Method readdir_snapdiff

src/client/Client.cc:10469–10543

}

int Client::readdir_snapdiff(dir_result_t* d1, snapid_t snap2,
                             struct dirent* out_de,
                             snapid_t* out_snap)
{
  if (!d1 || !d1->inode || d1->inode->snapid == snap2) {
    lderr(cct) << __func__ << " invalid parameters: "
               << " d1:" << d1
               << " d1->inode:" << (d1 ? d1->inode : nullptr)
               << " snap2 id :" << snap2
	       << dendl;
    errno = EINVAL;
    return -errno;
  }

  auto& de = d1->de;
  ceph_statx stx;
  single_readdir sr;
  sr.de = &de;
  sr.stx = &stx;
  sr.inode = NULL;
  sr.full = false;

  auto fill_snapdiff_cb = [&](dir_result_t* dirp,
    MetaRequest* req,
    InodeRef& diri,
    frag_t fg) {
      filepath path;
      diri->make_nosnap_relative_path(path);
      req->set_filepath(path);
      req->set_inode(diri.get());
      req->head.args.snapdiff.snap_other = snap2;
      req->head.args.snapdiff.frag = fg;
      req->head.args.snapdiff.flags = CEPH_READDIR_REPLY_BITFLAGS;
      if (dirp->last_name.length()) {
	req->path2.set_path(dirp->last_name);
      } else if (dirp->hash_order()) {
	req->head.args.snapdiff.offset_hash = dirp->offset_high();
      }
      req->dirp = dirp;
  };

  // our callback fills the dirent and sets sr.full=true on first
  // call, and returns -1 the second time around.
  int ret = _readdir_r_cb(CEPH_MDS_OP_READDIR_SNAPDIFF,
    d1,
    _readdir_single_dirent_cb,
    fill_snapdiff_cb,
    (void*)&sr,
    0,
    AT_STATX_DONT_SYNC,
    false,
    true);
  if (ret < -1) {
    lderr(cct) << __func__ << " error: "
               << cpp_strerror(ret)
               << dendl;
    errno = -ret;  // this sucks.
    return ret;