datapath: Split ovs_flow_cmd_new_or_set().
[sliver-openvswitch.git] / datapath / datapath.c
index f7c3391..f88147e 100644 (file)
 
 int ovs_net_id __read_mostly;
 
+/* Check if need to build a reply message.
+ * OVS userspace sets the NLM_F_ECHO flag if it needs the reply. */
+static bool ovs_must_notify(struct genl_info *info,
+                           const struct genl_multicast_group *grp)
+{
+       return info->nlhdr->nlmsg_flags & NLM_F_ECHO ||
+               netlink_has_listeners(genl_info_net(info)->genl_sock, grp->id);
+}
+
 static void ovs_notify(struct sk_buff *skb, struct genl_info *info,
                       struct genl_multicast_group *grp)
 {
@@ -175,6 +184,7 @@ static struct hlist_head *vport_hash_bucket(const struct datapath *dp,
        return &dp->ports[port_no & (DP_VPORT_HASH_BUCKETS - 1)];
 }
 
+/* Called with ovs_mutex or RCU read lock. */
 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no)
 {
        struct vport *vport;
@@ -653,8 +663,8 @@ static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts)
                + nla_total_size(acts->actions_len); /* OVS_FLOW_ATTR_ACTIONS */
 }
 
-/* Called with ovs_mutex. */
-static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
+/* Called with ovs_mutex or RCU read lock. */
+static int ovs_flow_cmd_fill_info(const struct sw_flow *flow, int dp_ifindex,
                                  struct sk_buff *skb, u32 portid,
                                  u32 seq, u32 flags, u8 cmd)
 {
@@ -671,7 +681,7 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
        if (!ovs_header)
                return -EMSGSIZE;
 
-       ovs_header->dp_ifindex = get_dpifindex(dp);
+       ovs_header->dp_ifindex = dp_ifindex;
 
        /* Fill flow key. */
        nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
@@ -694,6 +704,7 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
        nla_nest_end(skb, nla);
 
        ovs_flow_stats_get(flow, &stats, &used, &tcp_flags);
+
        if (used &&
            nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
                goto nla_put_failure;
@@ -721,9 +732,9 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
                const struct sw_flow_actions *sf_acts;
 
                sf_acts = rcu_dereference_ovsl(flow->sf_acts);
-
                err = ovs_nla_put_actions(sf_acts->actions,
                                          sf_acts->actions_len, skb);
+
                if (!err)
                        nla_nest_end(skb, start);
                else {
@@ -744,44 +755,55 @@ error:
        return err;
 }
 
-static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
-                                              struct genl_info *info)
+/* May not be called with RCU read lock. */
+static struct sk_buff *ovs_flow_cmd_alloc_info(const struct sw_flow_actions *acts,
+                                              struct genl_info *info,
+                                              bool always)
 {
-       size_t len;
+       struct sk_buff *skb;
+
+       if (!always && !ovs_must_notify(info, &ovs_dp_flow_multicast_group))
+               return NULL;
 
-       len = ovs_flow_cmd_msg_size(ovsl_dereference(flow->sf_acts));
+       skb = genlmsg_new_unicast(ovs_flow_cmd_msg_size(acts), info, GFP_KERNEL);
 
-       return genlmsg_new_unicast(len, info, GFP_KERNEL);
+       if (!skb)
+               return ERR_PTR(-ENOMEM);
+
+       return skb;
 }
 
-static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
-                                              struct datapath *dp,
-                                              struct genl_info *info,
-                                              u8 cmd)
+/* Called with ovs_mutex. */
+static struct sk_buff *ovs_flow_cmd_build_info(const struct sw_flow *flow,
+                                              int dp_ifindex,
+                                              struct genl_info *info, u8 cmd,
+                                              bool always)
 {
        struct sk_buff *skb;
        int retval;
 
-       skb = ovs_flow_cmd_alloc_info(flow, info);
-       if (!skb)
-               return ERR_PTR(-ENOMEM);
+       skb = ovs_flow_cmd_alloc_info(ovsl_dereference(flow->sf_acts), info,
+                                     always);
+       if (!skb || IS_ERR(skb))
+               return skb;
 
-       retval = ovs_flow_cmd_fill_info(flow, dp, skb, info->snd_portid,
-                                       info->snd_seq, 0, cmd);
+       retval = ovs_flow_cmd_fill_info(flow, dp_ifindex, skb,
+                                       info->snd_portid, info->snd_seq, 0,
+                                       cmd);
        BUG_ON(retval < 0);
        return skb;
 }
 
-static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
+static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
        struct ovs_header *ovs_header = info->userhdr;
        struct sw_flow_key key, masked_key;
-       struct sw_flow *flow = NULL;
+       struct sw_flow *flow;
        struct sw_flow_mask mask;
        struct sk_buff *reply;
        struct datapath *dp;
-       struct sw_flow_actions *acts = NULL;
+       struct sw_flow_actions *acts;
        struct sw_flow_match match;
        int error;
 
@@ -797,22 +819,21 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
                goto error;
 
        /* Validate actions. */
-       if (a[OVS_FLOW_ATTR_ACTIONS]) {
-               acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
-               error = PTR_ERR(acts);
-               if (IS_ERR(acts))
-                       goto error;
+       error = -EINVAL;
+       if (!a[OVS_FLOW_ATTR_ACTIONS])
+               goto error;
 
-               ovs_flow_mask_key(&masked_key, &key, &mask);
-               error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
-                                            &masked_key, 0, &acts);
-               if (error) {
-                       OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
-                       goto err_kfree;
-               }
-       } else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
-               error = -EINVAL;
+       acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
+       error = PTR_ERR(acts);
+       if (IS_ERR(acts))
                goto error;
+
+       ovs_flow_mask_key(&masked_key, &key, &mask);
+       error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
+                                    &masked_key, 0, &acts);
+       if (error) {
+               OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
+               goto err_kfree;
        }
 
        ovs_lock();
@@ -824,11 +845,6 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
        /* Check if this is a duplicate flow */
        flow = ovs_flow_tbl_lookup(&dp->table, &key);
        if (!flow) {
-               /* Bail out if we're not allowed to create a new flow. */
-               error = -ENOENT;
-               if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
-                       goto err_unlock_ovs;
-
                /* Allocate flow. */
                flow = ovs_flow_alloc();
                if (IS_ERR(flow)) {
@@ -846,10 +862,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
                        acts = NULL;
                        goto err_flow_free;
                }
-
-               reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
        } else {
-               /* We found a matching flow. */
                struct sw_flow_actions *old_acts;
 
                /* Bail out if we're not allowed to modify an existing flow.
@@ -859,8 +872,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
                 * gets fixed.
                 */
                error = -EEXIST;
-               if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW &&
-                   info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
+               if (info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
                        goto err_unlock_ovs;
 
                /* The unmasked key has to be the same for flow updates. */
@@ -871,20 +883,20 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
                old_acts = ovsl_dereference(flow->sf_acts);
                rcu_assign_pointer(flow->sf_acts, acts);
                ovs_nla_free_flow_actions(old_acts);
-
-               reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
-
-               /* Clear stats. */
-               if (a[OVS_FLOW_ATTR_CLEAR])
-                       ovs_flow_stats_clear(flow);
        }
+
+       reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
+                                       info, OVS_FLOW_CMD_NEW, false);
        ovs_unlock();
 
-       if (!IS_ERR(reply))
-               ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
-       else
-               netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
-                               ovs_dp_flow_multicast_group.id, PTR_ERR(reply));
+       if (reply) {
+               if (!IS_ERR(reply))
+                       ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
+               else
+                       netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
+                                       ovs_dp_flow_multicast_group.id,
+                                       PTR_ERR(reply));
+       }
        return 0;
 
 err_flow_free:
@@ -897,6 +909,97 @@ error:
        return error;
 }
 
+static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
+{
+       struct nlattr **a = info->attrs;
+       struct ovs_header *ovs_header = info->userhdr;
+       struct sw_flow_key key, masked_key;
+       struct sw_flow *flow;
+       struct sw_flow_mask mask;
+       struct sk_buff *reply = NULL;
+       struct datapath *dp;
+       struct sw_flow_actions *acts = NULL;
+       struct sw_flow_match match;
+       int error;
+
+       /* Extract key. */
+       error = -EINVAL;
+       if (!a[OVS_FLOW_ATTR_KEY])
+               goto error;
+
+       ovs_match_init(&match, &key, &mask);
+       error = ovs_nla_get_match(&match,
+                                 a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
+       if (error)
+               goto error;
+
+       /* Validate actions. */
+       if (a[OVS_FLOW_ATTR_ACTIONS]) {
+               acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
+               error = PTR_ERR(acts);
+               if (IS_ERR(acts))
+                       goto error;
+
+               ovs_flow_mask_key(&masked_key, &key, &mask);
+               error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
+                                            &masked_key, 0, &acts);
+               if (error) {
+                       OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
+                       goto err_kfree;
+               }
+       }
+
+       ovs_lock();
+       dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+       error = -ENODEV;
+       if (!dp)
+               goto err_unlock_ovs;
+
+       /* Check that the flow exists. */
+       flow = ovs_flow_tbl_lookup(&dp->table, &key);
+       error = -ENOENT;
+       if (!flow)
+               goto err_unlock_ovs;
+
+       /* The unmasked key has to be the same for flow updates. */
+       error = -EEXIST;
+       if (!ovs_flow_cmp_unmasked_key(flow, &match))
+               goto err_unlock_ovs;
+
+       /* Update actions, if present. */
+       if (acts) {
+               struct sw_flow_actions *old_acts;
+
+               old_acts = ovsl_dereference(flow->sf_acts);
+               rcu_assign_pointer(flow->sf_acts, acts);
+               ovs_nla_free_flow_actions(old_acts);
+       }
+
+       reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
+                                       info, OVS_FLOW_CMD_NEW, false);
+       /* Clear stats. */
+       if (a[OVS_FLOW_ATTR_CLEAR])
+               ovs_flow_stats_clear(flow);
+       ovs_unlock();
+
+       if (reply) {
+               if (!IS_ERR(reply))
+                       ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
+               else
+                       netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
+                                       ovs_dp_flow_multicast_group.id,
+                                       PTR_ERR(reply));
+       }
+       return 0;
+
+err_unlock_ovs:
+       ovs_unlock();
+err_kfree:
+       kfree(acts);
+error:
+       return error;
+}
+
 static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
@@ -931,7 +1034,8 @@ static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
                goto unlock;
        }
 
-       reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
+       reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex, info,
+                                       OVS_FLOW_CMD_NEW, true);
        if (IS_ERR(reply)) {
                err = PTR_ERR(reply);
                goto unlock;
@@ -955,45 +1059,54 @@ static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
        struct sw_flow_match match;
        int err;
 
+       if (likely(a[OVS_FLOW_ATTR_KEY])) {
+               ovs_match_init(&match, &key, NULL);
+               err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
+               if (unlikely(err))
+                       return err;
+       }
+
        ovs_lock();
        dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
-       if (!dp) {
+       if (unlikely(!dp)) {
                err = -ENODEV;
                goto unlock;
        }
-
-       if (!a[OVS_FLOW_ATTR_KEY]) {
+       if (unlikely(!a[OVS_FLOW_ATTR_KEY])) {
                err = ovs_flow_tbl_flush(&dp->table);
                goto unlock;
        }
-
-       ovs_match_init(&match, &key, NULL);
-       err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
-       if (err)
-               goto unlock;
-
        flow = ovs_flow_tbl_lookup(&dp->table, &key);
-       if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
+       if (unlikely(!flow || !ovs_flow_cmp_unmasked_key(flow, &match))) {
                err = -ENOENT;
                goto unlock;
        }
 
-       reply = ovs_flow_cmd_alloc_info(flow, info);
-       if (!reply) {
-               err = -ENOMEM;
-               goto unlock;
-       }
-
        ovs_flow_tbl_remove(&dp->table, flow);
+       ovs_unlock();
 
-       err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
-                                    info->snd_seq, 0, OVS_FLOW_CMD_DEL);
-       BUG_ON(err < 0);
+       reply = ovs_flow_cmd_alloc_info((const struct sw_flow_actions __force *)flow->sf_acts,
+                                       info, false);
+
+       if (likely(reply)) {
+               if (likely(!IS_ERR(reply))) {
+                       rcu_read_lock(); /* Keep RCU checker happy. */
+                       err = ovs_flow_cmd_fill_info(flow,
+                                                    ovs_header->dp_ifindex,
+                                                    reply, info->snd_portid,
+                                                    info->snd_seq, 0,
+                                                    OVS_FLOW_CMD_DEL);
+                       rcu_read_unlock();
+                       BUG_ON(err < 0);
+                       ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
+               } else {
+                       netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
+                                       ovs_dp_flow_multicast_group.id,
+                                       PTR_ERR(reply));
+               }
+       }
 
        ovs_flow_free(flow, true);
-       ovs_unlock();
-
-       ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
        return 0;
 unlock:
        ovs_unlock();
@@ -1024,7 +1137,7 @@ static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
                if (!flow)
                        break;
 
-               if (ovs_flow_cmd_fill_info(flow, dp, skb,
+               if (ovs_flow_cmd_fill_info(flow, ovs_header->dp_ifindex, skb,
                                           NETLINK_CB(cb->skb).portid,
                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
                                           OVS_FLOW_CMD_NEW) < 0)
@@ -1041,7 +1154,7 @@ static struct genl_ops dp_flow_genl_ops[] = {
        { .cmd = OVS_FLOW_CMD_NEW,
          .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
          .policy = flow_policy,
-         .doit = ovs_flow_cmd_new_or_set
+         .doit = ovs_flow_cmd_new
        },
        { .cmd = OVS_FLOW_CMD_DEL,
          .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
@@ -1057,7 +1170,7 @@ static struct genl_ops dp_flow_genl_ops[] = {
        { .cmd = OVS_FLOW_CMD_SET,
          .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
          .policy = flow_policy,
-         .doit = ovs_flow_cmd_new_or_set,
+         .doit = ovs_flow_cmd_set,
        },
 };
 
@@ -1093,6 +1206,7 @@ static size_t ovs_dp_cmd_msg_size(void)
        return msgsize;
 }
 
+/* Called with ovs_mutex or RCU read lock. */
 static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
                                u32 portid, u32 seq, u32 flags, u8 cmd)
 {
@@ -1108,9 +1222,7 @@ static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
 
        ovs_header->dp_ifindex = get_dpifindex(dp);
 
-       rcu_read_lock();
        err = nla_put_string(skb, OVS_DP_ATTR_NAME, ovs_dp_name(dp));
-       rcu_read_unlock();
        if (err)
                goto nla_put_failure;
 
@@ -1135,25 +1247,12 @@ error:
        return -EMSGSIZE;
 }
 
-static struct sk_buff *ovs_dp_cmd_build_info(struct datapath *dp,
-                                            struct genl_info *info, u8 cmd)
+static struct sk_buff *ovs_dp_cmd_alloc_info(struct genl_info *info)
 {
-       struct sk_buff *skb;
-       int retval;
-
-       skb = genlmsg_new_unicast(ovs_dp_cmd_msg_size(), info, GFP_KERNEL);
-       if (!skb)
-               return ERR_PTR(-ENOMEM);
-
-       retval = ovs_dp_cmd_fill_info(dp, skb, info->snd_portid, info->snd_seq, 0, cmd);
-       if (retval < 0) {
-               kfree_skb(skb);
-               return ERR_PTR(retval);
-       }
-       return skb;
+       return genlmsg_new_unicast(ovs_dp_cmd_msg_size(), info, GFP_KERNEL);
 }
 
-/* Called with ovs_mutex. */
+/* Called with rcu_read_lock or ovs_mutex. */
 static struct datapath *lookup_datapath(struct net *net,
                                        struct ovs_header *ovs_header,
                                        struct nlattr *a[OVS_DP_ATTR_MAX + 1])
@@ -1165,10 +1264,8 @@ static struct datapath *lookup_datapath(struct net *net,
        else {
                struct vport *vport;
 
-               rcu_read_lock();
                vport = ovs_vport_locate(net, nla_data(a[OVS_DP_ATTR_NAME]));
                dp = vport && vport->port_no == OVSP_LOCAL ? vport->dp : NULL;
-               rcu_read_unlock();
        }
        return dp ? dp : ERR_PTR(-ENODEV);
 }
@@ -1205,12 +1302,14 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
        if (!a[OVS_DP_ATTR_NAME] || !a[OVS_DP_ATTR_UPCALL_PID])
                goto err;
 
-       ovs_lock();
+       reply = ovs_dp_cmd_alloc_info(info);
+       if (!reply)
+               return -ENOMEM;
 
        err = -ENOMEM;
        dp = kzalloc(sizeof(*dp), GFP_KERNEL);
        if (dp == NULL)
-               goto err_unlock_ovs;
+               goto err_free_reply;
 
        ovs_dp_set_net(dp, hold_net(sock_net(skb->sk)));
 
@@ -1245,6 +1344,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 
        ovs_dp_change(dp, a);
 
+       /* So far only local changes have been made, now need the lock. */
+       ovs_lock();
+
        vport = new_vport(&parms);
        if (IS_ERR(vport)) {
                err = PTR_ERR(vport);
@@ -1263,10 +1365,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
                goto err_destroy_ports_array;
        }
 
-       reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_NEW);
-       err = PTR_ERR(reply);
-       if (IS_ERR(reply))
-               goto err_destroy_local_port;
+       err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
+                                  info->snd_seq, 0, OVS_DP_CMD_NEW);
+       BUG_ON(err < 0);
 
        ovs_net = net_generic(ovs_dp_get_net(dp), ovs_net_id);
        list_add_tail_rcu(&dp->list_node, &ovs_net->dps);
@@ -1276,9 +1377,8 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
        ovs_notify(reply, info, &ovs_dp_datapath_multicast_group);
        return 0;
 
-err_destroy_local_port:
-       ovs_dp_detach_port(ovs_vport_ovsl(dp, OVSP_LOCAL));
 err_destroy_ports_array:
+       ovs_unlock();
        kfree(dp->ports);
 err_destroy_percpu:
        free_percpu(dp->stats_percpu);
@@ -1287,8 +1387,8 @@ err_destroy_table:
 err_free_dp:
        release_net(ovs_dp_get_net(dp));
        kfree(dp);
-err_unlock_ovs:
-       ovs_unlock();
+err_free_reply:
+       kfree_skb(reply);
 err:
        return err;
 }
@@ -1326,25 +1426,29 @@ static int ovs_dp_cmd_del(struct sk_buff *skb, struct genl_info *info)
        struct datapath *dp;
        int err;
 
+       reply = ovs_dp_cmd_alloc_info(info);
+       if (!reply)
+               return -ENOMEM;
+
        ovs_lock();
        dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
        err = PTR_ERR(dp);
        if (IS_ERR(dp))
-               goto unlock;
+               goto err_unlock_free;
 
-       reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_DEL);
-       err = PTR_ERR(reply);
-       if (IS_ERR(reply))
-               goto unlock;
+       err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
+                                  info->snd_seq, 0, OVS_DP_CMD_DEL);
+       BUG_ON(err < 0);
 
        __dp_destroy(dp);
-       ovs_unlock();
 
+       ovs_unlock();
        ovs_notify(reply, info, &ovs_dp_datapath_multicast_group);
-
        return 0;
-unlock:
+
+err_unlock_free:
        ovs_unlock();
+       kfree_skb(reply);
        return err;
 }
 
@@ -1354,29 +1458,29 @@ static int ovs_dp_cmd_set(struct sk_buff *skb, struct genl_info *info)
        struct datapath *dp;
        int err;
 
+       reply = ovs_dp_cmd_alloc_info(info);
+       if (!reply)
+               return -ENOMEM;
+
        ovs_lock();
        dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
        err = PTR_ERR(dp);
        if (IS_ERR(dp))
-               goto unlock;
+               goto err_unlock_free;
 
        ovs_dp_change(dp, info->attrs);
 
-       reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_NEW);
-       if (IS_ERR(reply)) {
-               err = PTR_ERR(reply);
-               netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
-                               ovs_dp_datapath_multicast_group.id, err);
-               err = 0;
-               goto unlock;
-       }
+       err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
+                                  info->snd_seq, 0, OVS_DP_CMD_NEW);
+       BUG_ON(err < 0);
 
        ovs_unlock();
        ovs_notify(reply, info, &ovs_dp_datapath_multicast_group);
-
        return 0;
-unlock:
+
+err_unlock_free:
        ovs_unlock();
+       kfree_skb(reply);
        return err;
 }
 
@@ -1386,24 +1490,26 @@ static int ovs_dp_cmd_get(struct sk_buff *skb, struct genl_info *info)
        struct datapath *dp;
        int err;
 
-       ovs_lock();
+       reply = ovs_dp_cmd_alloc_info(info);
+       if (!reply)
+               return -ENOMEM;
+
+       rcu_read_lock();
        dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
        if (IS_ERR(dp)) {
                err = PTR_ERR(dp);
-               goto unlock;
-       }
-
-       reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_NEW);
-       if (IS_ERR(reply)) {
-               err = PTR_ERR(reply);
-               goto unlock;
+               goto err_unlock_free;
        }
+       err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
+                                  info->snd_seq, 0, OVS_DP_CMD_NEW);
+       BUG_ON(err < 0);
+       rcu_read_unlock();
 
-       ovs_unlock();
        return genlmsg_reply(reply, info);
 
-unlock:
-       ovs_unlock();
+err_unlock_free:
+       rcu_read_unlock();
+       kfree_skb(reply);
        return err;
 }
 
@@ -1516,7 +1622,12 @@ error:
        return err;
 }
 
-/* Called with ovs_mutex or RCU read lock. */
+static struct sk_buff *ovs_vport_cmd_alloc_info(void)
+{
+       return nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+}
+
+/* Called with ovs_mutex, only via ovs_dp_notify_wq(). */
 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, u32 portid,
                                         u32 seq, u8 cmd)
 {
@@ -1578,33 +1689,35 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
        u32 port_no;
        int err;
 
-       err = -EINVAL;
        if (!a[OVS_VPORT_ATTR_NAME] || !a[OVS_VPORT_ATTR_TYPE] ||
            !a[OVS_VPORT_ATTR_UPCALL_PID])
-               goto exit;
+               return -EINVAL;
+
+       port_no = a[OVS_VPORT_ATTR_PORT_NO]
+               ? nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]) : 0;
+       if (port_no >= DP_MAX_PORTS)
+               return -EFBIG;
+
+       reply = ovs_vport_cmd_alloc_info();
+       if (!reply)
+               return -ENOMEM;
 
        ovs_lock();
        dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
        err = -ENODEV;
        if (!dp)
-               goto exit_unlock;
-
-       if (a[OVS_VPORT_ATTR_PORT_NO]) {
-               port_no = nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]);
-
-               err = -EFBIG;
-               if (port_no >= DP_MAX_PORTS)
-                       goto exit_unlock;
+               goto exit_unlock_free;
 
+       if (port_no) {
                vport = ovs_vport_ovsl(dp, port_no);
                err = -EBUSY;
                if (vport)
-                       goto exit_unlock;
+                       goto exit_unlock_free;
        } else {
                for (port_no = 1; ; port_no++) {
                        if (port_no >= DP_MAX_PORTS) {
                                err = -EFBIG;
-                               goto exit_unlock;
+                               goto exit_unlock_free;
                        }
                        vport = ovs_vport_ovsl(dp, port_no);
                        if (!vport)
@@ -1622,25 +1735,23 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
        vport = new_vport(&parms);
        err = PTR_ERR(vport);
        if (IS_ERR(vport))
-               goto exit_unlock;
+               goto exit_unlock_free;
 
        err = 0;
        if (a[OVS_VPORT_ATTR_STATS])
                ovs_vport_set_stats(vport, nla_data(a[OVS_VPORT_ATTR_STATS]));
 
-       reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq,
-                                        OVS_VPORT_CMD_NEW);
-       if (IS_ERR(reply)) {
-               err = PTR_ERR(reply);
-               ovs_dp_detach_port(vport);
-               goto exit_unlock;
-       }
+       err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
+                                     info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+       BUG_ON(err < 0);
+       ovs_unlock();
 
        ovs_notify(reply, info, &ovs_dp_vport_multicast_group);
+       return 0;
 
-exit_unlock:
+exit_unlock_free:
        ovs_unlock();
-exit:
+       kfree_skb(reply);
        return err;
 }
 
@@ -1651,28 +1762,26 @@ static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
        struct vport *vport;
        int err;
 
+       reply = ovs_vport_cmd_alloc_info();
+       if (!reply)
+               return -ENOMEM;
+
        ovs_lock();
        vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
        err = PTR_ERR(vport);
        if (IS_ERR(vport))
-               goto exit_unlock;
+               goto exit_unlock_free;
 
        if (a[OVS_VPORT_ATTR_TYPE] &&
            nla_get_u32(a[OVS_VPORT_ATTR_TYPE]) != vport->ops->type) {
                err = -EINVAL;
-               goto exit_unlock;
-       }
-
-       reply = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-       if (!reply) {
-               err = -ENOMEM;
-               goto exit_unlock;
+               goto exit_unlock_free;
        }
 
        if (a[OVS_VPORT_ATTR_OPTIONS]) {
                err = ovs_vport_set_options(vport, a[OVS_VPORT_ATTR_OPTIONS]);
                if (err)
-                       goto exit_free;
+                       goto exit_unlock_free;
        }
 
        if (a[OVS_VPORT_ATTR_STATS])
@@ -1684,15 +1793,14 @@ static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
        err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
                                      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
        BUG_ON(err < 0);
-
        ovs_unlock();
+
        ovs_notify(reply, info, &ovs_dp_vport_multicast_group);
        return 0;
 
-exit_free:
-       kfree_skb(reply);
-exit_unlock:
+exit_unlock_free:
        ovs_unlock();
+       kfree_skb(reply);
        return err;
 }
 
@@ -1703,30 +1811,33 @@ static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
        struct vport *vport;
        int err;
 
+       reply = ovs_vport_cmd_alloc_info();
+       if (!reply)
+               return -ENOMEM;
+
        ovs_lock();
        vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
        err = PTR_ERR(vport);
        if (IS_ERR(vport))
-               goto exit_unlock;
+               goto exit_unlock_free;
 
        if (vport->port_no == OVSP_LOCAL) {
                err = -EINVAL;
-               goto exit_unlock;
+               goto exit_unlock_free;
        }
 
-       reply = ovs_vport_cmd_build_info(vport, info->snd_portid,
-                                        info->snd_seq, OVS_VPORT_CMD_DEL);
-       err = PTR_ERR(reply);
-       if (IS_ERR(reply))
-               goto exit_unlock;
-
-       err = 0;
+       err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
+                                     info->snd_seq, 0, OVS_VPORT_CMD_DEL);
+       BUG_ON(err < 0);
        ovs_dp_detach_port(vport);
+       ovs_unlock();
 
        ovs_notify(reply, info, &ovs_dp_vport_multicast_group);
+       return 0;
 
-exit_unlock:
+exit_unlock_free:
        ovs_unlock();
+       kfree_skb(reply);
        return err;
 }
 
@@ -1738,24 +1849,25 @@ static int ovs_vport_cmd_get(struct sk_buff *skb, struct genl_info *info)
        struct vport *vport;
        int err;
 
+       reply = ovs_vport_cmd_alloc_info();
+       if (!reply)
+               return -ENOMEM;
+
        rcu_read_lock();
        vport = lookup_vport(sock_net(skb->sk), ovs_header, a);
        err = PTR_ERR(vport);
        if (IS_ERR(vport))
-               goto exit_unlock;
-
-       reply = ovs_vport_cmd_build_info(vport, info->snd_portid,
-                                        info->snd_seq, OVS_VPORT_CMD_NEW);
-       err = PTR_ERR(reply);
-       if (IS_ERR(reply))
-               goto exit_unlock;
-
+               goto exit_unlock_free;
+       err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
+                                     info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+       BUG_ON(err < 0);
        rcu_read_unlock();
 
        return genlmsg_reply(reply, info);
 
-exit_unlock:
+exit_unlock_free:
        rcu_read_unlock();
+       kfree_skb(reply);
        return err;
 }