If the set size is known in advance, the table is sized accordingly,
otherwise the table size will default to 64. This is a slight change
in behaviour as previously the default was 4 which eventually required
many expansion iterations.
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 untouched.
Signed-off-by: Thomas Graf <tgraf@xxxxxxx>
---
net/netfilter/nft_hash.c | 291 +++++++++--------------------------------------
1 file changed, 52 insertions(+), 239 deletions(-)
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index 4080ed6..ba7a134 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -15,209 +15,37 @@
#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[];
-};
-
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;
-}
-
-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);
+ he = rhashtable_lookup(priv, key);
+ if (he && set->flags & NFT_SET_MAP)
+ nft_data_copy(data, he->data);
- /* 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 +62,7 @@ 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 +79,28 @@ 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));
-
- RCU_INIT_POINTER(*pprev, he->next);
- synchronize_rcu();
- kfree(he);
+ he = rht_dereference((*pprev), priv);
- /* 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);
+ rhashtable_remove_pprev(priv, he, pprev, GFP_KERNEL);
}
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 +116,15 @@ 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 +144,46 @@ 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,
+ .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], ht, 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 +196,8 @@ 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 {
--
1.9.3
--
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