Merge branch 'master' of git://blackhole.kfki.hu/nf

Jozsef Kadlecsik says:

====================
ipset patches for nf

The first one is larger than usual, but the issue could not be solved simpler.
Also, it's a resend of the patch I submitted a few days ago, with a one line
fix on top of that: the size of the comment extensions was not taken into
account at reporting the full size of the set.

- Fix "INFO: rcu detected stall in hash_xxx" reports of syzbot
by introducing region locking and using workqueue instead of timer based
gc of timed out entries in hash types of sets in ipset.
- Fix the forceadd evaluation path - the bug was also uncovered by the syzbot.
====================

Signed-off-by: Pablo Neira Ayuso <[e-mail]>

include/linux/netfilter/ipset/ip_set.h

···
 	u32 timeout;
 	u8 packets_op;
 	u8 bytes_op;
+	bool target;
 };
 
 struct ip_set;
···
 	/* Return true if "b" set is the same as "a"
 	 * according to the create set parameters */
 	bool (*same_set)(const struct ip_set *a, const struct ip_set *b);
+	/* Region-locking is used */
+	bool region_lock;
+};
+
+struct ip_set_region {
+	spinlock_t lock;	/* Region lock */
+	size_t ext_size;	/* Size of the dynamic extensions */
+	u32 elements;		/* Number of elements vs timeout */
 };
 
 /* The core set type structure */
···
 }
 
 #define IP_SET_INIT_KEXT(skb, opt, set)			\
-	{ .bytes = (skb)->len, .packets = 1,		\
+	{ .bytes = (skb)->len, .packets = 1, .target = true,\
 	  .timeout = ip_set_adt_opt_timeout(opt, set) }
 
 #define IP_SET_INIT_UEXT(set)				\

net/netfilter/ipset/ip_set_core.c

···
 	return set;
 }
 
+static inline void
+ip_set_lock(struct ip_set *set)
+{
+	if (!set->variant->region_lock)
+		spin_lock_bh(&set->lock);
+}
+
+static inline void
+ip_set_unlock(struct ip_set *set)
+{
+	if (!set->variant->region_lock)
+		spin_unlock_bh(&set->lock);
+}
+
 int
 ip_set_test(ip_set_id_t index, const struct sk_buff *skb,
 	    const struct xt_action_param *par, struct ip_set_adt_opt *opt)
···
 	if (ret == -EAGAIN) {
 		/* Type requests element to be completed */
 		pr_debug("element must be completed, ADD is triggered\n");
-		spin_lock_bh(&set->lock);
+		ip_set_lock(set);
 		set->variant->kadt(set, skb, par, IPSET_ADD, opt);
-		spin_unlock_bh(&set->lock);
+		ip_set_unlock(set);
 		ret = 1;
 	} else {
 		/* --return-nomatch: invert matched element */
···
 	    !(opt->family == set->family || set->family == NFPROTO_UNSPEC))
 		return -IPSET_ERR_TYPE_MISMATCH;
 
-	spin_lock_bh(&set->lock);
+	ip_set_lock(set);
 	ret = set->variant->kadt(set, skb, par, IPSET_ADD, opt);
-	spin_unlock_bh(&set->lock);
+	ip_set_unlock(set);
 
 	return ret;
 }
···
 	    !(opt->family == set->family || set->family == NFPROTO_UNSPEC))
 		return -IPSET_ERR_TYPE_MISMATCH;
 
-	spin_lock_bh(&set->lock);
+	ip_set_lock(set);
 	ret = set->variant->kadt(set, skb, par, IPSET_DEL, opt);
-	spin_unlock_bh(&set->lock);
+	ip_set_unlock(set);
 
 	return ret;
 }
···
 {
 	pr_debug("set: %s\n",  set->name);
 
-	spin_lock_bh(&set->lock);
+	ip_set_lock(set);
 	set->variant->flush(set);
-	spin_unlock_bh(&set->lock);
+	ip_set_unlock(set);
 }
 
 static int ip_set_flush(struct net *net, struct sock *ctnl, struct sk_buff *skb,
···
 	bool eexist = flags & IPSET_FLAG_EXIST, retried = false;
 
 	do {
-		spin_lock_bh(&set->lock);
+		ip_set_lock(set);
 		ret = set->variant->uadt(set, tb, adt, &lineno, flags, retried);
-		spin_unlock_bh(&set->lock);
+		ip_set_unlock(set);
 		retried = true;
 	} while (ret == -EAGAIN &&
 		 set->variant->resize &&

net/netfilter/ipset/ip_set_hash_gen.h

···
 #include <linux/rcupdate.h>
 #include <linux/jhash.h>
 #include <linux/types.h>
+#include <linux/netfilter/nfnetlink.h>
 #include <linux/netfilter/ipset/ip_set.h>
 
-#define __ipset_dereference_protected(p, c)	rcu_dereference_protected(p, c)
-#define ipset_dereference_protected(p, set) \
-	__ipset_dereference_protected(p, lockdep_is_held(&(set)->lock))
-
-#define rcu_dereference_bh_nfnl(p)	rcu_dereference_bh_check(p, 1)
+#define __ipset_dereference(p)		\
+	rcu_dereference_protected(p, 1)
+#define ipset_dereference_nfnl(p)	\
+	rcu_dereference_protected(p,	\
+		lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET))
+#define ipset_dereference_set(p, set) 	\
+	rcu_dereference_protected(p,	\
+		lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET) || \
+		lockdep_is_held(&(set)->lock))
+#define ipset_dereference_bh_nfnl(p)	\
+	rcu_dereference_bh_check(p, 	\
+		lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET))
 
 /* Hashing which uses arrays to resolve clashing. The hash table is resized
  * (doubled) when searching becomes too long.
···
 		__aligned(__alignof__(u64));
 };
 
+/* Region size for locking == 2^HTABLE_REGION_BITS */
+#define HTABLE_REGION_BITS	10
+#define ahash_numof_locks(htable_bits)		\
+	((htable_bits) < HTABLE_REGION_BITS ? 1	\
+		: jhash_size((htable_bits) - HTABLE_REGION_BITS))
+#define ahash_sizeof_regions(htable_bits)		\
+	(ahash_numof_locks(htable_bits) * sizeof(struct ip_set_region))
+#define ahash_region(n, htable_bits)		\
+	((n) % ahash_numof_locks(htable_bits))
+#define ahash_bucket_start(h,  htable_bits)	\
+	((htable_bits) < HTABLE_REGION_BITS ? 0	\
+		: (h) * jhash_size(HTABLE_REGION_BITS))
+#define ahash_bucket_end(h,  htable_bits)	\
+	((htable_bits) < HTABLE_REGION_BITS ? jhash_size(htable_bits)	\
+		: ((h) + 1) * jhash_size(HTABLE_REGION_BITS))
+
+struct htable_gc {
+	struct delayed_work dwork;
+	struct ip_set *set;	/* Set the gc belongs to */
+	u32 region;		/* Last gc run position */
+};
+
 /* 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 */
+	atomic_t uref;		/* References for dumping and gc */
 	u8 htable_bits;		/* size of hash table == 2^htable_bits */
+	u32 maxelem;		/* Maxelem per region */
+	struct ip_set_region *hregion;	/* Region locks and ext sizes */
 	struct hbucket __rcu *bucket[0]; /* hashtable buckets */
 };
 
···
 #define NLEN			0
 #endif /* IP_SET_HASH_WITH_NETS */
 
+#define SET_ELEM_EXPIRED(set, d)	\
+	(SET_WITH_TIMEOUT(set) &&	\
+	 ip_set_timeout_expired(ext_timeout(d, set)))
+
 #endif /* _IP_SET_HASH_GEN_H */
 
 #ifndef MTYPE
···
 #undef mtype_test_cidrs
 #undef mtype_test
 #undef mtype_uref
-#undef mtype_expire
 #undef mtype_resize
+#undef mtype_ext_size
+#undef mtype_resize_ad
 #undef mtype_head
 #undef mtype_list
+#undef mtype_gc_do
 #undef mtype_gc
 #undef mtype_gc_init
 #undef mtype_variant
···
 #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_ext_size		IPSET_TOKEN(MTYPE, _ext_size)
+#define mtype_resize_ad		IPSET_TOKEN(MTYPE, _resize_ad)
 #define mtype_head		IPSET_TOKEN(MTYPE, _head)
 #define mtype_list		IPSET_TOKEN(MTYPE, _list)
+#define mtype_gc_do		IPSET_TOKEN(MTYPE, _gc_do)
 #define mtype_gc		IPSET_TOKEN(MTYPE, _gc)
 #define mtype_gc_init		IPSET_TOKEN(MTYPE, _gc_init)
 #define mtype_variant		IPSET_TOKEN(MTYPE, _variant)
···
 /* The generic hash structure */
 struct htype {
 	struct htable __rcu *table; /* the hash table */
-	struct timer_list gc;	/* garbage collection when timeout enabled */
-	struct ip_set *set;	/* attached to this ip_set */
+	struct htable_gc gc;	/* gc workqueue */
 	u32 maxelem;		/* max elements in the hash */
 	u32 initval;		/* random jhash init value */
 #ifdef IP_SET_HASH_WITH_MARKMASK
···
 #ifdef IP_SET_HASH_WITH_NETMASK
 	u8 netmask;		/* netmask value for subnets to store */
 #endif
+	struct list_head ad;	/* Resize add|del backlist */
 	struct mtype_elem next; /* temporary storage for uadd */
 #ifdef IP_SET_HASH_WITH_NETS
 	struct net_prefixes nets[NLEN]; /* book-keeping of prefixes */
 #endif
+};
+
+/* ADD|DEL entries saved during resize */
+struct mtype_resize_ad {
+	struct list_head list;
+	enum ipset_adt ad;	/* ADD|DEL element */
+	struct mtype_elem d;	/* Element value */
+	struct ip_set_ext ext;	/* Extensions for ADD */
+	struct ip_set_ext mext;	/* Target extensions for ADD */
+	u32 flags;		/* Flags for ADD */
 };
 
 #ifdef IP_SET_HASH_WITH_NETS
···
  * sized networks. cidr == real cidr + 1 to support /0.
  */
 static void
-mtype_add_cidr(struct htype *h, u8 cidr, u8 n)
+mtype_add_cidr(struct ip_set *set, struct htype *h, u8 cidr, u8 n)
 {
 	int i, j;
 
+	spin_lock_bh(&set->lock);
 	/* Add in increasing prefix order, so larger cidr first */
 	for (i = 0, j = -1; i < NLEN && h->nets[i].cidr[n]; i++) {
 		if (j != -1) {
···
 			j = i;
 		} else if (h->nets[i].cidr[n] == cidr) {
 			h->nets[CIDR_POS(cidr)].nets[n]++;
-			return;
+			goto unlock;
 		}
 	}
 	if (j != -1) {
···
 	}
 	h->nets[i].cidr[n] = cidr;
 	h->nets[CIDR_POS(cidr)].nets[n] = 1;
+unlock:
+	spin_unlock_bh(&set->lock);
 }
 
 static void
-mtype_del_cidr(struct htype *h, u8 cidr, u8 n)
+mtype_del_cidr(struct ip_set *set, struct htype *h, u8 cidr, u8 n)
 {
 	u8 i, j, net_end = NLEN - 1;
 
+	spin_lock_bh(&set->lock);
 	for (i = 0; i < NLEN; i++) {
 		if (h->nets[i].cidr[n] != cidr)
 			continue;
 		h->nets[CIDR_POS(cidr)].nets[n]--;
 		if (h->nets[CIDR_POS(cidr)].nets[n] > 0)
-			return;
+			goto unlock;
 		for (j = i; j < net_end && h->nets[j].cidr[n]; j++)
 			h->nets[j].cidr[n] = h->nets[j + 1].cidr[n];
 		h->nets[j].cidr[n] = 0;
-		return;
+		goto unlock;
 	}
+unlock:
+	spin_unlock_bh(&set->lock);
 }
 #endif
 
···
 static size_t
 mtype_ahash_memsize(const struct htype *h, const struct htable *t)
 {
-	return sizeof(*h) + sizeof(*t);
+	return sizeof(*h) + sizeof(*t) + ahash_sizeof_regions(t->htable_bits);
 }
 
 /* Get the ith element from the array block n */
···
 	struct htype *h = set->data;
 	struct htable *t;
 	struct hbucket *n;
-	u32 i;
+	u32 r, i;
 
-	t = ipset_dereference_protected(h->table, set);
-	for (i = 0; i < jhash_size(t->htable_bits); i++) {
-		n = __ipset_dereference_protected(hbucket(t, i), 1);
-		if (!n)
-			continue;
-		if (set->extensions & IPSET_EXT_DESTROY)
-			mtype_ext_cleanup(set, n);
-		/* FIXME: use slab cache */
-		rcu_assign_pointer(hbucket(t, i), NULL);
-		kfree_rcu(n, rcu);
+	t = ipset_dereference_nfnl(h->table);
+	for (r = 0; r < ahash_numof_locks(t->htable_bits); r++) {
+		spin_lock_bh(&t->hregion[r].lock);
+		for (i = ahash_bucket_start(r, t->htable_bits);
+		     i < ahash_bucket_end(r, t->htable_bits); i++) {
+			n = __ipset_dereference(hbucket(t, i));
+			if (!n)
+				continue;
+			if (set->extensions & IPSET_EXT_DESTROY)
+				mtype_ext_cleanup(set, n);
+			/* FIXME: use slab cache */
+			rcu_assign_pointer(hbucket(t, i), NULL);
+			kfree_rcu(n, rcu);
+		}
+		t->hregion[r].ext_size = 0;
+		t->hregion[r].elements = 0;
+		spin_unlock_bh(&t->hregion[r].lock);
 	}
 #ifdef IP_SET_HASH_WITH_NETS
 	memset(h->nets, 0, sizeof(h->nets));
 #endif
-	set->elements = 0;
-	set->ext_size = 0;
 }
 
 /* Destroy the hashtable part of the set */
···
 	u32 i;
 
 	for (i = 0; i < jhash_size(t->htable_bits); i++) {
-		n = __ipset_dereference_protected(hbucket(t, i), 1);
+		n = __ipset_dereference(hbucket(t, i));
 		if (!n)
 			continue;
 		if (set->extensions & IPSET_EXT_DESTROY && ext_destroy)
···
 		kfree(n);
 	}
 
+	ip_set_free(t->hregion);
 	ip_set_free(t);
 }
 
···
 mtype_destroy(struct ip_set *set)
 {
 	struct htype *h = set->data;
+	struct list_head *l, *lt;
 
 	if (SET_WITH_TIMEOUT(set))
-		del_timer_sync(&h->gc);
+		cancel_delayed_work_sync(&h->gc.dwork);
 
-	mtype_ahash_destroy(set,
-			    __ipset_dereference_protected(h->table, 1), true);
+	mtype_ahash_destroy(set, ipset_dereference_nfnl(h->table), true);
+	list_for_each_safe(l, lt, &h->ad) {
+		list_del(l);
+		kfree(l);
+	}
 	kfree(h);
 
 	set->data = NULL;
-}
-
-static void
-mtype_gc_init(struct ip_set *set, void (*gc)(struct timer_list *t))
-{
-	struct htype *h = set->data;
-
-	timer_setup(&h->gc, gc, 0);
-	mod_timer(&h->gc, jiffies + IPSET_GC_PERIOD(set->timeout) * HZ);
-	pr_debug("gc initialized, run in every %u\n",
-		 IPSET_GC_PERIOD(set->timeout));
 }
 
 static bool
···
 	       a->extensions == b->extensions;
 }
 
-/* Delete expired elements from the hashtable */
 static void
-mtype_expire(struct ip_set *set, struct htype *h)
+mtype_gc_do(struct ip_set *set, struct htype *h, struct htable *t, u32 r)
 {
-	struct htable *t;
 	struct hbucket *n, *tmp;
 	struct mtype_elem *data;
 	u32 i, j, d;
···
 #ifdef IP_SET_HASH_WITH_NETS
 	u8 k;
 #endif
+	u8 htable_bits = t->htable_bits;
 
-	t = ipset_dereference_protected(h->table, set);
-	for (i = 0; i < jhash_size(t->htable_bits); i++) {
-		n = __ipset_dereference_protected(hbucket(t, i), 1);
+	spin_lock_bh(&t->hregion[r].lock);
+	for (i = ahash_bucket_start(r, htable_bits);
+	     i < ahash_bucket_end(r, htable_bits); i++) {
+		n = __ipset_dereference(hbucket(t, i));
 		if (!n)
 			continue;
 		for (j = 0, d = 0; j < n->pos; j++) {
···
 			smp_mb__after_atomic();
 #ifdef IP_SET_HASH_WITH_NETS
 			for (k = 0; k < IPSET_NET_COUNT; k++)
-				mtype_del_cidr(h,
+				mtype_del_cidr(set, h,
 					NCIDR_PUT(DCIDR_GET(data->cidr, k)),
 					k);
 #endif
+			t->hregion[r].elements--;
 			ip_set_ext_destroy(set, data);
-			set->elements--;
 			d++;
 		}
 		if (d >= AHASH_INIT_SIZE) {
 			if (d >= n->size) {
+				t->hregion[r].ext_size -=
+					ext_size(n->size, dsize);
 				rcu_assign_pointer(hbucket(t, i), NULL);
 				kfree_rcu(n, rcu);
 				continue;
 			}
 			tmp = kzalloc(sizeof(*tmp) +
-				      (n->size - AHASH_INIT_SIZE) * dsize,
-				      GFP_ATOMIC);
+				(n->size - AHASH_INIT_SIZE) * dsize,
+				GFP_ATOMIC);
 			if (!tmp)
-				/* Still try to delete expired elements */
+				/* Still try to delete expired elements. */
 				continue;
 			tmp->size = n->size - AHASH_INIT_SIZE;
 			for (j = 0, d = 0; j < n->pos; j++) {
 				if (!test_bit(j, n->used))
 					continue;
 				data = ahash_data(n, j, dsize);
-				memcpy(tmp->value + d * dsize, data, dsize);
+				memcpy(tmp->value + d * dsize,
+				       data, dsize);
 				set_bit(d, tmp->used);
 				d++;
 			}
 			tmp->pos = d;
-			set->ext_size -= ext_size(AHASH_INIT_SIZE, dsize);
+			t->hregion[r].ext_size -=
+				ext_size(AHASH_INIT_SIZE, dsize);
 			rcu_assign_pointer(hbucket(t, i), tmp);
 			kfree_rcu(n, rcu);
 		}
 	}
+	spin_unlock_bh(&t->hregion[r].lock);
 }
 
 static void
-mtype_gc(struct timer_list *t)
+mtype_gc(struct work_struct *work)
 {
-	struct htype *h = from_timer(h, t, gc);
-	struct ip_set *set = h->set;
+	struct htable_gc *gc;
+	struct ip_set *set;
+	struct htype *h;
+	struct htable *t;
+	u32 r, numof_locks;
+	unsigned int next_run;
 
-	pr_debug("called\n");
+	gc = container_of(work, struct htable_gc, dwork.work);
+	set = gc->set;
+	h = set->data;
+
 	spin_lock_bh(&set->lock);
-	mtype_expire(set, h);
+	t = ipset_dereference_set(h->table, set);
+	atomic_inc(&t->uref);
+	numof_locks = ahash_numof_locks(t->htable_bits);
+	r = gc->region++;
+	if (r >= numof_locks) {
+		r = gc->region = 0;
+	}
+	next_run = (IPSET_GC_PERIOD(set->timeout) * HZ) / numof_locks;
+	if (next_run < HZ/10)
+		next_run = HZ/10;
 	spin_unlock_bh(&set->lock);
 
-	h->gc.expires = jiffies + IPSET_GC_PERIOD(set->timeout) * HZ;
-	add_timer(&h->gc);
+	mtype_gc_do(set, h, t, r);
+
+	if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
+		pr_debug("Table destroy after resize by expire: %p\n", t);
+		mtype_ahash_destroy(set, t, false);
+	}
+
+	queue_delayed_work(system_power_efficient_wq, &gc->dwork, next_run);
+
 }
+
+static void
+mtype_gc_init(struct htable_gc *gc)
+{
+	INIT_DEFERRABLE_WORK(&gc->dwork, mtype_gc);
+	queue_delayed_work(system_power_efficient_wq, &gc->dwork, HZ);
+}
+
+static int
+mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
+	  struct ip_set_ext *mext, u32 flags);
+static int
+mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext,
+	  struct ip_set_ext *mext, u32 flags);
 
 /* Resize a hash: create a new hash table with doubling the hashsize
  * and inserting the elements to it. Repeat until we succeed or
···
 	struct htype *h = set->data;
 	struct htable *t, *orig;
 	u8 htable_bits;
-	size_t extsize, dsize = set->dsize;
+	size_t dsize = set->dsize;
 #ifdef IP_SET_HASH_WITH_NETS
 	u8 flags;
 	struct mtype_elem *tmp;
···
 	struct mtype_elem *data;
 	struct mtype_elem *d;
 	struct hbucket *n, *m;
-	u32 i, j, key;
+	struct list_head *l, *lt;
+	struct mtype_resize_ad *x;
+	u32 i, j, r, nr, key;
 	int ret;
 
 #ifdef IP_SET_HASH_WITH_NETS
···
 	if (!tmp)
 		return -ENOMEM;
 #endif
-	rcu_read_lock_bh();
-	orig = rcu_dereference_bh_nfnl(h->table);
+	orig = ipset_dereference_bh_nfnl(h->table);
 	htable_bits = orig->htable_bits;
-	rcu_read_unlock_bh();
 
 retry:
 	ret = 0;
···
 		ret = -ENOMEM;
 		goto out;
 	}
+	t->hregion = ip_set_alloc(ahash_sizeof_regions(htable_bits));
+	if (!t->hregion) {
+		kfree(t);
+		ret = -ENOMEM;
+		goto out;
+	}
 	t->htable_bits = htable_bits;
+	t->maxelem = h->maxelem / ahash_numof_locks(htable_bits);
+	for (i = 0; i < ahash_numof_locks(htable_bits); i++)
+		spin_lock_init(&t->hregion[i].lock);
 
-	spin_lock_bh(&set->lock);
-	orig = __ipset_dereference_protected(h->table, 1);
-	/* There can't be another parallel resizing, but dumping is possible */
+	/* There can't be another parallel resizing,
+	 * but dumping, gc, kernel side add/del are possible
+	 */
+	orig = ipset_dereference_bh_nfnl(h->table);
 	atomic_set(&orig->ref, 1);
 	atomic_inc(&orig->uref);
-	extsize = 0;
 	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++) {
-		n = __ipset_dereference_protected(hbucket(orig, i), 1);
-		if (!n)
-			continue;
-		for (j = 0; j < n->pos; j++) {
-			if (!test_bit(j, n->used))
+	for (r = 0; r < ahash_numof_locks(orig->htable_bits); r++) {
+		/* Expire may replace a hbucket with another one */
+		rcu_read_lock_bh();
+		for (i = ahash_bucket_start(r, orig->htable_bits);
+		     i < ahash_bucket_end(r, orig->htable_bits); i++) {
+			n = __ipset_dereference(hbucket(orig, i));
+			if (!n)
 				continue;
-			data = ahash_data(n, j, dsize);
+			for (j = 0; j < n->pos; j++) {
+				if (!test_bit(j, n->used))
+					continue;
+				data = ahash_data(n, j, dsize);
+				if (SET_ELEM_EXPIRED(set, data))
+					continue;
 #ifdef IP_SET_HASH_WITH_NETS
-			/* We have readers running parallel with us,
-			 * so the live data cannot be modified.
-			 */
-			flags = 0;
-			memcpy(tmp, data, dsize);
-			data = tmp;
-			mtype_data_reset_flags(data, &flags);
+				/* We have readers running parallel with us,
+				 * so the live data cannot be modified.
+				 */
+				flags = 0;
+				memcpy(tmp, data, dsize);
+				data = tmp;
+				mtype_data_reset_flags(data, &flags);
 #endif
-			key = HKEY(data, h->initval, htable_bits);
-			m = __ipset_dereference_protected(hbucket(t, key), 1);
-			if (!m) {
-				m = kzalloc(sizeof(*m) +
+				key = HKEY(data, h->initval, htable_bits);
+				m = __ipset_dereference(hbucket(t, key));
+				nr = ahash_region(key, htable_bits);
+				if (!m) {
+					m = kzalloc(sizeof(*m) +
 					    AHASH_INIT_SIZE * dsize,
 					    GFP_ATOMIC);
-				if (!m) {
-					ret = -ENOMEM;
-					goto cleanup;
-				}
-				m->size = AHASH_INIT_SIZE;
-				extsize += ext_size(AHASH_INIT_SIZE, dsize);
-				RCU_INIT_POINTER(hbucket(t, key), m);
-			} else if (m->pos >= m->size) {
-				struct hbucket *ht;
+					if (!m) {
+						ret = -ENOMEM;
+						goto cleanup;
+					}
+					m->size = AHASH_INIT_SIZE;
+					t->hregion[nr].ext_size +=
+						ext_size(AHASH_INIT_SIZE,
+							 dsize);
+					RCU_INIT_POINTER(hbucket(t, key), m);
+				} else if (m->pos >= m->size) {
+					struct hbucket *ht;
 
-				if (m->size >= AHASH_MAX(h)) {
-					ret = -EAGAIN;
-				} else {
-					ht = kzalloc(sizeof(*ht) +
+					if (m->size >= AHASH_MAX(h)) {
+						ret = -EAGAIN;
+					} else {
+						ht = kzalloc(sizeof(*ht) +
 						(m->size + AHASH_INIT_SIZE)
 						* dsize,
 						GFP_ATOMIC);
-					if (!ht)
-						ret = -ENOMEM;
+						if (!ht)
+							ret = -ENOMEM;
+					}
+					if (ret < 0)
+						goto cleanup;
+					memcpy(ht, m, sizeof(struct hbucket) +
+					       m->size * dsize);
+					ht->size = m->size + AHASH_INIT_SIZE;
+					t->hregion[nr].ext_size +=
+						ext_size(AHASH_INIT_SIZE,
+							 dsize);
+					kfree(m);
+					m = ht;
+					RCU_INIT_POINTER(hbucket(t, key), ht);
 				}
-				if (ret < 0)
-					goto cleanup;
-				memcpy(ht, m, sizeof(struct hbucket) +
-					      m->size * dsize);
-				ht->size = m->size + AHASH_INIT_SIZE;
-				extsize += ext_size(AHASH_INIT_SIZE, dsize);
-				kfree(m);
-				m = ht;
-				RCU_INIT_POINTER(hbucket(t, key), ht);
-			}
-			d = ahash_data(m, m->pos, dsize);
-			memcpy(d, data, dsize);
-			set_bit(m->pos++, m->used);
+				d = ahash_data(m, m->pos, dsize);
+				memcpy(d, data, dsize);
+				set_bit(m->pos++, m->used);
+				t->hregion[nr].elements++;
 #ifdef IP_SET_HASH_WITH_NETS
-			mtype_data_reset_flags(d, &flags);
+				mtype_data_reset_flags(d, &flags);
 #endif
+			}
 		}
+		rcu_read_unlock_bh();
 	}
-	rcu_assign_pointer(h->table, t);
-	set->ext_size = extsize;
 
-	spin_unlock_bh(&set->lock);
+	/* There can't be any other writer. */
+	rcu_assign_pointer(h->table, t);
 
 	/* Give time to other readers of the set */
 	synchronize_rcu();
 
 	pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name,
 		 orig->htable_bits, orig, t->htable_bits, t);
-	/* If there's nobody else dumping the table, destroy it */
+	/* Add/delete elements processed by the SET target during resize.
+	 * Kernel-side add cannot trigger a resize and userspace actions
+	 * are serialized by the mutex.
+	 */
+	list_for_each_safe(l, lt, &h->ad) {
+		x = list_entry(l, struct mtype_resize_ad, list);
+		if (x->ad == IPSET_ADD) {
+			mtype_add(set, &x->d, &x->ext, &x->mext, x->flags);
+		} else {
+			mtype_del(set, &x->d, NULL, NULL, 0);
+		}
+		list_del(l);
+		kfree(l);
+	}
+	/* If there's nobody else using 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 ret;
 
 cleanup:
+	rcu_read_unlock_bh();
 	atomic_set(&orig->ref, 0);
 	atomic_dec(&orig->uref);
-	spin_unlock_bh(&set->lock);
 	mtype_ahash_destroy(set, t, false);
 	if (ret == -EAGAIN)
 		goto retry;
 	goto out;
+}
+
+/* Get the current number of elements and ext_size in the set  */
+static void
+mtype_ext_size(struct ip_set *set, u32 *elements, size_t *ext_size)
+{
+	struct htype *h = set->data;
+	const struct htable *t;
+	u32 i, j, r;
+	struct hbucket *n;
+	struct mtype_elem *data;
+
+	t = rcu_dereference_bh(h->table);
+	for (r = 0; r < ahash_numof_locks(t->htable_bits); r++) {
+		for (i = ahash_bucket_start(r, t->htable_bits);
+		     i < ahash_bucket_end(r, t->htable_bits); i++) {
+			n = rcu_dereference_bh(hbucket(t, i));
+			if (!n)
+				continue;
+			for (j = 0; j < n->pos; j++) {
+				if (!test_bit(j, n->used))
+					continue;
+				data = ahash_data(n, j, set->dsize);
+				if (!SET_ELEM_EXPIRED(set, data))
+					(*elements)++;
+			}
+		}
+		*ext_size += t->hregion[r].ext_size;
+	}
 }
 
 /* Add an element to a hash and update the internal counters when succeeded,
···
 	const struct mtype_elem *d = value;
 	struct mtype_elem *data;
 	struct hbucket *n, *old = ERR_PTR(-ENOENT);
-	int i, j = -1;
+	int i, j = -1, ret;
 	bool flag_exist = flags & IPSET_FLAG_EXIST;
 	bool deleted = false, forceadd = false, reuse = false;
-	u32 key, multi = 0;
+	u32 r, key, multi = 0, elements, maxelem;
 
-	if (set->elements >= h->maxelem) {
-		if (SET_WITH_TIMEOUT(set))
-			/* FIXME: when set is full, we slow down here */
-			mtype_expire(set, h);
-		if (set->elements >= h->maxelem && SET_WITH_FORCEADD(set))
+	rcu_read_lock_bh();
+	t = rcu_dereference_bh(h->table);
+	key = HKEY(value, h->initval, t->htable_bits);
+	r = ahash_region(key, t->htable_bits);
+	atomic_inc(&t->uref);
+	elements = t->hregion[r].elements;
+	maxelem = t->maxelem;
+	if (elements >= maxelem) {
+		u32 e;
+		if (SET_WITH_TIMEOUT(set)) {
+			rcu_read_unlock_bh();
+			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++)
+			elements += t->hregion[e].elements;
+		if (elements >= maxelem && SET_WITH_FORCEADD(set))
 			forceadd = true;
 	}
+	rcu_read_unlock_bh();
 
-	t = ipset_dereference_protected(h->table, set);
-	key = HKEY(value, h->initval, t->htable_bits);
-	n = __ipset_dereference_protected(hbucket(t, key), 1);
+	spin_lock_bh(&t->hregion[r].lock);
+	n = rcu_dereference_bh(hbucket(t, key));
 	if (!n) {
-		if (forceadd || set->elements >= h->maxelem)
+		if (forceadd || elements >= maxelem)
 			goto set_full;
 		old = NULL;
 		n = kzalloc(sizeof(*n) + AHASH_INIT_SIZE * set->dsize,
 			    GFP_ATOMIC);
-		if (!n)
-			return -ENOMEM;
+		if (!n) {
+			ret = -ENOMEM;
+			goto unlock;
+		}
 		n->size = AHASH_INIT_SIZE;
-		set->ext_size += ext_size(AHASH_INIT_SIZE, set->dsize);
+		t->hregion[r].ext_size +=
+			ext_size(AHASH_INIT_SIZE, set->dsize);
 		goto copy_elem;
 	}
 	for (i = 0; i < n->pos; i++) {
···
 		}
 		data = ahash_data(n, i, set->dsize);
 		if (mtype_data_equal(data, d, &multi)) {
-			if (flag_exist ||
-			    (SET_WITH_TIMEOUT(set) &&
-			     ip_set_timeout_expired(ext_timeout(data, set)))) {
+			if (flag_exist || SET_ELEM_EXPIRED(set, data)) {
 				/* Just the extensions could be overwritten */
 				j = i;
 				goto overwrite_extensions;
 			}
-			return -IPSET_ERR_EXIST;
+			ret = -IPSET_ERR_EXIST;
+			goto unlock;
 		}
 		/* Reuse first timed out entry */
-		if (SET_WITH_TIMEOUT(set) &&
-		    ip_set_timeout_expired(ext_timeout(data, set)) &&
-		    j == -1) {
+		if (SET_ELEM_EXPIRED(set, data) && j == -1) {
 			j = i;
 			reuse = true;
 		}
 	}
 	if (reuse || forceadd) {
+		if (j == -1)
+			j = 0;
 		data = ahash_data(n, j, set->dsize);
 		if (!deleted) {
 #ifdef IP_SET_HASH_WITH_NETS
 			for (i = 0; i < IPSET_NET_COUNT; i++)
-				mtype_del_cidr(h,
+				mtype_del_cidr(set, h,
 					NCIDR_PUT(DCIDR_GET(data->cidr, i)),
 					i);
 #endif
 			ip_set_ext_destroy(set, data);
-			set->elements--;
+			t->hregion[r].elements--;
 		}
 		goto copy_data;
 	}
-	if (set->elements >= h->maxelem)
+	if (elements >= maxelem)
 		goto set_full;
 	/* Create a new slot */
 	if (n->pos >= n->size) {
···
 		if (n->size >= AHASH_MAX(h)) {
 			/* Trigger rehashing */
 			mtype_data_next(&h->next, d);
-			return -EAGAIN;
+			ret = -EAGAIN;
+			goto resize;
 		}
 		old = n;
 		n = kzalloc(sizeof(*n) +
 			    (old->size + AHASH_INIT_SIZE) * set->dsize,
 			    GFP_ATOMIC);
-		if (!n)
-			return -ENOMEM;
+		if (!n) {
+			ret = -ENOMEM;
+			goto unlock;
+		}
 		memcpy(n, old, sizeof(struct hbucket) +
 		       old->size * set->dsize);
 		n->size = old->size + AHASH_INIT_SIZE;
-		set->ext_size += ext_size(AHASH_INIT_SIZE, set->dsize);
+		t->hregion[r].ext_size +=
+			ext_size(AHASH_INIT_SIZE, set->dsize);
 	}
 
 copy_elem:
 	j = n->pos++;
 	data = ahash_data(n, j, set->dsize);
 copy_data:
-	set->elements++;
+	t->hregion[r].elements++;
 #ifdef IP_SET_HASH_WITH_NETS
 	for (i = 0; i < IPSET_NET_COUNT; i++)
-		mtype_add_cidr(h, NCIDR_PUT(DCIDR_GET(d->cidr, i)), i);
+		mtype_add_cidr(set, h, NCIDR_PUT(DCIDR_GET(d->cidr, i)), i);
 #endif
 	memcpy(data, d, sizeof(struct mtype_elem));
 overwrite_extensions:
···
 		if (old)
 			kfree_rcu(old, rcu);
 	}
+	ret = 0;
+resize:
+	spin_unlock_bh(&t->hregion[r].lock);
+	if (atomic_read(&t->ref) && ext->target) {
+		/* Resize is in process and kernel side add, save values */
+		struct mtype_resize_ad *x;
 
-	return 0;
+		x = kzalloc(sizeof(struct mtype_resize_ad), GFP_ATOMIC);
+		if (!x)
+			/* Don't bother */
+			goto out;
+		x->ad = IPSET_ADD;
+		memcpy(&x->d, value, sizeof(struct mtype_elem));
+		memcpy(&x->ext, ext, sizeof(struct ip_set_ext));
+		memcpy(&x->mext, mext, sizeof(struct ip_set_ext));
+		x->flags = flags;
+		spin_lock_bh(&set->lock);
+		list_add_tail(&x->list, &h->ad);
+		spin_unlock_bh(&set->lock);
+	}
+	goto out;
+
 set_full:
 	if (net_ratelimit())
 		pr_warn("Set %s is full, maxelem %u reached\n",
-			set->name, h->maxelem);
-	return -IPSET_ERR_HASH_FULL;
+			set->name, maxelem);
+	ret = -IPSET_ERR_HASH_FULL;
+unlock:
+	spin_unlock_bh(&t->hregion[r].lock);
+out:
+	if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
+		pr_debug("Table destroy after resize by add: %p\n", t);
+		mtype_ahash_destroy(set, t, false);
+	}
+	return ret;
 }
 
 /* Delete an element from the hash and free up space if possible.
···
 	const struct mtype_elem *d = value;
 	struct mtype_elem *data;
 	struct hbucket *n;
-	int i, j, k, ret = -IPSET_ERR_EXIST;
+	struct mtype_resize_ad *x = NULL;
+	int i, j, k, r, ret = -IPSET_ERR_EXIST;
 	u32 key, multi = 0;
 	size_t dsize = set->dsize;
 
-	t = ipset_dereference_protected(h->table, set);
+	/* Userspace add and resize is excluded by the mutex.
+	 * Kernespace add does not trigger resize.
+	 */
+	rcu_read_lock_bh();
+	t = rcu_dereference_bh(h->table);
 	key = HKEY(value, h->initval, t->htable_bits);
-	n = __ipset_dereference_protected(hbucket(t, key), 1);
+	r = ahash_region(key, t->htable_bits);
+	atomic_inc(&t->uref);
+	rcu_read_unlock_bh();
+
+	spin_lock_bh(&t->hregion[r].lock);
+	n = rcu_dereference_bh(hbucket(t, key));
 	if (!n)
 		goto out;
 	for (i = 0, k = 0; i < n->pos; i++) {
···
 		data = ahash_data(n, i, dsize);
 		if (!mtype_data_equal(data, d, &multi))
 			continue;
-		if (SET_WITH_TIMEOUT(set) &&
-		    ip_set_timeout_expired(ext_timeout(data, set)))
+		if (SET_ELEM_EXPIRED(set, data))
 			goto out;
 
 		ret = 0;
···
 		smp_mb__after_atomic();
 		if (i + 1 == n->pos)
 			n->pos--;
-		set->elements--;
+		t->hregion[r].elements--;
 #ifdef IP_SET_HASH_WITH_NETS
 		for (j = 0; j < IPSET_NET_COUNT; j++)
-			mtype_del_cidr(h, NCIDR_PUT(DCIDR_GET(d->cidr, j)),
-				       j);
+			mtype_del_cidr(set, h,
+				       NCIDR_PUT(DCIDR_GET(d->cidr, j)), j);
 #endif
 		ip_set_ext_destroy(set, data);
 
+		if (atomic_read(&t->ref) && ext->target) {
+			/* Resize is in process and kernel side del,
+			 * save values
+			 */
+			x = kzalloc(sizeof(struct mtype_resize_ad),
+				    GFP_ATOMIC);
+			if (x) {
+				x->ad = IPSET_DEL;
+				memcpy(&x->d, value,
+				       sizeof(struct mtype_elem));
+				x->flags = flags;
+			}
+		}
 		for (; i < n->pos; i++) {
 			if (!test_bit(i, n->used))
 				k++;
 		}
 		if (n->pos == 0 && k == 0) {
-			set->ext_size -= ext_size(n->size, dsize);
+			t->hregion[r].ext_size -= ext_size(n->size, dsize);
 			rcu_assign_pointer(hbucket(t, key), NULL);
 			kfree_rcu(n, rcu);
 		} else if (k >= AHASH_INIT_SIZE) {
···
 				k++;
 			}
 			tmp->pos = k;
-			set->ext_size -= ext_size(AHASH_INIT_SIZE, dsize);
+			t->hregion[r].ext_size -=
+				ext_size(AHASH_INIT_SIZE, dsize);
 			rcu_assign_pointer(hbucket(t, key), tmp);
 			kfree_rcu(n, rcu);
 		}
···
 	}
 
 out:
+	spin_unlock_bh(&t->hregion[r].lock);
+	if (x) {
+		spin_lock_bh(&set->lock);
+		list_add(&x->list, &h->ad);
+		spin_unlock_bh(&set->lock);
+	}
+	if (atomic_dec_and_test(&t->uref) && atomic_read(&t->ref)) {
+		pr_debug("Table destroy after resize by del: %p\n", t);
+		mtype_ahash_destroy(set, t, false);
+	}
 	return ret;
 }
 
···
 	int i, ret = 0;
 	u32 key, multi = 0;
 
+	rcu_read_lock_bh();
 	t = rcu_dereference_bh(h->table);
 #ifdef IP_SET_HASH_WITH_NETS
 	/* If we test an IP address and not a network address,
···
 			goto out;
 	}
 out:
+	rcu_read_unlock_bh();
 	return ret;
 }
 
···
 	const struct htable *t;
 	struct nlattr *nested;
 	size_t memsize;
+	u32 elements = 0;
+	size_t ext_size = 0;
 	u8 htable_bits;
 
-	/* If any members have expired, set->elements will be wrong
-	 * mytype_expire function will update it with the right count.
-	 * we do not hold set->lock here, so grab it first.
-	 * set->elements can still be incorrect in the case of a huge set,
-	 * because elements might time out during the listing.
-	 */
-	if (SET_WITH_TIMEOUT(set)) {
-		spin_lock_bh(&set->lock);
-		mtype_expire(set, h);
-		spin_unlock_bh(&set->lock);
-	}
-
 	rcu_read_lock_bh();
-	t = rcu_dereference_bh_nfnl(h->table);
-	memsize = mtype_ahash_memsize(h, t) + set->ext_size;
+	t = rcu_dereference_bh(h->table);
+	mtype_ext_size(set, &elements, &ext_size);
+	memsize = mtype_ahash_memsize(h, t) + ext_size + set->ext_size;
 	htable_bits = t->htable_bits;
 	rcu_read_unlock_bh();
 
···
 #endif
 	if (nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref)) ||
 	    nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)) ||
-	    nla_put_net32(skb, IPSET_ATTR_ELEMENTS, htonl(set->elements)))
+	    nla_put_net32(skb, IPSET_ATTR_ELEMENTS, htonl(elements)))
 		goto nla_put_failure;
 	if (unlikely(ip_set_put_flags(skb, set)))
 		goto nla_put_failure;
···
 
 	if (start) {
 		rcu_read_lock_bh();
-		t = rcu_dereference_bh_nfnl(h->table);
+		t = ipset_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);
+			pr_debug("Table destroy after resize "
+				 " by dump: %p\n", t);
 			mtype_ahash_destroy(set, t, false);
 		}
 		cb->args[IPSET_CB_PRIVATE] = 0;
···
 			if (!test_bit(i, n->used))
 				continue;
 			e = ahash_data(n, i, set->dsize);
-			if (SET_WITH_TIMEOUT(set) &&
-			    ip_set_timeout_expired(ext_timeout(e, set)))
+			if (SET_ELEM_EXPIRED(set, e))
 				continue;
 			pr_debug("list hash %lu hbucket %p i %u, data %p\n",
 				 cb->args[IPSET_CB_ARG0], n, i, e);
···
 	.uref	= mtype_uref,
 	.resize	= mtype_resize,
 	.same_set = mtype_same_set,
+	.region_lock = true,
 };
 
 #ifdef IP_SET_EMIT_CREATE
···
 	size_t hsize;
 	struct htype *h;
 	struct htable *t;
+	u32 i;
 
 	pr_debug("Create set %s with family %s\n",
 		 set->name, set->family == NFPROTO_IPV4 ? "inet" : "inet6");
···
 		kfree(h);
 		return -ENOMEM;
 	}
+	t->hregion = ip_set_alloc(ahash_sizeof_regions(hbits));
+	if (!t->hregion) {
+		kfree(t);
+		kfree(h);
+		return -ENOMEM;
+	}
+	h->gc.set = set;
+	for (i = 0; i < ahash_numof_locks(hbits); i++)
+		spin_lock_init(&t->hregion[i].lock);
 	h->maxelem = maxelem;
 #ifdef IP_SET_HASH_WITH_NETMASK
 	h->netmask = netmask;
···
 	get_random_bytes(&h->initval, sizeof(h->initval));
 
 	t->htable_bits = hbits;
+	t->maxelem = h->maxelem / ahash_numof_locks(hbits);
 	RCU_INIT_POINTER(h->table, t);
 
-	h->set = set;
+	INIT_LIST_HEAD(&h->ad);
 	set->data = h;
 #ifndef IP_SET_PROTO_UNDEF
 	if (set->family == NFPROTO_IPV4) {
···
 #ifndef IP_SET_PROTO_UNDEF
 		if (set->family == NFPROTO_IPV4)
 #endif
-			IPSET_TOKEN(HTYPE, 4_gc_init)(set,
-				IPSET_TOKEN(HTYPE, 4_gc));
+			IPSET_TOKEN(HTYPE, 4_gc_init)(&h->gc);
 #ifndef IP_SET_PROTO_UNDEF
 		else
-			IPSET_TOKEN(HTYPE, 6_gc_init)(set,
-				IPSET_TOKEN(HTYPE, 6_gc));
+			IPSET_TOKEN(HTYPE, 6_gc_init)(&h->gc);
 #endif
 	}
 	pr_debug("create %s hashsize %u (%u) maxelem %u: %p(%p)\n",