Method _open

src/client/Client.cc:10971–11097

}

int Client::_open(const InodeRef& in, int flags, mode_t mode, Fh **fhp,
		  const UserPerm& perms)
{
  if (in->snapid != CEPH_NOSNAP &&
      (flags & (O_WRONLY | O_RDWR | O_CREAT | O_TRUNC | O_APPEND))) {
    return -EROFS;
  }

  // use normalized flags to generate cmode
  int cflags = ceph_flags_sys2wire(flags);
  if (cct->_conf.get_val<bool>("client_force_lazyio"))
    cflags |= CEPH_O_LAZY;

  int cmode = ceph_flags_to_mode(cflags);

  int want = ceph_caps_for_mode(cmode);
  int result = 0;

#if defined(__linux__)
  FSCryptKeyHandlerRef kh;
  get_keyhandler(in->fscrypt_ctx, kh);
  if (kh) {
    auto& di = kh->get_di();
    if (di) {
      di->add_inode(in->ino);
    }
  }
#endif
  in->get_open_ref(cmode);  // make note of pending open, since it effects _wanted_ caps.

  int do_sync = true;
  if ((flags & O_TRUNC) == 0 && in->caps_issued_mask(want)) {
    int mask = MAY_READ;

    if (cmode & CEPH_FILE_MODE_WR) {
      mask |= MAY_WRITE;
    }

    std::string path;
    if (make_absolute_path_string(in, path)) {
      ldout(cct, 20) << __func__ << " absolute path: " << path << dendl;
      result = mds_check_access(path, perms, mask);
      if (result) {
        return result;
      }
      // update wanted?
      check_caps(in, CHECK_CAPS_NODELAY);
      do_sync = false;
    }
  }

  if (do_sync) {
    MetaRequest *req = new MetaRequest(CEPH_MDS_OP_OPEN);
    filepath path;
    in->make_nosnap_relative_path(path);
    req->set_filepath(path);
    req->head.args.open.flags = cflags & ~CEPH_O_CREAT;
    req->head.args.open.mode = mode;