Method _readdir_cache_cb

src/client/Client.cc:9885–9982

};

int Client::_readdir_cache_cb(dir_result_t *dirp, add_dirent_cb_t cb, void *p,
			      int caps, bool getref)
{
  ceph_assert(ceph_mutex_is_locked_by_me(client_lock));
  ldout(cct, 10) << __func__ << " " << dirp << " on " << dirp->inode->ino
	   << " last_name " << dirp->last_name
	   << " offset " << hex << dirp->offset << dec
	   << dendl;
  auto& diri = dirp->inode;
  Dir *dir = diri->dir;

  if (!dir) {
    ldout(cct, 10) << __func__ << " dir is empty" << dendl;
    dirp->set_end();
    return 0;
  }

  vector<Dentry*>::iterator pd = std::lower_bound(dir->readdir_cache.begin(),
						  dir->readdir_cache.end(),
						  dirp->offset, dentry_off_lt());

  string dn_name;
  for (unsigned idx = pd - dir->readdir_cache.begin();
       idx < dir->readdir_cache.size();
       ++idx) {
    int mask = caps;
    if (!dirp->inode->is_complete_and_ordered())
      return -EAGAIN;
    Dentry *dn = dir->readdir_cache[idx];
    if (dn->inode == NULL) {
      ldout(cct, 15) << " skipping null '" << dn->name << "'" << dendl;
      continue;
    }
    if (dn->cap_shared_gen != dir->parent_inode->shared_gen) {
      ldout(cct, 15) << " skipping mismatch shared gen '" << dn->name << "'" << dendl;
      continue;
    }

    if (dn->inode->is_dir() && cct->_conf->client_dirsize_rbytes) {
      mask |= CEPH_STAT_RSTAT;
    }
    int r = _getattr(dn->inode, mask, dirp->perms);
    if (r < 0)
      return r;

    /* fix https://tracker.ceph.com/issues/56288 */
    if (dirp->inode->dir == NULL) {
      ldout(cct, 0) << " dir is closed, so we should return" << dendl;
      return -EAGAIN;
    }
    
    // the content of readdir_cache may change after _getattr()
    if (idx >= dir->readdir_cache.size() || dir->readdir_cache[idx] != dn)
      return -EAGAIN;

    struct ceph_statx stx;
    struct dirent de;
    fill_statx(dn->inode, caps, &stx);