/*
- * Copyright (c) 2014 Nicira, Inc.
+ * Copyright (c) 2014, 2015 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
-#include "id-pool.h"
-#include "ovs-thread.h"
+#include "ofpbuf.h"
+#include "ofproto-dpif.h"
#include "ofproto-dpif-rid.h"
+#include "ofproto-provider.h"
+#include "openvswitch/vlog.h"
-struct recirc_id_pool {
- struct ovs_mutex lock;
- struct id_pool *rids;
-};
+VLOG_DEFINE_THIS_MODULE(ofproto_dpif_rid);
-#define RECIRC_ID_BASE 300
-#define RECIRC_ID_N_IDS 1024
+static struct ovs_mutex mutex;
-struct recirc_id_pool *
-recirc_id_pool_create(void)
+static struct cmap id_map;
+static struct cmap metadata_map;
+
+static struct ovs_list expiring OVS_GUARDED_BY(mutex);
+static struct ovs_list expired OVS_GUARDED_BY(mutex);
+
+static uint32_t next_id OVS_GUARDED_BY(mutex); /* Possible next free id. */
+
+#define RECIRC_POOL_STATIC_IDS 1024
+
+void
+recirc_init(void)
{
- struct recirc_id_pool *pool;
+ static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
- pool = xmalloc(sizeof *pool);
- pool->rids = id_pool_create(RECIRC_ID_BASE, RECIRC_ID_N_IDS);
- ovs_mutex_init(&pool->lock);
+ if (ovsthread_once_start(&once)) {
+ ovs_mutex_init(&mutex);
+ ovs_mutex_lock(&mutex);
+ next_id = 1; /* 0 is not a valid ID. */
+ cmap_init(&id_map);
+ cmap_init(&metadata_map);
+ list_init(&expiring);
+ list_init(&expired);
+ ovs_mutex_unlock(&mutex);
+
+ ovsthread_once_done(&once);
+ }
- return pool;
}
+/* This should be called by the revalidator once at each round (every 500ms or
+ * more). */
void
-recirc_id_pool_destroy(struct recirc_id_pool *pool)
+recirc_run(void)
+{
+ static long long int last = 0;
+ long long int now = time_msec();
+
+ /* Do maintenance at most 4 times / sec. */
+ ovs_mutex_lock(&mutex);
+ if (now - last > 250) {
+ struct recirc_id_node *node;
+
+ last = now;
+
+ /* Nodes in 'expiring' and 'expired' lists have the refcount of zero,
+ * which means that while they can still be found (by id), no new
+ * references can be taken on them. We have removed the entry from the
+ * 'metadata_map', at the time when refcount reached zero, causing any
+ * new translations to allocate a new ID. This allows the expiring
+ * entry to be safely deleted while any sudden new use of the similar
+ * recirculation will safely start using a new recirculation ID. When
+ * the refcount gets to zero, the node is also added to the 'expiring'
+ * list. At any time after that the nodes in the 'expiring' list can
+ * be moved to the 'expired' list, from which they are deleted at least
+ * 250ms afterwards. */
+
+ /* Delete the expired. These have been lingering for at least 250 ms,
+ * which should be enough for any ongoing recirculations to be
+ * finished. */
+ LIST_FOR_EACH_POP (node, exp_node, &expired) {
+ cmap_remove(&id_map, &node->id_node, node->id);
+ ovsrcu_postpone(free, node);
+ }
+
+ if (!list_is_empty(&expiring)) {
+ /* 'expired' is now empty, move nodes in 'expiring' to it. */
+ list_splice(&expired, list_front(&expiring), &expiring);
+ }
+ }
+ ovs_mutex_unlock(&mutex);
+}
+
+/* We use the id as the hash value, which works due to cmap internal rehashing.
+ * We also only insert nodes with unique IDs, so all possible hash collisions
+ * remain internal to the cmap. */
+static struct recirc_id_node *
+recirc_find__(uint32_t id)
+ OVS_REQUIRES(mutex)
+{
+ struct cmap_node *node = cmap_find_protected(&id_map, id);
+
+ return node ? CONTAINER_OF(node, struct recirc_id_node, id_node) : NULL;
+}
+
+/* Lockless RCU protected lookup. If node is needed accross RCU quiescent
+ * state, caller should copy the contents. */
+const struct recirc_id_node *
+recirc_id_node_find(uint32_t id)
+{
+ const struct cmap_node *node = cmap_find(&id_map, id);
+
+ return node
+ ? CONTAINER_OF(node, const struct recirc_id_node, id_node)
+ : NULL;
+}
+
+static uint32_t
+recirc_metadata_hash(const struct recirc_state *state)
{
- id_pool_destroy(pool->rids);
- ovs_mutex_destroy(&pool->lock);
- free(pool);
+ uint32_t hash;
+
+ hash = hash_pointer(state->ofproto, 0);
+ hash = hash_int(state->table_id, hash);
+ if (flow_tnl_dst_is_set(state->metadata.tunnel)) {
+ /* We may leave remainder bytes unhashed, but that is unlikely as
+ * the tunnel is not in the datapath format. */
+ hash = hash_words64((const uint64_t *) state->metadata.tunnel,
+ flow_tnl_size(state->metadata.tunnel)
+ / sizeof(uint64_t), hash);
+ }
+ hash = hash_boolean(state->conntracked, hash);
+ hash = hash_words64((const uint64_t *) &state->metadata.metadata,
+ (sizeof state->metadata - sizeof state->metadata.tunnel)
+ / sizeof(uint64_t),
+ hash);
+ if (state->stack && state->stack->size != 0) {
+ hash = hash_words64((const uint64_t *) state->stack->data,
+ state->stack->size / sizeof(uint64_t), hash);
+ }
+ hash = hash_int(state->mirrors, hash);
+ hash = hash_int(state->action_set_len, hash);
+ if (state->ofpacts_len) {
+ hash = hash_words64(ALIGNED_CAST(const uint64_t *, state->ofpacts),
+ state->ofpacts_len / sizeof(uint64_t),
+ hash);
+ }
+ return hash;
}
+static bool
+recirc_metadata_equal(const struct recirc_state *a,
+ const struct recirc_state *b)
+{
+ return (a->table_id == b->table_id
+ && a->ofproto == b->ofproto
+ && flow_tnl_equal(a->metadata.tunnel, b->metadata.tunnel)
+ && !memcmp(&a->metadata.metadata, &b->metadata.metadata,
+ sizeof a->metadata - sizeof a->metadata.tunnel)
+ && (((!a->stack || !a->stack->size) &&
+ (!b->stack || !b->stack->size))
+ || (a->stack && b->stack && ofpbuf_equal(a->stack, b->stack)))
+ && a->mirrors == b->mirrors
+ && a->conntracked == b->conntracked
+ && a->action_set_len == b->action_set_len
+ && ofpacts_equal(a->ofpacts, a->ofpacts_len,
+ b->ofpacts, b->ofpacts_len));
+}
+
+/* Lockless RCU protected lookup. If node is needed accross RCU quiescent
+ * state, caller should take a reference. */
+static struct recirc_id_node *
+recirc_find_equal(const struct recirc_state *target, uint32_t hash)
+{
+ struct recirc_id_node *node;
+
+ CMAP_FOR_EACH_WITH_HASH (node, metadata_node, hash, &metadata_map) {
+ if (recirc_metadata_equal(&node->state, target)) {
+ return node;
+ }
+ }
+ return NULL;
+}
+
+static struct recirc_id_node *
+recirc_ref_equal(const struct recirc_state *target, uint32_t hash)
+{
+ struct recirc_id_node *node;
+
+ do {
+ node = recirc_find_equal(target, hash);
+
+ /* Try again if the node was released before we get the reference. */
+ } while (node && !ovs_refcount_try_ref_rcu(&node->refcount));
+
+ return node;
+}
+
+static void
+recirc_state_clone(struct recirc_state *new, const struct recirc_state *old,
+ struct flow_tnl *tunnel)
+{
+ *new = *old;
+ flow_tnl_copy__(tunnel, old->metadata.tunnel);
+ new->metadata.tunnel = tunnel;
+
+ if (new->stack) {
+ new->stack = new->stack->size ? ofpbuf_clone(new->stack) : NULL;
+ }
+ if (new->ofpacts) {
+ new->ofpacts = (new->ofpacts_len
+ ? xmemdup(new->ofpacts, new->ofpacts_len)
+ : NULL);
+ }
+}
+
+/* Allocate a unique recirculation id for the given set of flow metadata.
+ * The ID space is 2^^32, so there should never be a situation in which all
+ * the IDs are used up. We loop until we find a free one.
+ * hash is recomputed if it is passed in as 0. */
+static struct recirc_id_node *
+recirc_alloc_id__(const struct recirc_state *state, uint32_t hash)
+{
+ ovs_assert(state->action_set_len <= state->ofpacts_len);
+
+ struct recirc_id_node *node = xzalloc(sizeof *node);
+
+ node->hash = hash;
+ ovs_refcount_init(&node->refcount);
+ recirc_state_clone(CONST_CAST(struct recirc_state *, &node->state), state,
+ &node->state_metadata_tunnel);
+
+ ovs_mutex_lock(&mutex);
+ for (;;) {
+ /* Claim the next ID. The ID space should be sparse enough for the
+ allocation to succeed at the first try. We do skip the first
+ RECIRC_POOL_STATIC_IDS IDs on the later rounds, though, as some of
+ the initial allocations may be for long term uses (like bonds). */
+ node->id = next_id++;
+ if (OVS_UNLIKELY(!node->id)) {
+ next_id = RECIRC_POOL_STATIC_IDS + 1;
+ node->id = next_id++;
+ }
+ /* Find if the id is free. */
+ if (OVS_LIKELY(!recirc_find__(node->id))) {
+ break;
+ }
+ }
+ cmap_insert(&id_map, &node->id_node, node->id);
+ cmap_insert(&metadata_map, &node->metadata_node, node->hash);
+ ovs_mutex_unlock(&mutex);
+ return node;
+}
+
+/* Look up an existing ID for the given flow's metadata and optional actions.
+ */
uint32_t
-recirc_id_alloc(struct recirc_id_pool *pool)
+recirc_find_id(const struct recirc_state *target)
{
- uint32_t id;
- bool ret;
+ uint32_t hash = recirc_metadata_hash(target);
+ struct recirc_id_node *node = recirc_find_equal(target, hash);
+ return node ? node->id : 0;
+}
- ovs_mutex_lock(&pool->lock);
- ret = id_pool_alloc_id(pool->rids, &id);
- ovs_mutex_unlock(&pool->lock);
+/* Allocate a unique recirculation id for the given set of flow metadata and
+ optional actions. */
+uint32_t
+recirc_alloc_id_ctx(const struct recirc_state *state)
+{
+ uint32_t hash = recirc_metadata_hash(state);
+ struct recirc_id_node *node = recirc_ref_equal(state, hash);
+ if (!node) {
+ node = recirc_alloc_id__(state, hash);
+ }
+ return node->id;
+}
+
+/* Allocate a unique recirculation id. */
+uint32_t
+recirc_alloc_id(struct ofproto_dpif *ofproto)
+{
+ struct flow_tnl tunnel;
+ tunnel.ip_dst = htonl(0);
+ tunnel.ipv6_dst = in6addr_any;
+ struct recirc_state state = {
+ .table_id = TBL_INTERNAL,
+ .ofproto = ofproto,
+ .metadata = { .tunnel = &tunnel, .in_port = OFPP_NONE },
+ };
+ return recirc_alloc_id__(&state, recirc_metadata_hash(&state))->id;
+}
+
+void
+recirc_id_node_unref(const struct recirc_id_node *node_)
+ OVS_EXCLUDED(mutex)
+{
+ struct recirc_id_node *node = CONST_CAST(struct recirc_id_node *, node_);
- if (!ret) {
- return 0;
+ if (node && ovs_refcount_unref(&node->refcount) == 1) {
+ ovs_mutex_lock(&mutex);
+ /* Prevent re-use of this node by removing the node from 'metadata_map'
+ */
+ cmap_remove(&metadata_map, &node->metadata_node, node->hash);
+ /* We keep the node in the 'id_map' so that it can be found as long
+ * as it lingers, and add it to the 'expiring' list. */
+ list_insert(&expiring, &node->exp_node);
+ ovs_mutex_unlock(&mutex);
}
+}
- return id;
+void
+recirc_free_id(uint32_t id)
+{
+ const struct recirc_id_node *node;
+
+ node = recirc_id_node_find(id);
+ if (node) {
+ recirc_id_node_unref(node);
+ } else {
+ VLOG_ERR("Freeing nonexistent recirculation ID: %"PRIu32, id);
+ }
}
+/* Called when 'ofproto' is destructed. Checks for and clears any
+ * recirc_id leak.
+ * No other thread may have access to the 'ofproto' being destructed.
+ * All related datapath flows must be deleted before calling this. */
void
-recirc_id_free(struct recirc_id_pool *pool, uint32_t id)
+recirc_free_ofproto(struct ofproto_dpif *ofproto, const char *ofproto_name)
{
- ovs_mutex_lock(&pool->lock);
- id_pool_free_id(pool->rids, id);
- ovs_mutex_unlock(&pool->lock);
+ struct recirc_id_node *n;
+
+ CMAP_FOR_EACH (n, metadata_node, &metadata_map) {
+ if (n->state.ofproto == ofproto) {
+ VLOG_ERR("recirc_id %"PRIu32
+ " left allocated when ofproto (%s)"
+ " is destructed", n->id, ofproto_name);
+ }
+ }
}
projects / cascardo / ovs.git / blobdiff