os/bluestore: recalc_allocated() when decoding bluefs_fnode_t

Fixes: http://tracker.ceph.com/issues/23212
Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit 25514e0)
Conflicts:
	src/os/bluestore/bluefs_types.h: replace C++17 stuff with C++11
counterparts.

src/os/bluestore/BlueFS.cc

@@ -780,7 +780,6 @@ int BlueFS::_replay(bool noop)
         {
 	  bluefs_fnode_t fnode;
 	  ::decode(fnode, p);
-	  fnode.recalc_allocated();
 	  dout(20) << __func__ << " 0x" << std::hex << pos << std::dec
                    << ":  op_file_update " << " " << fnode << dendl;
 	  if (!noop) {

src/os/bluestore/bluefs_types.h

@@ -51,7 +51,24 @@ struct bluefs_fnode_t {
       allocated += p.length;
   }
 
-  DENC(bluefs_fnode_t, v, p) {
+  DENC_HELPERS
+  void bound_encode(size_t& p) const {
+    _denc_friend(*this, p);
+  }
+  void encode(bufferlist::contiguous_appender& p) const {
+    DENC_DUMP_PRE(bluefs_fnode_t);
+    _denc_friend(*this, p);
+    DENC_DUMP_POST(bluefs_fnode_t);
+  }
+  void decode(buffer::ptr::iterator& p) {
+    _denc_friend(*this, p);
+    recalc_allocated();
+  }
+  template<typename T, typename P>
+  friend typename std::enable_if<
+    boost::is_same<T,bluefs_fnode_t>::value ||
+    boost::is_same<T,const bluefs_fnode_t>::value>::type
+  _denc_friend(T& v, P& p) {
     DENC_START(1, 1, p);
     denc_varint(v.ino, p);
     denc_varint(v.size, p);