ofp-errors: Add OFPET_FLOW_MONITOR_FAILED
[cascardo/ovs.git] / ofproto / ofproto.c
index 07fdffe..a05a444 100644 (file)
@@ -74,87 +74,15 @@ COVERAGE_DEFINE(ofproto_update_port);
 const enum mf_field_id default_prefix_fields[2] =
     { MFF_IPV4_DST, MFF_IPV4_SRC };
 
-enum ofproto_state {
-    S_OPENFLOW,                 /* Processing OpenFlow commands. */
-    S_EVICT,                    /* Evicting flows from over-limit tables. */
-    S_FLUSH,                    /* Deleting all flow table rules. */
-};
-
-enum ofoperation_type {
-    OFOPERATION_ADD,
-    OFOPERATION_DELETE,
-    OFOPERATION_MODIFY,
-    OFOPERATION_REPLACE
-};
-
-/* A single OpenFlow request can execute any number of operations.  The
- * ofopgroup maintain OpenFlow state common to all of the operations, e.g. the
- * ofconn to which an error reply should be sent if necessary.
- *
- * ofproto initiates some operations internally.  These operations are still
- * assigned to groups but will not have an associated ofconn. */
-struct ofopgroup {
-    struct ofproto *ofproto;    /* Owning ofproto. */
-    struct list ofproto_node;   /* In ofproto's "pending" list. */
-    struct list ops;            /* List of "struct ofoperation"s. */
-    int n_running;              /* Number of ops still pending. */
-
-    /* Data needed to send OpenFlow reply on failure or to send a buffered
-     * packet on success.
-     *
-     * If list_is_empty(ofconn_node) then this ofopgroup never had an
-     * associated ofconn or its ofconn's connection dropped after it initiated
-     * the operation.  In the latter case 'ofconn' is a wild pointer that
-     * refers to freed memory, so the 'ofconn' member must be used only if
-     * !list_is_empty(ofconn_node).
-     */
-    struct list ofconn_node;    /* In ofconn's list of pending opgroups. */
-    struct ofconn *ofconn;      /* ofconn for reply (but see note above). */
-    struct ofp_header *request; /* Original request (truncated at 64 bytes). */
-    uint32_t buffer_id;         /* Buffer id from original request. */
-};
-
-static struct ofopgroup *ofopgroup_create_unattached(struct ofproto *);
-static struct ofopgroup *ofopgroup_create(struct ofproto *, struct ofconn *,
-                                          const struct ofp_header *,
-                                          uint32_t buffer_id);
-static void ofopgroup_submit(struct ofopgroup *);
-static void ofopgroup_complete(struct ofopgroup *);
-
-/* A single flow table operation. */
-struct ofoperation {
-    struct ofopgroup *group;    /* Owning group. */
-    struct list group_node;     /* In ofopgroup's "ops" list. */
-    struct hmap_node hmap_node; /* In ofproto's "deletions" hmap. */
-    struct rule *rule;          /* Rule being operated upon. */
-    enum ofoperation_type type; /* Type of operation. */
-
-    /* OFOPERATION_MODIFY, OFOPERATION_REPLACE: The old actions, if the actions
-     * are changing. */
-    const struct rule_actions *actions;
-
-    /* OFOPERATION_DELETE. */
-    enum ofp_flow_removed_reason reason; /* Reason flow was removed. */
-
-    ovs_be64 flow_cookie;               /* Rule's old flow cookie. */
-    uint16_t idle_timeout;              /* Rule's old idle timeout. */
-    uint16_t hard_timeout;              /* Rule's old hard timeout. */
-    enum ofputil_flow_mod_flags flags;  /* Rule's old flags. */
-    enum ofperr error;                  /* 0 if no error. */
-};
-
-static struct ofoperation *ofoperation_create(struct ofopgroup *,
-                                              struct rule *,
-                                              enum ofoperation_type,
-                                              enum ofp_flow_removed_reason);
-static void ofoperation_destroy(struct ofoperation *);
-
 /* oftable. */
 static void oftable_init(struct oftable *);
 static void oftable_destroy(struct oftable *);
 
 static void oftable_set_name(struct oftable *, const char *name);
 
+static enum ofperr evict_rules_from_table(struct oftable *,
+                                          unsigned int extra_space)
+    OVS_REQUIRES(ofproto_mutex);
 static void oftable_disable_eviction(struct oftable *);
 static void oftable_enable_eviction(struct oftable *,
                                     const struct mf_subfield *fields,
@@ -188,8 +116,6 @@ struct eviction_group {
 
 static bool choose_rule_to_evict(struct oftable *table, struct rule **rulep)
     OVS_REQUIRES(ofproto_mutex);
-static void ofproto_evict(struct ofproto *)
-    OVS_EXCLUDED(ofproto_mutex);
 static uint32_t rule_eviction_priority(struct ofproto *ofproto, struct rule *)
     OVS_REQUIRES(ofproto_mutex);;
 static void eviction_group_add_rule(struct rule *)
@@ -235,6 +161,10 @@ static void rule_criteria_require_rw(struct rule_criteria *,
                                      bool can_write_readonly);
 static void rule_criteria_destroy(struct rule_criteria *);
 
+static enum ofperr collect_rules_loose(struct ofproto *,
+                                       const struct rule_criteria *,
+                                       struct rule_collection *);
+
 /* A packet that needs to be passed to rule_execute().
  *
  * (We can't do this immediately from ofopgroup_complete() because that holds
@@ -249,6 +179,37 @@ struct rule_execute {
 static void run_rule_executes(struct ofproto *) OVS_EXCLUDED(ofproto_mutex);
 static void destroy_rule_executes(struct ofproto *);
 
+struct learned_cookie {
+    union {
+        /* In struct ofproto's 'learned_cookies' hmap. */
+        struct hmap_node hmap_node OVS_GUARDED_BY(ofproto_mutex);
+
+        /* In 'dead_cookies' list when removed from hmap. */
+        struct list list_node;
+    } u;
+
+    /* Key. */
+    ovs_be64 cookie OVS_GUARDED_BY(ofproto_mutex);
+    uint8_t table_id OVS_GUARDED_BY(ofproto_mutex);
+
+    /* Number of references from "learn" actions.
+     *
+     * When this drops to 0, all of the flows in 'table_id' with the specified
+     * 'cookie' are deleted. */
+    int n OVS_GUARDED_BY(ofproto_mutex);
+};
+
+static const struct ofpact_learn *next_learn_with_delete(
+    const struct rule_actions *, const struct ofpact_learn *start);
+
+static void learned_cookies_inc(struct ofproto *, const struct rule_actions *)
+    OVS_REQUIRES(ofproto_mutex);
+static void learned_cookies_dec(struct ofproto *, const struct rule_actions *,
+                                struct list *dead_cookies)
+    OVS_REQUIRES(ofproto_mutex);
+static void learned_cookies_flush(struct ofproto *, struct list *dead_cookies)
+    OVS_REQUIRES(ofproto_mutex);
+
 /* ofport. */
 static void ofport_destroy__(struct ofport *) OVS_EXCLUDED(ofproto_mutex);
 static void ofport_destroy(struct ofport *);
@@ -276,20 +237,35 @@ struct ofport_usage {
 
 /* rule. */
 static void ofproto_rule_send_removed(struct rule *, uint8_t reason);
-static bool rule_is_modifiable(const struct rule *rule,
-                               enum ofputil_flow_mod_flags flag);
+static bool rule_is_readonly(const struct rule *);
+
+/* The source of a flow_mod request, in the code that processes flow_mods.
+ *
+ * A flow table modification request can be generated externally, via OpenFlow,
+ * or internally through a function call.  This structure indicates the source
+ * of an OpenFlow-generated flow_mod.  For an internal flow_mod, it isn't
+ * meaningful and thus supplied as NULL. */
+struct flow_mod_requester {
+    struct ofconn *ofconn;      /* Connection on which flow_mod arrived. */
+    ovs_be32 xid;               /* OpenFlow xid of flow_mod request. */
+};
 
 /* OpenFlow. */
-static enum ofperr add_flow(struct ofproto *, struct ofconn *,
-                            struct ofputil_flow_mod *,
-                            const struct ofp_header *);
-static enum ofperr modify_flows__(struct ofproto *, struct ofconn *,
-                                  struct ofputil_flow_mod *,
-                                  const struct ofp_header *,
-                                  const struct rule_collection *);
-static void delete_flow__(struct rule *rule, struct ofopgroup *,
-                          enum ofp_flow_removed_reason)
+static enum ofperr add_flow(struct ofproto *, struct ofputil_flow_mod *,
+                            const struct flow_mod_requester *);
+
+static enum ofperr modify_flows__(struct ofproto *, struct ofputil_flow_mod *,
+                                  const struct rule_collection *,
+                                  const struct flow_mod_requester *);
+static void delete_flows__(const struct rule_collection *,
+                           enum ofp_flow_removed_reason,
+                           const struct flow_mod_requester *)
     OVS_REQUIRES(ofproto_mutex);
+
+static enum ofperr send_buffered_packet(struct ofconn *, uint32_t buffer_id,
+                                        struct rule *)
+    OVS_REQUIRES(ofproto_mutex);
+
 static bool ofproto_group_exists__(const struct ofproto *ofproto,
                                    uint32_t group_id)
     OVS_REQ_RDLOCK(ofproto->groups_rwlock);
@@ -297,10 +273,10 @@ static bool ofproto_group_exists(const struct ofproto *ofproto,
                                  uint32_t group_id)
     OVS_EXCLUDED(ofproto->groups_rwlock);
 static enum ofperr add_group(struct ofproto *, struct ofputil_group_mod *);
-static bool handle_openflow(struct ofconn *, const struct ofpbuf *);
-static enum ofperr handle_flow_mod__(struct ofproto *, struct ofconn *,
+static void handle_openflow(struct ofconn *, const struct ofpbuf *);
+static enum ofperr handle_flow_mod__(struct ofproto *,
                                      struct ofputil_flow_mod *,
-                                     const struct ofp_header *)
+                                     const struct flow_mod_requester *)
     OVS_EXCLUDED(ofproto_mutex);
 static void calc_duration(long long int start, long long int now,
                           uint32_t *sec, uint32_t *nsec);
@@ -536,12 +512,9 @@ ofproto_create(const char *datapath_name, const char *datapath_type,
     ofproto->tables = NULL;
     ofproto->n_tables = 0;
     hindex_init(&ofproto->cookies);
+    hmap_init(&ofproto->learned_cookies);
     list_init(&ofproto->expirable);
     ofproto->connmgr = connmgr_create(ofproto, datapath_name, datapath_name);
-    ofproto->state = S_OPENFLOW;
-    list_init(&ofproto->pending);
-    ofproto->n_pending = 0;
-    hmap_init(&ofproto->deletions);
     guarded_list_init(&ofproto->rule_executes);
     ofproto->vlan_bitmap = NULL;
     ofproto->vlans_changed = false;
@@ -1204,26 +1177,13 @@ ofproto_configure_table(struct ofproto *ofproto, int table_id,
 
     table->max_flows = s->max_flows;
     fat_rwlock_wrlock(&table->cls.rwlock);
-    if (classifier_count(&table->cls) > table->max_flows
-        && table->eviction_fields) {
-        /* 'table' contains more flows than allowed.  We might not be able to
-         * evict them right away because of the asynchronous nature of flow
-         * table changes.  Schedule eviction for later. */
-        switch (ofproto->state) {
-        case S_OPENFLOW:
-            ofproto->state = S_EVICT;
-            break;
-        case S_EVICT:
-        case S_FLUSH:
-            /* We're already deleting flows, nothing more to do. */
-            break;
-        }
-    }
-
     classifier_set_prefix_fields(&table->cls,
                                  s->prefix_fields, s->n_prefix_fields);
-
     fat_rwlock_unlock(&table->cls.rwlock);
+
+    ovs_mutex_lock(&ofproto_mutex);
+    evict_rules_from_table(table, 0);
+    ovs_mutex_unlock(&ofproto_mutex);
 }
 \f
 bool
@@ -1239,17 +1199,15 @@ ofproto_get_snoops(const struct ofproto *ofproto, struct sset *snoops)
 }
 
 static void
-ofproto_rule_delete__(struct ofproto *ofproto, struct rule *rule,
-                      uint8_t reason)
+ofproto_rule_delete__(struct rule *rule, uint8_t reason)
     OVS_REQUIRES(ofproto_mutex)
 {
-    struct ofopgroup *group;
-
-    ovs_assert(!rule->pending);
+    struct rule_collection rules;
 
-    group = ofopgroup_create_unattached(ofproto);
-    delete_flow__(rule, group, reason);
-    ofopgroup_submit(group);
+    rules.rules = rules.stub;
+    rules.n = 1;
+    rules.stub[0] = rule;
+    delete_flows__(&rules, reason, NULL);
 }
 
 /* Deletes 'rule' from 'ofproto'.
@@ -1265,17 +1223,12 @@ void
 ofproto_rule_delete(struct ofproto *ofproto, struct rule *rule)
     OVS_EXCLUDED(ofproto_mutex)
 {
-    struct ofopgroup *group;
-
+    /* This skips the ofmonitor and flow-removed notifications because the
+     * switch is being deleted and any OpenFlow channels have been or soon will
+     * be killed. */
     ovs_mutex_lock(&ofproto_mutex);
-    ovs_assert(!rule->pending);
-
-    group = ofopgroup_create_unattached(ofproto);
-    ofoperation_create(group, rule, OFOPERATION_DELETE, OFPRR_DELETE);
     oftable_remove_rule__(ofproto, rule);
     ofproto->ofproto_class->rule_delete(rule);
-    ofopgroup_submit(group);
-
     ovs_mutex_unlock(&ofproto_mutex);
 }
 
@@ -1302,9 +1255,7 @@ ofproto_flush__(struct ofproto *ofproto)
         cls_cursor_init(&cursor, &table->cls, NULL);
         fat_rwlock_unlock(&table->cls.rwlock);
         CLS_CURSOR_FOR_EACH_SAFE (rule, next_rule, cr, &cursor) {
-            if (!rule->pending) {
-                ofproto_rule_delete__(ofproto, rule, OFPRR_DELETE);
-            }
+            ofproto_rule_delete__(rule, OFPRR_DELETE);
         }
     }
     ovs_mutex_unlock(&ofproto_mutex);
@@ -1318,8 +1269,6 @@ ofproto_destroy__(struct ofproto *ofproto)
 {
     struct oftable *table;
 
-    ovs_assert(list_is_empty(&ofproto->pending));
-
     destroy_rule_executes(ofproto);
     delete_group(ofproto, OFPG_ALL);
 
@@ -1347,11 +1296,12 @@ ofproto_destroy__(struct ofproto *ofproto)
     }
     free(ofproto->tables);
 
-    hmap_destroy(&ofproto->deletions);
-
     ovs_assert(hindex_is_empty(&ofproto->cookies));
     hindex_destroy(&ofproto->cookies);
 
+    ovs_assert(hmap_is_empty(&ofproto->learned_cookies));
+    hmap_destroy(&ofproto->learned_cookies);
+
     free(ofproto->vlan_bitmap);
 
     ofproto->ofproto_class->dealloc(ofproto);
@@ -1446,19 +1396,6 @@ ofproto_type_wait(const char *datapath_type)
     }
 }
 
-static bool
-any_pending_ops(const struct ofproto *p)
-    OVS_EXCLUDED(ofproto_mutex)
-{
-    bool b;
-
-    ovs_mutex_lock(&ofproto_mutex);
-    b = !list_is_empty(&p->pending);
-    ovs_mutex_unlock(&ofproto_mutex);
-
-    return b;
-}
-
 int
 ofproto_run(struct ofproto *p)
 {
@@ -1548,31 +1485,7 @@ ofproto_run(struct ofproto *p)
         p->change_seq = new_seq;
     }
 
-    switch (p->state) {
-    case S_OPENFLOW:
-        connmgr_run(p->connmgr, handle_openflow);
-        break;
-
-    case S_EVICT:
-        connmgr_run(p->connmgr, NULL);
-        ofproto_evict(p);
-        if (!any_pending_ops(p)) {
-            p->state = S_OPENFLOW;
-        }
-        break;
-
-    case S_FLUSH:
-        connmgr_run(p->connmgr, NULL);
-        ofproto_flush__(p);
-        if (!any_pending_ops(p)) {
-            connmgr_flushed(p->connmgr);
-            p->state = S_OPENFLOW;
-        }
-        break;
-
-    default:
-        OVS_NOT_REACHED();
-    }
+    connmgr_run(p->connmgr, handle_openflow);
 
     return error;
 }
@@ -1585,20 +1498,7 @@ ofproto_wait(struct ofproto *p)
         p->ofproto_class->port_poll_wait(p);
     }
     seq_wait(connectivity_seq_get(), p->change_seq);
-
-    switch (p->state) {
-    case S_OPENFLOW:
-        connmgr_wait(p->connmgr, true);
-        break;
-
-    case S_EVICT:
-    case S_FLUSH:
-        connmgr_wait(p->connmgr, false);
-        if (!any_pending_ops(p)) {
-            poll_immediate_wake();
-        }
-        break;
-    }
+    connmgr_wait(p->connmgr);
 }
 
 bool
@@ -1617,11 +1517,6 @@ ofproto_get_memory_usage(const struct ofproto *ofproto, struct simap *usage)
 
     simap_increase(usage, "ports", hmap_count(&ofproto->ports));
 
-    ovs_mutex_lock(&ofproto_mutex);
-    simap_increase(usage, "ops",
-                   ofproto->n_pending + hmap_count(&ofproto->deletions));
-    ovs_mutex_unlock(&ofproto_mutex);
-
     n_rules = 0;
     OFPROTO_FOR_EACH_TABLE (table, ofproto) {
         fat_rwlock_rdlock(&table->cls.rwlock);
@@ -1889,7 +1784,7 @@ simple_flow_mod(struct ofproto *ofproto,
 
     flow_mod_init(&fm, match, priority, ofpacts, ofpacts_len, command);
 
-    return handle_flow_mod__(ofproto, NULL, &fm, NULL);
+    return handle_flow_mod__(ofproto, &fm, NULL);
 }
 
 /* Adds a flow to OpenFlow flow table 0 in 'p' that matches 'cls_rule' and
@@ -1987,14 +1882,14 @@ ofproto_flow_mod(struct ofproto *ofproto, struct ofputil_flow_mod *fm)
         }
     }
 
-    return handle_flow_mod__(ofproto, NULL, fm, NULL);
+    return handle_flow_mod__(ofproto, fm, NULL);
 }
 
 /* Searches for a rule with matching criteria exactly equal to 'target' in
  * ofproto's table 0 and, if it finds one, deletes it.
  *
  * This is a helper function for in-band control and fail-open. */
-bool
+void
 ofproto_delete_flow(struct ofproto *ofproto,
                     const struct match *target, unsigned int priority)
     OVS_EXCLUDED(ofproto_mutex)
@@ -2009,24 +1904,23 @@ ofproto_delete_flow(struct ofproto *ofproto,
                                                             priority));
     fat_rwlock_unlock(&cls->rwlock);
     if (!rule) {
-        return true;
+        return;
     }
 
-    /* Fall back to a executing a full flow mod.  We can't optimize this at all
-     * because we didn't take enough locks above to ensure that the flow table
-     * didn't already change beneath us.  */
-    return simple_flow_mod(ofproto, target, priority, NULL, 0,
-                           OFPFC_DELETE_STRICT) != OFPROTO_POSTPONE;
+    /* Execute a flow mod.  We can't optimize this at all because we didn't
+     * take enough locks above to ensure that the flow table didn't already
+     * change beneath us. */
+    simple_flow_mod(ofproto, target, priority, NULL, 0, OFPFC_DELETE_STRICT);
 }
 
-/* Starts the process of deleting all of the flows from all of ofproto's flow
- * tables and then reintroducing the flows required by in-band control and
- * fail-open.  The process will complete in a later call to ofproto_run(). */
+/* Delete all of the flows from all of ofproto's flow tables, then reintroduce
+ * the flows required by in-band control and fail-open.  */
 void
 ofproto_flush_flows(struct ofproto *ofproto)
 {
     COVERAGE_INC(ofproto_flush);
-    ofproto->state = S_FLUSH;
+    ofproto_flush__(ofproto);
+    connmgr_flushed(ofproto->connmgr);
 }
 \f
 static void
@@ -2642,18 +2536,18 @@ static uint32_t get_provider_meter_id(const struct ofproto *,
 /* Creates and returns a new 'struct rule_actions', whose actions are a copy
  * of from the 'ofpacts_len' bytes of 'ofpacts'. */
 const struct rule_actions *
-rule_actions_create(const struct ofproto *ofproto,
-                    const struct ofpact *ofpacts, size_t ofpacts_len)
+rule_actions_create(const struct ofpact *ofpacts, size_t ofpacts_len)
 {
     struct rule_actions *actions;
 
     actions = xmalloc(sizeof *actions + ofpacts_len);
     actions->ofpacts_len = ofpacts_len;
-    actions->provider_meter_id
-        = get_provider_meter_id(ofproto,
-                                ofpacts_get_meter(ofpacts, ofpacts_len));
+    actions->has_meter = ofpacts_get_meter(ofpacts, ofpacts_len) != 0;
     memcpy(actions->ofpacts, ofpacts, ofpacts_len);
 
+    actions->has_learn_with_delete = (next_learn_with_delete(actions, NULL)
+                                      != NULL);
+
     return actions;
 }
 
@@ -2695,30 +2589,6 @@ ofproto_rule_has_out_group(const struct rule *rule, uint32_t group_id)
     }
 }
 
-/* Returns true if a rule related to 'op' has an OpenFlow OFPAT_OUTPUT or
- * OFPAT_ENQUEUE action that outputs to 'out_port'. */
-bool
-ofoperation_has_out_port(const struct ofoperation *op, ofp_port_t out_port)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    if (ofproto_rule_has_out_port(op->rule, out_port)) {
-        return true;
-    }
-
-    switch (op->type) {
-    case OFOPERATION_ADD:
-    case OFOPERATION_DELETE:
-        return false;
-
-    case OFOPERATION_MODIFY:
-    case OFOPERATION_REPLACE:
-        return ofpacts_output_to_port(op->actions->ofpacts,
-                                      op->actions->ofpacts_len, out_port);
-    }
-
-    OVS_NOT_REACHED();
-}
-
 static void
 rule_execute_destroy(struct rule_execute *e)
 {
@@ -2764,23 +2634,126 @@ destroy_rule_executes(struct ofproto *ofproto)
 }
 
 static bool
-oftable_is_modifiable(const struct oftable *table,
-                      enum ofputil_flow_mod_flags flags)
+rule_is_readonly(const struct rule *rule)
 {
-    if (flags & OFPUTIL_FF_NO_READONLY) {
-        return true;
+    const struct oftable *table = &rule->ofproto->tables[rule->table_id];
+    return (table->flags & OFTABLE_READONLY) != 0;
+}
+\f
+static uint32_t
+hash_learned_cookie(ovs_be64 cookie_, uint8_t table_id)
+{
+    uint64_t cookie = (OVS_FORCE uint64_t) cookie_;
+    return hash_3words(cookie, cookie >> 32, table_id);
+}
+
+static void
+learned_cookies_update_one__(struct ofproto *ofproto,
+                             const struct ofpact_learn *learn,
+                             int delta, struct list *dead_cookies)
+    OVS_REQUIRES(ofproto_mutex)
+{
+    uint32_t hash = hash_learned_cookie(learn->cookie, learn->table_id);
+    struct learned_cookie *c;
+
+    HMAP_FOR_EACH_WITH_HASH (c, u.hmap_node, hash, &ofproto->learned_cookies) {
+        if (c->cookie == learn->cookie && c->table_id == learn->table_id) {
+            c->n += delta;
+            ovs_assert(c->n >= 0);
+
+            if (!c->n) {
+                hmap_remove(&ofproto->learned_cookies, &c->u.hmap_node);
+                list_push_back(dead_cookies, &c->u.list_node);
+            }
+
+            return;
+        }
     }
 
-    return !(table->flags & OFTABLE_READONLY);
+    ovs_assert(delta > 0);
+    c = xmalloc(sizeof *c);
+    hmap_insert(&ofproto->learned_cookies, &c->u.hmap_node, hash);
+    c->cookie = learn->cookie;
+    c->table_id = learn->table_id;
+    c->n = delta;
 }
 
-static bool
-rule_is_modifiable(const struct rule *rule, enum ofputil_flow_mod_flags flags)
+static const struct ofpact_learn *
+next_learn_with_delete(const struct rule_actions *actions,
+                       const struct ofpact_learn *start)
+{
+    const struct ofpact *pos;
+
+    for (pos = start ? ofpact_next(&start->ofpact) : actions->ofpacts;
+         pos < ofpact_end(actions->ofpacts, actions->ofpacts_len);
+         pos = ofpact_next(pos)) {
+        if (pos->type == OFPACT_LEARN) {
+            const struct ofpact_learn *learn = ofpact_get_LEARN(pos);
+            if (learn->flags & NX_LEARN_F_DELETE_LEARNED) {
+                return learn;
+            }
+        }
+    }
+
+    return NULL;
+}
+
+static void
+learned_cookies_update__(struct ofproto *ofproto,
+                         const struct rule_actions *actions,
+                         int delta, struct list *dead_cookies)
+    OVS_REQUIRES(ofproto_mutex)
+{
+    if (actions->has_learn_with_delete) {
+        const struct ofpact_learn *learn;
+
+        for (learn = next_learn_with_delete(actions, NULL); learn;
+             learn = next_learn_with_delete(actions, learn)) {
+            learned_cookies_update_one__(ofproto, learn, delta, dead_cookies);
+        }
+    }
+}
+
+static void
+learned_cookies_inc(struct ofproto *ofproto,
+                    const struct rule_actions *actions)
+    OVS_REQUIRES(ofproto_mutex)
 {
-    const struct oftable *rule_table;
+    learned_cookies_update__(ofproto, actions, +1, NULL);
+}
 
-    rule_table = &rule->ofproto->tables[rule->table_id];
-    return oftable_is_modifiable(rule_table, flags);
+static void
+learned_cookies_dec(struct ofproto *ofproto,
+                    const struct rule_actions *actions,
+                    struct list *dead_cookies)
+    OVS_REQUIRES(ofproto_mutex)
+{
+    learned_cookies_update__(ofproto, actions, -1, dead_cookies);
+}
+
+static void
+learned_cookies_flush(struct ofproto *ofproto, struct list *dead_cookies)
+    OVS_REQUIRES(ofproto_mutex)
+{
+    struct learned_cookie *c, *next;
+
+    LIST_FOR_EACH_SAFE (c, next, u.list_node, dead_cookies) {
+        struct rule_criteria criteria;
+        struct rule_collection rules;
+        struct match match;
+
+        match_init_catchall(&match);
+        rule_criteria_init(&criteria, c->table_id, &match, 0,
+                           c->cookie, OVS_BE64_MAX, OFPP_ANY, OFPG_ANY);
+        rule_criteria_require_rw(&criteria, false);
+        collect_rules_loose(ofproto, &criteria, &rules);
+        delete_flows__(&rules, OFPRR_DELETE, NULL);
+        rule_criteria_destroy(&criteria);
+        rule_collection_destroy(&rules);
+
+        list_remove(&c->u.list_node);
+        free(c);
+    }
 }
 \f
 static enum ofperr
@@ -3232,22 +3205,6 @@ cookies_remove(struct ofproto *ofproto, struct rule *rule)
     hindex_remove(&ofproto->cookies, &rule->cookie_node);
 }
 
-static void
-ofproto_rule_change_cookie(struct ofproto *ofproto, struct rule *rule,
-                           ovs_be64 new_cookie)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    if (new_cookie != rule->flow_cookie) {
-        cookies_remove(ofproto, rule);
-
-        ovs_mutex_lock(&rule->mutex);
-        rule->flow_cookie = new_cookie;
-        ovs_mutex_unlock(&rule->mutex);
-
-        cookies_insert(ofproto, rule);
-    }
-}
-
 static void
 calc_duration(long long int start, long long int now,
               uint32_t *sec, uint32_t *nsec)
@@ -3440,11 +3397,8 @@ rule_collection_destroy(struct rule_collection *rules)
  * check 'c->cr' itself.
  *
  * Increments '*n_readonly' if 'rule' wasn't added because it's read-only (and
- * 'c' only includes modifiable rules).
- *
- * Returns 0 ordinarily, but OFPROTO_POSTPONE if we would otherwise collect a
- * rule that has a pending operation. */
-static enum ofperr
+ * 'c' only includes modifiable rules). */
+static void
 collect_rule(struct rule *rule, const struct rule_criteria *c,
              struct rule_collection *rules, size_t *n_readonly)
     OVS_REQUIRES(ofproto_mutex)
@@ -3454,12 +3408,8 @@ collect_rule(struct rule *rule, const struct rule_criteria *c,
         && ofproto_rule_has_out_group(rule, c->out_group)
         && !((rule->flow_cookie ^ c->cookie) & c->cookie_mask)
         && (!rule_is_hidden(rule) || c->include_hidden)) {
-        if (rule->pending) {
-            return OFPROTO_POSTPONE;
-        }
-
         /* Rule matches all the criteria... */
-        if (rule_is_modifiable(rule, 0) || c->include_readonly) {
+        if (!rule_is_readonly(rule) || c->include_readonly) {
             /* ...add it. */
             rule_collection_add(rules, rule);
         } else {
@@ -3467,7 +3417,6 @@ collect_rule(struct rule *rule, const struct rule_criteria *c,
             ++*n_readonly;
         }
     }
-    return 0;
 }
 
 /* Searches 'ofproto' for rules that match the criteria in 'criteria'.  Matches
@@ -3500,10 +3449,7 @@ collect_rules_loose(struct ofproto *ofproto,
                                    hash_cookie(criteria->cookie),
                                    &ofproto->cookies) {
             if (cls_rule_is_loose_match(&rule->cr, &criteria->cr.match)) {
-                error = collect_rule(rule, criteria, rules, &n_readonly);
-                if (error) {
-                    break;
-                }
+                collect_rule(rule, criteria, rules, &n_readonly);
             }
         }
     } else {
@@ -3514,10 +3460,7 @@ collect_rules_loose(struct ofproto *ofproto,
             fat_rwlock_rdlock(&table->cls.rwlock);
             cls_cursor_init(&cursor, &table->cls, &criteria->cr);
             CLS_CURSOR_FOR_EACH (rule, cr, &cursor) {
-                error = collect_rule(rule, criteria, rules, &n_readonly);
-                if (error) {
-                    break;
-                }
+                collect_rule(rule, criteria, rules, &n_readonly);
             }
             fat_rwlock_unlock(&table->cls.rwlock);
         }
@@ -3565,10 +3508,7 @@ collect_rules_strict(struct ofproto *ofproto,
                                    hash_cookie(criteria->cookie),
                                    &ofproto->cookies) {
             if (cls_rule_equal(&rule->cr, &criteria->cr)) {
-                error = collect_rule(rule, criteria, rules, &n_readonly);
-                if (error) {
-                    break;
-                }
+                collect_rule(rule, criteria, rules, &n_readonly);
             }
         }
     } else {
@@ -3580,15 +3520,17 @@ collect_rules_strict(struct ofproto *ofproto,
                                           &table->cls, &criteria->cr));
             fat_rwlock_unlock(&table->cls.rwlock);
             if (rule) {
-                error = collect_rule(rule, criteria, rules, &n_readonly);
-                if (error) {
-                    break;
-                }
+                collect_rule(rule, criteria, rules, &n_readonly);
             }
         }
     }
 
 exit:
+    if (!error && !rules->n && n_readonly) {
+        /* We didn't find any rules to modify.  We did find some read-only
+         * rules that we're not allowed to modify, so report that. */
+        error = OFPERR_OFPBRC_EPERM;
+    }
     if (error) {
         rule_collection_destroy(rules);
     }
@@ -3933,28 +3875,6 @@ handle_queue_stats_request(struct ofconn *ofconn,
     return error;
 }
 
-static bool
-is_flow_deletion_pending(const struct ofproto *ofproto,
-                         const struct cls_rule *cls_rule,
-                         uint8_t table_id)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    if (!hmap_is_empty(&ofproto->deletions)) {
-        struct ofoperation *op;
-
-        HMAP_FOR_EACH_WITH_HASH (op, hmap_node,
-                                 cls_rule_hash(cls_rule, table_id),
-                                 &ofproto->deletions) {
-            if (op->rule->table_id == table_id
-                && cls_rule_equal(cls_rule, &op->rule->cr)) {
-                return true;
-            }
-        }
-    }
-
-    return false;
-}
-
 static bool
 should_evict_a_rule(struct oftable *table, unsigned int extra_space)
     OVS_REQUIRES(ofproto_mutex)
@@ -3964,8 +3884,7 @@ should_evict_a_rule(struct oftable *table, unsigned int extra_space)
 }
 
 static enum ofperr
-evict_rules_from_table(struct ofproto *ofproto, struct oftable *table,
-                       unsigned int extra_space)
+evict_rules_from_table(struct oftable *table, unsigned int extra_space)
     OVS_REQUIRES(ofproto_mutex)
 {
     while (should_evict_a_rule(table, extra_space)) {
@@ -3973,12 +3892,8 @@ evict_rules_from_table(struct ofproto *ofproto, struct oftable *table,
 
         if (!choose_rule_to_evict(table, &rule)) {
             return OFPERR_OFPFMFC_TABLE_FULL;
-        } else if (rule->pending) {
-            return OFPROTO_POSTPONE;
         } else {
-            struct ofopgroup *group = ofopgroup_create_unattached(ofproto);
-            delete_flow__(rule, group, OFPRR_EVICTION);
-            ofopgroup_submit(group);
+            ofproto_rule_delete__(rule, OFPRR_EVICTION);
         }
     }
 
@@ -3998,12 +3913,11 @@ evict_rules_from_table(struct ofproto *ofproto, struct oftable *table,
  * 'ofconn' is used to retrieve the packet buffer specified in ofm->buffer_id,
  * if any. */
 static enum ofperr
-add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
-         struct ofputil_flow_mod *fm, const struct ofp_header *request)
+add_flow(struct ofproto *ofproto, struct ofputil_flow_mod *fm,
+         const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
     const struct rule_actions *actions;
-    struct ofopgroup *group;
     struct oftable *table;
     struct cls_rule cr;
     struct rule *rule;
@@ -4035,8 +3949,8 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
     }
 
     table = &ofproto->tables[table_id];
-
-    if (!oftable_is_modifiable(table, fm->flags)) {
+    if (table->flags & OFTABLE_READONLY
+        && !(fm->flags & OFPUTIL_FF_NO_READONLY)) {
         return OFPERR_OFPBRC_EPERM;
     }
 
@@ -4055,28 +3969,17 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
     rule = rule_from_cls_rule(classifier_find_rule_exactly(&table->cls, &cr));
     fat_rwlock_unlock(&table->cls.rwlock);
     if (rule) {
-        cls_rule_destroy(&cr);
-        if (!rule_is_modifiable(rule, fm->flags)) {
-            return OFPERR_OFPBRC_EPERM;
-        } else if (rule->pending) {
-            return OFPROTO_POSTPONE;
-        } else {
-            struct rule_collection rules;
+        struct rule_collection rules;
 
-            rule_collection_init(&rules);
-            rule_collection_add(&rules, rule);
-            fm->modify_cookie = true;
-            error = modify_flows__(ofproto, ofconn, fm, request, &rules);
-            rule_collection_destroy(&rules);
+        cls_rule_destroy(&cr);
 
-            return error;
-        }
-    }
+        rule_collection_init(&rules);
+        rule_collection_add(&rules, rule);
+        fm->modify_cookie = true;
+        error = modify_flows__(ofproto, fm, &rules, req);
+        rule_collection_destroy(&rules);
 
-    /* Serialize against pending deletion. */
-    if (is_flow_deletion_pending(ofproto, &cr, table_id)) {
-        cls_rule_destroy(&cr);
-        return OFPROTO_POSTPONE;
+        return error;
     }
 
     /* Check for overlap, if requested. */
@@ -4094,7 +3997,7 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
     }
 
     /* If necessary, evict an existing rule to clear out space. */
-    error = evict_rules_from_table(ofproto, table, 1);
+    error = evict_rules_from_table(table, 1);
     if (error) {
         cls_rule_destroy(&cr);
         return error;
@@ -4113,7 +4016,6 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
     *CONST_CAST(struct ofproto **, &rule->ofproto) = ofproto;
     cls_rule_move(CONST_CAST(struct cls_rule *, &rule->cr), &cr);
     ovs_refcount_init(&rule->ref_count);
-    rule->pending = NULL;
     rule->flow_cookie = fm->new_cookie;
     rule->created = rule->modified = time_msec();
 
@@ -4125,7 +4027,7 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
 
     *CONST_CAST(uint8_t *, &rule->table_id) = table - ofproto->tables;
     rule->flags = fm->flags & OFPUTIL_FF_STATE;
-    actions = rule_actions_create(ofproto, fm->ofpacts, fm->ofpacts_len);
+    actions = rule_actions_create(fm->ofpacts, fm->ofpacts_len);
     ovsrcu_set(&rule->actions, actions);
     list_init(&rule->meter_list_node);
     rule->eviction_group = NULL;
@@ -4146,7 +4048,7 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
     }
     cookies_insert(ofproto, rule);
     eviction_group_add_rule(rule);
-    if (actions->provider_meter_id != UINT32_MAX) {
+    if (actions->has_meter) {
         meter_insert_rule(rule);
     }
 
@@ -4154,12 +4056,30 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
     classifier_insert(&table->cls, CONST_CAST(struct cls_rule *, &rule->cr));
     fat_rwlock_unlock(&table->cls.rwlock);
 
-    group = ofopgroup_create(ofproto, ofconn, request, fm->buffer_id);
-    ofoperation_create(group, rule, OFOPERATION_ADD, 0);
-    ofproto->ofproto_class->rule_insert(rule);
-    ofopgroup_submit(group);
+    error = ofproto->ofproto_class->rule_insert(rule);
+    if (error) {
+        oftable_remove_rule(rule);
+        ofproto_rule_unref(rule);
+        return error;
+    }
+    learned_cookies_inc(ofproto, actions);
+
+    if (minimask_get_vid_mask(&rule->cr.match.mask) == VLAN_VID_MASK) {
+        if (ofproto->vlan_bitmap) {
+            uint16_t vid = miniflow_get_vid(&rule->cr.match.flow);
+            if (!bitmap_is_set(ofproto->vlan_bitmap, vid)) {
+                bitmap_set1(ofproto->vlan_bitmap, vid);
+                ofproto->vlans_changed = true;
+            }
+        } else {
+            ofproto->vlans_changed = true;
+        }
+    }
 
-    return error;
+    ofmonitor_report(ofproto->connmgr, rule, NXFME_ADDED, 0,
+                     req ? req->ofconn : NULL, req ? req->xid : 0);
+
+    return req ? send_buffered_packet(req->ofconn, fm->buffer_id, rule) : 0;
 }
 \f
 /* OFPFC_MODIFY and OFPFC_MODIFY_STRICT. */
@@ -4172,19 +4092,19 @@ add_flow(struct ofproto *ofproto, struct ofconn *ofconn,
  *
  * Returns 0 on success, otherwise an OpenFlow error code. */
 static enum ofperr
-modify_flows__(struct ofproto *ofproto, struct ofconn *ofconn,
-               struct ofputil_flow_mod *fm, const struct ofp_header *request,
-               const struct rule_collection *rules)
+modify_flows__(struct ofproto *ofproto, struct ofputil_flow_mod *fm,
+               const struct rule_collection *rules,
+               const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
-    enum ofoperation_type type;
-    struct ofopgroup *group;
-    enum ofperr error;
+    struct list dead_cookies = LIST_INITIALIZER(&dead_cookies);
+    enum nx_flow_update_event event;
     size_t i;
 
     if (ofproto->ofproto_class->rule_premodify_actions) {
         for (i = 0; i < rules->n; i++) {
             struct rule *rule = rules->rules[i];
+            enum ofperr error;
 
             error = ofproto->ofproto_class->rule_premodify_actions(
                 rule, fm->ofpacts, fm->ofpacts_len);
@@ -4194,35 +4114,47 @@ modify_flows__(struct ofproto *ofproto, struct ofconn *ofconn,
         }
     }
 
-    type = fm->command == OFPFC_ADD ? OFOPERATION_REPLACE : OFOPERATION_MODIFY;
-    group = ofopgroup_create(ofproto, ofconn, request, fm->buffer_id);
+    event = fm->command == OFPFC_ADD ? NXFME_ADDED : NXFME_MODIFIED;
     for (i = 0; i < rules->n; i++) {
         struct rule *rule = rules->rules[i];
-        const struct rule_actions *actions;
-        struct ofoperation *op;
-        bool actions_changed;
-        bool reset_counters;
 
-        /* FIXME: Implement OFPFUTIL_FF_RESET_COUNTS */
+        /*  'fm' says that  */
+        bool change_cookie = (fm->modify_cookie
+                              && fm->new_cookie != OVS_BE64_MAX
+                              && fm->new_cookie != rule->flow_cookie);
 
+        const struct rule_actions *actions = rule_get_actions(rule);
+        bool change_actions = !ofpacts_equal(fm->ofpacts, fm->ofpacts_len,
+                                             actions->ofpacts,
+                                             actions->ofpacts_len);
 
-        actions = rule_get_actions(rule);
-        actions_changed = !ofpacts_equal(fm->ofpacts, fm->ofpacts_len,
-                                         actions->ofpacts,
-                                         actions->ofpacts_len);
+        bool reset_counters = (fm->flags & OFPUTIL_FF_RESET_COUNTS) != 0;
 
-        op = ofoperation_create(group, rule, type, 0);
+        long long int now = time_msec();
+
+        /* FIXME: Implement OFPFUTIL_FF_RESET_COUNTS */
 
-        if (fm->modify_cookie && fm->new_cookie != OVS_BE64_MAX) {
-            ofproto_rule_change_cookie(ofproto, rule, fm->new_cookie);
+        if (change_cookie) {
+            cookies_remove(ofproto, rule);
         }
-        if (type == OFOPERATION_REPLACE) {
-            ovs_mutex_lock(&rule->mutex);
+
+        ovs_mutex_lock(&rule->mutex);
+        if (fm->command == OFPFC_ADD) {
             rule->idle_timeout = fm->idle_timeout;
             rule->hard_timeout = fm->hard_timeout;
-            ovs_mutex_unlock(&rule->mutex);
-
             rule->flags = fm->flags & OFPUTIL_FF_STATE;
+            rule->created = now;
+        }
+        if (change_cookie) {
+            rule->flow_cookie = fm->new_cookie;
+        }
+        rule->modified = now;
+        ovs_mutex_unlock(&rule->mutex);
+
+        if (change_cookie) {
+            cookies_insert(ofproto, rule);
+        }
+        if (fm->command == OFPFC_ADD) {
             if (fm->idle_timeout || fm->hard_timeout) {
                 if (!rule->eviction_group) {
                     eviction_group_add_rule(rule);
@@ -4232,35 +4164,45 @@ modify_flows__(struct ofproto *ofproto, struct ofconn *ofconn,
             }
         }
 
-        reset_counters = (fm->flags & OFPUTIL_FF_RESET_COUNTS) != 0;
-        if (actions_changed || reset_counters) {
-            const struct rule_actions *new_actions;
+        if (change_actions) {
+            ovsrcu_set(&rule->actions, rule_actions_create(fm->ofpacts,
+                                                           fm->ofpacts_len));
+            rule_actions_destroy(actions);
+        }
 
-            op->actions = rule_get_actions(rule);
-            new_actions = rule_actions_create(ofproto,
-                                              fm->ofpacts, fm->ofpacts_len);
+        if (change_actions || reset_counters) {
+            ofproto->ofproto_class->rule_modify_actions(rule, reset_counters);
+        }
 
-            ovsrcu_set(&rule->actions, new_actions);
+        if (event != NXFME_MODIFIED || change_actions || change_cookie) {
+            ofmonitor_report(ofproto->connmgr, rule, event, 0,
+                             req ? req->ofconn : NULL, req ? req->xid : 0);
+        }
 
-            ofproto->ofproto_class->rule_modify_actions(rule, reset_counters);
-        } else {
-            ofoperation_complete(op, 0);
+        if (change_actions) {
+            learned_cookies_inc(ofproto, rule_get_actions(rule));
+            learned_cookies_dec(ofproto, actions, &dead_cookies);
         }
     }
-    ofopgroup_submit(group);
+    learned_cookies_flush(ofproto, &dead_cookies);
 
-    return error;
+    if (fm->buffer_id != UINT32_MAX && req) {
+        return send_buffered_packet(req->ofconn, fm->buffer_id,
+                                    rules->rules[0]);
+    }
+
+    return 0;
 }
 
 static enum ofperr
-modify_flows_add(struct ofproto *ofproto, struct ofconn *ofconn,
-                 struct ofputil_flow_mod *fm, const struct ofp_header *request)
+modify_flows_add(struct ofproto *ofproto, struct ofputil_flow_mod *fm,
+                 const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
     if (fm->cookie_mask != htonll(0) || fm->new_cookie == OVS_BE64_MAX) {
         return 0;
     }
-    return add_flow(ofproto, ofconn, fm, request);
+    return add_flow(ofproto, fm, req);
 }
 
 /* Implements OFPFC_MODIFY.  Returns 0 on success or an OpenFlow error code on
@@ -4269,9 +4211,8 @@ modify_flows_add(struct ofproto *ofproto, struct ofconn *ofconn,
  * 'ofconn' is used to retrieve the packet buffer specified in fm->buffer_id,
  * if any. */
 static enum ofperr
-modify_flows_loose(struct ofproto *ofproto, struct ofconn *ofconn,
-                   struct ofputil_flow_mod *fm,
-                   const struct ofp_header *request)
+modify_flows_loose(struct ofproto *ofproto, struct ofputil_flow_mod *fm,
+                   const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
     struct rule_criteria criteria;
@@ -4287,8 +4228,8 @@ modify_flows_loose(struct ofproto *ofproto, struct ofconn *ofconn,
 
     if (!error) {
         error = (rules.n > 0
-                 ? modify_flows__(ofproto, ofconn, fm, request, &rules)
-                 : modify_flows_add(ofproto, ofconn, fm, request));
+                 ? modify_flows__(ofproto, fm, &rules, req)
+                 : modify_flows_add(ofproto, fm, req));
     }
 
     rule_collection_destroy(&rules);
@@ -4297,14 +4238,10 @@ modify_flows_loose(struct ofproto *ofproto, struct ofconn *ofconn,
 }
 
 /* Implements OFPFC_MODIFY_STRICT.  Returns 0 on success or an OpenFlow error
- * code on failure.
- *
- * 'ofconn' is used to retrieve the packet buffer specified in fm->buffer_id,
- * if any. */
+ * code on failure. */
 static enum ofperr
-modify_flow_strict(struct ofproto *ofproto, struct ofconn *ofconn,
-                   struct ofputil_flow_mod *fm,
-                   const struct ofp_header *request)
+modify_flow_strict(struct ofproto *ofproto, struct ofputil_flow_mod *fm,
+                   const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
     struct rule_criteria criteria;
@@ -4320,9 +4257,9 @@ modify_flow_strict(struct ofproto *ofproto, struct ofconn *ofconn,
 
     if (!error) {
         if (rules.n == 0) {
-            error =  modify_flows_add(ofproto, ofconn, fm, request);
+            error = modify_flows_add(ofproto, fm, req);
         } else if (rules.n == 1) {
-            error = modify_flows__(ofproto, ofconn, fm, request, &rules);
+            error = modify_flows__(ofproto, fm, &rules, req);
         }
     }
 
@@ -4333,47 +4270,41 @@ modify_flow_strict(struct ofproto *ofproto, struct ofconn *ofconn,
 \f
 /* OFPFC_DELETE implementation. */
 
+/* Deletes the rules listed in 'rules'. */
 static void
-delete_flow__(struct rule *rule, struct ofopgroup *group,
-              enum ofp_flow_removed_reason reason)
+delete_flows__(const struct rule_collection *rules,
+               enum ofp_flow_removed_reason reason,
+               const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
-    struct ofproto *ofproto = rule->ofproto;
+    if (rules->n) {
+        struct list dead_cookies = LIST_INITIALIZER(&dead_cookies);
+        struct ofproto *ofproto = rules->rules[0]->ofproto;
+        size_t i;
 
-    ofproto_rule_send_removed(rule, reason);
+        for (i = 0; i < rules->n; i++) {
+            struct rule *rule = rules->rules[i];
+            const struct rule_actions *actions = rule_get_actions(rule);
 
-    ofoperation_create(group, rule, OFOPERATION_DELETE, reason);
-    oftable_remove_rule(rule);
-    ofproto->ofproto_class->rule_delete(rule);
-}
+            ofproto_rule_send_removed(rule, reason);
 
-/* Deletes the rules listed in 'rules'.
- *
- * Returns 0 on success, otherwise an OpenFlow error code. */
-static enum ofperr
-delete_flows__(struct ofproto *ofproto, struct ofconn *ofconn,
-               const struct ofp_header *request,
-               const struct rule_collection *rules,
-               enum ofp_flow_removed_reason reason)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    struct ofopgroup *group;
-    size_t i;
+            ofmonitor_report(ofproto->connmgr, rule, NXFME_DELETED, reason,
+                             req ? req->ofconn : NULL, req ? req->xid : 0);
+            oftable_remove_rule(rule);
+            ofproto->ofproto_class->rule_delete(rule);
 
-    group = ofopgroup_create(ofproto, ofconn, request, UINT32_MAX);
-    for (i = 0; i < rules->n; i++) {
-        delete_flow__(rules->rules[i], group, reason);
+            learned_cookies_dec(ofproto, actions, &dead_cookies);
+        }
+        learned_cookies_flush(ofproto, &dead_cookies);
+        ofmonitor_flush(ofproto->connmgr);
     }
-    ofopgroup_submit(group);
-
-    return 0;
 }
 
 /* Implements OFPFC_DELETE. */
 static enum ofperr
-delete_flows_loose(struct ofproto *ofproto, struct ofconn *ofconn,
+delete_flows_loose(struct ofproto *ofproto,
                    const struct ofputil_flow_mod *fm,
-                   const struct ofp_header *request)
+                   const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
     struct rule_criteria criteria;
@@ -4389,8 +4320,7 @@ delete_flows_loose(struct ofproto *ofproto, struct ofconn *ofconn,
     rule_criteria_destroy(&criteria);
 
     if (!error && rules.n > 0) {
-        error = delete_flows__(ofproto, ofconn, request, &rules,
-                               fm->delete_reason);
+        delete_flows__(&rules, fm->delete_reason, req);
     }
     rule_collection_destroy(&rules);
 
@@ -4399,9 +4329,8 @@ delete_flows_loose(struct ofproto *ofproto, struct ofconn *ofconn,
 
 /* Implements OFPFC_DELETE_STRICT. */
 static enum ofperr
-delete_flow_strict(struct ofproto *ofproto, struct ofconn *ofconn,
-                   const struct ofputil_flow_mod *fm,
-                   const struct ofp_header *request)
+delete_flow_strict(struct ofproto *ofproto, const struct ofputil_flow_mod *fm,
+                   const struct flow_mod_requester *req)
     OVS_REQUIRES(ofproto_mutex)
 {
     struct rule_criteria criteria;
@@ -4417,8 +4346,7 @@ delete_flow_strict(struct ofproto *ofproto, struct ofconn *ofconn,
     rule_criteria_destroy(&criteria);
 
     if (!error && rules.n > 0) {
-        error = delete_flows__(ofproto, ofconn, request, &rules,
-                               fm->delete_reason);
+        delete_flows__(&rules, fm->delete_reason, req);
     }
     rule_collection_destroy(&rules);
 
@@ -4432,7 +4360,8 @@ ofproto_rule_send_removed(struct rule *rule, uint8_t reason)
     struct ofputil_flow_removed fr;
     long long int used;
 
-    if (rule_is_hidden(rule) || !(rule->flags & OFPUTIL_FF_SEND_FLOW_REM)) {
+    if (rule_is_hidden(rule) ||
+        !(rule->flags & OFPUTIL_FF_SEND_FLOW_REM)) {
         return;
     }
 
@@ -4457,21 +4386,13 @@ ofproto_rule_send_removed(struct rule *rule, uint8_t reason)
  * OFPRR_HARD_TIMEOUT or OFPRR_IDLE_TIMEOUT), and then removes 'rule' from its
  * ofproto.
  *
- * 'rule' must not have a pending operation (that is, 'rule->pending' must be
- * NULL).
- *
  * ofproto implementation ->run() functions should use this function to expire
  * OpenFlow flows. */
 void
 ofproto_rule_expire(struct rule *rule, uint8_t reason)
     OVS_REQUIRES(ofproto_mutex)
 {
-    struct ofproto *ofproto = rule->ofproto;
-
-    ovs_assert(reason == OFPRR_HARD_TIMEOUT || reason == OFPRR_IDLE_TIMEOUT
-               || reason == OFPRR_DELETE || reason == OFPRR_GROUP_DELETE);
-
-    ofproto_rule_delete__(ofproto, rule, reason);
+    ofproto_rule_delete__(rule, reason);
 }
 
 /* Reduces '*timeout' to no more than 'max'.  A value of zero in either case
@@ -4534,7 +4455,11 @@ handle_flow_mod(struct ofconn *ofconn, const struct ofp_header *oh)
         error = ofproto_check_ofpacts(ofproto, fm.ofpacts, fm.ofpacts_len);
     }
     if (!error) {
-        error = handle_flow_mod__(ofproto, ofconn, &fm, oh);
+        struct flow_mod_requester req;
+
+        req.ofconn = ofconn;
+        req.xid = oh->xid;
+        error = handle_flow_mod__(ofproto, &fm, &req);
     }
     if (error) {
         goto exit_free_ofpacts;
@@ -4549,48 +4474,44 @@ exit:
 }
 
 static enum ofperr
-handle_flow_mod__(struct ofproto *ofproto, struct ofconn *ofconn,
-                  struct ofputil_flow_mod *fm, const struct ofp_header *oh)
+handle_flow_mod__(struct ofproto *ofproto, struct ofputil_flow_mod *fm,
+                  const struct flow_mod_requester *req)
     OVS_EXCLUDED(ofproto_mutex)
 {
     enum ofperr error;
 
     ovs_mutex_lock(&ofproto_mutex);
-    if (ofproto->n_pending < 50) {
-        switch (fm->command) {
-        case OFPFC_ADD:
-            error = add_flow(ofproto, ofconn, fm, oh);
-            break;
+    switch (fm->command) {
+    case OFPFC_ADD:
+        error = add_flow(ofproto, fm, req);
+        break;
 
-        case OFPFC_MODIFY:
-            error = modify_flows_loose(ofproto, ofconn, fm, oh);
-            break;
+    case OFPFC_MODIFY:
+        error = modify_flows_loose(ofproto, fm, req);
+        break;
 
-        case OFPFC_MODIFY_STRICT:
-            error = modify_flow_strict(ofproto, ofconn, fm, oh);
-            break;
+    case OFPFC_MODIFY_STRICT:
+        error = modify_flow_strict(ofproto, fm, req);
+        break;
 
-        case OFPFC_DELETE:
-            error = delete_flows_loose(ofproto, ofconn, fm, oh);
-            break;
+    case OFPFC_DELETE:
+        error = delete_flows_loose(ofproto, fm, req);
+        break;
 
-        case OFPFC_DELETE_STRICT:
-            error = delete_flow_strict(ofproto, ofconn, fm, oh);
-            break;
+    case OFPFC_DELETE_STRICT:
+        error = delete_flow_strict(ofproto, fm, req);
+        break;
 
-        default:
-            if (fm->command > 0xff) {
-                VLOG_WARN_RL(&rl, "%s: flow_mod has explicit table_id but "
-                             "flow_mod_table_id extension is not enabled",
-                             ofproto->name);
-            }
-            error = OFPERR_OFPFMFC_BAD_COMMAND;
-            break;
+    default:
+        if (fm->command > 0xff) {
+            VLOG_WARN_RL(&rl, "%s: flow_mod has explicit table_id but "
+                         "flow_mod_table_id extension is not enabled",
+                         ofproto->name);
         }
-    } else {
-        ovs_assert(!list_is_empty(&ofproto->pending));
-        error = OFPROTO_POSTPONE;
+        error = OFPERR_OFPFMFC_BAD_COMMAND;
+        break;
     }
+    ofmonitor_flush(ofproto->connmgr);
     ovs_mutex_unlock(&ofproto_mutex);
 
     run_rule_executes(ofproto);
@@ -4611,11 +4532,6 @@ handle_role_request(struct ofconn *ofconn, const struct ofp_header *oh)
     }
 
     if (request.role != OFPCR12_ROLE_NOCHANGE) {
-        if (ofconn_get_role(ofconn) != request.role
-            && ofconn_has_pending_opgroups(ofconn)) {
-            return OFPROTO_POSTPONE;
-        }
-
         if (request.have_generation_id
             && !ofconn_set_master_election_id(ofconn, request.generation_id)) {
                 return OFPERR_OFPRRFC_STALE;
@@ -4661,12 +4577,8 @@ handle_nxt_set_flow_format(struct ofconn *ofconn, const struct ofp_header *oh)
 
     cur = ofconn_get_protocol(ofconn);
     next = ofputil_protocol_set_base(cur, next_base);
-    if (cur != next && ofconn_has_pending_opgroups(ofconn)) {
-        /* Avoid sending async messages in surprising protocol. */
-        return OFPROTO_POSTPONE;
-    }
-
     ofconn_set_protocol(ofconn, next);
+
     return 0;
 }
 
@@ -4682,12 +4594,6 @@ handle_nxt_set_packet_in_format(struct ofconn *ofconn,
         return OFPERR_OFPBRC_EPERM;
     }
 
-    if (format != ofconn_get_packet_in_format(ofconn)
-        && ofconn_has_pending_opgroups(ofconn)) {
-        /* Avoid sending async message in surprsing packet in format. */
-        return OFPROTO_POSTPONE;
-    }
-
     ofconn_set_packet_in_format(ofconn, format);
     return 0;
 }
@@ -4760,10 +4666,6 @@ handle_barrier_request(struct ofconn *ofconn, const struct ofp_header *oh)
 {
     struct ofpbuf *buf;
 
-    if (ofconn_has_pending_opgroups(ofconn)) {
-        return OFPROTO_POSTPONE;
-    }
-
     buf = ofpraw_alloc_reply((oh->version == OFP10_VERSION
                               ? OFPRAW_OFPT10_BARRIER_REPLY
                               : OFPRAW_OFPT11_BARRIER_REPLY), oh, 0);
@@ -4777,17 +4679,10 @@ ofproto_compose_flow_refresh_update(const struct rule *rule,
                                     struct list *msgs)
     OVS_REQUIRES(ofproto_mutex)
 {
-    struct ofoperation *op = rule->pending;
     const struct rule_actions *actions;
     struct ofputil_flow_update fu;
     struct match match;
 
-    if (op && op->type == OFOPERATION_ADD) {
-        /* We'll report the final flow when the operation completes.  Reporting
-         * it now would cause a duplicate report later. */
-        return;
-    }
-
     fu.event = (flags & (NXFMF_INITIAL | NXFMF_ADD)
                 ? NXFME_ADDED : NXFME_MODIFIED);
     fu.reason = 0;
@@ -4801,30 +4696,7 @@ ofproto_compose_flow_refresh_update(const struct rule *rule,
     fu.match = &match;
     fu.priority = rule->cr.priority;
 
-    if (!(flags & NXFMF_ACTIONS)) {
-        actions = NULL;
-    } else if (!op) {
-        actions = rule_get_actions(rule);
-    } else {
-        /* An operation is in progress.  Use the previous version of the flow's
-         * actions, so that when the operation commits we report the change. */
-        switch (op->type) {
-        case OFOPERATION_ADD:
-            OVS_NOT_REACHED();
-
-        case OFOPERATION_MODIFY:
-        case OFOPERATION_REPLACE:
-            actions = op->actions ? op->actions : rule_get_actions(rule);
-            break;
-
-        case OFOPERATION_DELETE:
-            actions = rule_get_actions(rule);
-            break;
-
-        default:
-            OVS_NOT_REACHED();
-        }
-    }
+    actions = flags & NXFMF_ACTIONS ? rule_get_actions(rule) : NULL;
     fu.ofpacts = actions ? actions->ofpacts : NULL;
     fu.ofpacts_len = actions ? actions->ofpacts_len : 0;
 
@@ -4862,9 +4734,7 @@ ofproto_collect_ofmonitor_refresh_rule(const struct ofmonitor *m,
         return;
     }
 
-    if (!(rule->pending
-          ? ofoperation_has_out_port(rule->pending, m->out_port)
-          : ofproto_rule_has_out_port(rule, m->out_port))) {
+    if (!ofproto_rule_has_out_port(rule, m->out_port)) {
         return;
     }
 
@@ -4897,7 +4767,6 @@ ofproto_collect_ofmonitor_refresh_rules(const struct ofmonitor *m,
     OVS_REQUIRES(ofproto_mutex)
 {
     const struct ofproto *ofproto = ofconn_get_ofproto(m->ofconn);
-    const struct ofoperation *op;
     const struct oftable *table;
     struct cls_rule target;
 
@@ -4909,22 +4778,10 @@ ofproto_collect_ofmonitor_refresh_rules(const struct ofmonitor *m,
         fat_rwlock_rdlock(&table->cls.rwlock);
         cls_cursor_init(&cursor, &table->cls, &target);
         CLS_CURSOR_FOR_EACH (rule, cr, &cursor) {
-            ovs_assert(!rule->pending); /* XXX */
             ofproto_collect_ofmonitor_refresh_rule(m, rule, seqno, rules);
         }
         fat_rwlock_unlock(&table->cls.rwlock);
     }
-
-    HMAP_FOR_EACH (op, hmap_node, &ofproto->deletions) {
-        struct rule *rule = op->rule;
-
-        if (((m->table_id == 0xff
-              ? !(ofproto->tables[rule->table_id].flags & OFTABLE_HIDDEN)
-              : m->table_id == rule->table_id))
-            && cls_rule_is_loose_match(&rule->cr, &target.match)) {
-            ofproto_collect_ofmonitor_refresh_rule(m, rule, seqno, rules);
-        }
-    }
     cls_rule_destroy(&target);
 }
 
@@ -5038,7 +4895,7 @@ handle_flow_monitor_cancel(struct ofconn *ofconn, const struct ofp_header *oh)
         ofmonitor_destroy(m);
         error = 0;
     } else {
-        error = OFPERR_NXBRC_FM_BAD_ID;
+        error = OFPERR_OFPMOFC_UNKNOWN_MONITOR;
     }
     ovs_mutex_unlock(&ofproto_mutex);
 
@@ -5178,8 +5035,7 @@ handle_modify_meter(struct ofproto *ofproto, struct ofputil_meter_mod *mm)
 }
 
 static enum ofperr
-handle_delete_meter(struct ofconn *ofconn, const struct ofp_header *oh,
-                    struct ofputil_meter_mod *mm)
+handle_delete_meter(struct ofconn *ofconn, struct ofputil_meter_mod *mm)
     OVS_EXCLUDED(ofproto_mutex)
 {
     struct ofproto *ofproto = ofconn_get_ofproto(ofconn);
@@ -5208,22 +5064,17 @@ handle_delete_meter(struct ofconn *ofconn, const struct ofp_header *oh,
             struct rule *rule;
 
             LIST_FOR_EACH (rule, meter_list_node, &meter->rules) {
-                if (rule->pending) {
-                    error = OFPROTO_POSTPONE;
-                    goto exit;
-                }
                 rule_collection_add(&rules, rule);
             }
         }
     }
     if (rules.n > 0) {
-        delete_flows__(ofproto, ofconn, oh, &rules, OFPRR_METER_DELETE);
+        delete_flows__(&rules, OFPRR_METER_DELETE, NULL);
     }
 
     /* Delete the meters. */
     meter_delete(ofproto, first, last);
 
-exit:
     ovs_mutex_unlock(&ofproto_mutex);
     rule_collection_destroy(&rules);
 
@@ -5279,7 +5130,7 @@ handle_meter_mod(struct ofconn *ofconn, const struct ofp_header *oh)
         break;
 
     case OFPMC13_DELETE:
-        error = handle_delete_meter(ofconn, oh, &mm);
+        error = handle_delete_meter(ofconn, &mm);
         break;
 
     default:
@@ -5773,7 +5624,7 @@ delete_group__(struct ofproto *ofproto, struct ofgroup *ofgroup)
     flow_mod_init(&fm, &match, 0, NULL, 0, OFPFC_DELETE);
     fm.delete_reason = OFPRR_GROUP_DELETE;
     fm.out_group = ofgroup->group_id;
-    handle_flow_mod__(ofproto, NULL, &fm, NULL);
+    handle_flow_mod__(ofproto, &fm, NULL);
 
     hmap_remove(&ofproto->groups, &ofgroup->hmap_node);
     /* No-one can find this group any more. */
@@ -6142,349 +5993,50 @@ handle_openflow__(struct ofconn *ofconn, const struct ofpbuf *msg)
     }
 }
 
-static bool
+static void
 handle_openflow(struct ofconn *ofconn, const struct ofpbuf *ofp_msg)
     OVS_EXCLUDED(ofproto_mutex)
 {
     int error = handle_openflow__(ofconn, ofp_msg);
-    if (error && error != OFPROTO_POSTPONE) {
+    if (error) {
         ofconn_send_error(ofconn, ofpbuf_data(ofp_msg), error);
     }
     COVERAGE_INC(ofproto_recv_openflow);
-    return error != OFPROTO_POSTPONE;
 }
 \f
 /* Asynchronous operations. */
 
-/* Creates and returns a new ofopgroup that is not associated with any
- * OpenFlow connection.
- *
- * The caller should add operations to the returned group with
- * ofoperation_create() and then submit it with ofopgroup_submit(). */
-static struct ofopgroup *
-ofopgroup_create_unattached(struct ofproto *ofproto)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    struct ofopgroup *group = xzalloc(sizeof *group);
-    group->ofproto = ofproto;
-    list_init(&group->ofproto_node);
-    list_init(&group->ops);
-    list_init(&group->ofconn_node);
-    return group;
-}
-
-/* Creates and returns a new ofopgroup for 'ofproto'.
- *
- * If 'ofconn' is NULL, the new ofopgroup is not associated with any OpenFlow
- * connection.  The 'request' and 'buffer_id' arguments are ignored.
- *
- * If 'ofconn' is nonnull, then the new ofopgroup is associated with 'ofconn'.
- * If the ofopgroup eventually fails, then the error reply will include
- * 'request'.  If the ofopgroup eventually succeeds, then the packet with
- * buffer id 'buffer_id' on 'ofconn' will be sent by 'ofconn''s ofproto.
- *
- * The caller should add operations to the returned group with
- * ofoperation_create() and then submit it with ofopgroup_submit(). */
-static struct ofopgroup *
-ofopgroup_create(struct ofproto *ofproto, struct ofconn *ofconn,
-                 const struct ofp_header *request, uint32_t buffer_id)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    struct ofopgroup *group = ofopgroup_create_unattached(ofproto);
-    if (ofconn) {
-        size_t request_len = ntohs(request->length);
-
-        ovs_assert(ofconn_get_ofproto(ofconn) == ofproto);
-
-        ofconn_add_opgroup(ofconn, &group->ofconn_node);
-        group->ofconn = ofconn;
-        group->request = xmemdup(request, MIN(request_len, 64));
-        group->buffer_id = buffer_id;
-    }
-    return group;
-}
-
-/* Submits 'group' for processing.
- *
- * If 'group' contains no operations (e.g. none were ever added, or all of the
- * ones that were added completed synchronously), then it is destroyed
- * immediately.  Otherwise it is added to the ofproto's list of pending
- * groups. */
-static void
-ofopgroup_submit(struct ofopgroup *group)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    if (!group->n_running) {
-        ofopgroup_complete(group);
-    } else {
-        list_push_back(&group->ofproto->pending, &group->ofproto_node);
-        group->ofproto->n_pending++;
-    }
-}
-
-static void
-ofopgroup_complete(struct ofopgroup *group)
+static enum ofperr
+send_buffered_packet(struct ofconn *ofconn, uint32_t buffer_id,
+                     struct rule *rule)
     OVS_REQUIRES(ofproto_mutex)
 {
-    struct ofproto *ofproto = group->ofproto;
-
-    struct ofconn *abbrev_ofconn;
-    ovs_be32 abbrev_xid;
-
-    struct ofoperation *op, *next_op;
-    int error;
-
-    ovs_assert(!group->n_running);
-
-    error = 0;
-    LIST_FOR_EACH (op, group_node, &group->ops) {
-        if (op->error) {
-            error = op->error;
-            break;
-        }
-    }
-
-    if (!error && group->ofconn && group->buffer_id != UINT32_MAX) {
-        LIST_FOR_EACH (op, group_node, &group->ops) {
-            if (op->type != OFOPERATION_DELETE) {
-                struct ofpbuf *packet;
-                ofp_port_t in_port;
-
-                error = ofconn_pktbuf_retrieve(group->ofconn, group->buffer_id,
-                                               &packet, &in_port);
-                if (packet) {
-                    struct rule_execute *re;
-
-                    ovs_assert(!error);
-
-                    ofproto_rule_ref(op->rule);
-
-                    re = xmalloc(sizeof *re);
-                    re->rule = op->rule;
-                    re->in_port = in_port;
-                    re->packet = packet;
-
-                    if (!guarded_list_push_back(&ofproto->rule_executes,
-                                                &re->list_node, 1024)) {
-                        ofproto_rule_unref(op->rule);
-                        ofpbuf_delete(re->packet);
-                        free(re);
-                    }
-                }
-                break;
-            }
-        }
-    }
-
-    if (!error && !list_is_empty(&group->ofconn_node)) {
-        abbrev_ofconn = group->ofconn;
-        abbrev_xid = group->request->xid;
-    } else {
-        abbrev_ofconn = NULL;
-        abbrev_xid = htonl(0);
-    }
-    LIST_FOR_EACH_SAFE (op, next_op, group_node, &group->ops) {
-        struct rule *rule = op->rule;
-
-        /* We generally want to report the change to active OpenFlow flow
-           monitors (e.g. NXST_FLOW_MONITOR).  There are three exceptions:
-
-              - The operation failed.
-
-              - The affected rule is not visible to controllers.
-
-              - The operation's only effect was to update rule->modified. */
-        if (!(op->error
-              || rule_is_hidden(rule)
-              || (op->type == OFOPERATION_MODIFY
-                  && !op->actions
-                  && rule->flow_cookie == op->flow_cookie))) {
-            enum nx_flow_update_event event_type;
-
-            switch (op->type) {
-            case OFOPERATION_ADD:
-            case OFOPERATION_REPLACE:
-                event_type = NXFME_ADDED;
-                break;
+    enum ofperr error = 0;
+    if (ofconn && buffer_id != UINT32_MAX) {
+        struct ofproto *ofproto = ofconn_get_ofproto(ofconn);
+        struct ofpbuf *packet;
+        ofp_port_t in_port;
 
-            case OFOPERATION_DELETE:
-                event_type = NXFME_DELETED;
-                break;
+        error = ofconn_pktbuf_retrieve(ofconn, buffer_id, &packet, &in_port);
+        if (packet) {
+            struct rule_execute *re;
 
-            case OFOPERATION_MODIFY:
-                event_type = NXFME_MODIFIED;
-                break;
+            ofproto_rule_ref(rule);
 
-            default:
-                OVS_NOT_REACHED();
-            }
-
-            ofmonitor_report(ofproto->connmgr, rule, event_type,
-                             op->reason, abbrev_ofconn, abbrev_xid);
-        }
+            re = xmalloc(sizeof *re);
+            re->rule = rule;
+            re->in_port = in_port;
+            re->packet = packet;
 
-        rule->pending = NULL;
-
-        ovs_assert(!op->error || op->type == OFOPERATION_ADD);
-        switch (op->type) {
-        case OFOPERATION_ADD:
-            if (!op->error) {
-                uint16_t vid_mask;
-
-                vid_mask = minimask_get_vid_mask(&rule->cr.match.mask);
-                if (vid_mask == VLAN_VID_MASK) {
-                    if (ofproto->vlan_bitmap) {
-                        uint16_t vid = miniflow_get_vid(&rule->cr.match.flow);
-                        if (!bitmap_is_set(ofproto->vlan_bitmap, vid)) {
-                            bitmap_set1(ofproto->vlan_bitmap, vid);
-                            ofproto->vlans_changed = true;
-                        }
-                    } else {
-                        ofproto->vlans_changed = true;
-                    }
-                }
-            } else {
-                oftable_remove_rule(rule);
+            if (!guarded_list_push_back(&ofproto->rule_executes,
+                                        &re->list_node, 1024)) {
                 ofproto_rule_unref(rule);
+                ofpbuf_delete(re->packet);
+                free(re);
             }
-            break;
-
-        case OFOPERATION_DELETE:
-            ofproto_rule_unref(rule);
-            op->rule = NULL;
-            break;
-
-        case OFOPERATION_MODIFY:
-        case OFOPERATION_REPLACE: {
-            long long now = time_msec();
-
-            ovs_mutex_lock(&rule->mutex);
-            rule->modified = now;
-            if (op->type == OFOPERATION_REPLACE) {
-                rule->created = now;
-            }
-            ovs_mutex_unlock(&rule->mutex);
-            break;
         }
-
-        default:
-            OVS_NOT_REACHED();
-        }
-
-        ofoperation_destroy(op);
-    }
-
-    ofmonitor_flush(ofproto->connmgr);
-
-    if (!list_is_empty(&group->ofproto_node)) {
-        ovs_assert(ofproto->n_pending > 0);
-        ofproto->n_pending--;
-        list_remove(&group->ofproto_node);
-    }
-    if (!list_is_empty(&group->ofconn_node)) {
-        list_remove(&group->ofconn_node);
-        if (error) {
-            ofconn_send_error(group->ofconn, group->request, error);
-        }
-        connmgr_retry(ofproto->connmgr);
-    }
-    free(group->request);
-    free(group);
-}
-
-/* Initiates a new operation on 'rule', of the specified 'type', within
- * 'group'.  Prior to calling, 'rule' must not have any pending operation.
- *
- * For a 'type' of OFOPERATION_DELETE, 'reason' should specify the reason that
- * the flow is being deleted.  For other 'type's, 'reason' is ignored (use 0).
- *
- * Returns the newly created ofoperation (which is also available as
- * rule->pending). */
-static struct ofoperation *
-ofoperation_create(struct ofopgroup *group, struct rule *rule,
-                   enum ofoperation_type type,
-                   enum ofp_flow_removed_reason reason)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    struct ofproto *ofproto = group->ofproto;
-    struct ofoperation *op;
-
-    ovs_assert(!rule->pending);
-
-    op = rule->pending = xzalloc(sizeof *op);
-    op->group = group;
-    list_push_back(&group->ops, &op->group_node);
-    op->rule = rule;
-    op->type = type;
-    op->reason = reason;
-    op->flow_cookie = rule->flow_cookie;
-    ovs_mutex_lock(&rule->mutex);
-    op->idle_timeout = rule->idle_timeout;
-    op->hard_timeout = rule->hard_timeout;
-    ovs_mutex_unlock(&rule->mutex);
-    op->flags = rule->flags;
-
-    group->n_running++;
-
-    if (type == OFOPERATION_DELETE) {
-        hmap_insert(&ofproto->deletions, &op->hmap_node,
-                    cls_rule_hash(&rule->cr, rule->table_id));
-    }
-
-    return op;
-}
-
-static void
-ofoperation_destroy(struct ofoperation *op)
-    OVS_REQUIRES(ofproto_mutex)
-{
-    struct ofopgroup *group = op->group;
-
-    if (op->rule) {
-        op->rule->pending = NULL;
-    }
-    if (op->type == OFOPERATION_DELETE) {
-        hmap_remove(&group->ofproto->deletions, &op->hmap_node);
-    }
-    list_remove(&op->group_node);
-    rule_actions_destroy(op->actions);
-    free(op);
-}
-
-/* Indicates that 'op' completed with status 'error', which is either 0 to
- * indicate success or an OpenFlow error code on failure.
- *
- * If 'error' is 0, indicating success, the operation will be committed
- * permanently to the flow table.
- *
- * Flow modifications and deletions must always succeed.  Flow additions may
- * fail, indicated by nonzero 'error'.  If an "add flow" operation fails, this
- * function removes the new rule.  The caller must have uninitialized any
- * derived state in the new rule, as in step 5 of in the "Life Cycle" in
- * ofproto/ofproto-provider.h.  ofoperation_complete() performs steps 6 and and
- * 7 for the new rule, calling its ->rule_dealloc() function.
- *
- * Please see the large comment in ofproto/ofproto-provider.h titled
- * "Asynchronous Operation Support" for more information. */
-void
-ofoperation_complete(struct ofoperation *op, enum ofperr error)
-{
-    struct ofopgroup *group = op->group;
-
-    ovs_assert(group->n_running > 0);
-    ovs_assert(!error || op->type == OFOPERATION_ADD);
-
-    op->error = error;
-    if (!--group->n_running && !list_is_empty(&group->ofproto_node)) {
-        /* This function can be called from ->rule_construct(), in which case
-         * ofproto_mutex is held, or it can be called from ->run(), in which
-         * case ofproto_mutex is not held.  But only in the latter case can we
-         * arrive here, so we can safely take ofproto_mutex now. */
-        ovs_mutex_lock(&ofproto_mutex);
-        ovs_assert(op->rule->pending == op);
-        ofopgroup_complete(group);
-        ovs_mutex_unlock(&ofproto_mutex);
     }
+    return error;
 }
 \f
 static uint64_t
@@ -6556,24 +6108,6 @@ choose_rule_to_evict(struct oftable *table, struct rule **rulep)
 
     return false;
 }
-
-/* Searches 'ofproto' for tables that have more flows than their configured
- * maximum and that have flow eviction enabled, and evicts as many flows as
- * necessary and currently feasible from them.
- *
- * This triggers only when an OpenFlow table has N flows in it and then the
- * client configures a maximum number of flows less than N. */
-static void
-ofproto_evict(struct ofproto *ofproto)
-{
-    struct oftable *table;
-
-    ovs_mutex_lock(&ofproto_mutex);
-    OFPROTO_FOR_EACH_TABLE (table, ofproto) {
-        evict_rules_from_table(ofproto, table, 0);
-    }
-    ovs_mutex_unlock(&ofproto_mutex);
-}
 \f
 /* Eviction groups. */