netfilter: nf_ct_helper: unlink helper again when hash resize happen

From: Liping Zhang <liping.zhang@spreadtrum.com>

Similar to ctnl_untimeout, when hash resize happened, we should try
to do unhelp from the 0# bucket again.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 3a1a88b9bafa08d9ecc5c2eb48fe8bcb012e418a..a4294e949cdc0762d4bb5a80d6b8a6d8f5a91ff6 100644 (file)
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -409,6 +409,8 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
        struct nf_conntrack_expect *exp;
        const struct hlist_node *next;
        const struct hlist_nulls_node *nn;
+       unsigned int last_hsize;
+       spinlock_t *lock;
        struct net *net;
        unsigned int i;
 
@@ -446,13 +448,18 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
        rtnl_unlock();
 
        local_bh_disable();
-       for (i = 0; i < nf_conntrack_htable_size; i++) {
-               nf_conntrack_lock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
-               if (i < nf_conntrack_htable_size) {
-                       hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
-                               unhelp(h, me);
+restart:
+       last_hsize = nf_conntrack_htable_size;
+       for (i = 0; i < last_hsize; i++) {
+               lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
+               nf_conntrack_lock(lock);
+               if (last_hsize != nf_conntrack_htable_size) {
+                       spin_unlock(lock);
+                       goto restart;
                }
-               spin_unlock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
+               hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
+                       unhelp(h, me);
+               spin_unlock(lock);
        }
        local_bh_enable();
 }