src/lib/isolated_devmgr/v2_component/ram_disk.cc

// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ram_disk.h"

#include <lib/syslog/cpp/macros.h>
#include <lib/zx/job.h>
#include <lib/zx/time.h>
#include <zircon/syscalls.h>

#include "bind_devfs_to_namespace.h"

namespace isolated_devmgr {

static zx::status<> OneTimeSetUp() {
  static zx::status<> status = []() -> zx::status<> {
    // Mark this process as critical so that if this process terminates, all other processes
    // within this job get terminated (e.g. file system processes).
    auto status = zx::make_status(zx::job::default_job()->set_critical(0, *zx::process::self()));
    if (status.is_error()) {
      FX_LOGS(ERROR) << "Unable to make process critical: " << status.status_string();
      return status;
    }
    status = isolated_devmgr::BindDevfsToNamespace();
    if (status.is_error()) {
      FX_LOGS(ERROR) << "Unable to bind devfs to namespace: " << status.status_string();
      return status;
    }
    return zx::ok();
  }();
  return status;
}

zx::status<RamDisk> RamDisk::Create(int block_size, int block_count) {
  auto status = OneTimeSetUp();
  if (status.is_error()) {
    return status.take_error();
  }
  status = zx::make_status(wait_for_device("/dev/misc/ramctl", zx::sec(10).get()));
  if (status.is_error()) {
    FX_LOGS(ERROR) << "Timed-out waiting for ramctl: " << status.status_string();
    return status.take_error();
  }
  ramdisk_client_t* client;
  status = zx::make_status(ramdisk_create(block_size, block_count, &client));
  if (status.is_error()) {
    FX_LOGS(ERROR) << "Could not create ramdisk for test: " << status.status_string();
    return status.take_error();
  }
  return zx::ok(RamDisk(client));
}

}  // namespace isolated_devmgr