netfilter: ipset: mark the rcu locked areas properly

When we bump the uref counter, there's no need to keep
the rcu lock because the referred hash table can't
disappear. Also, from the same reason in mtype_gc we
need the rcu lock and not a spinlock.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index dedf59b661ddf37d3a93ef5a049ad75b7413f7d8..c9a07176624388b3772c07be8ed01dfcb58eea2d 100644 (file)
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -569,9 +569,10 @@ mtype_gc(struct work_struct *work)
        set = gc->set;
        h = set->data;
 
-       spin_lock_bh(&set->lock);
-       t = ipset_dereference_set(h->table, set);
+       rcu_read_lock_bh();
+       t = rcu_dereference_bh(h->table);
        atomic_inc(&t->uref);
+       rcu_read_unlock_bh();
        numof_locks = ahash_numof_locks(t->htable_bits);
        r = gc->region++;
        if (r >= numof_locks) {
@@ -580,7 +581,6 @@ mtype_gc(struct work_struct *work)
        next_run = (IPSET_GC_PERIOD(set->timeout) * HZ) / numof_locks;
        if (next_run < HZ/10)
                next_run = HZ/10;
-       spin_unlock_bh(&set->lock);
 
        mtype_gc_do(set, h, t, r);
 
@@ -860,15 +860,13 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
        key = HKEY(value, h->initval, t->htable_bits);
        r = ahash_region(key);
        atomic_inc(&t->uref);
+       rcu_read_unlock_bh();
        elements = t->hregion[r].elements;
        maxelem = t->maxelem;
        if (elements >= maxelem) {
                u32 e;
-               if (SET_WITH_TIMEOUT(set)) {
-                       rcu_read_unlock_bh();
+               if (SET_WITH_TIMEOUT(set))
                        mtype_gc_do(set, h, t, r);
-                       rcu_read_lock_bh();
-               }
                maxelem = h->maxelem;
                elements = 0;
                for (e = 0; e < ahash_numof_locks(t->htable_bits); e++)
@@ -876,7 +874,6 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
                if (elements >= maxelem && SET_WITH_FORCEADD(set))
                        forceadd = true;
        }
-       rcu_read_unlock_bh();
 
        spin_lock_bh(&t->hregion[r].lock);
        n = rcu_dereference_bh(hbucket(t, key));