Initial support for blkin (LTTng + Zipkin) tracing

index 4673c1b..5c25d5a 100644
@@ -24,6 +24,8 @@
 
 class TrackedOp;
 typedef ceph::shared_ptr<TrackedOp> TrackedOpRef;
+typedef ZTracer::ZTraceEndpointRef TrackedOpEndpointRef;
+typedef ZTracer::ZTraceRef TrackedOpTraceRef;
 
 class OpTracker;
 class OpHistory {

@@ -98,6 +100,9 @@ public:
   void mark_event(TrackedOp *op, const string &evt);
   void _mark_event(TrackedOp *op, const string &evt, utime_t now);
 
+  void trace_event(TrackedOp *op, TrackedOpTraceRef t, const string &evt, TrackedOpEndpointRef ep);
+  void trace_keyval(TrackedOp *op, TrackedOpTraceRef t, const string &key,
+		    const string &val, TrackedOpEndpointRef ep);
   void on_shutdown() {
     Mutex::Locker l(ops_in_flight_lock);
     history.on_shutdown();

@@ -128,6 +133,10 @@ private:
   friend class OpHistory;
   friend class OpTracker;
   xlist<TrackedOp*>::item xitem;
+  TrackedOpTraceRef osd_trace;
+  TrackedOpTraceRef pg_trace;
+  TrackedOpTraceRef journal_trace;
+  TrackedOpTraceRef filestore_trace;
 protected:
   Message *request; /// the logical request we are tracking
   OpTracker *tracker; /// the tracker we are associated with

@@ -175,6 +184,18 @@ public:
     return events.rbegin()->second.c_str();
   }
   void dump(utime_t now, Formatter *f) const;
+
+  bool create_osd_trace(TrackedOpEndpointRef ep);
+  void trace_osd(string event);
+  void trace_osd(string key, string val);
+  bool create_pg_trace(TrackedOpEndpointRef ep);
+  void trace_pg(string event);
+  void get_pg_trace_info(struct blkin_trace_info *info);
+  bool create_journal_trace(TrackedOpEndpointRef ep);
+  void trace_journal(string event);
+  bool create_filestore_trace(TrackedOpEndpointRef ep);
+  void trace_filestore(string event);
+  TrackedOpTraceRef get_osd_trace() { return osd_trace; };
 };
 
 #endif

index a69944f..0f28a31 100644
@@ -18,6 +18,8 @@
 #include <stdlib.h>
 #include <ostream>
 
+#include "blkin/ztracer.hpp"
+
 #include <boost/intrusive_ptr.hpp>
 // Because intusive_ptr clobbers our assert...
 #include "include/assert.h"

@@ -340,6 +342,9 @@ protected:
   // currently throttled.
   uint64_t dispatch_throttle_size;
 
+  ZTracer::ZTraceEndpointRef message_endpoint;
+  ZTracer::ZTraceRef master_trace;
+  ZTracer::ZTraceRef messenger_trace;
   friend class Messenger;
 
 public:

@@ -350,6 +355,7 @@ public:
       dispatch_throttle_size(0) {
     memset(&header, 0, sizeof(header));
     memset(&footer, 0, sizeof(footer));
+    trace_end_after_span = false;
   };
   Message(int t, int version=1, int compat_version=0)
     : connection(NULL),

@@ -363,8 +369,10 @@ public:
     header.priority = 0;  // undef
     header.data_off = 0;
     memset(&footer, 0, sizeof(footer));
+    trace_end_after_span = false;
   }
 
+  bool trace_end_after_span;
   Message *get() {
     return static_cast<Message *>(RefCountedObject::get());
   }

@@ -394,6 +402,9 @@ public:
   void set_header(const ceph_msg_header &e) { header = e; }
   void set_footer(const ceph_msg_footer &e) { footer = e; }
   ceph_msg_footer &get_footer() { return footer; }
+  ZTracer::ZTraceRef get_master_trace() { return master_trace; }
+  ZTracer::ZTraceRef get_messenger_trace() { return messenger_trace; }
+  void set_messenger_trace(ZTracer::ZTraceRef t) { messenger_trace = t; }
 
   /*
    * If you use get_[data, middle, payload] you shouldn't

@@ -525,6 +536,15 @@ public:
   virtual void dump(Formatter *f) const;
 
   void encode(uint64_t features, bool datacrc);
+
+  int init_trace_info();
+  int init_trace_info(struct blkin_trace_info *tinfo);
+  int init_trace_info(ZTracer::ZTraceRef t);
+  void trace(string event);
+  void trace(string key, string val);
+  int trace_basic_info();
+  virtual void trace_msg_info() { };
+  virtual bool create_message_endpoint();
 };
 typedef boost::intrusive_ptr<Message> MessageRef;
 

@@ -541,4 +561,5 @@ inline ostream& operator<<(ostream& out, Message& m) {
 extern void encode_message(Message *m, uint64_t features, bufferlist& bl);
 extern Message *decode_message(CephContext *cct, bufferlist::iterator& bl);
 
+
 #endif

index 468a6a5..14d3dbc 100644
@@ -151,6 +151,7 @@ class DispatchQueue;
     ceph::shared_ptr<AuthSessionHandler> session_security;
 
   protected:
+    ZTracer::ZTraceEndpointRef pipe_endpoint;
     friend class SimpleMessenger;
     ConnectionRef connection_state;
 

@@ -174,6 +175,7 @@ class DispatchQueue;
     uint64_t in_seq, in_seq_acked;
     
     void set_socket_options();
+    void set_endpoint();
 
     int accept();   // server handshake
     int connect();  // client handshake

index 5d86b3a..443f8c5 100644
@@ -343,6 +343,7 @@ struct entity_addr_t {
   }
 
   void dump(Formatter *f) const;
+  int to_string(string &host, int &port);
 
   static void generate_test_instances(list<entity_addr_t*>& o);
 };