X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fclassifier.c;h=558714145c10765d967404d037fa8dca245925c2;hb=57ad4e9ed5da05b81eba8a7dd3e712201792002d;hp=719260226d338b6d9282fe46e6e31ac220056f20;hpb=cb22974d773942d66da42b700b8bca0db27a0920;p=sliver-openvswitch.git

diff --git a/lib/classifier.c b/lib/classifier.c
index 719260226..558714145 100644
--- a/lib/classifier.c
+++ b/lib/classifier.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
+ * Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,19 +25,28 @@
 #include "odp-util.h"
 #include "ofp-util.h"
 #include "packets.h"
+#include "ovs-thread.h"
 
-static struct cls_table *find_table(const struct classifier *,
-                                    const struct minimask *);
-static struct cls_table *insert_table(struct classifier *,
-                                      const struct minimask *);
+static struct cls_subtable *find_subtable(const struct classifier *,
+                                          const struct minimask *);
+static struct cls_subtable *insert_subtable(struct classifier *,
+                                            const struct minimask *);
 
-static void destroy_table(struct classifier *, struct cls_table *);
+static void destroy_subtable(struct classifier *, struct cls_subtable *);
 
-static struct cls_rule *find_match(const struct cls_table *,
+static void update_subtables_after_insertion(struct classifier *,
+                                             struct cls_subtable *,
+                                             unsigned int new_priority);
+static void update_subtables_after_removal(struct classifier *,
+                                           struct cls_subtable *,
+                                           unsigned int del_priority);
+
+static struct cls_rule *find_match(const struct cls_subtable *,
                                    const struct flow *);
-static struct cls_rule *find_equal(struct cls_table *,
+static struct cls_rule *find_equal(struct cls_subtable *,
                                    const struct miniflow *, uint32_t hash);
-static struct cls_rule *insert_rule(struct cls_table *, struct cls_rule *);
+static struct cls_rule *insert_rule(struct classifier *,
+                                    struct cls_subtable *, struct cls_rule *);
 
 /* Iterates RULE over HEAD and all of the cls_rules on HEAD->list. */
 #define FOR_EACH_RULE_IN_LIST(RULE, HEAD)                               \
@@ -80,7 +89,7 @@ cls_rule_init_from_minimatch(struct cls_rule *rule,
 
 /* Initializes 'dst' as a copy of 'src'.
  *
- * The caller must eventually destroy 'rule' with cls_rule_destroy(). */
+ * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
 void
 cls_rule_clone(struct cls_rule *dst, const struct cls_rule *src)
 {
@@ -88,6 +97,16 @@ cls_rule_clone(struct cls_rule *dst, const struct cls_rule *src)
     dst->priority = src->priority;
 }
 
+/* Initializes 'dst' with the data in 'src', destroying 'src'.
+ *
+ * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
+void
+cls_rule_move(struct cls_rule *dst, struct cls_rule *src)
+{
+    minimatch_move(&dst->match, &src->match);
+    dst->priority = src->priority;
+}
+
 /* Frees memory referenced by 'rule'.  Doesn't free 'rule' itself (it's
  * normally embedded into a larger structure).
  *
@@ -133,7 +152,10 @@ void
 classifier_init(struct classifier *cls)
 {
     cls->n_rules = 0;
-    hmap_init(&cls->tables);
+    hmap_init(&cls->subtables);
+    list_init(&cls->subtables_priority);
+    hmap_init(&cls->partitions);
+    ovs_rwlock_init(&cls->rwlock);
 }
 
 /* Destroys 'cls'.  Rules within 'cls', if any, are not freed; this is the
@@ -142,12 +164,22 @@ void
 classifier_destroy(struct classifier *cls)
 {
     if (cls) {
-        struct cls_table *table, *next_table;
+        struct cls_subtable *partition, *next_partition;
+        struct cls_subtable *subtable, *next_subtable;
+
+        HMAP_FOR_EACH_SAFE (subtable, next_subtable, hmap_node,
+                            &cls->subtables) {
+            destroy_subtable(cls, subtable);
+        }
+        hmap_destroy(&cls->subtables);
 
-        HMAP_FOR_EACH_SAFE (table, next_table, hmap_node, &cls->tables) {
-            destroy_table(cls, table);
+        HMAP_FOR_EACH_SAFE (partition, next_partition, hmap_node,
+                            &cls->partitions) {
+            hmap_remove(&cls->partitions, &partition->hmap_node);
+            free(partition);
         }
-        hmap_destroy(&cls->tables);
+        hmap_destroy(&cls->partitions);
+        ovs_rwlock_destroy(&cls->rwlock);
     }
 }
 
@@ -165,6 +197,44 @@ classifier_count(const struct classifier *cls)
     return cls->n_rules;
 }
 
+static uint32_t
+hash_metadata(ovs_be64 metadata_)
+{
+    uint64_t metadata = (OVS_FORCE uint64_t) metadata_;
+    return hash_2words(metadata, metadata >> 32);
+}
+
+static struct cls_partition *
+find_partition(const struct classifier *cls, ovs_be64 metadata, uint32_t hash)
+{
+    struct cls_partition *partition;
+
+    HMAP_FOR_EACH_IN_BUCKET (partition, hmap_node, hash, &cls->partitions) {
+        if (partition->metadata == metadata) {
+            return partition;
+        }
+    }
+
+    return NULL;
+}
+
+static struct cls_partition *
+create_partition(struct classifier *cls, struct cls_subtable *subtable,
+                 ovs_be64 metadata)
+{
+    uint32_t hash = hash_metadata(metadata);
+    struct cls_partition *partition = find_partition(cls, metadata, hash);
+    if (!partition) {
+        partition = xmalloc(sizeof *partition);
+        partition->metadata = metadata;
+        partition->tags = 0;
+        tag_tracker_init(&partition->tracker);
+        hmap_insert(&cls->partitions, &partition->hmap_node, hash);
+    }
+    tag_tracker_add(&partition->tracker, &partition->tags, subtable->tag);
+    return partition;
+}
+
 /* Inserts 'rule' into 'cls'.  Until 'rule' is removed from 'cls', the caller
  * must not modify or free it.
  *
@@ -182,17 +252,26 @@ struct cls_rule *
 classifier_replace(struct classifier *cls, struct cls_rule *rule)
 {
     struct cls_rule *old_rule;
-    struct cls_table *table;
+    struct cls_subtable *subtable;
 
-    table = find_table(cls, &rule->match.mask);
-    if (!table) {
-        table = insert_table(cls, &rule->match.mask);
+    subtable = find_subtable(cls, &rule->match.mask);
+    if (!subtable) {
+        subtable = insert_subtable(cls, &rule->match.mask);
     }
 
-    old_rule = insert_rule(table, rule);
+    old_rule = insert_rule(cls, subtable, rule);
     if (!old_rule) {
-        table->n_table_rules++;
+        if (minimask_get_metadata_mask(&rule->match.mask) == OVS_BE64_MAX) {
+            ovs_be64 metadata = miniflow_get_metadata(&rule->match.flow);
+            rule->partition = create_partition(cls, subtable, metadata);
+        } else {
+            rule->partition = NULL;
+        }
+
+        subtable->n_rules++;
         cls->n_rules++;
+    } else {
+        rule->partition = old_rule->partition;
     }
     return old_rule;
 }
@@ -216,44 +295,117 @@ classifier_insert(struct classifier *cls, struct cls_rule *rule)
 void
 classifier_remove(struct classifier *cls, struct cls_rule *rule)
 {
+    struct cls_partition *partition;
     struct cls_rule *head;
-    struct cls_table *table;
+    struct cls_subtable *subtable;
 
-    table = find_table(cls, &rule->match.mask);
-    head = find_equal(table, &rule->match.flow, rule->hmap_node.hash);
+    subtable = find_subtable(cls, &rule->match.mask);
+    head = find_equal(subtable, &rule->match.flow, rule->hmap_node.hash);
     if (head != rule) {
         list_remove(&rule->list);
     } else if (list_is_empty(&rule->list)) {
-        hmap_remove(&table->rules, &rule->hmap_node);
+        hmap_remove(&subtable->rules, &rule->hmap_node);
     } else {
         struct cls_rule *next = CONTAINER_OF(rule->list.next,
                                              struct cls_rule, list);
 
         list_remove(&rule->list);
-        hmap_replace(&table->rules, &rule->hmap_node, &next->hmap_node);
+        hmap_replace(&subtable->rules, &rule->hmap_node, &next->hmap_node);
     }
 
-    if (--table->n_table_rules == 0) {
-        destroy_table(cls, table);
+    partition = rule->partition;
+    if (partition) {
+        tag_tracker_subtract(&partition->tracker, &partition->tags,
+                             subtable->tag);
+        if (!partition->tags) {
+            hmap_remove(&cls->partitions, &partition->hmap_node);
+            free(partition);
+        }
     }
 
+    if (--subtable->n_rules == 0) {
+        destroy_subtable(cls, subtable);
+    } else {
+        update_subtables_after_removal(cls, subtable, rule->priority);
+    }
     cls->n_rules--;
 }
 
 /* Finds and returns the highest-priority rule in 'cls' that matches 'flow'.
  * Returns a null pointer if no rules in 'cls' match 'flow'.  If multiple rules
- * of equal priority match 'flow', returns one arbitrarily. */
+ * of equal priority match 'flow', returns one arbitrarily.
+ *
+ * If a rule is found and 'wc' is non-null, bitwise-OR's 'wc' with the
+ * set of bits that were significant in the lookup.  At some point
+ * earlier, 'wc' should have been initialized (e.g., by
+ * flow_wildcards_init_catchall()). */
 struct cls_rule *
-classifier_lookup(const struct classifier *cls, const struct flow *flow)
+classifier_lookup(const struct classifier *cls, const struct flow *flow,
+                  struct flow_wildcards *wc)
 {
-    struct cls_table *table;
+    const struct cls_partition *partition;
+    struct cls_subtable *subtable;
     struct cls_rule *best;
+    tag_type tags;
+
+    /* Determine 'tags' such that, if 'subtable->tag' doesn't intersect them,
+     * then 'flow' cannot possibly match in 'subtable':
+     *
+     *     - If flow->metadata maps to a given 'partition', then we can use
+     *       'tags' for 'partition->tags'.
+     *
+     *     - If flow->metadata has no partition, then no rule in 'cls' has an
+     *       exact-match for flow->metadata.  That means that we don't need to
+     *       search any subtable that includes flow->metadata in its mask.
+     *
+     * In either case, we always need to search any cls_subtables that do not
+     * include flow->metadata in its mask.  One way to do that would be to
+     * check the "cls_subtable"s explicitly for that, but that would require an
+     * extra branch per subtable.  Instead, we mark such a cls_subtable's
+     * 'tags' as TAG_ALL and make sure that 'tags' is never empty.  This means
+     * that 'tags' always intersects such a cls_subtable's 'tags', so we don't
+     * need a special case.
+     */
+    partition = (hmap_is_empty(&cls->partitions)
+                 ? NULL
+                 : find_partition(cls, flow->metadata,
+                                  hash_metadata(flow->metadata)));
+    tags = partition ? partition->tags : TAG_ARBITRARY;
 
     best = NULL;
-    HMAP_FOR_EACH (table, hmap_node, &cls->tables) {
-        struct cls_rule *rule = find_match(table, flow);
-        if (rule && (!best || rule->priority > best->priority)) {
+    LIST_FOR_EACH (subtable, list_node, &cls->subtables_priority) {
+        struct cls_rule *rule;
+
+        if (!tag_intersects(tags, subtable->tag)) {
+            continue;
+        }
+
+        rule = find_match(subtable, flow);
+        if (wc) {
+            flow_wildcards_fold_minimask(wc, &subtable->mask);
+        }
+        if (rule) {
             best = rule;
+            LIST_FOR_EACH_CONTINUE (subtable, list_node,
+                                    &cls->subtables_priority) {
+                if (subtable->max_priority <= best->priority) {
+                    /* Subtables are in descending priority order,
+                     * can not find anything better. */
+                    return best;
+                }
+                if (!tag_intersects(tags, subtable->tag)) {
+                    continue;
+                }
+
+                rule = find_match(subtable, flow);
+                if (wc) {
+                    flow_wildcards_fold_minimask(wc, &subtable->mask);
+                }
+                if (rule && rule->priority > best->priority) {
+                    best = rule;
+                }
+            }
+            break;
         }
     }
     return best;
@@ -267,14 +419,19 @@ classifier_find_rule_exactly(const struct classifier *cls,
                              const struct cls_rule *target)
 {
     struct cls_rule *head, *rule;
-    struct cls_table *table;
+    struct cls_subtable *subtable;
+
+    subtable = find_subtable(cls, &target->match.mask);
+    if (!subtable) {
+        return NULL;
+    }
 
-    table = find_table(cls, &target->match.mask);
-    if (!table) {
+    /* Skip if there is no hope. */
+    if (target->priority > subtable->max_priority) {
         return NULL;
     }
 
-    head = find_equal(table, &target->match.flow,
+    head = find_equal(subtable, &target->match.flow,
                       miniflow_hash_in_minimask(&target->match.flow,
                                                 &target->match.mask, 0));
     FOR_EACH_RULE_IN_LIST (rule, head) {
@@ -310,18 +467,26 @@ bool
 classifier_rule_overlaps(const struct classifier *cls,
                          const struct cls_rule *target)
 {
-    struct cls_table *table;
+    struct cls_subtable *subtable;
 
-    HMAP_FOR_EACH (table, hmap_node, &cls->tables) {
+    /* Iterate subtables in the descending max priority order. */
+    LIST_FOR_EACH (subtable, list_node, &cls->subtables_priority) {
         uint32_t storage[FLOW_U32S];
         struct minimask mask;
         struct cls_rule *head;
 
-        minimask_combine(&mask, &target->match.mask, &table->mask, storage);
-        HMAP_FOR_EACH (head, hmap_node, &table->rules) {
+        if (target->priority > subtable->max_priority) {
+            break; /* Can skip this and the rest of the subtables. */
+        }
+
+        minimask_combine(&mask, &target->match.mask, &subtable->mask, storage);
+        HMAP_FOR_EACH (head, hmap_node, &subtable->rules) {
             struct cls_rule *rule;
 
             FOR_EACH_RULE_IN_LIST (rule, head) {
+                if (rule->priority < target->priority) {
+                    break; /* Rules in descending priority order. */
+                }
                 if (rule->priority == target->priority
                     && miniflow_equal_in_minimask(&target->match.flow,
                                                   &rule->match.flow, &mask)) {
@@ -388,12 +553,13 @@ rule_matches(const struct cls_rule *rule, const struct cls_rule *target)
 }
 
 static struct cls_rule *
-search_table(const struct cls_table *table, const struct cls_rule *target)
+search_subtable(const struct cls_subtable *subtable,
+                const struct cls_rule *target)
 {
-    if (!target || !minimask_has_extra(&table->mask, &target->match.mask)) {
+    if (!target || !minimask_has_extra(&subtable->mask, &target->match.mask)) {
         struct cls_rule *rule;
 
-        HMAP_FOR_EACH (rule, hmap_node, &table->rules) {
+        HMAP_FOR_EACH (rule, hmap_node, &subtable->rules) {
             if (rule_matches(rule, target)) {
                 return rule;
             }
@@ -423,12 +589,12 @@ cls_cursor_init(struct cls_cursor *cursor, const struct classifier *cls,
 struct cls_rule *
 cls_cursor_first(struct cls_cursor *cursor)
 {
-    struct cls_table *table;
+    struct cls_subtable *subtable;
 
-    HMAP_FOR_EACH (table, hmap_node, &cursor->cls->tables) {
-        struct cls_rule *rule = search_table(table, cursor->target);
+    HMAP_FOR_EACH (subtable, hmap_node, &cursor->cls->subtables) {
+        struct cls_rule *rule = search_subtable(subtable, cursor->target);
         if (rule) {
-            cursor->table = table;
+            cursor->subtable = subtable;
             return rule;
         }
     }
@@ -439,9 +605,10 @@ cls_cursor_first(struct cls_cursor *cursor)
 /* Returns the next matching cls_rule in 'cursor''s iteration, or a null
  * pointer if there are no more matches. */
 struct cls_rule *
-cls_cursor_next(struct cls_cursor *cursor, struct cls_rule *rule)
+cls_cursor_next(struct cls_cursor *cursor, const struct cls_rule *rule_)
 {
-    const struct cls_table *table;
+    struct cls_rule *rule = CONST_CAST(struct cls_rule *, rule_);
+    const struct cls_subtable *subtable;
     struct cls_rule *next;
 
     next = next_rule_in_list__(rule);
@@ -450,20 +617,20 @@ cls_cursor_next(struct cls_cursor *cursor, struct cls_rule *rule)
     }
 
     /* 'next' is the head of the list, that is, the rule that is included in
-     * the table's hmap.  (This is important when the classifier contains rules
-     * that differ only in priority.) */
+     * the subtable's hmap.  (This is important when the classifier contains
+     * rules that differ only in priority.) */
     rule = next;
-    HMAP_FOR_EACH_CONTINUE (rule, hmap_node, &cursor->table->rules) {
+    HMAP_FOR_EACH_CONTINUE (rule, hmap_node, &cursor->subtable->rules) {
         if (rule_matches(rule, cursor->target)) {
             return rule;
         }
     }
 
-    table = cursor->table;
-    HMAP_FOR_EACH_CONTINUE (table, hmap_node, &cursor->cls->tables) {
-        rule = search_table(table, cursor->target);
+    subtable = cursor->subtable;
+    HMAP_FOR_EACH_CONTINUE (subtable, hmap_node, &cursor->cls->subtables) {
+        rule = search_subtable(subtable, cursor->target);
         if (rule) {
-            cursor->table = table;
+            cursor->subtable = subtable;
             return rule;
         }
     }
@@ -471,51 +638,150 @@ cls_cursor_next(struct cls_cursor *cursor, struct cls_rule *rule)
     return NULL;
 }
 
-static struct cls_table *
-find_table(const struct classifier *cls, const struct minimask *mask)
+static struct cls_subtable *
+find_subtable(const struct classifier *cls, const struct minimask *mask)
 {
-    struct cls_table *table;
+    struct cls_subtable *subtable;
 
-    HMAP_FOR_EACH_IN_BUCKET (table, hmap_node, minimask_hash(mask, 0),
-                             &cls->tables) {
-        if (minimask_equal(mask, &table->mask)) {
-            return table;
+    HMAP_FOR_EACH_IN_BUCKET (subtable, hmap_node, minimask_hash(mask, 0),
+                             &cls->subtables) {
+        if (minimask_equal(mask, &subtable->mask)) {
+            return subtable;
         }
     }
     return NULL;
 }
 
-static struct cls_table *
-insert_table(struct classifier *cls, const struct minimask *mask)
+static struct cls_subtable *
+insert_subtable(struct classifier *cls, const struct minimask *mask)
 {
-    struct cls_table *table;
+    uint32_t hash = minimask_hash(mask, 0);
+    struct cls_subtable *subtable;
 
-    table = xzalloc(sizeof *table);
-    hmap_init(&table->rules);
-    minimask_clone(&table->mask, mask);
-    hmap_insert(&cls->tables, &table->hmap_node, minimask_hash(mask, 0));
+    subtable = xzalloc(sizeof *subtable);
+    hmap_init(&subtable->rules);
+    minimask_clone(&subtable->mask, mask);
+    hmap_insert(&cls->subtables, &subtable->hmap_node, minimask_hash(mask, 0));
+    list_push_back(&cls->subtables_priority, &subtable->list_node);
+    subtable->tag = (minimask_get_metadata_mask(mask) == OVS_BE64_MAX
+                     ? tag_create_deterministic(hash)
+                     : TAG_ALL);
 
-    return table;
+    return subtable;
 }
 
 static void
-destroy_table(struct classifier *cls, struct cls_table *table)
+destroy_subtable(struct classifier *cls, struct cls_subtable *subtable)
 {
-    minimask_destroy(&table->mask);
-    hmap_remove(&cls->tables, &table->hmap_node);
-    hmap_destroy(&table->rules);
-    free(table);
+    minimask_destroy(&subtable->mask);
+    hmap_remove(&cls->subtables, &subtable->hmap_node);
+    hmap_destroy(&subtable->rules);
+    list_remove(&subtable->list_node);
+    free(subtable);
+}
+
+/* This function performs the following updates for 'subtable' in 'cls'
+ * following the addition of a new rule with priority 'new_priority' to
+ * 'subtable':
+ *
+ *    - Update 'subtable->max_priority' and 'subtable->max_count' if necessary.
+ *
+ *    - Update 'subtable''s position in 'cls->subtables_priority' if necessary.
+ *
+ * This function should only be called after adding a new rule, not after
+ * replacing a rule by an identical one or modifying a rule in-place. */
+static void
+update_subtables_after_insertion(struct classifier *cls,
+                                 struct cls_subtable *subtable,
+                                 unsigned int new_priority)
+{
+    if (new_priority == subtable->max_priority) {
+        ++subtable->max_count;
+    } else if (new_priority > subtable->max_priority) {
+        struct cls_subtable *iter;
+
+        subtable->max_priority = new_priority;
+        subtable->max_count = 1;
+
+        /* Possibly move 'subtable' earlier in the priority list.  If we break
+         * out of the loop, then 'subtable' should be moved just after that
+         * 'iter'.  If the loop terminates normally, then 'iter' will be the
+         * list head and we'll move subtable just after that (e.g. to the front
+         * of the list). */
+        iter = subtable;
+        LIST_FOR_EACH_REVERSE_CONTINUE (iter, list_node,
+                                        &cls->subtables_priority) {
+            if (iter->max_priority >= subtable->max_priority) {
+                break;
+            }
+        }
+
+        /* Move 'subtable' just after 'iter' (unless it's already there). */
+        if (iter->list_node.next != &subtable->list_node) {
+            list_splice(iter->list_node.next,
+                        &subtable->list_node, subtable->list_node.next);
+        }
+    }
+}
+
+/* This function performs the following updates for 'subtable' in 'cls'
+ * following the deletion of a rule with priority 'del_priority' from
+ * 'subtable':
+ *
+ *    - Update 'subtable->max_priority' and 'subtable->max_count' if necessary.
+ *
+ *    - Update 'subtable''s position in 'cls->subtables_priority' if necessary.
+ *
+ * This function should only be called after removing a rule, not after
+ * replacing a rule by an identical one or modifying a rule in-place. */
+static void
+update_subtables_after_removal(struct classifier *cls,
+                               struct cls_subtable *subtable,
+                               unsigned int del_priority)
+{
+    struct cls_subtable *iter;
+
+    if (del_priority == subtable->max_priority && --subtable->max_count == 0) {
+        struct cls_rule *head;
+
+        subtable->max_priority = 0;
+        HMAP_FOR_EACH (head, hmap_node, &subtable->rules) {
+            if (head->priority > subtable->max_priority) {
+                subtable->max_priority = head->priority;
+                subtable->max_count = 1;
+            } else if (head->priority == subtable->max_priority) {
+                ++subtable->max_count;
+            }
+        }
+
+        /* Possibly move 'subtable' later in the priority list.  If we break
+         * out of the loop, then 'subtable' should be moved just before that
+         * 'iter'.  If the loop terminates normally, then 'iter' will be the
+         * list head and we'll move subtable just before that (e.g. to the back
+         * of the list). */
+        iter = subtable;
+        LIST_FOR_EACH_CONTINUE (iter, list_node, &cls->subtables_priority) {
+            if (iter->max_priority <= subtable->max_priority) {
+                break;
+            }
+        }
+
+        /* Move 'subtable' just before 'iter' (unless it's already there). */
+        if (iter->list_node.prev != &subtable->list_node) {
+            list_splice(&iter->list_node,
+                        &subtable->list_node, subtable->list_node.next);
+        }
+    }
 }
 
 static struct cls_rule *
-find_match(const struct cls_table *table, const struct flow *flow)
+find_match(const struct cls_subtable *subtable, const struct flow *flow)
 {
-    uint32_t hash = flow_hash_in_minimask(flow, &table->mask, 0);
+    uint32_t hash = flow_hash_in_minimask(flow, &subtable->mask, 0);
     struct cls_rule *rule;
 
-    HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, hash, &table->rules) {
-        if (miniflow_equal_flow_in_minimask(&rule->match.flow, flow,
-                                            &table->mask)) {
+    HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, hash, &subtable->rules) {
+        if (minimatch_matches_flow(&rule->match, flow)) {
             return rule;
         }
     }
@@ -524,11 +790,12 @@ find_match(const struct cls_table *table, const struct flow *flow)
 }
 
 static struct cls_rule *
-find_equal(struct cls_table *table, const struct miniflow *flow, uint32_t hash)
+find_equal(struct cls_subtable *subtable, const struct miniflow *flow,
+           uint32_t hash)
 {
     struct cls_rule *head;
 
-    HMAP_FOR_EACH_WITH_HASH (head, hmap_node, hash, &table->rules) {
+    HMAP_FOR_EACH_WITH_HASH (head, hmap_node, hash, &subtable->rules) {
         if (miniflow_equal(&head->match.flow, flow)) {
             return head;
         }
@@ -537,18 +804,20 @@ find_equal(struct cls_table *table, const struct miniflow *flow, uint32_t hash)
 }
 
 static struct cls_rule *
-insert_rule(struct cls_table *table, struct cls_rule *new)
+insert_rule(struct classifier *cls, struct cls_subtable *subtable,
+            struct cls_rule *new)
 {
     struct cls_rule *head;
+    struct cls_rule *old = NULL;
 
     new->hmap_node.hash = miniflow_hash_in_minimask(&new->match.flow,
                                                     &new->match.mask, 0);
 
-    head = find_equal(table, &new->match.flow, new->hmap_node.hash);
+    head = find_equal(subtable, &new->match.flow, new->hmap_node.hash);
     if (!head) {
-        hmap_insert(&table->rules, &new->hmap_node, new->hmap_node.hash);
+        hmap_insert(&subtable->rules, &new->hmap_node, new->hmap_node.hash);
         list_init(&new->list);
-        return NULL;
+        goto out;
     } else {
         /* Scan the list for the insertion point that will keep the list in
          * order of decreasing priority. */
@@ -557,24 +826,30 @@ insert_rule(struct cls_table *table, struct cls_rule *new)
             if (new->priority >= rule->priority) {
                 if (rule == head) {
                     /* 'new' is the new highest-priority flow in the list. */
-                    hmap_replace(&table->rules,
+                    hmap_replace(&subtable->rules,
                                  &rule->hmap_node, &new->hmap_node);
                 }
 
                 if (new->priority == rule->priority) {
                     list_replace(&new->list, &rule->list);
-                    return rule;
+                    old = rule;
+                    goto out;
                 } else {
                     list_insert(&rule->list, &new->list);
-                    return NULL;
+                    goto out;
                 }
             }
         }
 
         /* Insert 'new' at the end of the list. */
         list_push_back(&head->list, &new->list);
-        return NULL;
     }
+
+ out:
+    if (!old) {
+        update_subtables_after_insertion(cls, subtable, new->priority);
+    }
+    return old;
 }
 
 static struct cls_rule *