openvswitch: Refactor ovs_flow_cmd_fill_info().

Split up ovs_flow_cmd_fill_info() to make it easier to cache parts of a
dump reply. This will be used to streamline flow_dump in a future patch.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Thomas Graf <tgraf@noironetworks.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

1 files changed, 66 insertions, 27 deletions

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 04a26ae4a4f6..bbb920bf48da 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -674,58 +674,67 @@ static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts)
 }
 
 /* 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)
+static int ovs_flow_cmd_fill_match(const struct sw_flow *flow,
+                                   struct sk_buff *skb)
 {
-        const int skb_orig_len = skb->len;
-        struct nlattr *start;
-        struct ovs_flow_stats stats;
-        __be16 tcp_flags;
-        unsigned long used;
-        struct ovs_header *ovs_header;
         struct nlattr *nla;
         int err;
 
-        ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
-        if (!ovs_header)
-                return -EMSGSIZE;
-
-        ovs_header->dp_ifindex = dp_ifindex;
-
         /* Fill flow key. */
         nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
         if (!nla)
-                goto nla_put_failure;
+                return -EMSGSIZE;
 
         err = ovs_nla_put_flow(&flow->unmasked_key, &flow->unmasked_key, skb);
         if (err)
-                goto error;
+                return err;
+
         nla_nest_end(skb, nla);
 
+        /* Fill flow mask. */
         nla = nla_nest_start(skb, OVS_FLOW_ATTR_MASK);
         if (!nla)
-                goto nla_put_failure;
+                return -EMSGSIZE;
 
         err = ovs_nla_put_flow(&flow->key, &flow->mask->key, skb);
         if (err)
-                goto error;
+                return err;
 
         nla_nest_end(skb, nla);
+        return 0;
+}
+
+/* Called with ovs_mutex or RCU read lock. */
+static int ovs_flow_cmd_fill_stats(const struct sw_flow *flow,
+                                   struct sk_buff *skb)
+{
+        struct ovs_flow_stats stats;
+        __be16 tcp_flags;
+        unsigned long used;
 
         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;
+                return -EMSGSIZE;
 
         if (stats.n_packets &&
             nla_put(skb, OVS_FLOW_ATTR_STATS, sizeof(struct ovs_flow_stats), &stats))
-                goto nla_put_failure;
+                return -EMSGSIZE;
 
         if ((u8)ntohs(tcp_flags) &&
              nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, (u8)ntohs(tcp_flags)))
-                goto nla_put_failure;
+                return -EMSGSIZE;
+
+        return 0;
+}
+
+/* Called with ovs_mutex or RCU read lock. */
+static int ovs_flow_cmd_fill_actions(const struct sw_flow *flow,
+                                     struct sk_buff *skb, int skb_orig_len)
+{
+        struct nlattr *start;
+        int err;
 
         /* If OVS_FLOW_ATTR_ACTIONS doesn't fit, skip dumping the actions if
          * this is the first flow to be dumped into 'skb'.  This is unusual for
@@ -749,17 +758,47 @@ static int ovs_flow_cmd_fill_info(const struct sw_flow *flow, int dp_ifindex,
                         nla_nest_end(skb, start);
                 else {
                         if (skb_orig_len)
-                                goto error;
+                                return err;
 
                         nla_nest_cancel(skb, start);
                 }
-        } else if (skb_orig_len)
-                goto nla_put_failure;
+        } else if (skb_orig_len) {
+                return -EMSGSIZE;
+        }
+
+        return 0;
+}
+
+/* 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)
+{
+        const int skb_orig_len = skb->len;
+        struct ovs_header *ovs_header;
+        int err;
+
+        ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family,
+                                 flags, cmd);
+        if (!ovs_header)
+                return -EMSGSIZE;
+
+        ovs_header->dp_ifindex = dp_ifindex;
+
+        err = ovs_flow_cmd_fill_match(flow, skb);
+        if (err)
+                goto error;
+
+        err = ovs_flow_cmd_fill_stats(flow, skb);
+        if (err)
+                goto error;
+
+        err = ovs_flow_cmd_fill_actions(flow, skb, skb_orig_len);
+        if (err)
+                goto error;
 
         return genlmsg_end(skb, ovs_header);
 
-nla_put_failure:
-        err = -EMSGSIZE;
 error:
         genlmsg_cancel(skb, ovs_header);
         return err;