1 files changed, 18 insertions, 34 deletions

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index fb7fcb773a3f..017c95966aa8 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -90,7 +90,7 @@ struct dsthash_ent {
 
 struct xt_hashlimit_htable {
         struct hlist_node node;         /* global list of all htables */
-        atomic_t use;
+        int use;
         u_int8_t family;
         bool rnd_initialized;
 
@@ -109,8 +109,7 @@ struct xt_hashlimit_htable {
         struct hlist_head hash[0];      /* hashtable itself */
 };
 
-static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
-static DEFINE_MUTEX(hlimit_mutex);      /* additional checkentry protection */
+static DEFINE_MUTEX(hashlimit_mutex);   /* protects htables list */
 static struct kmem_cache *hashlimit_cachep __read_mostly;
 
 static inline bool dst_cmp(const struct dsthash_ent *ent,
@@ -244,7 +243,7 @@ static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_
         for (i = 0; i < hinfo->cfg.size; i++)
                 INIT_HLIST_HEAD(&hinfo->hash[i]);
 
-        atomic_set(&hinfo->use, 1);
+        hinfo->use = 1;
         hinfo->count = 0;
         hinfo->family = family;
         hinfo->rnd_initialized = false;
@@ -263,9 +262,9 @@ static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_
         hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
         add_timer(&hinfo->timer);
 
-        spin_lock_bh(&hashlimit_lock);
+        mutex_lock(&hashlimit_mutex);
         hlist_add_head(&hinfo->node, &hashlimit_net->htables);
-        spin_unlock_bh(&hashlimit_lock);
+        mutex_unlock(&hashlimit_mutex);
 
         return 0;
 }
@@ -308,7 +307,7 @@ static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
         for (i = 0; i < hinfo->cfg.size; i++)
                 INIT_HLIST_HEAD(&hinfo->hash[i]);
 
-        atomic_set(&hinfo->use, 1);
+        hinfo->use = 1;
         hinfo->count = 0;
         hinfo->family = family;
         hinfo->rnd_initialized = false;
@@ -328,9 +327,9 @@ static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
         hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
         add_timer(&hinfo->timer);
 
-        spin_lock_bh(&hashlimit_lock);
+        mutex_lock(&hashlimit_mutex);
         hlist_add_head(&hinfo->node, &hashlimit_net->htables);
-        spin_unlock_bh(&hashlimit_lock);
+        mutex_unlock(&hashlimit_mutex);
 
         return 0;
 }
@@ -402,27 +401,24 @@ static struct xt_hashlimit_htable *htable_find_get(struct net *net,
         struct xt_hashlimit_htable *hinfo;
         struct hlist_node *pos;
 
-        spin_lock_bh(&hashlimit_lock);
         hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
                 if (!strcmp(name, hinfo->pde->name) &&
                     hinfo->family == family) {
-                        atomic_inc(&hinfo->use);
-                        spin_unlock_bh(&hashlimit_lock);
+                        hinfo->use++;
                         return hinfo;
                 }
         }
-        spin_unlock_bh(&hashlimit_lock);
         return NULL;
 }
 
 static void htable_put(struct xt_hashlimit_htable *hinfo)
 {
-        if (atomic_dec_and_test(&hinfo->use)) {
-                spin_lock_bh(&hashlimit_lock);
+        mutex_lock(&hashlimit_mutex);
+        if (--hinfo->use == 0) {
                 hlist_del(&hinfo->node);
-                spin_unlock_bh(&hashlimit_lock);
                 htable_destroy(hinfo);
         }
+        mutex_unlock(&hashlimit_mutex);
 }
 
 /* The algorithm used is the Simple Token Bucket Filter (TBF)
@@ -710,19 +706,13 @@ static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
         if (r->name[sizeof(r->name) - 1] != '\0')
                 return false;
 
-        /* This is the best we've got: We cannot release and re-grab lock,
-         * since checkentry() is called before x_tables.c grabs xt_mutex.
-         * We also cannot grab the hashtable spinlock, since htable_create will
-         * call vmalloc, and that can sleep.  And we cannot just re-search
-         * the list of htable's in htable_create(), since then we would
-         * create duplicate proc files. -HW */
-        mutex_lock(&hlimit_mutex);
+        mutex_lock(&hashlimit_mutex);
         r->hinfo = htable_find_get(net, r->name, par->match->family);
         if (!r->hinfo && htable_create_v0(net, r, par->match->family) != 0) {
-                mutex_unlock(&hlimit_mutex);
+                mutex_unlock(&hashlimit_mutex);
                 return false;
         }
-        mutex_unlock(&hlimit_mutex);
+        mutex_unlock(&hashlimit_mutex);
 
         return true;
 }
@@ -752,19 +742,13 @@ static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
                         return false;
         }
 
-        /* This is the best we've got: We cannot release and re-grab lock,
-         * since checkentry() is called before x_tables.c grabs xt_mutex.
-         * We also cannot grab the hashtable spinlock, since htable_create will
-         * call vmalloc, and that can sleep.  And we cannot just re-search
-         * the list of htable's in htable_create(), since then we would
-         * create duplicate proc files. -HW */
-        mutex_lock(&hlimit_mutex);
+        mutex_lock(&hashlimit_mutex);
         info->hinfo = htable_find_get(net, info->name, par->match->family);
         if (!info->hinfo && htable_create(net, info, par->match->family) != 0) {
-                mutex_unlock(&hlimit_mutex);
+                mutex_unlock(&hashlimit_mutex);
                 return false;
         }
-        mutex_unlock(&hlimit_mutex);
+        mutex_unlock(&hashlimit_mutex);
         return true;
 }