src/storage/fshost/filesystem-mounter.h

// Copyright 2019 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.

#ifndef SRC_STORAGE_FSHOST_FILESYSTEM_MOUNTER_H_
#define SRC_STORAGE_FSHOST_FILESYSTEM_MOUNTER_H_

#include <fidl/fuchsia.fs.startup/cpp/wire.h>
#include <fidl/fuchsia.fxfs/cpp/wire.h>
#include <lib/zx/channel.h>
#include <lib/zx/status.h>
#include <zircon/types.h>

#include <memory>

#include <fbl/unique_fd.h>

#include "src/lib/storage/fs_management/cpp/mount.h"
#include "src/storage/fshost/fs-manager.h"
#include "src/storage/fshost/fshost-boot-args.h"
#include "src/storage/fshost/fshost_config.h"
#include "src/storage/fshost/inspect-manager.h"

namespace fshost {

// FilesystemMounter is a utility class which wraps the FsManager
// and helps clients mount filesystems within the fshost namespace.
class FilesystemMounter {
 public:
  FilesystemMounter(FsManager& fshost, const fshost_config::Config* config)
      : fshost_(fshost), config_(*config) {}

  virtual ~FilesystemMounter() = default;

  bool Netbooting() const { return config_.netboot(); }
  bool ShouldCheckFilesystems() const { return config_.check_filesystems(); }

  // Attempts to mount a block device to "/data".
  // Fails if already mounted.
  zx_status_t MountData(zx::channel block_device_client, const fs_management::MountOptions& options,
                        fs_management::DiskFormat format);

  // Attempts to mount a block device to "/durable".
  // Fails if already mounted.
  zx_status_t MountDurable(zx::channel block_device_client,
                           const fs_management::MountOptions& options);

  // Attempts to mount a block device to "/blob".
  // Fails if already mounted.
  zx_status_t MountBlob(zx::channel block_device_client,
                        fuchsia_fs_startup::wire::StartOptions options);

  // Attempts to mount a block device to "/factory".
  // Fails if already mounted.
  zx_status_t MountFactoryFs(zx::channel block_device_client,
                             const fs_management::MountOptions& options);

  // Actually launches the filesystem component.
  //
  // TODO(fxbug.dev/91577): All filesystems should be launched as components. Once they are, remove
  // LaunchFs.
  //
  // Virtualized to enable testing.
  virtual zx::status<> LaunchFsComponent(zx::channel block_device,
                                         fuchsia_fs_startup::wire::StartOptions options,
                                         const std::string& fs_name);

  std::shared_ptr<FshostBootArgs> boot_args() { return fshost_.boot_args(); }
  void ReportPartitionCorrupted(fs_management::DiskFormat format);

  bool BlobMounted() const { return blob_mounted_; }
  bool DataMounted() const { return data_mounted_; }
  bool FactoryMounted() const { return factory_mounted_; }
  bool DurableMounted() const { return durable_mounted_; }

  // If configuration indicates the data filesystem requires a crypt client, initializes it.  Does
  // nothing otherwise.
  zx::status<> MaybeInitCryptClient();

  FsManager& manager() { return fshost_; }
  FshostInspectManager& inspect_manager() { return fshost_.inspect_manager(); }

 private:
  // Performs the mechanical action of mounting a filesystem, without
  // validating the type of filesystem being mounted.
  zx::status<> MountFilesystem(FsManager::MountPoint point, const char* binary,
                               const fs_management::MountOptions& options,
                               zx::channel block_device_client,
                               fidl::ClientEnd<fuchsia_fxfs::Crypt> crypt_client = {});

  // Actually launches the filesystem process.
  //
  // Virtualized to enable testing.
  virtual zx_status_t LaunchFs(int argc, const char** argv, zx_handle_t* hnd, uint32_t* ids,
                               size_t len);

  static std::string GetDevicePath(const zx::channel& block_device);

  FsManager& fshost_;
  const fshost_config::Config& config_;
  bool data_mounted_ = false;
  bool durable_mounted_ = false;
  bool blob_mounted_ = false;
  bool factory_mounted_ = false;
  fidl::ClientEnd<fuchsia_io::Directory> crypt_outgoing_directory_;
};

std::string_view BinaryPathForFormat(fs_management::DiskFormat format);

}  // namespace fshost

#endif  // SRC_STORAGE_FSHOST_FILESYSTEM_MOUNTER_H_