diff --git a/lib/conntrack-icmp.c b/lib/conntrack-icmp.c
index 40fd1d8..4c7960b 100644
--- a/lib/conntrack-icmp.c
+++ b/lib/conntrack-icmp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2016 Nicira, Inc.
+ * Copyright (c) 2015, 2016, 2017, 2018 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -46,16 +46,17 @@ conn_icmp_cast(const struct conn *conn)
 }
 
 static enum ct_update_res
-icmp_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
-                 struct dp_packet *pkt OVS_UNUSED, bool reply, long long now)
+icmp_conn_update(struct conn *conn_, struct dp_packet *pkt OVS_UNUSED,
+                 bool reply, long long now)
 {
     struct conn_icmp *conn = conn_icmp_cast(conn_);
 
-    if (reply && conn->state != ICMPS_REPLY) {
+    conn->state = ICMPS_FIRST;
+    if (reply) {
         conn->state = ICMPS_REPLY;
     }
 
-    conn_update_expiration(ctb, &conn->up, icmp_timeouts[conn->state], now);
+    conn_update_expiration(&conn->up, icmp_timeouts[conn->state], now);
 
     return CT_UPDATE_VALID;
 }
@@ -79,15 +80,12 @@ icmp6_valid_new(struct dp_packet *pkt)
 }
 
 static struct conn *
-icmp_new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt OVS_UNUSED,
-               long long now)
+icmp_new_conn(struct dp_packet *pkt OVS_UNUSED, long long now)
 {
-    struct conn_icmp *conn;
-
-    conn = xzalloc(sizeof *conn);
+    struct conn_icmp *conn = xzalloc(sizeof *conn);
     conn->state = ICMPS_FIRST;
 
-    conn_init_expiration(ctb, &conn->up, icmp_timeouts[conn->state], now);
+    conn_init_expiration(&conn->up, icmp_timeouts[conn->state], now);
 
     return &conn->up;
 }
diff --git a/lib/conntrack-other.c b/lib/conntrack-other.c
index 2920889..79efb5f 100644
--- a/lib/conntrack-other.c
+++ b/lib/conntrack-other.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2016 Nicira, Inc.
+ * Copyright (c) 2015, 2016, 2017, 2018 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -43,8 +43,8 @@ conn_other_cast(const struct conn *conn)
 }
 
 static enum ct_update_res
-other_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
-                  struct dp_packet *pkt OVS_UNUSED, bool reply, long long now)
+other_conn_update(struct conn *conn_, struct dp_packet *pkt OVS_UNUSED,
+                  bool reply, long long now)
 {
     struct conn_other *conn = conn_other_cast(conn_);
 
@@ -54,7 +54,7 @@ other_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
         conn->state = OTHERS_MULTIPLE;
     }
 
-    conn_update_expiration(ctb, &conn->up, other_timeouts[conn->state], now);
+    conn_update_expiration(&conn->up, other_timeouts[conn->state], now);
 
     return CT_UPDATE_VALID;
 }
@@ -66,15 +66,13 @@ other_valid_new(struct dp_packet *pkt OVS_UNUSED)
 }
 
 static struct conn *
-other_new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt OVS_UNUSED,
-               long long now)
+other_new_conn(struct dp_packet *pkt OVS_UNUSED, long long now)
 {
     struct conn_other *conn;
 
     conn = xzalloc(sizeof *conn);
     conn->state = OTHERS_FIRST;
-
-    conn_init_expiration(ctb, &conn->up, other_timeouts[conn->state], now);
+    conn_init_expiration(&conn->up, other_timeouts[conn->state], now);
 
     return &conn->up;
 }
diff --git a/lib/conntrack-private.h b/lib/conntrack-private.h
index a344801..eafe739 100644
--- a/lib/conntrack-private.h
+++ b/lib/conntrack-private.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2016, 2017 Nicira, Inc.
+ * Copyright (c) 2015, 2016, 2017, 2018 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@
 #include <netinet/in.h>
 #include <netinet/ip6.h>
 
+#include "cmap.h"
 #include "conntrack.h"
 #include "ct-dpif.h"
 #include "openvswitch/hmap.h"
@@ -57,12 +58,6 @@ struct conn_key {
     uint8_t nw_proto;
 };
 
-struct nat_conn_key_node {
-    struct hmap_node node;
-    struct conn_key key;
-    struct conn_key value;
-};
-
 /* This is used for alg expectations; an expectation is a
  * context created in preparation for establishing a data
  * connection. The expectation is created by the control
@@ -87,18 +82,107 @@ struct alg_exp_node {
     bool nat_rpl_dst;
 };
 
+struct OVS_LOCKABLE ct_ce_lock {
+    struct ovs_mutex lock;
+};
+
+static inline void ct_ce_lock_init(struct ct_ce_lock *ce_lock)
+{
+    ovs_mutex_init_adaptive(&ce_lock->lock);
+}
+
+static inline void ct_ce_lock_lock(struct ct_ce_lock *ce_lock)
+    OVS_ACQUIRES(ce_lock)
+    OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+    ovs_mutex_lock(&ce_lock->lock);
+}
+
+static inline void ct_ce_lock_unlock(struct ct_ce_lock *ce_lock)
+    OVS_RELEASES(ce_lock)
+    OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+    ovs_mutex_unlock(&ce_lock->lock);
+}
+
+static inline void ct_ce_lock_destroy(struct ct_ce_lock *ce_lock)
+{
+    ovs_mutex_destroy(&ce_lock->lock);
+}
+
+struct OVS_LOCKABLE ct_expiry_lock {
+    struct ovs_mutex lock;
+};
+
+static inline void ct_ex_lock_init(struct ct_expiry_lock *ex_lock)
+{
+    ovs_mutex_init_adaptive(&ex_lock->lock);
+}
+
+static inline void ct_ex_lock_lock(struct ct_expiry_lock *ex_lock)
+    OVS_ACQUIRES(ex_lock)
+    OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+    ovs_mutex_lock(&ex_lock->lock);
+}
+
+static inline void ct_ex_lock_unlock(struct ct_expiry_lock *ex_lock)
+    OVS_RELEASES(ex_lock)
+    OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+    ovs_mutex_unlock(&ex_lock->lock);
+}
+
+static inline void ct_ex_lock_destroy(struct ct_expiry_lock *ex_lock)
+{
+    ovs_mutex_destroy(&ex_lock->lock);
+}
+
+struct OVS_LOCKABLE ct_lock {
+    struct ovs_mutex lock;
+};
+
+static inline void ct_lock_init(struct ct_lock *lock)
+{
+    ovs_mutex_init_adaptive(&lock->lock);
+}
+
+static inline void ct_lock_lock(struct ct_lock *lock)
+    OVS_ACQUIRES(lock)
+    OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+    ovs_mutex_lock(&lock->lock);
+}
+
+static inline void ct_lock_unlock(struct ct_lock *lock)
+    OVS_RELEASES(lock)
+    OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+    ovs_mutex_unlock(&lock->lock);
+}
+
+static inline void ct_lock_destroy(struct ct_lock *lock)
+{
+    ovs_mutex_destroy(&lock->lock);
+}
+
+extern struct ct_lock lock;
+
 struct conn {
     struct conn_key key;
     struct conn_key rev_key;
     /* Only used for orig_tuple support. */
     struct conn_key master_key;
+    struct ct_ce_lock lock;
     long long expiration;
     struct ovs_list exp_node;
     struct hmap_node node;
+    struct cmap_node cm_node;
     ovs_u128 label;
     /* XXX: consider flattening. */
     struct nat_action_info_t *nat_info;
     char *alg;
+    struct conn *nat_conn;
     int seq_skew;
     uint32_t mark;
     uint8_t conn_type;
@@ -119,39 +203,42 @@ enum ct_conn_type {
     CT_CONN_TYPE_UN_NAT,
 };
 
+extern struct ct_l4_proto ct_proto_tcp;
+extern struct ct_l4_proto ct_proto_other;
+extern struct ct_l4_proto ct_proto_icmp4;
+extern struct ct_l4_proto ct_proto_icmp6;
+
 struct ct_l4_proto {
-    struct conn *(*new_conn)(struct conntrack_bucket *, struct dp_packet *pkt,
-                             long long now);
+    struct conn *(*new_conn)(struct dp_packet *pkt, long long now);
     bool (*valid_new)(struct dp_packet *pkt);
     enum ct_update_res (*conn_update)(struct conn *conn,
-                                      struct conntrack_bucket *,
                                       struct dp_packet *pkt, bool reply,
                                       long long now);
     void (*conn_get_protoinfo)(const struct conn *,
                                struct ct_dpif_protoinfo *);
 };
 
-extern struct ct_l4_proto ct_proto_tcp;
-extern struct ct_l4_proto ct_proto_other;
-extern struct ct_l4_proto ct_proto_icmp4;
-extern struct ct_l4_proto ct_proto_icmp6;
-
 extern long long ct_timeout_val[];
+extern struct ovs_list cm_exp_lists[N_CT_TM];
+extern struct ct_expiry_lock ex_lock;
 
 static inline void
-conn_init_expiration(struct conntrack_bucket *ctb, struct conn *conn,
-                        enum ct_timeout tm, long long now)
+conn_init_expiration(struct conn *conn, enum ct_timeout tm, long long now)
 {
     conn->expiration = now + ct_timeout_val[tm];
-    ovs_list_push_back(&ctb->exp_lists[tm], &conn->exp_node);
+    ct_ex_lock_lock(&ex_lock);
+    ovs_list_push_back(&cm_exp_lists[tm], &conn->exp_node);
+    ct_ex_lock_unlock(&ex_lock);
 }
 
 static inline void
-conn_update_expiration(struct conntrack_bucket *ctb, struct conn *conn,
-                       enum ct_timeout tm, long long now)
+conn_update_expiration(struct conn *conn, enum ct_timeout tm, long long now)
 {
+    ct_ex_lock_lock(&ex_lock);
     ovs_list_remove(&conn->exp_node);
-    conn_init_expiration(ctb, conn, tm, now);
+    conn->expiration = now + ct_timeout_val[tm];
+    ovs_list_push_back(&cm_exp_lists[tm], &conn->exp_node);
+    ct_ex_lock_unlock(&ex_lock);
 }
 
 static inline uint32_t
diff --git a/lib/conntrack-tcp.c b/lib/conntrack-tcp.c
index 86d313d..e0b4d11 100644
--- a/lib/conntrack-tcp.c
+++ b/lib/conntrack-tcp.c
@@ -145,8 +145,8 @@ tcp_get_wscale(const struct tcp_header *tcp)
 }
 
 static enum ct_update_res
-tcp_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
-                struct dp_packet *pkt, bool reply, long long now)
+tcp_conn_update(struct conn *conn_, struct dp_packet *pkt, bool reply,
+                long long now)
 {
     struct conn_tcp *conn = conn_tcp_cast(conn_);
     struct tcp_header *tcp = dp_packet_l4(pkt);
@@ -156,20 +156,23 @@ tcp_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
     struct tcp_peer *dst = &conn->peer[reply ? 0 : 1];
     uint8_t sws = 0, dws = 0;
     uint16_t tcp_flags = TCP_FLAGS(tcp->tcp_ctl);
+    enum ct_update_res rc = CT_UPDATE_VALID;
 
     uint16_t win = ntohs(tcp->tcp_winsz);
     uint32_t ack, end, seq, orig_seq;
     uint32_t p_len = tcp_payload_length(pkt);
 
     if (tcp_invalid_flags(tcp_flags)) {
-        return CT_UPDATE_INVALID;
+        rc = CT_UPDATE_INVALID;
+        goto out;
     }
 
     if (((tcp_flags & (TCP_SYN | TCP_ACK)) == TCP_SYN)
         && dst->state >= CT_DPIF_TCPS_FIN_WAIT_2
         && src->state >= CT_DPIF_TCPS_FIN_WAIT_2) {
         src->state = dst->state = CT_DPIF_TCPS_CLOSED;
-        return CT_UPDATE_NEW;
+        rc = CT_UPDATE_NEW;
+        goto out;
     }
 
     if (src->wscale & CT_WSCALE_FLAG
@@ -317,18 +320,18 @@ tcp_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
 
         if (src->state >= CT_DPIF_TCPS_FIN_WAIT_2
             && dst->state >= CT_DPIF_TCPS_FIN_WAIT_2) {
-            conn_update_expiration(ctb, &conn->up, CT_TM_TCP_CLOSED, now);
+            conn_update_expiration(&conn->up, CT_TM_TCP_CLOSED, now);
         } else if (src->state >= CT_DPIF_TCPS_CLOSING
                    && dst->state >= CT_DPIF_TCPS_CLOSING) {
-            conn_update_expiration(ctb, &conn->up, CT_TM_TCP_FIN_WAIT, now);
+            conn_update_expiration(&conn->up, CT_TM_TCP_FIN_WAIT, now);
         } else if (src->state < CT_DPIF_TCPS_ESTABLISHED
                    || dst->state < CT_DPIF_TCPS_ESTABLISHED) {
-            conn_update_expiration(ctb, &conn->up, CT_TM_TCP_OPENING, now);
+            conn_update_expiration(&conn->up, CT_TM_TCP_OPENING, now);
         } else if (src->state >= CT_DPIF_TCPS_CLOSING
                    || dst->state >= CT_DPIF_TCPS_CLOSING) {
-            conn_update_expiration(ctb, &conn->up, CT_TM_TCP_CLOSING, now);
+            conn_update_expiration(&conn->up, CT_TM_TCP_CLOSING, now);
         } else {
-            conn_update_expiration(ctb, &conn->up, CT_TM_TCP_ESTABLISHED, now);
+            conn_update_expiration(&conn->up, CT_TM_TCP_ESTABLISHED, now);
         }
     } else if ((dst->state < CT_DPIF_TCPS_SYN_SENT
                 || dst->state >= CT_DPIF_TCPS_FIN_WAIT_2
@@ -385,10 +388,12 @@ tcp_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
             src->state = dst->state = CT_DPIF_TCPS_TIME_WAIT;
         }
     } else {
-        return CT_UPDATE_INVALID;
+        rc = CT_UPDATE_INVALID;
+        goto out;
     }
 
-    return CT_UPDATE_VALID;
+out:
+    return rc;
 }
 
 static bool
@@ -412,8 +417,7 @@ tcp_valid_new(struct dp_packet *pkt)
 }
 
 static struct conn *
-tcp_new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt,
-             long long now)
+tcp_new_conn(struct dp_packet *pkt, long long now)
 {
     struct conn_tcp* newconn = NULL;
     struct tcp_header *tcp = dp_packet_l4(pkt);
@@ -449,8 +453,7 @@ tcp_new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt,
     src->state = CT_DPIF_TCPS_SYN_SENT;
     dst->state = CT_DPIF_TCPS_CLOSED;
 
-    conn_init_expiration(ctb, &newconn->up, CT_TM_TCP_FIRST_PACKET,
-                         now);
+    conn_init_expiration(&newconn->up, CT_TM_TCP_FIRST_PACKET, now);
 
     return &newconn->up;
 }
diff --git a/lib/conntrack.c b/lib/conntrack.c
index 974f985..fe4099a 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2016, 2017 Nicira, Inc.
+ * Copyright (c) 2015, 2016, 2017, 2018 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -76,22 +76,25 @@ enum ct_alg_ctl_type {
     CT_ALG_CTL_SIP,
 };
 
+static struct cmap cm_conns;
+struct ct_lock lock;
+struct ct_expiry_lock ex_lock;
+struct ovs_list cm_exp_lists[N_CT_TM];
+
 static bool conn_key_extract(struct conntrack *, struct dp_packet *,
                              ovs_be16 dl_type, struct conn_lookup_ctx *,
                              uint16_t zone);
 static uint32_t conn_key_hash(const struct conn_key *, uint32_t basis);
 static void conn_key_reverse(struct conn_key *);
-static void conn_key_lookup(struct conntrack_bucket *ctb,
-                            struct conn_lookup_ctx *ctx,
-                            long long now);
 static bool valid_new(struct dp_packet *pkt, struct conn_key *);
-static struct conn *new_conn(struct conntrack_bucket *, struct dp_packet *pkt,
-                             struct conn_key *, long long now);
-static void delete_conn(struct conn *);
-static enum ct_update_res conn_update(struct conn *,
-                                      struct conntrack_bucket *ctb,
-                                      struct dp_packet *, bool reply,
+static struct conn *new_conn(struct dp_packet *pkt, struct conn_key *,
+                             long long now);
+static enum ct_update_res conn_update(struct dp_packet *pkt,
+                                      struct conn *conn,
+                                      struct conn_lookup_ctx *ctx,
                                       long long now);
+static void delete_conn(struct conn *);
+static void delete_conn_one(struct conn *conn);
 static bool conn_expired(struct conn *, long long now);
 static void set_mark(struct dp_packet *, struct conn *,
                      uint32_t val, uint32_t mask);
@@ -100,21 +103,6 @@ static void set_label(struct dp_packet *, struct conn *,
                       const struct ovs_key_ct_labels *mask);
 static void *clean_thread_main(void *f_);
 
-static struct nat_conn_key_node *
-nat_conn_keys_lookup(struct hmap *nat_conn_keys,
-                     const struct conn_key *key,
-                     uint32_t basis);
-
-static bool
-nat_conn_keys_insert(struct hmap *nat_conn_keys,
-                     const struct conn *nat_conn,
-                     uint32_t hash_basis);
-
-static void
-nat_conn_keys_remove(struct hmap *nat_conn_keys,
-                     const struct conn_key *key,
-                     uint32_t basis);
-
 static bool
 nat_select_range_tuple(struct conntrack *ct, const struct conn *conn,
                        struct conn *nat_conn);
@@ -151,8 +139,7 @@ detect_ftp_ctl_type(const struct conn_lookup_ctx *ctx,
                     struct dp_packet *pkt);
 
 static void
-expectation_clean(struct conntrack *ct, const struct conn_key *master_key,
-                  uint32_t basis);
+expectation_clean(struct conntrack *ct, const struct conn_key *master_key);
 
 static struct ct_l4_proto *l4_protos[] = {
     [IPPROTO_TCP] = &ct_proto_tcp,
@@ -250,6 +237,50 @@ conn_key_cmp(const struct conn_key *key1, const struct conn_key *key2)
 }
 
 static void
+conn_key_lookup(const struct conn_key *key, uint32_t hash, long long now,
+                struct conn **conn_out, bool *reply)
+{
+    struct conn *conn;
+    *conn_out = NULL;
+
+    CMAP_FOR_EACH_WITH_HASH (conn, cm_node, hash, &cm_conns) {
+        if (!conn_key_cmp(&conn->key, key) && !conn_expired(conn, now)) {
+            *conn_out = conn;
+            *reply = false;
+            break;
+        }
+        if (!conn_key_cmp(&conn->rev_key, key) && !conn_expired(conn, now)) {
+            *conn_out = conn;
+            *reply = true;
+            break;
+        }
+    }
+}
+
+static bool
+conn_available(const struct conn_key *key, uint32_t hash, long long now)
+{
+    struct conn *conn;
+    bool found = false;
+
+    CMAP_FOR_EACH_WITH_HASH (conn, cm_node, hash, &cm_conns) {
+        if (!conn_key_cmp(&conn->key, key)
+            && !conn_expired(conn, now)) {
+            found = true;
+            break;
+        }
+
+        if (!conn_key_cmp(&conn->rev_key, key)
+                && !conn_expired(conn, now)) {
+            found = true;
+            break;
+        }
+    }
+
+    return !found;
+}
+
+static void
 ct_print_conn_info(const struct conn *c, const char *log_msg,
                    enum vlog_level vll, bool force, bool rl_on)
 {
@@ -309,31 +340,25 @@ ct_print_conn_info(const struct conn *c, const char *log_msg,
 void
 conntrack_init(struct conntrack *ct)
 {
-    long long now = time_msec();
-
     ct_rwlock_init(&ct->resources_lock);
     ct_rwlock_wrlock(&ct->resources_lock);
-    hmap_init(&ct->nat_conn_keys);
     hmap_init(&ct->alg_expectations);
     hindex_init(&ct->alg_expectation_refs);
     ovs_list_init(&ct->alg_exp_list);
     ct_rwlock_unlock(&ct->resources_lock);
 
-    for (unsigned i = 0; i < CONNTRACK_BUCKETS; i++) {
-        struct conntrack_bucket *ctb = &ct->buckets[i];
+    ct_lock_init(&lock);
+    ct_lock_lock(&lock);
+    cmap_init(&cm_conns);
+    ct_lock_unlock(&lock);
 
-        ct_lock_init(&ctb->lock);
-        ct_lock_lock(&ctb->lock);
-        hmap_init(&ctb->connections);
-        for (unsigned j = 0; j < ARRAY_SIZE(ctb->exp_lists); j++) {
-            ovs_list_init(&ctb->exp_lists[j]);
-        }
-        ct_lock_unlock(&ctb->lock);
-        ovs_mutex_init(&ctb->cleanup_mutex);
-        ovs_mutex_lock(&ctb->cleanup_mutex);
-        ctb->next_cleanup = now + CT_TM_MIN;
-        ovs_mutex_unlock(&ctb->cleanup_mutex);
+    ct_ex_lock_init(&ex_lock);
+    ct_ex_lock_lock(&ex_lock);
+    for (unsigned i = 0; i < ARRAY_SIZE(cm_exp_lists); i++) {
+        ovs_list_init(&cm_exp_lists[i]);
     }
+    ct_ex_lock_unlock(&ex_lock);
+
     ct->hash_basis = random_uint32();
     atomic_count_init(&ct->n_conn, 0);
     atomic_init(&ct->n_conn_limit, DEFAULT_N_CONN_LIMIT);
@@ -341,36 +366,73 @@ conntrack_init(struct conntrack *ct)
     ct->clean_thread = ovs_thread_create("ct_clean", clean_thread_main, ct);
 }
 
+/* Must be called with 'conn' of 'conn_type' CT_CONN_TYPE_DEFAULT.  Also
+ * removes the associated nat 'conn' from the lookup datastructures. */
+static void
+conn_clean(struct conntrack *ct, struct conn *conn)
+    OVS_REQUIRES(lock)
+{
+    ovs_assert(conn->conn_type == CT_CONN_TYPE_DEFAULT);
+
+    if (conn->alg) {
+        expectation_clean(ct, &conn->key);
+    }
+
+    uint32_t hash = conn_key_hash(&conn->key, ct->hash_basis);
+    cmap_remove(&cm_conns, &conn->cm_node, hash);
+    ct_ex_lock_lock(&ex_lock);
+    ovs_list_remove(&conn->exp_node);
+    ct_ex_lock_unlock(&ex_lock);
+    if (conn->nat_conn) {
+        hash = conn_key_hash(&conn->nat_conn->key, ct->hash_basis);
+        cmap_remove(&cm_conns, &conn->nat_conn->cm_node, hash);
+        ct_ex_lock_lock(&ex_lock);
+        ovs_list_remove(&conn->nat_conn->exp_node);
+        ct_ex_lock_unlock(&ex_lock);
+    }
+    ovsrcu_postpone(delete_conn, conn);
+    atomic_count_dec(&ct->n_conn);
+}
+
+static void
+conn_clean_one(struct conntrack *ct, struct conn *conn)
+    OVS_REQUIRES(lock)
+{
+    if (conn->alg) {
+        expectation_clean(ct, &conn->key);
+    }
+
+    uint32_t hash = conn_key_hash(&conn->key, ct->hash_basis);
+    cmap_remove(&cm_conns, &conn->cm_node, hash);
+    ct_ex_lock_lock(&ex_lock);
+    ovs_list_remove(&conn->exp_node);
+    ct_ex_lock_unlock(&ex_lock);
+    if (conn->conn_type == CT_CONN_TYPE_DEFAULT) {
+        atomic_count_dec(&ct->n_conn);
+    }
+    ovsrcu_postpone(delete_conn_one, conn);
+}
+
 /* Destroys the connection tracker 'ct' and frees all the allocated memory. */
 void
 conntrack_destroy(struct conntrack *ct)
 {
+    struct conn *conn;
     latch_set(&ct->clean_thread_exit);
     pthread_join(ct->clean_thread, NULL);
     latch_destroy(&ct->clean_thread_exit);
-    for (unsigned i = 0; i < CONNTRACK_BUCKETS; i++) {
-        struct conntrack_bucket *ctb = &ct->buckets[i];
-        struct conn *conn;
 
-        ovs_mutex_destroy(&ctb->cleanup_mutex);
-        ct_lock_lock(&ctb->lock);
-        HMAP_FOR_EACH_POP (conn, node, &ctb->connections) {
-            if (conn->conn_type == CT_CONN_TYPE_DEFAULT) {
-                atomic_count_dec(&ct->n_conn);
-            }
-            delete_conn(conn);
-        }
-        hmap_destroy(&ctb->connections);
-        ct_lock_unlock(&ctb->lock);
-        ct_lock_destroy(&ctb->lock);
-    }
-    ct_rwlock_wrlock(&ct->resources_lock);
-    struct nat_conn_key_node *nat_conn_key_node;
-    HMAP_FOR_EACH_POP (nat_conn_key_node, node, &ct->nat_conn_keys) {
-        free(nat_conn_key_node);
+    ct_lock_lock(&lock);
+    CMAP_FOR_EACH (conn, cm_node, &cm_conns) {
+        conn_clean_one(ct, conn);
     }
-    hmap_destroy(&ct->nat_conn_keys);
+    cmap_destroy(&cm_conns);
+    ct_lock_unlock(&lock);
+    ct_lock_destroy(&lock);
+
+    ct_ex_lock_destroy(&ex_lock);
 
+    ct_rwlock_wrlock(&ct->resources_lock);
     struct alg_exp_node *alg_exp_node;
     HMAP_FOR_EACH_POP (alg_exp_node, node, &ct->alg_expectations) {
         free(alg_exp_node);
@@ -383,14 +445,6 @@ conntrack_destroy(struct conntrack *ct)
     ct_rwlock_destroy(&ct->resources_lock);
 }
 
-static unsigned hash_to_bucket(uint32_t hash)
-{
-    /* Extracts the most significant bits in hash. The least significant bits
-     * are already used internally by the hmap implementation. */
-    BUILD_ASSERT(CONNTRACK_BUCKETS_SHIFT < 32 && CONNTRACK_BUCKETS_SHIFT >= 1);
-
-    return (hash >> (32 - CONNTRACK_BUCKETS_SHIFT)) % CONNTRACK_BUCKETS;
-}
 
 static void
 write_ct_md(struct dp_packet *pkt, uint16_t zone, const struct conn *conn,
@@ -738,87 +792,19 @@ un_nat_packet(struct dp_packet *pkt, const struct conn *conn,
     }
 }
 
-/* Typical usage of this helper is in non per-packet code;
- * this is because the bucket lock needs to be held for lookup
- * and a hash would have already been needed. Hence, this function
- * is just intended for code clarity. */
-static struct conn *
-conn_lookup(struct conntrack *ct, const struct conn_key *key, long long now)
-{
-    struct conn_lookup_ctx ctx;
-    ctx.conn = NULL;
-    ctx.key = *key;
-    ctx.hash = conn_key_hash(key, ct->hash_basis);
-    unsigned bucket = hash_to_bucket(ctx.hash);
-    conn_key_lookup(&ct->buckets[bucket], &ctx, now);
-    return ctx.conn;
-}
-
 static void
 conn_seq_skew_set(struct conntrack *ct, const struct conn_key *key,
                   long long now, int seq_skew, bool seq_skew_dir)
 {
-    unsigned bucket = hash_to_bucket(conn_key_hash(key, ct->hash_basis));
-    ct_lock_lock(&ct->buckets[bucket].lock);
-    struct conn *conn = conn_lookup(ct, key, now);
+    struct conn *conn;
+    bool reply;
+    uint32_t hash = conn_key_hash(key, ct->hash_basis);
+    conn_key_lookup(key, hash, now, &conn, &reply);
+
     if (conn && seq_skew) {
         conn->seq_skew = seq_skew;
         conn->seq_skew_dir = seq_skew_dir;
     }
-    ct_lock_unlock(&ct->buckets[bucket].lock);
-}
-
-static void
-nat_clean(struct conntrack *ct, struct conn *conn,
-          struct conntrack_bucket *ctb)
-    OVS_REQUIRES(ctb->lock)
-{
-    ct_rwlock_wrlock(&ct->resources_lock);
-    nat_conn_keys_remove(&ct->nat_conn_keys, &conn->rev_key, ct->hash_basis);
-    ct_rwlock_unlock(&ct->resources_lock);
-    ct_lock_unlock(&ctb->lock);
-    unsigned bucket_rev_conn =
-        hash_to_bucket(conn_key_hash(&conn->rev_key, ct->hash_basis));
-    ct_lock_lock(&ct->buckets[bucket_rev_conn].lock);
-    ct_rwlock_wrlock(&ct->resources_lock);
-    long long now = time_msec();
-    struct conn *rev_conn = conn_lookup(ct, &conn->rev_key, now);
-    struct nat_conn_key_node *nat_conn_key_node =
-        nat_conn_keys_lookup(&ct->nat_conn_keys, &conn->rev_key,
-                             ct->hash_basis);
-
-    /* In the unlikely event, rev conn was recreated, then skip
-     * rev_conn cleanup. */
-    if (rev_conn && (!nat_conn_key_node ||
-                     conn_key_cmp(&nat_conn_key_node->value,
-                                  &rev_conn->rev_key))) {
-        hmap_remove(&ct->buckets[bucket_rev_conn].connections,
-                    &rev_conn->node);
-        free(rev_conn);
-    }
-
-    delete_conn(conn);
-    ct_rwlock_unlock(&ct->resources_lock);
-    ct_lock_unlock(&ct->buckets[bucket_rev_conn].lock);
-    ct_lock_lock(&ctb->lock);
-}
-
-static void
-conn_clean(struct conntrack *ct, struct conn *conn,
-           struct conntrack_bucket *ctb)
-    OVS_REQUIRES(ctb->lock)
-{
-    if (conn->alg) {
-        expectation_clean(ct, &conn->key, ct->hash_basis);
-    }
-    ovs_list_remove(&conn->exp_node);
-    hmap_remove(&ctb->connections, &conn->node);
-    atomic_count_dec(&ct->n_conn);
-    if (conn->nat_info) {
-        nat_clean(ct, conn, ctb);
-    } else {
-        delete_conn(conn);
-    }
 }
 
 static bool
@@ -841,17 +827,16 @@ ct_verify_helper(const char *helper, enum ct_alg_ctl_type ct_alg_ctl)
     }
 }
 
-/* This function is called with the bucket lock held. */
 static struct conn *
 conn_not_found(struct conntrack *ct, struct dp_packet *pkt,
                struct conn_lookup_ctx *ctx, bool commit, long long now,
                const struct nat_action_info_t *nat_action_info,
-               struct conn *conn_for_un_nat_copy,
-               const char *helper,
-               const struct alg_exp_node *alg_exp,
+               const char *helper, const struct alg_exp_node *alg_exp,
                enum ct_alg_ctl_type ct_alg_ctl)
+    OVS_REQUIRES(lock)
 {
     struct conn *nc = NULL;
+    struct conn *nat_conn = NULL;
 
     if (!valid_new(pkt, &ctx->key)) {
         pkt->md.ct_state = CS_INVALID;
@@ -873,8 +858,7 @@ conn_not_found(struct conntrack *ct, struct dp_packet *pkt,
             return nc;
         }
 
-        unsigned bucket = hash_to_bucket(ctx->hash);
-        nc = new_conn(&ct->buckets[bucket], pkt, &ctx->key, now);
+        nc = new_conn(pkt, &ctx->key, now);
         ctx->conn = nc;
         nc->rev_key = nc->key;
         conn_key_reverse(&nc->rev_key);
@@ -893,6 +877,8 @@ conn_not_found(struct conntrack *ct, struct dp_packet *pkt,
         if (nat_action_info) {
             nc->nat_info = xmemdup(nat_action_info, sizeof *nc->nat_info);
 
+            nat_conn = xzalloc(sizeof *nat_conn);
+
             if (alg_exp) {
                 if (alg_exp->nat_rpl_dst) {
                     nc->rev_key.dst.addr = alg_exp->alg_nat_repl_addr;
@@ -901,70 +887,60 @@ conn_not_found(struct conntrack *ct, struct dp_packet *pkt,
                     nc->rev_key.src.addr = alg_exp->alg_nat_repl_addr;
                     nc->nat_info->nat_action = NAT_ACTION_DST;
                 }
-                *conn_for_un_nat_copy = *nc;
-                ct_rwlock_wrlock(&ct->resources_lock);
-                bool new_insert = nat_conn_keys_insert(&ct->nat_conn_keys,
-                                                       conn_for_un_nat_copy,
-                                                       ct->hash_basis);
-                ct_rwlock_unlock(&ct->resources_lock);
-                if (!new_insert) {
-                    char *log_msg = xasprintf("Pre-existing alg "
-                                              "nat_conn_key");
-                    ct_print_conn_info(conn_for_un_nat_copy, log_msg, VLL_INFO,
-                                       true, false);
-                    free(log_msg);
-                }
+                *nat_conn = *nc;
             } else {
-                *conn_for_un_nat_copy = *nc;
-                ct_rwlock_wrlock(&ct->resources_lock);
-                bool nat_res = nat_select_range_tuple(ct, nc,
-                                                      conn_for_un_nat_copy);
+                *nat_conn = *nc;
+                bool nat_res = nat_select_range_tuple(ct, nc, nat_conn);
 
                 if (!nat_res) {
                     goto nat_res_exhaustion;
                 }
 
-                /* Update nc with nat adjustments made to
-                 * conn_for_un_nat_copy by nat_select_range_tuple(). */
-                *nc = *conn_for_un_nat_copy;
-                ct_rwlock_unlock(&ct->resources_lock);
+                /* Update nc with nat adjustments. */
+                *nc = *nat_conn;
             }
-            conn_for_un_nat_copy->conn_type = CT_CONN_TYPE_UN_NAT;
-            conn_for_un_nat_copy->nat_info = NULL;
-            conn_for_un_nat_copy->alg = NULL;
             nat_packet(pkt, nc, ctx->icmp_related);
-        }
-        hmap_insert(&ct->buckets[bucket].connections, &nc->node, ctx->hash);
+
+            nat_conn->key = nc->rev_key;
+            nat_conn->rev_key = nc->key;
+            nat_conn->conn_type = CT_CONN_TYPE_UN_NAT;
+            nat_conn->nat_info = NULL;
+            nat_conn->alg = NULL;
+            nat_conn->nat_conn = NULL;
+            uint32_t nat_hash = conn_key_hash(&nat_conn->key,
+                                              ct->hash_basis);
+            cmap_insert(&cm_conns, &nat_conn->cm_node, nat_hash);
+        }
+
+        nc->nat_conn = nat_conn;
+        ct_ce_lock_init(&nc->lock);
+        nc->conn_type = CT_CONN_TYPE_DEFAULT;
+        cmap_insert(&cm_conns, &nc->cm_node, ctx->hash);
         atomic_count_inc(&ct->n_conn);
     }
 
     return nc;
 
-    /* This would be a user error or a DOS attack.
-     * A user error is prevented by allocating enough
-     * combinations of NAT addresses when combined with
-     * ephemeral ports.  A DOS attack should be protected
-     * against with firewall rules or a separate firewall.
-     * Also using zone partitioning can limit DoS impact. */
+    /* This would be a user error or a DOS attack.  A user error is prevented
+     * by allocating enough combinations of NAT addresses when combined with
+     * ephemeral ports.  A DOS attack should be protected against with
+     * firewall rules or a separate firewall.  Also using zone partitioning
+     * can limit DoS impact. */
 nat_res_exhaustion:
+    free(nat_conn);
     ovs_list_remove(&nc->exp_node);
     delete_conn(nc);
-    /* conn_for_un_nat_copy is a local variable in process_one; this
-     * memset() serves to document that conn_for_un_nat_copy is from
-     * this point on unused. */
-    memset(conn_for_un_nat_copy, 0, sizeof *conn_for_un_nat_copy);
-    ct_rwlock_unlock(&ct->resources_lock);
     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5);
     VLOG_WARN_RL(&rl, "Unable to NAT due to tuple space exhaustion - "
                  "if DoS attack, use firewalling and/or zone partitioning.");
     return NULL;
 }
 
+/* Reminder: change **conn to *conn. */
 static bool
 conn_update_state(struct conntrack *ct, struct dp_packet *pkt,
-                  struct conn_lookup_ctx *ctx, struct conn **conn,
-                  long long now, unsigned bucket)
-    OVS_REQUIRES(ct->buckets[bucket].lock)
+                  struct conn_lookup_ctx *ctx, struct conn *conn,
+                  long long now)
 {
     bool create_new_conn = false;
 
@@ -974,12 +950,13 @@ conn_update_state(struct conntrack *ct, struct dp_packet *pkt,
             pkt->md.ct_state |= CS_REPLY_DIR;
         }
     } else {
-        if ((*conn)->alg_related) {
+        if (conn->alg_related) {
             pkt->md.ct_state |= CS_RELATED;
         }
 
-        enum ct_update_res res = conn_update(*conn, &ct->buckets[bucket],
-                                             pkt, ctx->reply, now);
+        ct_lock_lock(&lock);
+        enum ct_update_res res = conn_update(pkt, conn, ctx, now);
+        ct_lock_unlock(&lock);
 
         switch (res) {
         case CT_UPDATE_VALID:
@@ -993,7 +970,9 @@ conn_update_state(struct conntrack *ct, struct dp_packet *pkt,
             pkt->md.ct_state = CS_INVALID;
             break;
         case CT_UPDATE_NEW:
-            conn_clean(ct, *conn, &ct->buckets[bucket]);
+            ct_lock_lock(&lock);
+            conn_clean(ct, conn);
+            ct_lock_unlock(&lock);
             create_new_conn = true;
             break;
         default:
@@ -1004,51 +983,6 @@ conn_update_state(struct conntrack *ct, struct dp_packet *pkt,
 }
 
 static void
-create_un_nat_conn(struct conntrack *ct, struct conn *conn_for_un_nat_copy,
-                   long long now, bool alg_un_nat)
-{
-    struct conn *nc = xmemdup(conn_for_un_nat_copy, sizeof *nc);
-    nc->key = conn_for_un_nat_copy->rev_key;
-    nc->rev_key = conn_for_un_nat_copy->key;
-    uint32_t un_nat_hash = conn_key_hash(&nc->key, ct->hash_basis);
-    unsigned un_nat_conn_bucket = hash_to_bucket(un_nat_hash);
-    ct_lock_lock(&ct->buckets[un_nat_conn_bucket].lock);
-    struct conn *rev_conn = conn_lookup(ct, &nc->key, now);
-
-    if (alg_un_nat) {
-        if (!rev_conn) {
-            hmap_insert(&ct->buckets[un_nat_conn_bucket].connections,
-                        &nc->node, un_nat_hash);
-        } else {
-            char *log_msg = xasprintf("Unusual condition for un_nat conn "
-                                      "create for alg: rev_conn %p", rev_conn);
-            ct_print_conn_info(nc, log_msg, VLL_INFO, true, false);
-            free(log_msg);
-            free(nc);
-        }
-    } else {
-        ct_rwlock_rdlock(&ct->resources_lock);
-
-        struct nat_conn_key_node *nat_conn_key_node =
-            nat_conn_keys_lookup(&ct->nat_conn_keys, &nc->key, ct->hash_basis);
-        if (nat_conn_key_node && !conn_key_cmp(&nat_conn_key_node->value,
-            &nc->rev_key) && !rev_conn) {
-            hmap_insert(&ct->buckets[un_nat_conn_bucket].connections,
-                        &nc->node, un_nat_hash);
-        } else {
-            char *log_msg = xasprintf("Unusual condition for un_nat conn "
-                                      "create: nat_conn_key_node/rev_conn "
-                                      "%p/%p", nat_conn_key_node, rev_conn);
-            ct_print_conn_info(nc, log_msg, VLL_INFO, true, false);
-            free(log_msg);
-            free(nc);
-        }
-        ct_rwlock_unlock(&ct->resources_lock);
-    }
-    ct_lock_unlock(&ct->buckets[un_nat_conn_bucket].lock);
-}
-
-static void
 handle_nat(struct dp_packet *pkt, struct conn *conn,
            uint16_t zone, bool reply, bool related)
 {
@@ -1071,9 +1005,8 @@ handle_nat(struct dp_packet *pkt, struct conn *conn,
 static bool
 check_orig_tuple(struct conntrack *ct, struct dp_packet *pkt,
                  struct conn_lookup_ctx *ctx_in, long long now,
-                 unsigned *bucket, struct conn **conn,
+                 struct conn **conn,
                  const struct nat_action_info_t *nat_action_info)
-    OVS_REQUIRES(ct->buckets[*bucket].lock)
 {
     if ((ctx_in->key.dl_type == htons(ETH_TYPE_IP) &&
          !pkt->md.ct_orig_tuple.ipv4.ipv4_proto) ||
@@ -1084,57 +1017,48 @@ check_orig_tuple(struct conntrack *ct, struct dp_packet *pkt,
         return false;
     }
 
-    ct_lock_unlock(&ct->buckets[*bucket].lock);
-    struct conn_lookup_ctx ctx;
-    memset(&ctx, 0 , sizeof ctx);
-    ctx.conn = NULL;
+    struct conn_key key;
+    memset(&key, 0 , sizeof key);
 
     if (ctx_in->key.dl_type == htons(ETH_TYPE_IP)) {
-        ctx.key.src.addr.ipv4_aligned = pkt->md.ct_orig_tuple.ipv4.ipv4_src;
-        ctx.key.dst.addr.ipv4_aligned = pkt->md.ct_orig_tuple.ipv4.ipv4_dst;
+        key.src.addr.ipv4_aligned = pkt->md.ct_orig_tuple.ipv4.ipv4_src;
+        key.dst.addr.ipv4_aligned = pkt->md.ct_orig_tuple.ipv4.ipv4_dst;
 
         if (ctx_in->key.nw_proto == IPPROTO_ICMP) {
-            ctx.key.src.icmp_id = ctx_in->key.src.icmp_id;
-            ctx.key.dst.icmp_id = ctx_in->key.dst.icmp_id;
+            key.src.icmp_id = ctx_in->key.src.icmp_id;
+            key.dst.icmp_id = ctx_in->key.dst.icmp_id;
             uint16_t src_port = ntohs(pkt->md.ct_orig_tuple.ipv4.src_port);
-            ctx.key.src.icmp_type = (uint8_t) src_port;
-            ctx.key.dst.icmp_type = reverse_icmp_type(ctx.key.src.icmp_type);
+            key.src.icmp_type = (uint8_t) src_port;
+            key.dst.icmp_type = reverse_icmp_type(key.src.icmp_type);
         } else {
-            ctx.key.src.port = pkt->md.ct_orig_tuple.ipv4.src_port;
-            ctx.key.dst.port = pkt->md.ct_orig_tuple.ipv4.dst_port;
+            key.src.port = pkt->md.ct_orig_tuple.ipv4.src_port;
+            key.dst.port = pkt->md.ct_orig_tuple.ipv4.dst_port;
         }
-        ctx.key.nw_proto = pkt->md.ct_orig_tuple.ipv4.ipv4_proto;
+        key.nw_proto = pkt->md.ct_orig_tuple.ipv4.ipv4_proto;
     } else {
-        ctx.key.src.addr.ipv6_aligned = pkt->md.ct_orig_tuple.ipv6.ipv6_src;
-        ctx.key.dst.addr.ipv6_aligned = pkt->md.ct_orig_tuple.ipv6.ipv6_dst;
+        key.src.addr.ipv6_aligned = pkt->md.ct_orig_tuple.ipv6.ipv6_src;
+        key.dst.addr.ipv6_aligned = pkt->md.ct_orig_tuple.ipv6.ipv6_dst;
 
         if (ctx_in->key.nw_proto == IPPROTO_ICMPV6) {
-            ctx.key.src.icmp_id = ctx_in->key.src.icmp_id;
-            ctx.key.dst.icmp_id = ctx_in->key.dst.icmp_id;
+            key.src.icmp_id = ctx_in->key.src.icmp_id;
+            key.dst.icmp_id = ctx_in->key.dst.icmp_id;
             uint16_t src_port = ntohs(pkt->md.ct_orig_tuple.ipv6.src_port);
-            ctx.key.src.icmp_type = (uint8_t) src_port;
-            ctx.key.dst.icmp_type = reverse_icmp6_type(ctx.key.src.icmp_type);
+            key.src.icmp_type = (uint8_t) src_port;
+            key.dst.icmp_type = reverse_icmp6_type(key.src.icmp_type);
         } else {
-            ctx.key.src.port = pkt->md.ct_orig_tuple.ipv6.src_port;
-            ctx.key.dst.port = pkt->md.ct_orig_tuple.ipv6.dst_port;
+            key.src.port = pkt->md.ct_orig_tuple.ipv6.src_port;
+            key.dst.port = pkt->md.ct_orig_tuple.ipv6.dst_port;
         }
-        ctx.key.nw_proto = pkt->md.ct_orig_tuple.ipv6.ipv6_proto;
+        key.nw_proto = pkt->md.ct_orig_tuple.ipv6.ipv6_proto;
     }
 
-    ctx.key.dl_type = ctx_in->key.dl_type;
-    ctx.key.zone = pkt->md.ct_zone;
-    ctx.hash = conn_key_hash(&ctx.key, ct->hash_basis);
-    *bucket = hash_to_bucket(ctx.hash);
-    ct_lock_lock(&ct->buckets[*bucket].lock);
-    conn_key_lookup(&ct->buckets[*bucket], &ctx, now);
-    *conn = ctx.conn;
-    return *conn ? true : false;
-}
+    key.dl_type = ctx_in->key.dl_type;
+    key.zone = pkt->md.ct_zone;
+    uint32_t hash = conn_key_hash(&key, ct->hash_basis);
+    bool reply;
+    conn_key_lookup(&key, hash, now, conn, &reply);
 
-static bool
-is_un_nat_conn_valid(const struct conn *un_nat_conn)
-{
-    return un_nat_conn->conn_type == CT_CONN_TYPE_UN_NAT;
+    return *conn ? true : false;
 }
 
 static bool
@@ -1142,24 +1066,25 @@ conn_update_state_alg(struct conntrack *ct, struct dp_packet *pkt,
                       struct conn_lookup_ctx *ctx, struct conn *conn,
                       const struct nat_action_info_t *nat_action_info,
                       enum ct_alg_ctl_type ct_alg_ctl, long long now,
-                      unsigned bucket, bool *create_new_conn)
-    OVS_REQUIRES(ct->buckets[bucket].lock)
+                      bool *create_new_conn)
 {
     if (is_ftp_ctl(ct_alg_ctl)) {
         /* Keep sequence tracking in sync with the source of the
          * sequence skew. */
         if (ctx->reply != conn->seq_skew_dir) {
+            ct_ce_lock_lock(&conn->lock);
             handle_ftp_ctl(ct, ctx, pkt, conn, now, CT_FTP_CTL_OTHER,
                            !!nat_action_info);
-            *create_new_conn = conn_update_state(ct, pkt, ctx, &conn, now,
-                                                bucket);
+            ct_ce_lock_unlock(&conn->lock);
+            *create_new_conn = conn_update_state(ct, pkt, ctx, conn, now);
         } else {
-            *create_new_conn = conn_update_state(ct, pkt, ctx, &conn, now,
-                                                bucket);
+            *create_new_conn = conn_update_state(ct, pkt, ctx, conn, now);
 
             if (*create_new_conn == false) {
+                ct_ce_lock_lock(&conn->lock);
                 handle_ftp_ctl(ct, ctx, pkt, conn, now, CT_FTP_CTL_OTHER,
                                !!nat_action_info);
+                ct_ce_lock_unlock(&conn->lock);
             }
         }
         return true;
@@ -1170,74 +1095,59 @@ conn_update_state_alg(struct conntrack *ct, struct dp_packet *pkt,
 static void
 process_one(struct conntrack *ct, struct dp_packet *pkt,
             struct conn_lookup_ctx *ctx, uint16_t zone,
-            bool force, bool commit, long long now, const uint32_t *setmark,
+            bool force, bool commit, long long now,
+            const uint32_t *setmark,
             const struct ovs_key_ct_labels *setlabel,
             const struct nat_action_info_t *nat_action_info,
             ovs_be16 tp_src, ovs_be16 tp_dst, const char *helper)
 {
-    struct conn *conn;
-    unsigned bucket = hash_to_bucket(ctx->hash);
-    ct_lock_lock(&ct->buckets[bucket].lock);
-    conn_key_lookup(&ct->buckets[bucket], ctx, now);
-    conn = ctx->conn;
+    bool create_new_conn = false;
+
+    conn_key_lookup(&ctx->key, ctx->hash, now, &ctx->conn, &ctx->reply);
+    struct conn *conn = ctx->conn;
 
     /* Delete found entry if in wrong direction. 'force' implies commit. */
     if (conn && force && ctx->reply) {
-        conn_clean(ct, conn, &ct->buckets[bucket]);
+        ct_lock_lock(&lock);
+        conn_clean(ct, conn);
+        ct_lock_unlock(&lock);
         conn = NULL;
     }
 
     if (OVS_LIKELY(conn)) {
         if (conn->conn_type == CT_CONN_TYPE_UN_NAT) {
-
             ctx->reply = true;
+            struct conn *rev_conn = conn;  /* Save for debugging. */
+            uint32_t hash = conn_key_hash(&conn->rev_key, ct->hash_basis);
+            conn_key_lookup(&ctx->key, hash, now, &conn, &ctx->reply);
 
-            struct conn_lookup_ctx ctx2;
-            ctx2.conn = NULL;
-            ctx2.key = conn->rev_key;
-            ctx2.hash = conn_key_hash(&conn->rev_key, ct->hash_basis);
-
-            ct_lock_unlock(&ct->buckets[bucket].lock);
-            bucket = hash_to_bucket(ctx2.hash);
-
-            ct_lock_lock(&ct->buckets[bucket].lock);
-            conn_key_lookup(&ct->buckets[bucket], &ctx2, now);
-
-            if (ctx2.conn) {
-                conn = ctx2.conn;
-            } else {
-                /* It is a race condition where conn has timed out and removed
-                 * between unlock of the rev_conn and lock of the forward conn;
-                 * nothing to do. */
+            if (!conn) {
                 pkt->md.ct_state |= CS_TRACKED | CS_INVALID;
-                ct_lock_unlock(&ct->buckets[bucket].lock);
+                char *log_msg = xasprintf("Missing master conn %p", rev_conn);
+                ct_print_conn_info(conn, log_msg, VLL_ERR, true, false);
+                free(log_msg);
                 return;
             }
         }
     }
 
-    bool create_new_conn = false;
-    struct conn conn_for_un_nat_copy;
-    conn_for_un_nat_copy.conn_type = CT_CONN_TYPE_DEFAULT;
-
     enum ct_alg_ctl_type ct_alg_ctl = get_alg_ctl_type(pkt, tp_src, tp_dst,
                                                        helper);
 
     if (OVS_LIKELY(conn)) {
         if (OVS_LIKELY(!conn_update_state_alg(ct, pkt, ctx, conn,
                                               nat_action_info,
-                                              ct_alg_ctl, now, bucket,
+                                              ct_alg_ctl, now,
                                               &create_new_conn))) {
-            create_new_conn = conn_update_state(ct, pkt, ctx, &conn, now,
-                                                bucket);
+
+            create_new_conn = conn_update_state(ct, pkt, ctx, conn, now);
         }
         if (nat_action_info && !create_new_conn) {
             handle_nat(pkt, conn, zone, ctx->reply, ctx->icmp_related);
         }
 
-    } else if (check_orig_tuple(ct, pkt, ctx, now, &bucket, &conn,
-                               nat_action_info)) {
-        create_new_conn = conn_update_state(ct, pkt, ctx, &conn, now, bucket);
+    } else if (check_orig_tuple(ct, pkt, ctx, now, &conn, nat_action_info)) {
+        create_new_conn = conn_update_state(ct, pkt, ctx, conn, now);
     } else {
         if (ctx->icmp_related) {
             /* An icmp related conn should always be found; no new
@@ -1252,7 +1162,6 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
     struct alg_exp_node alg_exp_entry;
 
     if (OVS_UNLIKELY(create_new_conn)) {
-
         ct_rwlock_rdlock(&ct->resources_lock);
         alg_exp = expectation_lookup(&ct->alg_expectations, &ctx->key,
                                      ct->hash_basis,
@@ -1263,9 +1172,10 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
         }
         ct_rwlock_unlock(&ct->resources_lock);
 
+        ct_lock_lock(&lock);
         conn = conn_not_found(ct, pkt, ctx, commit, now, nat_action_info,
-                              &conn_for_un_nat_copy, helper, alg_exp,
-                              ct_alg_ctl);
+                              helper, alg_exp, ct_alg_ctl);
+        ct_lock_unlock(&lock);
     }
 
     write_ct_md(pkt, zone, conn, &ctx->key, alg_exp);
@@ -1278,23 +1188,12 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
         set_label(pkt, conn, &setlabel[0], &setlabel[1]);
     }
 
-    struct conn conn_for_expectation;
-    if (OVS_UNLIKELY((ct_alg_ctl != CT_ALG_CTL_NONE) && conn)) {
-        conn_for_expectation = *conn;
-    }
-
-    ct_lock_unlock(&ct->buckets[bucket].lock);
-
-    if (is_un_nat_conn_valid(&conn_for_un_nat_copy)) {
-        create_un_nat_conn(ct, &conn_for_un_nat_copy, now, !!alg_exp);
-    }
-
     handle_alg_ctl(ct, ctx, pkt, ct_alg_ctl, conn, now, !!nat_action_info,
-                   &conn_for_expectation);
+                   conn);
 }
 
 /* Sends the packets in '*pkt_batch' through the connection tracker 'ct'.  All
- * the packets should have the same 'dl_type' (IPv4 or IPv6) and should have
+ * the packets must have the same 'dl_type' (IPv4 or IPv6) and should have
  * the l3 and and l4 offset properly set.
  *
  * If 'commit' is true, the packets are allowed to create new entries in the
@@ -1310,12 +1209,12 @@ conntrack_execute(struct conntrack *ct, struct dp_packet_batch *pkt_batch,
                   const struct nat_action_info_t *nat_action_info,
                   long long now)
 {
-
     struct dp_packet *packet;
     struct conn_lookup_ctx ctx;
 
     DP_PACKET_BATCH_FOR_EACH (i, packet, pkt_batch) {
-        if (!conn_key_extract(ct, packet, dl_type, &ctx, zone)) {
+        if (packet->md.ct_state == CS_INVALID
+            || !conn_key_extract(ct, packet, dl_type, &ctx, zone)) {
             packet->md.ct_state = CS_INVALID;
             write_ct_md(packet, zone, NULL, NULL, NULL);
             continue;
@@ -1373,31 +1272,37 @@ set_label(struct dp_packet *pkt, struct conn *conn,
  * LLONG_MAX if 'ctb' is empty.  The return value might be smaller than 'now',
  * if 'limit' is reached */
 static long long
-sweep_bucket(struct conntrack *ct, struct conntrack_bucket *ctb,
-             long long now, size_t limit)
-    OVS_REQUIRES(ctb->lock)
+ct_sweep(struct conntrack *ct OVS_UNUSED, long long now, size_t limit)
 {
     struct conn *conn, *next;
     long long min_expiration = LLONG_MAX;
     size_t count = 0;
 
+    ct_lock_lock(&lock);
+
     for (unsigned i = 0; i < N_CT_TM; i++) {
-        LIST_FOR_EACH_SAFE (conn, next, exp_node, &ctb->exp_lists[i]) {
+        /* Does not need to be 'safe' anymore. */
+        LIST_FOR_EACH_SAFE (conn, next, exp_node, &cm_exp_lists[i]) {
             if (conn->conn_type == CT_CONN_TYPE_DEFAULT) {
                 if (!conn_expired(conn, now) || count >= limit) {
                     min_expiration = MIN(min_expiration, conn->expiration);
                     if (count >= limit) {
                         /* Do not check other lists. */
                         COVERAGE_INC(conntrack_long_cleanup);
-                        return min_expiration;
+                        goto out;
                     }
                     break;
                 }
-                conn_clean(ct, conn, ctb);
+                conn_clean(ct, conn);
                 count++;
             }
         }
     }
+
+out:
+    VLOG_DBG("conntrack cleanup %"PRIuSIZE" entries in %lld msec", count,
+             time_msec() - now);
+    ct_lock_unlock(&lock);
     return min_expiration;
 }
 
@@ -1410,48 +1315,12 @@ conntrack_clean(struct conntrack *ct, long long now)
 {
     long long next_wakeup = now + CT_TM_MIN;
     unsigned int n_conn_limit;
-    size_t clean_count = 0;
 
     atomic_read_relaxed(&ct->n_conn_limit, &n_conn_limit);
 
-    for (unsigned i = 0; i < CONNTRACK_BUCKETS; i++) {
-        struct conntrack_bucket *ctb = &ct->buckets[i];
-        size_t prev_count;
-        long long min_exp;
-
-        ovs_mutex_lock(&ctb->cleanup_mutex);
-        if (ctb->next_cleanup > now) {
-            goto next_bucket;
-        }
-
-        ct_lock_lock(&ctb->lock);
-        prev_count = hmap_count(&ctb->connections);
-        /* If the connections are well distributed among buckets, we want to
-         * limit to 10% of the global limit equally split among buckets. If
-         * the bucket is busier than the others, we limit to 10% of its
-         * current size. */
-        min_exp = sweep_bucket(ct, ctb, now,
-                MAX(prev_count/10, n_conn_limit/(CONNTRACK_BUCKETS*10)));
-        clean_count += prev_count - hmap_count(&ctb->connections);
-
-        if (min_exp > now) {
-            /* We call hmap_shrink() only if sweep_bucket() managed to delete
-             * every expired connection. */
-            hmap_shrink(&ctb->connections);
-        }
-
-        ct_lock_unlock(&ctb->lock);
-
-        ctb->next_cleanup = MIN(min_exp, now + CT_TM_MIN);
-
-next_bucket:
-        next_wakeup = MIN(next_wakeup, ctb->next_cleanup);
-        ovs_mutex_unlock(&ctb->cleanup_mutex);
-    }
-
-    VLOG_DBG("conntrack cleanup %"PRIuSIZE" entries in %lld msec",
-             clean_count, time_msec() - now);
-
+    long long cm_min_exp =
+        ct_sweep(ct, now, MAX(cmap_count(&cm_conns) / 10, n_conn_limit / 10));
+    next_wakeup = MIN(cm_min_exp, next_wakeup);
     return next_wakeup;
 }
 
@@ -2172,7 +2041,9 @@ nat_select_range_tuple(struct conntrack *ct, const struct conn *conn,
 
     uint16_t port = first_port;
     bool all_ports_tried = false;
-    bool original_ports_tried = false;
+    /* For DNAT, we don't try ephemeral ports. */
+    bool ephemeral_ports_tried =
+        conn->nat_info->nat_action & NAT_ACTION_DST ? true : false;
     struct ct_addr first_addr = ct_addr;
 
     while (true) {
@@ -2191,8 +2062,11 @@ nat_select_range_tuple(struct conntrack *ct, const struct conn *conn,
             nat_conn->rev_key.src.port = htons(port);
         }
 
-        bool new_insert = nat_conn_keys_insert(&ct->nat_conn_keys, nat_conn,
-                                               ct->hash_basis);
+        uint32_t conn_hash = conn_key_hash(&nat_conn->rev_key,
+                                           ct->hash_basis);
+        bool new_insert = conn_available(&nat_conn->rev_key, conn_hash,
+                                         time_msec());
+
         if (new_insert) {
             return true;
         } else if (!all_ports_tried) {
@@ -2218,8 +2092,8 @@ nat_select_range_tuple(struct conntrack *ct, const struct conn *conn,
                 ct_addr = conn->nat_info->min_addr;
             }
             if (!memcmp(&ct_addr, &first_addr, sizeof ct_addr)) {
-                if (!original_ports_tried) {
-                    original_ports_tried = true;
+                if (!ephemeral_ports_tried) {
+                    ephemeral_ports_tried = true;
                     ct_addr = conn->nat_info->min_addr;
                     min_port = MIN_NAT_EPHEMERAL_PORT;
                     max_port = MAX_NAT_EPHEMERAL_PORT;
@@ -2235,94 +2109,6 @@ nat_select_range_tuple(struct conntrack *ct, const struct conn *conn,
     return false;
 }
 
-/* This function must be called with the ct->resources lock taken. */
-static struct nat_conn_key_node *
-nat_conn_keys_lookup(struct hmap *nat_conn_keys,
-                     const struct conn_key *key,
-                     uint32_t basis)
-{
-    struct nat_conn_key_node *nat_conn_key_node;
-
-    HMAP_FOR_EACH_WITH_HASH (nat_conn_key_node, node,
-                             conn_key_hash(key, basis), nat_conn_keys) {
-        if (!conn_key_cmp(&nat_conn_key_node->key, key)) {
-            return nat_conn_key_node;
-        }
-    }
-    return NULL;
-}
-
-/* This function must be called with the ct->resources lock taken. */
-static bool
-nat_conn_keys_insert(struct hmap *nat_conn_keys, const struct conn *nat_conn,
-                     uint32_t basis)
-{
-    struct nat_conn_key_node *nat_conn_key_node =
-        nat_conn_keys_lookup(nat_conn_keys, &nat_conn->rev_key, basis);
-
-    if (!nat_conn_key_node) {
-        struct nat_conn_key_node *nat_conn_key = xzalloc(sizeof *nat_conn_key);
-        nat_conn_key->key = nat_conn->rev_key;
-        nat_conn_key->value = nat_conn->key;
-        hmap_insert(nat_conn_keys, &nat_conn_key->node,
-                    conn_key_hash(&nat_conn_key->key, basis));
-        return true;
-    }
-    return false;
-}
-
-/* This function must be called with the ct->resources write lock taken. */
-static void
-nat_conn_keys_remove(struct hmap *nat_conn_keys,
-                     const struct conn_key *key,
-                     uint32_t basis)
-{
-    struct nat_conn_key_node *nat_conn_key_node;
-
-    HMAP_FOR_EACH_WITH_HASH (nat_conn_key_node, node,
-                             conn_key_hash(key, basis), nat_conn_keys) {
-        if (!conn_key_cmp(&nat_conn_key_node->key, key)) {
-            hmap_remove(nat_conn_keys, &nat_conn_key_node->node);
-            free(nat_conn_key_node);
-            return;
-        }
-    }
-}
-
-static void
-conn_key_lookup(struct conntrack_bucket *ctb, struct conn_lookup_ctx *ctx,
-                long long now)
-    OVS_REQUIRES(ctb->lock)
-{
-    uint32_t hash = ctx->hash;
-    struct conn *conn;
-
-    ctx->conn = NULL;
-
-    HMAP_FOR_EACH_WITH_HASH (conn, node, hash, &ctb->connections) {
-        if (!conn_key_cmp(&conn->key, &ctx->key)
-                && !conn_expired(conn, now)) {
-            ctx->conn = conn;
-            ctx->reply = false;
-            break;
-        }
-        if (!conn_key_cmp(&conn->rev_key, &ctx->key)
-                && !conn_expired(conn, now)) {
-            ctx->conn = conn;
-            ctx->reply = true;
-            break;
-        }
-    }
-}
-
-static enum ct_update_res
-conn_update(struct conn *conn, struct conntrack_bucket *ctb,
-            struct dp_packet *pkt, bool reply, long long now)
-{
-    return l4_protos[conn->key.nw_proto]->conn_update(conn, ctb, pkt,
-                                                      reply, now);
-}
-
 static bool
 conn_expired(struct conn *conn, long long now)
 {
@@ -2339,10 +2125,9 @@ valid_new(struct dp_packet *pkt, struct conn_key *key)
 }
 
 static struct conn *
-new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt,
-         struct conn_key *key, long long now)
+new_conn(struct dp_packet *pkt, struct conn_key *key, long long now)
 {
-    struct conn *newconn = l4_protos[key->nw_proto]->new_conn(ctb, pkt, now);
+    struct conn *newconn = l4_protos[key->nw_proto]->new_conn(pkt, now);
     if (newconn) {
         newconn->key = *key;
     }
@@ -2350,11 +2135,40 @@ new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt,
     return newconn;
 }
 
+static enum ct_update_res
+conn_update(struct dp_packet *pkt, struct conn *conn,
+            struct conn_lookup_ctx *ctx, long long now)
+{
+    ct_ce_lock_lock(&conn->lock);
+    enum ct_update_res update_res =
+        l4_protos[conn->key.nw_proto]->conn_update(conn, pkt, ctx->reply,
+                                                   now);
+    ct_ce_lock_unlock(&conn->lock);
+    return update_res;
+}
+
 static void
 delete_conn(struct conn *conn)
 {
-    free(conn->nat_info);
-    free(conn->alg);
+    if (conn->conn_type == CT_CONN_TYPE_DEFAULT) {
+        free(conn->nat_info);
+        free(conn->alg);
+        ct_ce_lock_destroy(&conn->lock);
+        if (conn->nat_conn) {
+            free(conn->nat_conn);
+        }
+        free(conn);
+    }
+}
+
+static void
+delete_conn_one(struct conn *conn)
+{
+    if (conn->conn_type == CT_CONN_TYPE_DEFAULT) {
+        free(conn->nat_info);
+        free(conn->alg);
+        ct_ce_lock_destroy(&conn->lock);
+    }
     free(conn);
 }
 
@@ -2487,46 +2301,30 @@ conntrack_dump_start(struct conntrack *ct, struct conntrack_dump *dump,
     }
 
     dump->ct = ct;
-    *ptot_bkts = CONNTRACK_BUCKETS;
+    *ptot_bkts = 1; /* Need to clean up the callers. */
     return 0;
 }
 
 int
 conntrack_dump_next(struct conntrack_dump *dump, struct ct_dpif_entry *entry)
 {
-    struct conntrack *ct = dump->ct;
     long long now = time_msec();
 
-    while (dump->bucket < CONNTRACK_BUCKETS) {
-        struct hmap_node *node;
-
-        ct_lock_lock(&ct->buckets[dump->bucket].lock);
-        for (;;) {
-            struct conn *conn;
-
-            node = hmap_at_position(&ct->buckets[dump->bucket].connections,
-                                    &dump->bucket_pos);
-            if (!node) {
-                break;
-            }
-            INIT_CONTAINER(conn, node, node);
-            if ((!dump->filter_zone || conn->key.zone == dump->zone) &&
-                 (conn->conn_type != CT_CONN_TYPE_UN_NAT)) {
-                conn_to_ct_dpif_entry(conn, entry, now, dump->bucket);
-                break;
-            }
-            /* Else continue, until we find an entry in the appropriate zone
-             * or the bucket has been scanned completely. */
+    for (;;) {
+        struct cmap_node *cm_node = cmap_next_position(&cm_conns,
+                                                       &dump->cm_pos);
+        if (!cm_node) {
+            break;
         }
-        ct_lock_unlock(&ct->buckets[dump->bucket].lock);
-
-        if (!node) {
-            memset(&dump->bucket_pos, 0, sizeof dump->bucket_pos);
-            dump->bucket++;
-        } else {
+        struct conn *conn;
+        INIT_CONTAINER(conn, cm_node, cm_node);
+        if ((!dump->filter_zone || conn->key.zone == dump->zone) &&
+             (conn->conn_type != CT_CONN_TYPE_UN_NAT)) {
+            conn_to_ct_dpif_entry(conn, entry, now, 0);
             return 0;
         }
     }
+
     return EOF;
 }
 
@@ -2539,19 +2337,18 @@ conntrack_dump_done(struct conntrack_dump *dump OVS_UNUSED)
 int
 conntrack_flush(struct conntrack *ct, const uint16_t *zone)
 {
-    for (unsigned i = 0; i < CONNTRACK_BUCKETS; i++) {
-        struct conn *conn, *next;
+    struct conn *conn;
 
-        ct_lock_lock(&ct->buckets[i].lock);
-        HMAP_FOR_EACH_SAFE (conn, next, node, &ct->buckets[i].connections) {
-            if ((!zone || *zone == conn->key.zone) &&
-                (conn->conn_type == CT_CONN_TYPE_DEFAULT)) {
-                conn_clean(ct, conn, &ct->buckets[i]);
-            }
+    ct_lock_lock(&lock);
+
+    CMAP_FOR_EACH (conn, cm_node, &cm_conns) {
+        if (!zone || *zone == conn->key.zone) {
+            conn_clean_one(ct, conn);
         }
-        ct_lock_unlock(&ct->buckets[i].lock);
     }
 
+    ct_lock_unlock(&lock);
+
     return 0;
 }
 
@@ -2559,22 +2356,24 @@ int
 conntrack_flush_tuple(struct conntrack *ct, const struct ct_dpif_tuple *tuple,
                       uint16_t zone)
 {
-    struct conn_lookup_ctx ctx;
     int error = 0;
+    struct conn_lookup_ctx ctx;
 
     memset(&ctx, 0, sizeof(ctx));
     tuple_to_conn_key(tuple, zone, &ctx.key);
     ctx.hash = conn_key_hash(&ctx.key, ct->hash_basis);
-    unsigned bucket = hash_to_bucket(ctx.hash);
 
-    ct_lock_lock(&ct->buckets[bucket].lock);
-    conn_key_lookup(&ct->buckets[bucket], &ctx, time_msec());
-    if (ctx.conn) {
-        conn_clean(ct, ctx.conn, &ct->buckets[bucket]);
+    ct_lock_lock(&lock);
+    conn_key_lookup(&ctx.key, ctx.hash, time_msec(), &ctx.conn, &ctx.reply);
+
+    if (ctx.conn && ctx.conn->conn_type == CT_CONN_TYPE_DEFAULT) {
+        conn_clean(ct, ctx.conn);
     } else {
         error = ENOENT;
     }
-    ct_lock_unlock(&ct->buckets[bucket].lock);
+
+    ct_lock_unlock(&lock);
+
     return error;
 }
 
@@ -2674,17 +2473,17 @@ expectation_ref_create(struct hindex *alg_expectation_refs,
 }
 
 static void
-expectation_clean(struct conntrack *ct, const struct conn_key *master_key,
-                  uint32_t basis)
+expectation_clean(struct conntrack *ct, const struct conn_key *master_key)
 {
     ct_rwlock_wrlock(&ct->resources_lock);
 
     struct alg_exp_node *node, *next;
     HINDEX_FOR_EACH_WITH_HASH_SAFE (node, next, node_ref,
-                                    conn_key_hash(master_key, basis),
+                                    conn_key_hash(master_key, ct->hash_basis),
                                     &ct->alg_expectation_refs) {
         if (!conn_key_cmp(&node->master_key, master_key)) {
-            expectation_remove(&ct->alg_expectations, &node->key, basis);
+            expectation_remove(&ct->alg_expectations, &node->key,
+                               ct->hash_basis);
             hindex_remove(&ct->alg_expectation_refs, &node->node_ref);
             free(node);
         }
diff --git a/lib/conntrack.h b/lib/conntrack.h
index e3a5dcc..2ab9ac1 100644
--- a/lib/conntrack.h
+++ b/lib/conntrack.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2016, 2017 Nicira, Inc.
+ * Copyright (c) 2015, 2016, 2017, 2018 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@
 
 #include <stdbool.h>
 
+#include "cmap.h"
 #include "latch.h"
 #include "odp-netlink.h"
 #include "openvswitch/hmap.h"
@@ -104,6 +105,7 @@ struct conntrack_dump {
     struct conntrack *ct;
     unsigned bucket;
     struct hmap_position bucket_pos;
+    struct cmap_position cm_pos;
     bool filter_zone;
     uint16_t zone;
 };
@@ -123,41 +125,11 @@ int conntrack_set_maxconns(struct conntrack *ct, uint32_t maxconns);
 int conntrack_get_maxconns(struct conntrack *ct, uint32_t *maxconns);
 int conntrack_get_nconns(struct conntrack *ct, uint32_t *nconns);
 
-/* 'struct ct_lock' is a wrapper for an adaptive mutex.  It's useful to try
- * different types of locks (e.g. spinlocks) */
-
-struct OVS_LOCKABLE ct_lock {
-    struct ovs_mutex lock;
-};
 
 struct OVS_LOCKABLE ct_rwlock {
     struct ovs_rwlock lock;
 };
 
-static inline void ct_lock_init(struct ct_lock *lock)
-{
-    ovs_mutex_init_adaptive(&lock->lock);
-}
-
-static inline void ct_lock_lock(struct ct_lock *lock)
-    OVS_ACQUIRES(lock)
-    OVS_NO_THREAD_SAFETY_ANALYSIS
-{
-    ovs_mutex_lock(&lock->lock);
-}
-
-static inline void ct_lock_unlock(struct ct_lock *lock)
-    OVS_RELEASES(lock)
-    OVS_NO_THREAD_SAFETY_ANALYSIS
-{
-    ovs_mutex_unlock(&lock->lock);
-}
-
-static inline void ct_lock_destroy(struct ct_lock *lock)
-{
-    ovs_mutex_destroy(&lock->lock);
-}
-
 static inline void ct_rwlock_init(struct ct_rwlock *lock)
 {
     ovs_rwlock_init(&lock->lock);
@@ -222,42 +194,7 @@ enum ct_timeout {
     N_CT_TM
 };
 
-/* Locking:
- *
- * The connections are kept in different buckets, which are completely
- * independent. The connection bucket is determined by the hash of its key.
- *
- * Each bucket has two locks. Acquisition order is, from outermost to
- * innermost:
- *
- *    cleanup_mutex
- *    lock
- *
- * */
-struct conntrack_bucket {
-    /* Protects 'connections' and 'exp_lists'.  Used in the fast path */
-    struct ct_lock lock;
-    /* Contains the connections in the bucket, indexed by 'struct conn_key' */
-    struct hmap connections OVS_GUARDED;
-    /* For each possible timeout we have a list of connections. When the
-     * timeout of a connection is updated, we move it to the back of the list.
-     * Since the connection in a list have the same relative timeout, the list
-     * will be ordered, with the oldest connections to the front. */
-    struct ovs_list exp_lists[N_CT_TM] OVS_GUARDED;
-
-    /* Protects 'next_cleanup'. Used to make sure that there's only one thread
-     * performing the cleanup. */
-    struct ovs_mutex cleanup_mutex;
-    long long next_cleanup OVS_GUARDED;
-};
-
-#define CONNTRACK_BUCKETS_SHIFT 8
-#define CONNTRACK_BUCKETS (1 << CONNTRACK_BUCKETS_SHIFT)
-
 struct conntrack {
-    /* Independent buckets containing the connections */
-    struct conntrack_bucket buckets[CONNTRACK_BUCKETS];
-
     /* Salt for hashing a connection key. */
     uint32_t hash_basis;
 
@@ -273,24 +210,17 @@ struct conntrack {
      * will be accepted. */
     atomic_uint n_conn_limit;
 
-    /* The following resources are referenced during nat connection
-     * creation and deletion. */
-    struct hmap nat_conn_keys OVS_GUARDED;
     /* Hash table for alg expectations. Expectations are created
      * by control connections to help create data connections. */
     struct hmap alg_expectations OVS_GUARDED;
-    /* Used to lookup alg expectations from the control context. */
+    /* Only needed to be able to cleanup expectations from non-control
+     * connection context; otherwise a pointer to the expectation from
+     * the control connection would suffice. */
     struct hindex alg_expectation_refs OVS_GUARDED;
     /* Expiry list for alg expectations. */
     struct ovs_list alg_exp_list OVS_GUARDED;
-    /* This lock is used during NAT connection creation and deletion;
-     * it is taken after a bucket lock and given back before that
-     * bucket unlock.
-     * This lock is similarly used to guard alg_expectations and
-     * alg_expectation_refs. If a bucket lock is also held during
-     * the normal code flow, then is must be taken first and released
-     * last.
-     */
+    /* This lock is used to guard alg_expectations and
+     * alg_expectation_refs. */
     struct ct_rwlock resources_lock;
 
 };
