netfilter: ipset: references are protected by rwlock instead of mutex

The timeout variant of the list:set type must reference the member sets.
However, its garbage collector runs at timer interrupt so the mutex
protection of the references is a no go. Therefore the reference protection
is converted to rwlock.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

2 files changed, 2 insertions, 3 deletions

diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h
index ec333d83f3b4..5a262e3ae715 100644
--- a/include/linux/netfilter/ipset/ip_set.h
+++ b/include/linux/netfilter/ipset/ip_set.h
@@ -293,7 +293,7 @@ struct ip_set {
         /* Lock protecting the set data */
         rwlock_t lock;
         /* References to the set */
-        atomic_t ref;
+        u32 ref;
         /* The core set type */
         struct ip_set_type *type;
         /* The type variant doing the real job */
diff --git a/include/linux/netfilter/ipset/ip_set_ahash.h b/include/linux/netfilter/ipset/ip_set_ahash.h
index ec9d9bea1e37..a0196ac79051 100644
--- a/include/linux/netfilter/ipset/ip_set_ahash.h
+++ b/include/linux/netfilter/ipset/ip_set_ahash.h
@@ -515,8 +515,7 @@ type_pf_head(struct ip_set *set, struct sk_buff *skb)
         if (h->netmask != HOST_MASK)
                 NLA_PUT_U8(skb, IPSET_ATTR_NETMASK, h->netmask);
 #endif
-        NLA_PUT_NET32(skb, IPSET_ATTR_REFERENCES,
-                      htonl(atomic_read(&set->ref) - 1));
+        NLA_PUT_NET32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1));
         NLA_PUT_NET32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize));
         if (with_timeout(h->timeout))
                 NLA_PUT_NET32(skb, IPSET_ATTR_TIMEOUT, htonl(h->timeout));