
|
||||
nft_hash_for_each_entry(he, tbl->buckets[h]) {
|
||||
if (nft_hash_data(&he->key, ntbl->size, set->klen) != i)
|
||||
continue;
|
||||
RCU_INIT_POINTER(ntbl->buckets[i], he);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/* Publish new table */
|
||||
rcu_assign_pointer(priv->tbl, ntbl);
|
||||
|
||||
/* Unzip interleaved hash chains */
|
||||
do {
|
||||
/* Wait for readers to use new table/unzipped chains */
|
||||
synchronize_rcu();
|
||||
|
||||
complete = true;
|
||||
for (i = 0; i < tbl->size; i++) {
|
||||
nft_hash_chain_unzip(set, ntbl, tbl, i);
|
||||
if (tbl->buckets[i] != NULL)
|
||||
complete = false;
|
||||
}
|
||||
} while (!complete);
|
||||
|
||||
nft_hash_tbl_free(tbl);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int nft_hash_tbl_shrink(const struct nft_set *set, struct nft_hash *priv)
|
||||
{
|
||||
struct nft_hash_table *tbl = nft_dereference(priv->tbl), *ntbl;
|
||||
struct nft_hash_elem __rcu **pprev;
|
||||
unsigned int i;
|
||||
|
||||
ntbl = nft_hash_tbl_alloc(tbl->size / 2);
|
||||
if (ntbl == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
for (i = 0; i < ntbl->size; i++) {
|
||||
ntbl->buckets[i] = tbl->buckets[i];
|
||||
|
||||
for (pprev = &ntbl->buckets[i]; *pprev != NULL;
|
||||
pprev = &nft_dereference(*pprev)->next)
|
||||
;
|
||||
RCU_INIT_POINTER(*pprev, tbl->buckets[i + ntbl->size]);
|
||||
}
|
||||
|
||||
/* Publish new table */
|
||||
rcu_assign_pointer(priv->tbl, ntbl);
|
||||
synchronize_rcu();
|
||||
|
||||
nft_hash_tbl_free(tbl);
|
||||
return 0;
|
||||
return !!he;
|
||||
}
|
||||
|
||||
static int nft_hash_insert(const struct nft_set *set,
|
||||
const struct nft_set_elem *elem)
|
||||
{
|
||||
struct nft_hash *priv = nft_set_priv(set);
|
||||
struct nft_hash_table *tbl = nft_dereference(priv->tbl);
|
||||
struct rhashtable *priv = nft_set_priv(set);
|
||||
struct nft_hash_elem *he;
|
||||
unsigned int size, h;
|
||||
unsigned int size;
|
||||
|
||||
if (elem->flags != 0)
|
||||
return -EINVAL;
|
||||
@ -234,13 +65,7 @@ static int nft_hash_insert(const struct nft_set *set,
|
||||
if (set->flags & NFT_SET_MAP)
|
||||
nft_data_copy(he->data, &elem->data);
|
||||
|
||||
h = nft_hash_data(&he->key, tbl->size, set->klen);
|
||||
RCU_INIT_POINTER(he->next, tbl->buckets[h]);
|
||||
rcu_assign_pointer(tbl->buckets[h], he);
|
||||
|
||||
/* Expand table when exceeding 75% load */
|
||||
if (set->nelems + 1 > tbl->size / 4 * 3)
|
||||
nft_hash_tbl_expand(set, priv);
|
||||
rhashtable_insert(priv, &he->node, GFP_KERNEL);
|
||||
|
||||
return 0;
|
||||
}
|
||||
@ -257,36 +82,31 @@ static void nft_hash_elem_destroy(const struct nft_set *set,
|
||||
static void nft_hash_remove(const struct nft_set *set,
|
||||
const struct nft_set_elem *elem)
|
||||
{
|
||||
struct nft_hash *priv = nft_set_priv(set);
|
||||
struct nft_hash_table *tbl = nft_dereference(priv->tbl);
|
||||
struct nft_hash_elem *he, __rcu **pprev;
|
||||
struct rhashtable *priv = nft_set_priv(set);
|
||||
struct rhash_head *he, __rcu **pprev;
|
||||
|
||||
pprev = elem->cookie;
|
||||
he = nft_dereference((*pprev));
|
||||
he = rht_dereference((*pprev), priv);
|
||||
|
||||
rhashtable_remove_pprev(priv, he, pprev, GFP_KERNEL);
|
||||
|
||||
RCU_INIT_POINTER(*pprev, he->next);
|
||||
synchronize_rcu();
|
||||
kfree(he);
|
||||
|
||||
/* Shrink table beneath 30% load */
|
||||
if (set->nelems - 1 < tbl->size * 3 / 10 &&
|
||||
tbl->size > NFT_HASH_MIN_SIZE)
|
||||
nft_hash_tbl_shrink(set, priv);
|
||||
}
|
||||
|
||||
static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
|
||||
{
|
||||
const struct nft_hash *priv = nft_set_priv(set);
|
||||
const struct nft_hash_table *tbl = nft_dereference(priv->tbl);
|
||||
struct nft_hash_elem __rcu * const *pprev;
|
||||
const struct rhashtable *priv = nft_set_priv(set);
|
||||
const struct bucket_table *tbl = rht_dereference_rcu(priv->tbl, priv);
|
||||
struct rhash_head __rcu * const *pprev;
|
||||
struct nft_hash_elem *he;
|
||||
unsigned int h;
|
||||
u32 h;
|
||||
|
||||
h = nft_hash_data(&elem->key, tbl->size, set->klen);
|
||||
h = rhashtable_hashfn(priv, &elem->key, set->klen);
|
||||
pprev = &tbl->buckets[h];
|
||||
nft_hash_for_each_entry(he, tbl->buckets[h]) {
|
||||
rht_for_each_entry_rcu(he, tbl->buckets[h], node) {
|
||||
if (nft_data_cmp(&he->key, &elem->key, set->klen)) {
|
||||
pprev = &he->next;
|
||||
pprev = &he->node.next;
|
||||
continue;
|
||||
}
|
||||
|
||||
@ -302,14 +122,15 @@ static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
|
||||
static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
|
||||
struct nft_set_iter *iter)
|
||||
{
|
||||
const struct nft_hash *priv = nft_set_priv(set);
|
||||
const struct nft_hash_table *tbl = nft_dereference(priv->tbl);
|
||||
const struct rhashtable *priv = nft_set_priv(set);
|
||||
const struct bucket_table *tbl;
|
||||
const struct nft_hash_elem *he;
|
||||
struct nft_set_elem elem;
|
||||
unsigned int i;
|
||||
|
||||
tbl = rht_dereference_rcu(priv->tbl, priv);
|
||||
for (i = 0; i < tbl->size; i++) {
|
||||
nft_hash_for_each_entry(he, tbl->buckets[i]) {
|
||||
rht_for_each_entry_rcu(he, tbl->buckets[i], node) {
|
||||
if (iter->count < iter->skip)
|
||||
goto cont;
|
||||
|
||||
@ -329,48 +150,46 @@ cont:
|
||||
|
||||
static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
|
||||
{
|
||||
return sizeof(struct nft_hash);
|
||||
return sizeof(struct rhashtable);
|
||||
}
|
||||
|
||||
static int lockdep_nfnl_lock_is_held(void)
|
||||
{
|
||||
return lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES);
|
||||
}
|
||||
|
||||
static int nft_hash_init(const struct nft_set *set,
|
||||
const struct nft_set_desc *desc,
|
||||
const struct nlattr * const tb[])
|
||||
{
|
||||
struct nft_hash *priv = nft_set_priv(set);
|
||||
struct nft_hash_table *tbl;
|
||||
unsigned int size;
|
||||
struct rhashtable *priv = nft_set_priv(set);
|
||||
struct rhashtable_params params = {
|
||||
.nelem_hint = desc->size ? : NFT_HASH_ELEMENT_HINT,
|
||||
.head_offset = offsetof(struct nft_hash_elem, node),
|
||||
.key_offset = offsetof(struct nft_hash_elem, key),
|
||||
.key_len = set->klen,
|
||||
.hashfn = jhash,
|
||||
.grow_decision = rht_grow_above_75,
|
||||
.shrink_decision = rht_shrink_below_30,
|
||||
.mutex_is_held = lockdep_nfnl_lock_is_held,
|
||||
};
|
||||
|
||||
if (unlikely(!nft_hash_rnd_initted)) {
|
||||
get_random_bytes(&nft_hash_rnd, 4);
|
||||
nft_hash_rnd_initted = true;
|
||||
}
|
||||
|
||||
size = NFT_HASH_MIN_SIZE;
|
||||
if (desc->size)
|
||||
size = nft_hash_tbl_size(desc->size);
|
||||
|
||||
tbl = nft_hash_tbl_alloc(size);
|
||||
if (tbl == NULL)
|
||||
return -ENOMEM;
|
||||
RCU_INIT_POINTER(priv->tbl, tbl);
|
||||
return 0;
|
||||
return rhashtable_init(priv, ¶ms);
|
||||
}
|
||||
|
||||
static void nft_hash_destroy(const struct nft_set *set)
|
||||
{
|
||||
const struct nft_hash *priv = nft_set_priv(set);
|
||||
const struct nft_hash_table *tbl = nft_dereference(priv->tbl);
|
||||
const struct rhashtable *priv = nft_set_priv(set);
|
||||
const struct bucket_table *tbl;
|
||||
struct nft_hash_elem *he, *next;
|
||||
unsigned int i;
|
||||
|
||||
for (i = 0; i < tbl->size; i++) {
|
||||
for (he = nft_dereference(tbl->buckets[i]); he != NULL;
|
||||
he = next) {
|
||||
next = nft_dereference(he->next);
|
||||
tbl = rht_dereference(priv->tbl, priv);
|
||||
for (i = 0; i < tbl->size; i++)
|
||||
rht_for_each_entry_safe(he, next, tbl->buckets[i], priv, node)
|
||||
nft_hash_elem_destroy(set, he);
|
||||
}
|
||||
}
|
||||
kfree(tbl);
|
||||
|
||||
rhashtable_destroy(priv);
|
||||
}
|
||||
|
||||
static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
|
||||
@ -383,8 +202,8 @@ static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
|
||||
esize += FIELD_SIZEOF(struct nft_hash_elem, data[0]);
|
||||
|
||||
if (desc->size) {
|
||||
est->size = sizeof(struct nft_hash) +
|
||||
nft_hash_tbl_size(desc->size) *
|
||||
est->size = sizeof(struct rhashtable) +
|
||||
roundup_pow_of_two(desc->size * 4 / 3) *
|
||||
sizeof(struct nft_hash_elem *) +
|
||||
desc->size * esize;
|
||||
} else {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user