diff --git a/src/osdc/ObjectCacher.cc b/src/osdc/ObjectCacher.cc
index 7e26d20d5f6..5253755d3cb 100644
--- a/src/osdc/ObjectCacher.cc
+++ b/src/osdc/ObjectCacher.cc
@@ -197,8 +197,8 @@ int ObjectCacher::Object::map_read(OSDRead *rd,
       if (p == data.end()) {
         // rest is a miss.
         BufferHead *n = new BufferHead(this);
-        n->set_start( cur );
-        n->set_length( left );
+        n->set_start(cur);
+        n->set_length(left);
         oc->bh_add(this, n);
         missing[cur] = n;
         dout(20) << "map_read miss " << left << " left, " << *n << dendl;
@@ -303,14 +303,16 @@ ObjectCacher::BufferHead *ObjectCacher::Object::map_write(OSDWrite *wr)
           oc->bh_add(this, final);
           dout(10) << "map_write adding trailing bh " << *final << dendl;
         } else {
-          final->set_length( final->length() + max );
+	  oc->bh_stat_sub(final);
+          final->set_length(final->length() + max);
+	  oc->bh_stat_add(final);
         }
         left -= max;
         cur += max;
         continue;
       }
       
-      dout(10) << "p is " << *p->second << dendl;
+      dout(10) << "cur is " << cur << ", p is " << *p->second << dendl;
 
       if (p->first <= cur) {
         BufferHead *bh = p->second;
@@ -359,7 +361,9 @@ ObjectCacher::BufferHead *ObjectCacher::Object::map_write(OSDWrite *wr)
         loff_t glen = MIN(next - cur, max);
         dout(10) << "map_write gap " << cur << "~" << glen << dendl;
         if (final) {
-          final->set_length( final->length() + glen );
+	  oc->bh_stat_sub(final);
+          final->set_length(final->length() + glen);
+	  oc->bh_stat_add(final);
         } else {
           final = new BufferHead(this);
           final->set_start( cur );
diff --git a/src/osdc/ObjectCacher.h b/src/osdc/ObjectCacher.h
index fd90e2d4111..79fbdff0a7f 100644
--- a/src/osdc/ObjectCacher.h
+++ b/src/osdc/ObjectCacher.h
@@ -90,12 +90,12 @@ class ObjectCacher {
       last_write_tid(0) {}
   
     // extent
-    loff_t start() { return ex.start; }
+    loff_t start() const { return ex.start; }
     void set_start(loff_t s) { ex.start = s; }
-    loff_t length() { return ex.length; }
+    loff_t length() const { return ex.length; }
     void set_length(loff_t l) { ex.length = l; }
-    loff_t end() { return ex.start + ex.length; }
-    loff_t last() { return end() - 1; }
+    loff_t end() const { return ex.start + ex.length; }
+    loff_t last() const { return end() - 1; }
 
     // states
     void set_state(int s) {
@@ -103,7 +103,7 @@ class ObjectCacher {
       if (state == STATE_RX || state == STATE_TX) put();
       state = s;
     }
-    int get_state() { return state; }
+    int get_state() const { return state; }
     
     bool is_missing() { return state == STATE_MISSING; }
     bool is_dirty() { return state == STATE_DIRTY; }
@@ -321,6 +321,8 @@ class ObjectCacher {
   loff_t stat_tx;
   loff_t stat_missing;
 
+  void verify_stats() const;
+
   void bh_stat_add(BufferHead *bh) {
     switch (bh->get_state()) {
     case BufferHead::STATE_MISSING: