netfilter: Use rhashtable walk iterator

This patch gets rid of the manual rhashtable walk in nft_hash
which touches rhashtable internals that should not be exposed.
It does so by using the rhashtable iterator primitives.

Note that I'm leaving nft_hash_destroy alone since it's only
invoked on shutdown and it shouldn't be affected by changes
to rhashtable internals (or at least not what I'm planning to
change).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 36 insertions, 17 deletions

diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index 75887d7d2c6a..61e6c407476a 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -130,31 +130,50 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
                           struct nft_set_iter *iter)
 {
         struct rhashtable *priv = nft_set_priv(set);
-        const struct bucket_table *tbl;
         const struct nft_hash_elem *he;
+        struct rhashtable_iter hti;
         struct nft_set_elem elem;
-        unsigned int i;
+        int err;
 
-        tbl = rht_dereference_rcu(priv->tbl, priv);
-        for (i = 0; i < tbl->size; i++) {
-                struct rhash_head *pos;
+        err = rhashtable_walk_init(priv, &hti);
+        iter->err = err;
+        if (err)
+                return;
+
+        err = rhashtable_walk_start(&hti);
+        if (err && err != -EAGAIN) {
+                iter->err = err;
+                goto out;
+        }
 
-                rht_for_each_entry_rcu(he, pos, tbl, i, node) {
-                        if (iter->count < iter->skip)
-                                goto cont;
+        while ((he = rhashtable_walk_next(&hti))) {
+                if (IS_ERR(he)) {
+                        err = PTR_ERR(he);
+                        if (err != -EAGAIN) {
+                                iter->err = err;
+                                goto out;
+                        }
+                }
+
+                if (iter->count < iter->skip)
+                        goto cont;
+
+                memcpy(&elem.key, &he->key, sizeof(elem.key));
+                if (set->flags & NFT_SET_MAP)
+                        memcpy(&elem.data, he->data, sizeof(elem.data));
+                elem.flags = 0;
 
-                        memcpy(&elem.key, &he->key, sizeof(elem.key));
-                        if (set->flags & NFT_SET_MAP)
-                                memcpy(&elem.data, he->data, sizeof(elem.data));
-                        elem.flags = 0;
+                iter->err = iter->fn(ctx, set, iter, &elem);
+                if (iter->err < 0)
+                        goto out;
 
-                        iter->err = iter->fn(ctx, set, iter, &elem);
-                        if (iter->err < 0)
-                                return;
 cont:
-                        iter->count++;
-                }
+                iter->count++;
         }
+
+out:
+        rhashtable_walk_stop(&hti);
+        rhashtable_walk_exit(&hti);
 }
 
 static unsigned int nft_hash_privsize(const struct nlattr * const nla[])