Method insert_readdir_results

src/client/Client.cc:1557–1746

* insert results from readdir or lssnap into the metadata cache. */

 * insert results from readdir or lssnap into the metadata cache.
 */
void Client::insert_readdir_results(MetaRequest *request, MetaSession *session,
                                    Inode *diri, Inode *diri_other) {

  auto& reply = request->reply;
  ConnectionRef con = request->reply->get_connection();
  uint64_t features;
  if(session->mds_features.test(CEPHFS_FEATURE_REPLY_ENCODING)) {
    features = (uint64_t)-1;
  }
  else {
    features = con->get_features();
  }

  dir_result_t *dirp = request->dirp;
  ceph_assert(dirp);

  // the extra buffer list is only set for readdir, lssnap and
  // readdir_snapdiff replies
  auto p = reply->get_extra_bl().cbegin();
  if (!p.end()) {
    // snapdir?
    if (request->head.op == CEPH_MDS_OP_LSSNAP) {
      ceph_assert(diri);
      auto snapdir = open_snapdir(diri);
      diri = snapdir.get();
    }
    bool snapdiff_req = request->head.op == CEPH_MDS_OP_READDIR_SNAPDIFF;
    frag_t fg;
    unsigned offset_hash;
    if (snapdiff_req) {
      fg = (unsigned)request->head.args.snapdiff.frag;
      offset_hash = (unsigned)request->head.args.snapdiff.offset_hash;
    } else {
      fg = (unsigned)request->head.args.readdir.frag;
      offset_hash = (unsigned)request->head.args.readdir.offset_hash;
    }

    // only open dir if we're actually adding stuff to it!
    Dir *dir = diri->open_dir();
    ceph_assert(dir);
    //open opponent dir for snapdiff if any
    Dir *dir_other = nullptr;
    if (snapdiff_req) {
      ceph_assert(diri_other);
      dir_other = diri_other->open_dir();
      ceph_assert(dir_other);
    }

    // dirstat
    DirStat dst(p, features);
    __u32 numdn;
    __u16 flags;
    decode(numdn, p);
    decode(flags, p);

    bool end = ((unsigned)flags & CEPH_READDIR_FRAG_END);
    bool hash_order = ((unsigned)flags & CEPH_READDIR_HASH_ORDER);