[ovs-dev] [dpif 2/5] dpif-linux: Make port change notification thread-safe.
Ben Pfaff
blp at nicira.com
Wed Jul 24 00:07:48 UTC 2013
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
lib/dpif-linux.c | 154 ++++++++++++++++++++++++++---------------------------
1 files changed, 76 insertions(+), 78 deletions(-)
diff --git a/lib/dpif-linux.c b/lib/dpif-linux.c
index c972197..3935eff 100644
--- a/lib/dpif-linux.c
+++ b/lib/dpif-linux.c
@@ -148,26 +148,26 @@ struct dpif_linux {
int event_offset; /* Offset into 'epoll_events'. */
/* Change notification. */
- struct sset changed_ports; /* Ports that have changed. */
- struct nln_notifier *port_notifier;
- bool change_error;
+ struct nl_sock *port_notifier; /* vport multicast group subscriber. */
};
static struct vlog_rate_limit error_rl = VLOG_RATE_LIMIT_INIT(9999, 5);
-/* Generic Netlink family numbers for OVS. */
+/* Generic Netlink family numbers for OVS.
+ *
+ * Initialized by dpif_linux_init(). */
static int ovs_datapath_family;
static int ovs_vport_family;
static int ovs_flow_family;
static int ovs_packet_family;
-/* Generic Netlink socket. */
-static struct nln *nln = NULL;
+/* Generic Netlink multicast groups for OVS.
+ *
+ * Initialized by dpif_linux_init(). */
+static unsigned int ovs_vport_mcgroup;
static int dpif_linux_init(void);
-static void open_dpif(const struct dpif_linux_dp *, struct dpif **);
-static bool dpif_linux_nln_parse(struct ofpbuf *, void *);
-static void dpif_linux_port_changed(const void *vport, void *dpif);
+static int open_dpif(const struct dpif_linux_dp *, struct dpif **);
static uint32_t dpif_linux_port_get_pid(const struct dpif *,
odp_port_t port_no);
@@ -235,27 +235,27 @@ dpif_linux_open(const struct dpif_class *class OVS_UNUSED, const char *name,
return error;
}
- open_dpif(&dp, dpifp);
+ error = open_dpif(&dp, dpifp);
ofpbuf_delete(buf);
- return 0;
+ return error;
}
-static void
+static int
open_dpif(const struct dpif_linux_dp *dp, struct dpif **dpifp)
{
struct dpif_linux *dpif;
dpif = xzalloc(sizeof *dpif);
- dpif->port_notifier = nln_notifier_create(nln, dpif_linux_port_changed,
- dpif);
+ dpif->port_notifier = NULL;
dpif->epoll_fd = -1;
dpif_init(&dpif->dpif, &dpif_linux_class, dp->name,
dp->dp_ifindex, dp->dp_ifindex);
dpif->dp_ifindex = dp->dp_ifindex;
- sset_init(&dpif->changed_ports);
*dpifp = &dpif->dpif;
+
+ return 0;
}
static void
@@ -374,9 +374,8 @@ dpif_linux_close(struct dpif *dpif_)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
- nln_notifier_destroy(dpif->port_notifier);
+ nl_sock_destroy(dpif->port_notifier);
destroy_channels(dpif);
- sset_destroy(&dpif->changed_ports);
free(dpif);
}
@@ -392,22 +391,6 @@ dpif_linux_destroy(struct dpif *dpif_)
return dpif_linux_dp_transact(&dp, NULL, NULL);
}
-static void
-dpif_linux_run(struct dpif *dpif_ OVS_UNUSED)
-{
- if (nln) {
- nln_run(nln);
- }
-}
-
-static void
-dpif_linux_wait(struct dpif *dpif OVS_UNUSED)
-{
- if (nln) {
- nln_wait(nln);
- }
-}
-
static int
dpif_linux_get_stats(const struct dpif *dpif_, struct dpif_dp_stats *stats)
{
@@ -736,15 +719,61 @@ dpif_linux_port_poll(const struct dpif *dpif_, char **devnamep)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
- if (dpif->change_error) {
- dpif->change_error = false;
- sset_clear(&dpif->changed_ports);
+ /* Lazily create the Netlink socket to listen for notifications. */
+ if (!dpif->port_notifier) {
+ struct nl_sock *sock;
+ int error;
+
+ error = nl_sock_create(NETLINK_GENERIC, &sock);
+ if (error) {
+ return error;
+ }
+
+ error = nl_sock_join_mcgroup(sock, ovs_vport_mcgroup);
+ if (error) {
+ nl_sock_destroy(sock);
+ return error;
+ }
+ dpif->port_notifier = sock;
+
+ /* We have no idea of the current state so report that everything
+ * changed. */
+ return ENOBUFS;
+ }
+
+ for (;;) {
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+ uint64_t buf_stub[4096 / 8];
+ struct ofpbuf buf;
+ int error;
+
+ ofpbuf_use_stub(&buf, buf_stub, sizeof buf_stub);
+ error = nl_sock_recv(dpif->port_notifier, &buf, false);
+ if (!error) {
+ struct dpif_linux_vport vport;
+
+ error = dpif_linux_vport_from_ofpbuf(&vport, &buf);
+ if (!error) {
+ if (vport.dp_ifindex == dpif->dp_ifindex
+ && (vport.cmd == OVS_VPORT_CMD_NEW
+ || vport.cmd == OVS_VPORT_CMD_DEL
+ || vport.cmd == OVS_VPORT_CMD_SET)) {
+ VLOG_DBG("port_changed: dpif:%s vport:%s cmd:%"PRIu8,
+ dpif->dpif.full_name, vport.name, vport.cmd);
+ *devnamep = xstrdup(vport.name);
+ return 0;
+ } else {
+ continue;
+ }
+ }
+ } else if (error == EAGAIN) {
+ return EAGAIN;
+ }
+
+ VLOG_WARN_RL(&rl, "error reading or parsing netlink (%s)",
+ ovs_strerror(error));
+ nl_sock_drain(dpif->port_notifier);
return ENOBUFS;
- } else if (!sset_is_empty(&dpif->changed_ports)) {
- *devnamep = sset_pop(&dpif->changed_ports);
- return 0;
- } else {
- return EAGAIN;
}
}
@@ -752,7 +781,10 @@ static void
dpif_linux_port_poll_wait(const struct dpif *dpif_)
{
const struct dpif_linux *dpif = dpif_linux_cast(dpif_);
- if (!sset_is_empty(&dpif->changed_ports) || dpif->change_error) {
+
+ if (dpif->port_notifier) {
+ nl_sock_wait(dpif->port_notifier, POLLIN);
+ } else {
poll_immediate_wake();
}
}
@@ -1407,8 +1439,8 @@ const struct dpif_class dpif_linux_class = {
dpif_linux_open,
dpif_linux_close,
dpif_linux_destroy,
- dpif_linux_run,
- dpif_linux_wait,
+ NULL, /* run */
+ NULL, /* wait */
dpif_linux_get_stats,
dpif_linux_port_add,
dpif_linux_port_del,
@@ -1444,8 +1476,6 @@ dpif_linux_init(void)
static int error;
if (ovsthread_once_start(&once)) {
- unsigned int ovs_vport_mcgroup;
-
error = nl_lookup_genl_family(OVS_DATAPATH_FAMILY,
&ovs_datapath_family);
if (error) {
@@ -1468,11 +1498,6 @@ dpif_linux_init(void)
&ovs_vport_mcgroup,
OVS_VPORT_MCGROUP_FALLBACK_ID);
}
- if (!error) {
- static struct dpif_linux_vport vport;
- nln = nln_create(NETLINK_GENERIC, ovs_vport_mcgroup,
- dpif_linux_nln_parse, &vport);
- }
ovsthread_once_done(&once);
}
@@ -1497,33 +1522,6 @@ dpif_linux_is_internal_device(const char *name)
return reply.type == OVS_VPORT_TYPE_INTERNAL;
}
-
-static bool
-dpif_linux_nln_parse(struct ofpbuf *buf, void *vport_)
-{
- struct dpif_linux_vport *vport = vport_;
- return dpif_linux_vport_from_ofpbuf(vport, buf) == 0;
-}
-
-static void
-dpif_linux_port_changed(const void *vport_, void *dpif_)
-{
- const struct dpif_linux_vport *vport = vport_;
- struct dpif_linux *dpif = dpif_;
-
- if (vport) {
- if (vport->dp_ifindex == dpif->dp_ifindex
- && (vport->cmd == OVS_VPORT_CMD_NEW
- || vport->cmd == OVS_VPORT_CMD_DEL
- || vport->cmd == OVS_VPORT_CMD_SET)) {
- VLOG_DBG("port_changed: dpif:%s vport:%s cmd:%"PRIu8,
- dpif->dpif.full_name, vport->name, vport->cmd);
- sset_add(&dpif->changed_ports, vport->name);
- }
- } else {
- dpif->change_error = true;
- }
-}
/* Parses the contents of 'buf', which contains a "struct ovs_header" followed
* by Netlink attributes, into 'vport'. Returns 0 if successful, otherwise a
--
1.7.2.5
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