diff options
Diffstat (limited to 'kernel/net/netfilter/ipset/ip_set_hash_gen.h')
| -rw-r--r-- | kernel/net/netfilter/ipset/ip_set_hash_gen.h | 44 |
1 files changed, 40 insertions, 4 deletions
diff --git a/kernel/net/netfilter/ipset/ip_set_hash_gen.h b/kernel/net/netfilter/ipset/ip_set_hash_gen.h index 6fd7db7..6c8fc0b 100644 --- a/kernel/net/netfilter/ipset/ip_set_hash_gen.h +++ b/kernel/net/netfilter/ipset/ip_set_hash_gen.h @@ -75,6 +75,8 @@ struct hbucket { /* The hash table: the table size stored here in order to make resizing easy */ struct htable { + atomic_t ref; /* References for resizing */ + atomic_t uref; /* References for dumping */ u8 htable_bits; /* size of hash table == 2^htable_bits */ struct hbucket * __rcu bucket[0]; /* hashtable buckets */ }; @@ -184,6 +186,7 @@ htable_bits(u32 hashsize) #undef mtype_del #undef mtype_test_cidrs #undef mtype_test +#undef mtype_uref #undef mtype_expire #undef mtype_resize #undef mtype_head @@ -225,6 +228,7 @@ htable_bits(u32 hashsize) #define mtype_del IPSET_TOKEN(MTYPE, _del) #define mtype_test_cidrs IPSET_TOKEN(MTYPE, _test_cidrs) #define mtype_test IPSET_TOKEN(MTYPE, _test) +#define mtype_uref IPSET_TOKEN(MTYPE, _uref) #define mtype_expire IPSET_TOKEN(MTYPE, _expire) #define mtype_resize IPSET_TOKEN(MTYPE, _resize) #define mtype_head IPSET_TOKEN(MTYPE, _head) @@ -562,6 +566,8 @@ retry: spin_lock_bh(&set->lock); orig = h->table; + atomic_set(&orig->ref, 1); + atomic_inc(&orig->uref); pr_debug("attempt to resize set %s from %u to %u, t %p\n", set->name, orig->htable_bits, htable_bits, orig); for (i = 0; i < jhash_size(orig->htable_bits); i++) { @@ -605,6 +611,8 @@ retry: ret = -ENOMEM; } if (ret < 0) { + atomic_set(&orig->ref, 0); + atomic_dec(&orig->uref); spin_unlock_bh(&set->lock); mtype_ahash_destroy(set, t, false); if (ret == -EAGAIN) @@ -634,7 +642,11 @@ retry: pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name, orig->htable_bits, orig, t->htable_bits, t); - mtype_ahash_destroy(set, orig, false); + /* If there's nobody else dumping the table, destroy it */ + if (atomic_dec_and_test(&orig->uref)) { + pr_debug("Table destroy by resize %p\n", orig); + mtype_ahash_destroy(set, orig, false); + } return 0; @@ -1032,12 +1044,35 @@ nla_put_failure: return -EMSGSIZE; } +/* Make possible to run dumping parallel with resizing */ +static void +mtype_uref(struct ip_set *set, struct netlink_callback *cb, bool start) +{ + struct htype *h = set->data; + struct htable *t; + + if (start) { + rcu_read_lock_bh(); + t = rcu_dereference_bh_nfnl(h->table); + atomic_inc(&t->uref); + cb->args[IPSET_CB_PRIVATE] = (unsigned long) t; + rcu_read_unlock_bh(); + } else if (cb->args[IPSET_CB_PRIVATE]) { + t = (struct htable *) cb->args[IPSET_CB_PRIVATE]; + if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) { + /* Resizing didn't destroy the hash table */ + pr_debug("Table destroy by dump: %p\n", t); + mtype_ahash_destroy(set, t, false); + } + cb->args[IPSET_CB_PRIVATE] = 0; + } +} + /* Reply a LIST/SAVE request: dump the elements of the specified set */ static int mtype_list(const struct ip_set *set, struct sk_buff *skb, struct netlink_callback *cb) { - const struct htype *h = set->data; const struct htable *t; struct nlattr *atd, *nested; const struct hbucket *n; @@ -1052,11 +1087,11 @@ mtype_list(const struct ip_set *set, return -EMSGSIZE; pr_debug("list hash set %s\n", set->name); - t = rcu_dereference_bh_nfnl(h->table); + t = (const struct htable *) cb->args[IPSET_CB_PRIVATE]; for (; cb->args[IPSET_CB_ARG0] < jhash_size(t->htable_bits); cb->args[IPSET_CB_ARG0]++) { incomplete = skb_tail_pointer(skb); - n = rcu_dereference_bh(hbucket(t, cb->args[IPSET_CB_ARG0])); + n = hbucket(t, cb->args[IPSET_CB_ARG0]); pr_debug("cb->arg bucket: %lu, t %p n %p\n", cb->args[IPSET_CB_ARG0], t, n); if (n == NULL) @@ -1126,6 +1161,7 @@ static const struct ip_set_type_variant mtype_variant = { .flush = mtype_flush, .head = mtype_head, .list = mtype_list, + .uref = mtype_uref, .resize = mtype_resize, .same_set = mtype_same_set, }; |