Method _link

src/client/Client.cc:16664–16721

}

int Client::_link(Inode *diri_from, const char* path_from, Inode* diri_to, const char* path_to, const UserPerm& perm, std::string alternate_name)
{
  ldout(cct, 8) << "_link(" << diri_from->ino << " to " << diri_to->ino << " " << path_to << " " << perm << dendl;

  walk_dentry_result wdr_from;
  if (int rc = path_walk(diri_from, filepath(path_from), &wdr_from, perm, {}); rc < 0) {
    return rc;
  }

  walk_dentry_result wdr_to;
  if (int rc = path_walk(diri_to, filepath(path_to), &wdr_to, perm, {}); rc == 0) {
    return -EEXIST;
  } else if (rc != -ENOENT) {
    return rc;
  }

  if (should_check_perms()) {
    if (S_ISDIR(wdr_from.target->mode)) {
      return -EPERM;
    }
    if (int rc = may_hardlink(wdr_from.target.get(), perm); rc < 0) {
      return rc;
    }
    if (int rc = may_create(wdr_to.diri.get(), perm); rc < 0) {
      return rc;
    }
  }

  auto* in = wdr_from.target.get();
  if (in->snapid != CEPH_NOSNAP || wdr_to.diri->snapid != CEPH_NOSNAP) {
    return -EROFS;
  }
  if (is_quota_files_exceeded(wdr_to.diri.get(), perm)) {
    return -EDQUOT;
  }

  in->break_all_delegs();
  MetaRequest *req = new MetaRequest(CEPH_MDS_OP_LINK);

  req->set_filepath(wdr_to.getpath());
  req->set_alternate_name(alternate_name.empty() ? wdr_to.alternate_name : alternate_name);
#if defined(__linux__)
  wdr_to.diri->gen_inherited_fscrypt_auth(&req->fscrypt_auth);
#endif
  req->set_filepath2(wdr_from.getpath());
  req->set_inode(wdr_to.diri);
  req->inode_drop = CEPH_CAP_FILE_SHARED;
  req->inode_unless = CEPH_CAP_FILE_EXCL;
  req->set_dentry(wdr_to.dn);

  int res = make_request(req, perm);

  ldout(cct, 10) << "link result is " << res << dendl;

  trim_cache();
  ldout(cct, 8) << "link(" << wdr_from.getpath() << ", " << wdr_to.getpath() << ") = " << res << dendl;
  return res;
}