blob: bf38ebbb8645fddc9f2c0eb18328781299f5644c [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// StorageMonitorLinux processes mount point change events, notifies listeners
// about the addition and deletion of media devices, and answers queries about
// mounted devices. StorageMonitorLinux uses a MtabWatcherLinux on a separate
// background sequence that is file IO capable.
#if defined(OS_CHROMEOS)
#error "Use the ChromeOS-specific implementation instead."
#include <map>
#include <memory>
#include <string>
#include "base/compiler_specific.h"
#include "base/files/file_path.h"
#include "base/files/file_path_watcher.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/sequence_checker.h"
#include "build/build_config.h"
#include "components/storage_monitor/mtab_watcher_linux.h"
#include "components/storage_monitor/storage_monitor.h"
namespace base {
class SequencedTaskRunner;
namespace storage_monitor {
class StorageMonitorLinux : public StorageMonitor {
// Should only be called by browser start up code.
// Use StorageMonitor::GetInstance() instead.
// |mtab_file_path| is the path to a mtab file to watch for mount points.
explicit StorageMonitorLinux(const base::FilePath& mtab_file_path);
~StorageMonitorLinux() override;
// Must be called for StorageMonitorLinux to work.
void Init() override;
// Gets device information given a |device_path| and |mount_point|.
using GetDeviceInfoCallback = base::Callback<std::unique_ptr<StorageInfo>(
const base::FilePath& device_path,
const base::FilePath& mount_point)>;
void SetGetDeviceInfoCallbackForTest(
const GetDeviceInfoCallback& get_device_info_callback);
// Parses |new_mtab| and find all changes.
virtual void UpdateMtab(
const MtabWatcherLinux::MountPointDeviceMap& new_mtab);
// Structure to save mounted device information such as device path, unique
// identifier, device name and partition size.
struct MountPointInfo {
base::FilePath mount_device;
StorageInfo storage_info;
// Mapping of mount points to MountPointInfo.
typedef std::map<base::FilePath, MountPointInfo> MountMap;
// (mount point, priority)
// For devices that are mounted to multiple mount points, this helps us track
// which one we've notified system monitor about.
typedef std::map<base::FilePath, bool> ReferencedMountPoint;
// (mount device, map of known mount points)
// For each mount device, track the places it is mounted and which one (if
// any) we have notified system monitor about.
typedef std::map<base::FilePath, ReferencedMountPoint> MountPriorityMap;
// StorageMonitor implementation.
bool GetStorageInfoForPath(const base::FilePath& path,
StorageInfo* device_info) const override;
void EjectDevice(const std::string& device_id,
base::Callback<void(EjectStatus)> callback) override;
// Called when the MtabWatcher has been created.
void OnMtabWatcherCreated(MtabWatcherLinux* watcher);
bool IsDeviceAlreadyMounted(const base::FilePath& mount_device) const;
// Assuming |mount_device| is already mounted, and it gets mounted again at
// |mount_point|, update the mappings.
void HandleDeviceMountedMultipleTimes(const base::FilePath& mount_device,
const base::FilePath& mount_point);
// Adds |mount_device| to the mappings and notify listeners, if any.
void AddNewMount(const base::FilePath& mount_device,
std::unique_ptr<StorageInfo> storage_info);
// Mtab file that lists the mount points.
const base::FilePath mtab_path_;
// Callback to get device information. Set this to a custom callback for
// testing.
GetDeviceInfoCallback get_device_info_callback_;
// Mapping of relevant mount points and their corresponding mount devices.
// Keep in mind on Linux, a device can be mounted at multiple mount points,
// and multiple devices can be mounted at a mount point.
MountMap mount_info_map_;
// Because a device can be mounted to multiple places, we only want to
// notify about one of them. If (and only if) that one is unmounted, we need
// to notify about it's departure and notify about another one of it's mount
// points.
MountPriorityMap mount_priority_map_;
// Must be created and destroyed on |mtab_watcher_task_runner_|.
std::unique_ptr<MtabWatcherLinux> mtab_watcher_;
scoped_refptr<base::SequencedTaskRunner> mtab_watcher_task_runner_;
base::WeakPtrFactory<StorageMonitorLinux> weak_ptr_factory_;
} // namespace storage_monitor