src/storage/lib/paver/fvm.h

// Copyright 2018 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_LIB_PAVER_FVM_H_
#define SRC_STORAGE_LIB_PAVER_FVM_H_

#include <lib/zx/result.h>

#include "partition-client.h"
#include "src/storage/fvm/fvm_sparse.h"
#include "src/storage/fvm/sparse_reader.h"

namespace paver {

constexpr std::string_view kBlobfsPartitionLabel = "blobfs";
constexpr std::string_view kDataPartitionLabel = "data";

// Options for locating an FVM within a partition.
enum class BindOption {
  // Bind to the FVM, if it exists already.
  TryBind,
  // Reformat the partition, regardless of if it already exists as an FVM.
  Reformat,
};

// Describes the result of attempting to format an Fvm Partition.
enum class FormatResult {
  kUnknown,
  kPreserved,
  kReformatted,
};

// Attempts to bind an FVM driver to a partition device. Returns a connection for the FVM's device.
zx::result<fidl::ClientEnd<fuchsia_device::Controller>> TryBindToFvmDriver(
    const fbl::unique_fd& devfs_root, fidl::UnownedClientEnd<fuchsia_device::Controller> partition,
    zx::duration timeout);

// Formats the FVM within the provided partition if it is not already formatted.
// Returns a connection to the FVM's device.
zx::result<fidl::ClientEnd<fuchsia_device::Controller>> FvmPartitionFormat(
    const fbl::unique_fd& devfs_root,
    fidl::UnownedClientEnd<fuchsia_hardware_block::Block> partition,
    fidl::UnownedClientEnd<fuchsia_device::Controller> partition_controller,
    const fvm::SparseImage& header, BindOption option, FormatResult* format_result = nullptr);

// Allocates empty partitions inside the volume manager. Note that the partitions
// are simply allocated; the actual size of each partition (number of slices etc)
// is determined when formatting each volume.
zx::result<> AllocateEmptyPartitions(
    const fbl::unique_fd& devfs_root,
    fidl::UnownedClientEnd<fuchsia_hardware_block_volume::VolumeManager> fvm_device);

// Given an fd representing a "sparse FVM format", fill the FVM with the
// provided partitions described by |partition_fd|.
//
// Decides to overwrite or create new partitions based on the type
// GUID, not the instance GUID.
zx::result<> FvmStreamPartitions(const fbl::unique_fd& devfs_root,
                                 std::unique_ptr<PartitionClient> partition_client,
                                 std::unique_ptr<fvm::ReaderInterface> payload);

// Unbinds the FVM driver from the given device. Assumes that the driver is either
// loaded or not (but not in the process of being loaded).
zx_status_t FvmUnbind(const fbl::unique_fd& devfs_root, const char* device);

// Exposed for unit testing only.
zx_status_t WipeAllFvmPartitionsWithGuid(fidl::UnownedClientEnd<fuchsia_device::Controller> fvm,
                                         const uint8_t type_guid[]);

}  // namespace paver

#endif  // SRC_STORAGE_LIB_PAVER_FVM_H_