[ovs-dev] [thread-safety 03/11] cfm: Make the CFM module thread safe.
Ethan Jackson
ethan at nicira.com
Sat Jul 27 01:07:04 UTC 2013
Signed-off-by: Ethan Jackson <ethan at nicira.com>
---
lib/cfm.c | 168 +++++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 120 insertions(+), 48 deletions(-)
diff --git a/lib/cfm.c b/lib/cfm.c
index a76a3ec..fc58a81 100644
--- a/lib/cfm.c
+++ b/lib/cfm.c
@@ -91,8 +91,6 @@ struct cfm {
uint64_t rx_packets; /* Packets received by 'netdev'. */
uint64_t mpid;
- bool check_tnl_key; /* Verify the tunnel key of inbound packets? */
- bool extended; /* Extended mode. */
bool demand; /* Demand mode. */
bool booted; /* A full fault interval has occurred. */
enum cfm_fault_reason fault; /* Connectivity fault status. */
@@ -128,7 +126,9 @@ struct cfm {
recomputed. */
long long int last_tx; /* Last CCM transmission time. */
- int ref_cnt;
+ atomic_bool check_tnl_key; /* Verify the tunnel key of inbound packets? */
+ atomic_bool extended; /* Extended mode. */
+ atomic_int ref_cnt;
};
/* Remote MPs represent foreign network entities that are configured to have
@@ -147,13 +147,16 @@ struct remote_mp {
};
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(20, 30);
-static struct hmap all_cfms = HMAP_INITIALIZER(&all_cfms);
+
+static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
+static struct hmap all_cfms__ = HMAP_INITIALIZER(&all_cfms__);
+static struct hmap *all_cfms OVS_GUARDED_BY(mutex) = &all_cfms__;
static unixctl_cb_func cfm_unixctl_show;
static unixctl_cb_func cfm_unixctl_set_fault;
static uint64_t
-cfm_rx_packets(const struct cfm *cfm)
+cfm_rx_packets(const struct cfm *cfm) OVS_REQ_WRLOCK(mutex)
{
struct netdev_stats stats;
@@ -167,12 +170,15 @@ cfm_rx_packets(const struct cfm *cfm)
static const uint8_t *
cfm_ccm_addr(const struct cfm *cfm)
{
- return cfm->extended ? eth_addr_ccm_x : eth_addr_ccm;
+ bool extended;
+ atomic_read(&cfm->extended, &extended);
+ return extended ? eth_addr_ccm_x : eth_addr_ccm;
}
/* Returns the string representation of the given cfm_fault_reason 'reason'. */
const char *
-cfm_fault_reason_to_str(int reason) {
+cfm_fault_reason_to_str(int reason)
+{
switch (reason) {
#define CFM_FAULT_REASON(NAME, STR) case CFM_FAULT_##NAME: return #STR;
CFM_FAULT_REASONS
@@ -198,7 +204,7 @@ ds_put_cfm_fault(struct ds *ds, int fault)
}
static void
-cfm_generate_maid(struct cfm *cfm)
+cfm_generate_maid(struct cfm *cfm) OVS_REQ_WRLOCK(mutex)
{
const char *ovs_md_name = "ovs";
const char *ovs_ma_name = "ovs";
@@ -241,7 +247,7 @@ ccm_interval_to_ms(uint8_t interval)
}
static long long int
-cfm_fault_interval(struct cfm *cfm)
+cfm_fault_interval(struct cfm *cfm) OVS_REQ_WRLOCK(mutex)
{
/* According to the 802.1ag specification we should assume every other MP
* with the same MAID has the same transmission interval that we have. If
@@ -283,7 +289,7 @@ cfm_is_valid_mpid(bool extended, uint64_t mpid)
}
static struct remote_mp *
-lookup_remote_mp(const struct cfm *cfm, uint64_t mpid)
+lookup_remote_mp(const struct cfm *cfm, uint64_t mpid) OVS_REQ_WRLOCK(mutex)
{
struct remote_mp *rmp;
@@ -316,13 +322,18 @@ cfm_create(const struct netdev *netdev)
cfm->netdev = netdev_ref(netdev);
cfm->name = netdev_get_name(cfm->netdev);
hmap_init(&cfm->remote_mps);
- cfm_generate_maid(cfm);
- hmap_insert(&all_cfms, &cfm->hmap_node, hash_string(cfm->name, 0));
cfm->remote_opup = true;
cfm->fault_override = -1;
cfm->health = -1;
cfm->last_tx = 0;
- cfm->ref_cnt = 1;
+ atomic_init(&cfm->extended, false);
+ atomic_init(&cfm->check_tnl_key, false);
+ atomic_init(&cfm->ref_cnt, 1);
+
+ ovs_mutex_lock(&mutex);
+ cfm_generate_maid(cfm);
+ hmap_insert(all_cfms, &cfm->hmap_node, hash_string(cfm->name, 0));
+ ovs_mutex_unlock(&mutex);
return cfm;
}
@@ -330,23 +341,28 @@ void
cfm_unref(struct cfm *cfm)
{
struct remote_mp *rmp, *rmp_next;
+ int orig;
if (!cfm) {
return;
}
- ovs_assert(cfm->ref_cnt);
- if (--cfm->ref_cnt) {
+ atomic_sub(&cfm->ref_cnt, 1, &orig);
+ ovs_assert(orig > 0);
+ if (orig != 1) {
return;
}
+ ovs_mutex_lock(&mutex);
+ hmap_remove(all_cfms, &cfm->hmap_node);
+ ovs_mutex_unlock(&mutex);
+
HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
hmap_remove(&cfm->remote_mps, &rmp->node);
free(rmp);
}
hmap_destroy(&cfm->remote_mps);
- hmap_remove(&all_cfms, &cfm->hmap_node);
netdev_close(cfm->netdev);
free(cfm->rmps_array);
free(cfm);
@@ -357,8 +373,9 @@ cfm_ref(const struct cfm *cfm_)
{
struct cfm *cfm = CONST_CAST(struct cfm *, cfm_);
if (cfm) {
- ovs_assert(cfm->ref_cnt > 0);
- cfm->ref_cnt++;
+ int orig;
+ atomic_add(&cfm->ref_cnt, 1, &orig);
+ ovs_assert(orig > 0);
}
return cfm;
}
@@ -367,6 +384,7 @@ cfm_ref(const struct cfm *cfm_)
void
cfm_run(struct cfm *cfm)
{
+ ovs_mutex_lock(&mutex);
if (timer_expired(&cfm->fault_timer)) {
long long int interval = cfm_fault_interval(cfm);
struct remote_mp *rmp, *rmp_next;
@@ -461,6 +479,7 @@ cfm_run(struct cfm *cfm)
timer_set_duration(&cfm->fault_timer, interval);
VLOG_DBG("%s: new fault interval", cfm->name);
}
+ ovs_mutex_unlock(&mutex);
}
/* Should be run periodically to check if the CFM module has a CCM message it
@@ -468,7 +487,12 @@ cfm_run(struct cfm *cfm)
bool
cfm_should_send_ccm(struct cfm *cfm)
{
- return timer_expired(&cfm->tx_timer);
+ bool ret;
+
+ ovs_mutex_lock(&mutex);
+ ret = timer_expired(&cfm->tx_timer);
+ ovs_mutex_unlock(&mutex);
+ return ret;
}
/* Composes a CCM message into 'packet'. Messages generated with this function
@@ -479,7 +503,9 @@ cfm_compose_ccm(struct cfm *cfm, struct ofpbuf *packet,
{
uint16_t ccm_vlan;
struct ccm *ccm;
+ bool extended;
+ ovs_mutex_lock(&mutex);
timer_set_duration(&cfm->tx_timer, cfm->ccm_interval_ms);
eth_compose(packet, cfm_ccm_addr(cfm), eth_src, ETH_TYPE_CFM, sizeof *ccm);
@@ -503,7 +529,8 @@ cfm_compose_ccm(struct cfm *cfm, struct ofpbuf *packet,
memset(ccm->zero, 0, sizeof ccm->zero);
ccm->end_tlv = 0;
- if (cfm->extended) {
+ atomic_read(&cfm->extended, &extended);
+ if (extended) {
ccm->mpid = htons(hash_mpid(cfm->mpid));
ccm->mpid64 = htonll(cfm->mpid);
ccm->opdown = !cfm->opup;
@@ -514,7 +541,7 @@ cfm_compose_ccm(struct cfm *cfm, struct ofpbuf *packet,
}
if (cfm->ccm_interval == 0) {
- ovs_assert(cfm->extended);
+ ovs_assert(extended);
ccm->interval_ms_x = htons(cfm->ccm_interval_ms);
} else {
ccm->interval_ms_x = htons(0);
@@ -533,13 +560,16 @@ cfm_compose_ccm(struct cfm *cfm, struct ofpbuf *packet,
}
}
cfm->last_tx = time_msec();
+ ovs_mutex_unlock(&mutex);
}
void
cfm_wait(struct cfm *cfm)
{
+ ovs_mutex_lock(&mutex);
timer_wait(&cfm->tx_timer);
timer_wait(&cfm->fault_timer);
+ ovs_mutex_unlock(&mutex);
}
/* Configures 'cfm' with settings from 's'. */
@@ -553,21 +583,23 @@ cfm_configure(struct cfm *cfm, const struct cfm_settings *s)
return false;
}
+ ovs_mutex_lock(&mutex);
cfm->mpid = s->mpid;
- cfm->check_tnl_key = s->check_tnl_key;
- cfm->extended = s->extended;
cfm->opup = s->opup;
interval = ms_to_ccm_interval(s->interval);
interval_ms = ccm_interval_to_ms(interval);
+ atomic_store(&cfm->check_tnl_key, s->check_tnl_key);
+ atomic_store(&cfm->extended, s->extended);
+
cfm->ccm_vlan = s->ccm_vlan;
cfm->ccm_pcp = s->ccm_pcp & (VLAN_PCP_MASK >> VLAN_PCP_SHIFT);
- if (cfm->extended && interval_ms != s->interval) {
+ if (s->extended && interval_ms != s->interval) {
interval = 0;
interval_ms = MIN(s->interval, UINT16_MAX);
}
- if (cfm->extended && s->demand) {
+ if (s->extended && s->demand) {
interval_ms = MAX(interval_ms, 500);
if (!cfm->demand) {
cfm->demand = true;
@@ -585,6 +617,7 @@ cfm_configure(struct cfm *cfm, const struct cfm_settings *s)
timer_set_duration(&cfm->fault_timer, cfm_fault_interval(cfm));
}
+ ovs_mutex_unlock(&mutex);
return true;
}
@@ -592,10 +625,12 @@ cfm_configure(struct cfm *cfm, const struct cfm_settings *s)
void
cfm_set_netdev(struct cfm *cfm, const struct netdev *netdev)
{
+ ovs_mutex_lock(&mutex);
if (cfm->netdev != netdev) {
netdev_close(cfm->netdev);
cfm->netdev = netdev_ref(netdev);
}
+ ovs_mutex_unlock(&mutex);
}
/* Returns true if 'cfm' should process packets from 'flow'. Sets
@@ -604,13 +639,16 @@ bool
cfm_should_process_flow(const struct cfm *cfm, const struct flow *flow,
struct flow_wildcards *wc)
{
+ bool check_tnl_key;
+
+ atomic_read(&cfm->check_tnl_key, &check_tnl_key);
memset(&wc->masks.dl_dst, 0xff, sizeof wc->masks.dl_dst);
- if (cfm->check_tnl_key) {
+ if (check_tnl_key) {
memset(&wc->masks.tunnel.tun_id, 0xff, sizeof wc->masks.tunnel.tun_id);
}
return (ntohs(flow->dl_type) == ETH_TYPE_CFM
&& eth_addr_equals(flow->dl_dst, cfm_ccm_addr(cfm))
- && (!cfm->check_tnl_key || flow->tunnel.tun_id == htonll(0)));
+ && (!check_tnl_key || flow->tunnel.tun_id == htonll(0)));
}
/* Updates internal statistics relevant to packet 'p'. Should be called on
@@ -622,19 +660,21 @@ cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
struct ccm *ccm;
struct eth_header *eth;
+ ovs_mutex_lock(&mutex);
+
eth = p->l2;
ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_ACCEPT_LEN);
if (!ccm) {
VLOG_INFO_RL(&rl, "%s: Received an unparseable 802.1ag CCM heartbeat.",
cfm->name);
- return;
+ goto out;
}
if (ccm->opcode != CCM_OPCODE) {
VLOG_INFO_RL(&rl, "%s: Received an unsupported 802.1ag message. "
"(opcode %u)", cfm->name, ccm->opcode);
- return;
+ goto out;
}
/* According to the 802.1ag specification, reception of a CCM with an
@@ -659,9 +699,11 @@ cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
uint64_t ccm_mpid;
uint32_t ccm_seq;
bool ccm_opdown;
+ bool extended;
enum cfm_fault_reason cfm_fault = 0;
- if (cfm->extended) {
+ atomic_read(&cfm->extended, &extended);
+ if (extended) {
ccm_mpid = ntohll(ccm->mpid64);
ccm_opdown = ccm->opdown;
} else {
@@ -677,7 +719,7 @@ cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
ccm_interval, ccm_mpid);
}
- if (cfm->extended && ccm_interval == 0
+ if (extended && ccm_interval == 0
&& ccm_interval_ms_x != cfm->ccm_interval_ms) {
cfm_fault |= CFM_FAULT_INTERVAL;
VLOG_WARN_RL(&rl, "%s: received a CCM with an unexpected extended"
@@ -734,6 +776,9 @@ cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
rmp->last_rx = time_msec();
}
}
+
+out:
+ ovs_mutex_unlock(&mutex);
}
/* Gets the fault status of 'cfm'. Returns a bit mask of 'cfm_fault_reason's
@@ -742,10 +787,16 @@ cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
int
cfm_get_fault(const struct cfm *cfm)
{
+ int fault;
+
+ ovs_mutex_lock(&mutex);
if (cfm->fault_override >= 0) {
- return cfm->fault_override ? CFM_FAULT_OVERRIDE : 0;
+ fault = cfm->fault_override ? CFM_FAULT_OVERRIDE : 0;
+ } else {
+ fault = cfm->fault;
}
- return cfm->fault;
+ ovs_mutex_unlock(&mutex);
+ return fault;
}
/* Gets the health of 'cfm'. Returns an integer between 0 and 100 indicating
@@ -756,7 +807,12 @@ cfm_get_fault(const struct cfm *cfm)
int
cfm_get_health(const struct cfm *cfm)
{
- return cfm->health;
+ int health;
+
+ ovs_mutex_lock(&mutex);
+ health = cfm->health;
+ ovs_mutex_unlock(&mutex);
+ return health;
}
/* Gets the operational state of 'cfm'. 'cfm' is considered operationally down
@@ -767,11 +823,15 @@ cfm_get_health(const struct cfm *cfm)
int
cfm_get_opup(const struct cfm *cfm)
{
- if (cfm->extended) {
- return cfm->remote_opup;
- } else {
- return -1;
- }
+ bool extended;
+ int opup;
+
+ ovs_mutex_lock(&mutex);
+ atomic_read(&cfm->extended, &extended);
+ opup = extended ? cfm->remote_opup : -1;
+ ovs_mutex_unlock(&mutex);
+
+ return opup;
}
/* Populates 'rmps' with an array of remote maintenance points reachable by
@@ -781,16 +841,18 @@ void
cfm_get_remote_mpids(const struct cfm *cfm, const uint64_t **rmps,
size_t *n_rmps)
{
+ ovs_mutex_lock(&mutex);
*rmps = cfm->rmps_array;
*n_rmps = cfm->rmps_array_len;
+ ovs_mutex_unlock(&mutex);
}
static struct cfm *
-cfm_find(const char *name)
+cfm_find(const char *name) OVS_REQ_WRLOCK(&mutex)
{
struct cfm *cfm;
- HMAP_FOR_EACH_WITH_HASH (cfm, hmap_node, hash_string(name, 0), &all_cfms) {
+ HMAP_FOR_EACH_WITH_HASH (cfm, hmap_node, hash_string(name, 0), all_cfms) {
if (!strcmp(cfm->name, name)) {
return cfm;
}
@@ -799,14 +861,17 @@ cfm_find(const char *name)
}
static void
-cfm_print_details(struct ds *ds, const struct cfm *cfm)
+cfm_print_details(struct ds *ds, const struct cfm *cfm) OVS_REQ_WRLOCK(&mutex)
{
struct remote_mp *rmp;
+ bool extended;
int fault;
+ atomic_read(&cfm->extended, &extended);
+
ds_put_format(ds, "---- %s ----\n", cfm->name);
ds_put_format(ds, "MPID %"PRIu64":%s%s\n", cfm->mpid,
- cfm->extended ? " extended" : "",
+ extended ? " extended" : "",
cfm->fault_override >= 0 ? " fault_override" : "");
fault = cfm_get_fault(cfm);
@@ -845,21 +910,24 @@ cfm_unixctl_show(struct unixctl_conn *conn, int argc, const char *argv[],
struct ds ds = DS_EMPTY_INITIALIZER;
const struct cfm *cfm;
+ ovs_mutex_lock(&mutex);
if (argc > 1) {
cfm = cfm_find(argv[1]);
if (!cfm) {
unixctl_command_reply_error(conn, "no such CFM object");
- return;
+ goto out;
}
cfm_print_details(&ds, cfm);
} else {
- HMAP_FOR_EACH (cfm, hmap_node, &all_cfms) {
+ HMAP_FOR_EACH (cfm, hmap_node, all_cfms) {
cfm_print_details(&ds, cfm);
}
}
unixctl_command_reply(conn, ds_cstr(&ds));
ds_destroy(&ds);
+out:
+ ovs_mutex_unlock(&mutex);
}
static void
@@ -870,6 +938,7 @@ cfm_unixctl_set_fault(struct unixctl_conn *conn, int argc, const char *argv[],
int fault_override;
struct cfm *cfm;
+ ovs_mutex_lock(&mutex);
if (!strcasecmp("true", fault_str)) {
fault_override = 1;
} else if (!strcasecmp("false", fault_str)) {
@@ -878,21 +947,24 @@ cfm_unixctl_set_fault(struct unixctl_conn *conn, int argc, const char *argv[],
fault_override = -1;
} else {
unixctl_command_reply_error(conn, "unknown fault string");
- return;
+ goto out;
}
if (argc > 2) {
cfm = cfm_find(argv[1]);
if (!cfm) {
unixctl_command_reply_error(conn, "no such CFM object");
- return;
+ goto out;
}
cfm->fault_override = fault_override;
} else {
- HMAP_FOR_EACH (cfm, hmap_node, &all_cfms) {
+ HMAP_FOR_EACH (cfm, hmap_node, all_cfms) {
cfm->fault_override = fault_override;
}
}
unixctl_command_reply(conn, "OK");
+
+out:
+ ovs_mutex_unlock(&mutex);
}
--
1.7.9.5
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