chrome/browser/chromeos/drive/file_cache.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/chromeos/drive/file_cache.h"
   6
   7 #include <vector>
   8
   9 #include "base/callback_helpers.h"
  10 #include "base/files/file_enumerator.h"
  11 #include "base/files/file_util.h"
  12 #include "base/logging.h"
  13 #include "base/metrics/histogram.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/strings/stringprintf.h"
  16 #include "base/sys_info.h"
  17 #include "chrome/browser/chromeos/drive/drive.pb.h"
  18 #include "chrome/browser/chromeos/drive/file_system_util.h"
  19 #include "chrome/browser/chromeos/drive/resource_metadata_storage.h"
  20 #include "chrome/browser/drive/drive_api_util.h"
  21 #include "chromeos/chromeos_constants.h"
  22 #include "content/public/browser/browser_thread.h"
  23 #include "google_apis/drive/task_util.h"
  24 #include "net/base/filename_util.h"
  25 #include "net/base/mime_sniffer.h"
  26 #include "net/base/mime_util.h"
  27 #include "third_party/cros_system_api/constants/cryptohome.h"
  28
  29 using content::BrowserThread;
  30
  31 namespace drive {
  32 namespace internal {
  33 namespace {
  34
  35 // Returns ID extracted from the path.
  36 std::string GetIdFromPath(const base::FilePath& path) {
  37   return util::UnescapeCacheFileName(path.BaseName().AsUTF8Unsafe());
  38 }
  39
  40 }  // namespace
  41
  42 FileCache::FileCache(ResourceMetadataStorage* storage,
  43                      const base::FilePath& cache_file_directory,
  44                      base::SequencedTaskRunner* blocking_task_runner,
  45                      FreeDiskSpaceGetterInterface* free_disk_space_getter)
  46     : cache_file_directory_(cache_file_directory),
  47       blocking_task_runner_(blocking_task_runner),
  48       storage_(storage),
  49       free_disk_space_getter_(free_disk_space_getter),
  50       weak_ptr_factory_(this) {
  51   DCHECK(blocking_task_runner_.get());
  52   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  53 }
  54
  55 FileCache::~FileCache() {
  56   // Must be on the sequenced worker pool, as |metadata_| must be deleted on
  57   // the sequenced worker pool.
  58   AssertOnSequencedWorkerPool();
  59 }
  60
  61 base::FilePath FileCache::GetCacheFilePath(const std::string& id) const {
  62   return cache_file_directory_.Append(
  63       base::FilePath::FromUTF8Unsafe(util::EscapeCacheFileName(id)));
  64 }
  65
  66 void FileCache::AssertOnSequencedWorkerPool() {
  67   DCHECK(blocking_task_runner_->RunsTasksOnCurrentThread());
  68 }
  69
  70 bool FileCache::IsUnderFileCacheDirectory(const base::FilePath& path) const {
  71   return cache_file_directory_.IsParent(path);
  72 }
  73
  74 bool FileCache::FreeDiskSpaceIfNeededFor(int64 num_bytes) {
  75   AssertOnSequencedWorkerPool();
  76
  77   // Do nothing and return if we have enough space.
  78   if (HasEnoughSpaceFor(num_bytes, cache_file_directory_))
  79     return true;
  80
  81   // Otherwise, try to free up the disk space.
  82   DVLOG(1) << "Freeing up disk space for " << num_bytes;
  83
  84   // Remove all entries unless specially marked.
  85   scoped_ptr<ResourceMetadataStorage::Iterator> it = storage_->GetIterator();
  86   for (; !it->IsAtEnd(); it->Advance()) {
  87     if (it->GetValue().file_specific_info().has_cache_state() &&
  88         !it->GetValue().file_specific_info().cache_state().is_pinned() &&
  89         !it->GetValue().file_specific_info().cache_state().is_dirty() &&
  90         !mounted_files_.count(it->GetID())) {
  91       ResourceEntry entry(it->GetValue());
  92       entry.mutable_file_specific_info()->clear_cache_state();
  93       storage_->PutEntry(entry);
  94     }
  95   }
  96   if (it->HasError())
  97     return false;
  98
  99   // Remove all files which have no corresponding cache entries.
 100   base::FileEnumerator enumerator(cache_file_directory_,
 101                                   false,  // not recursive
 102                                   base::FileEnumerator::FILES);
 103   ResourceEntry entry;
 104   for (base::FilePath current = enumerator.Next(); !current.empty();
 105        current = enumerator.Next()) {
 106     std::string id = GetIdFromPath(current);
 107     FileError error = storage_->GetEntry(id, &entry);
 108     if (error == FILE_ERROR_NOT_FOUND ||
 109         (error == FILE_ERROR_OK &&
 110          !entry.file_specific_info().cache_state().is_present()))
 111       base::DeleteFile(current, false /* recursive */);
 112     else if (error != FILE_ERROR_OK)
 113       return false;
 114   }
 115
 116   // Check the disk space again.
 117   return HasEnoughSpaceFor(num_bytes, cache_file_directory_);
 118 }
 119
 120 FileError FileCache::GetFile(const std::string& id,
 121                              base::FilePath* cache_file_path) {
 122   AssertOnSequencedWorkerPool();
 123   DCHECK(cache_file_path);
 124
 125   ResourceEntry entry;
 126   FileError error = storage_->GetEntry(id, &entry);
 127   if (error != FILE_ERROR_OK)
 128     return error;
 129   if (!entry.file_specific_info().cache_state().is_present())
 130     return FILE_ERROR_NOT_FOUND;
 131
 132   *cache_file_path = GetCacheFilePath(id);
 133   return FILE_ERROR_OK;
 134 }
 135
 136 FileError FileCache::Store(const std::string& id,
 137                            const std::string& md5,
 138                            const base::FilePath& source_path,
 139                            FileOperationType file_operation_type) {
 140   AssertOnSequencedWorkerPool();
 141
 142   ResourceEntry entry;
 143   FileError error = storage_->GetEntry(id, &entry);
 144   if (error != FILE_ERROR_OK)
 145     return error;
 146
 147   int64 file_size = 0;
 148   if (file_operation_type == FILE_OPERATION_COPY) {
 149     if (!base::GetFileSize(source_path, &file_size)) {
 150       LOG(WARNING) << "Couldn't get file size for: " << source_path.value();
 151       return FILE_ERROR_FAILED;
 152     }
 153   }
 154   if (!FreeDiskSpaceIfNeededFor(file_size))
 155     return FILE_ERROR_NO_LOCAL_SPACE;
 156
 157   // If file is mounted, return error.
 158   if (mounted_files_.count(id))
 159     return FILE_ERROR_IN_USE;
 160
 161   base::FilePath dest_path = GetCacheFilePath(id);
 162   bool success = false;
 163   switch (file_operation_type) {
 164     case FILE_OPERATION_MOVE:
 165       success = base::Move(source_path, dest_path);
 166       break;
 167     case FILE_OPERATION_COPY:
 168       success = base::CopyFile(source_path, dest_path);
 169       break;
 170     default:
 171       NOTREACHED();
 172   }
 173
 174   if (!success) {
 175     LOG(ERROR) << "Failed to store: "
 176                << "source_path = " << source_path.value() << ", "
 177                << "dest_path = " << dest_path.value() << ", "
 178                << "file_operation_type = " << file_operation_type;
 179     return FILE_ERROR_FAILED;
 180   }
 181
 182   // Now that file operations have completed, update metadata.
 183   FileCacheEntry* cache_state =
 184       entry.mutable_file_specific_info()->mutable_cache_state();
 185   cache_state->set_md5(md5);
 186   cache_state->set_is_present(true);
 187   if (md5.empty())
 188     cache_state->set_is_dirty(true);
 189   return storage_->PutEntry(entry);
 190 }
 191
 192 FileError FileCache::Pin(const std::string& id) {
 193   AssertOnSequencedWorkerPool();
 194
 195   ResourceEntry entry;
 196   FileError error = storage_->GetEntry(id, &entry);
 197   if (error != FILE_ERROR_OK)
 198     return error;
 199   entry.mutable_file_specific_info()->mutable_cache_state()->set_is_pinned(
 200       true);
 201   return storage_->PutEntry(entry);
 202 }
 203
 204 FileError FileCache::Unpin(const std::string& id) {
 205   AssertOnSequencedWorkerPool();
 206
 207   // Unpinning a file means its entry must exist in cache.
 208   ResourceEntry entry;
 209   FileError error = storage_->GetEntry(id, &entry);
 210   if (error != FILE_ERROR_OK)
 211     return error;
 212
 213   // Now that file operations have completed, update metadata.
 214   if (entry.file_specific_info().cache_state().is_present()) {
 215     entry.mutable_file_specific_info()->mutable_cache_state()->set_is_pinned(
 216         false);
 217   } else {
 218     // Remove the existing entry if we are unpinning a non-present file.
 219     entry.mutable_file_specific_info()->clear_cache_state();
 220   }
 221   error = storage_->PutEntry(entry);
 222   if (error != FILE_ERROR_OK)
 223     return error;
 224
 225   // Now it's a chance to free up space if needed.
 226   FreeDiskSpaceIfNeededFor(0);
 227
 228   return FILE_ERROR_OK;
 229 }
 230
 231 FileError FileCache::MarkAsMounted(const std::string& id,
 232                                    base::FilePath* cache_file_path) {
 233   AssertOnSequencedWorkerPool();
 234   DCHECK(cache_file_path);
 235
 236   // Get cache entry associated with the id and md5
 237   ResourceEntry entry;
 238   FileError error = storage_->GetEntry(id, &entry);
 239   if (error != FILE_ERROR_OK)
 240     return error;
 241   if (!entry.file_specific_info().cache_state().is_present())
 242     return FILE_ERROR_NOT_FOUND;
 243
 244   if (mounted_files_.count(id))
 245     return FILE_ERROR_INVALID_OPERATION;
 246
 247   // Ensure the file is readable to cros_disks. See crbug.com/236994.
 248   base::FilePath path = GetCacheFilePath(id);
 249   if (!base::SetPosixFilePermissions(
 250           path,
 251           base::FILE_PERMISSION_READ_BY_USER |
 252           base::FILE_PERMISSION_WRITE_BY_USER |
 253           base::FILE_PERMISSION_READ_BY_GROUP |
 254           base::FILE_PERMISSION_READ_BY_OTHERS))
 255     return FILE_ERROR_FAILED;
 256
 257   mounted_files_.insert(id);
 258
 259   *cache_file_path = path;
 260   return FILE_ERROR_OK;
 261 }
 262
 263 FileError FileCache::OpenForWrite(
 264     const std::string& id,
 265     scoped_ptr<base::ScopedClosureRunner>* file_closer) {
 266   AssertOnSequencedWorkerPool();
 267
 268   // Marking a file dirty means its entry and actual file blob must exist in
 269   // cache.
 270   ResourceEntry entry;
 271   FileError error = storage_->GetEntry(id, &entry);
 272   if (error != FILE_ERROR_OK)
 273     return error;
 274   if (!entry.file_specific_info().cache_state().is_present()) {
 275     LOG(WARNING) << "Can't mark dirty a file that wasn't cached: " << id;
 276     return FILE_ERROR_NOT_FOUND;
 277   }
 278
 279   entry.mutable_file_specific_info()->mutable_cache_state()->set_is_dirty(true);
 280   entry.mutable_file_specific_info()->mutable_cache_state()->clear_md5();
 281   error = storage_->PutEntry(entry);
 282   if (error != FILE_ERROR_OK)
 283     return error;
 284
 285   write_opened_files_[id]++;
 286   file_closer->reset(new base::ScopedClosureRunner(
 287       base::Bind(&google_apis::RunTaskWithTaskRunner,
 288                  blocking_task_runner_,
 289                  base::Bind(&FileCache::CloseForWrite,
 290                             weak_ptr_factory_.GetWeakPtr(),
 291                             id))));
 292   return FILE_ERROR_OK;
 293 }
 294
 295 bool FileCache::IsOpenedForWrite(const std::string& id) {
 296   AssertOnSequencedWorkerPool();
 297   return write_opened_files_.count(id);
 298 }
 299
 300 FileError FileCache::UpdateMd5(const std::string& id) {
 301   AssertOnSequencedWorkerPool();
 302
 303   if (IsOpenedForWrite(id))
 304     return FILE_ERROR_IN_USE;
 305
 306   ResourceEntry entry;
 307   FileError error = storage_->GetEntry(id, &entry);
 308   if (error != FILE_ERROR_OK)
 309     return error;
 310   if (!entry.file_specific_info().cache_state().is_present())
 311     return FILE_ERROR_NOT_FOUND;
 312
 313   const std::string& md5 = util::GetMd5Digest(GetCacheFilePath(id));
 314   if (md5.empty())
 315     return FILE_ERROR_NOT_FOUND;
 316
 317   entry.mutable_file_specific_info()->mutable_cache_state()->set_md5(md5);
 318   return storage_->PutEntry(entry);
 319 }
 320
 321 FileError FileCache::ClearDirty(const std::string& id) {
 322   AssertOnSequencedWorkerPool();
 323
 324   if (IsOpenedForWrite(id))
 325     return FILE_ERROR_IN_USE;
 326
 327   // Clearing a dirty file means its entry and actual file blob must exist in
 328   // cache.
 329   ResourceEntry entry;
 330   FileError error = storage_->GetEntry(id, &entry);
 331   if (error != FILE_ERROR_OK)
 332     return error;
 333   if (!entry.file_specific_info().cache_state().is_present()) {
 334     LOG(WARNING) << "Can't clear dirty state of a file that wasn't cached: "
 335                  << id;
 336     return FILE_ERROR_NOT_FOUND;
 337   }
 338
 339   // If a file is not dirty (it should have been marked dirty via OpenForWrite),
 340   // clearing its dirty state is an invalid operation.
 341   if (!entry.file_specific_info().cache_state().is_dirty()) {
 342     LOG(WARNING) << "Can't clear dirty state of a non-dirty file: " << id;
 343     return FILE_ERROR_INVALID_OPERATION;
 344   }
 345
 346   entry.mutable_file_specific_info()->mutable_cache_state()->set_is_dirty(
 347       false);
 348   return storage_->PutEntry(entry);
 349 }
 350
 351 FileError FileCache::Remove(const std::string& id) {
 352   AssertOnSequencedWorkerPool();
 353
 354   ResourceEntry entry;
 355
 356   // If entry doesn't exist, nothing to do.
 357   FileError error = storage_->GetEntry(id, &entry);
 358   if (error == FILE_ERROR_NOT_FOUND)
 359     return FILE_ERROR_OK;
 360   if (error != FILE_ERROR_OK)
 361     return error;
 362   if (!entry.file_specific_info().has_cache_state())
 363     return FILE_ERROR_OK;
 364
 365   // Cannot delete a mounted file.
 366   if (mounted_files_.count(id))
 367     return FILE_ERROR_IN_USE;
 368
 369   // Delete the file.
 370   base::FilePath path = GetCacheFilePath(id);
 371   if (!base::DeleteFile(path, false /* recursive */))
 372     return FILE_ERROR_FAILED;
 373
 374   // Now that all file operations have completed, remove from metadata.
 375   entry.mutable_file_specific_info()->clear_cache_state();
 376   return storage_->PutEntry(entry);
 377 }
 378
 379 bool FileCache::ClearAll() {
 380   AssertOnSequencedWorkerPool();
 381
 382   // Remove files.
 383   base::FileEnumerator enumerator(cache_file_directory_,
 384                                   false,  // not recursive
 385                                   base::FileEnumerator::FILES);
 386   for (base::FilePath file = enumerator.Next(); !file.empty();
 387        file = enumerator.Next())
 388     base::DeleteFile(file, false /* recursive */);
 389
 390   return true;
 391 }
 392
 393 bool FileCache::Initialize() {
 394   AssertOnSequencedWorkerPool();
 395
 396   // Older versions do not clear MD5 when marking entries dirty.
 397   // Clear MD5 of all dirty entries to deal with old data.
 398   scoped_ptr<ResourceMetadataStorage::Iterator> it = storage_->GetIterator();
 399   for (; !it->IsAtEnd(); it->Advance()) {
 400     if (it->GetValue().file_specific_info().cache_state().is_dirty()) {
 401       ResourceEntry new_entry(it->GetValue());
 402       new_entry.mutable_file_specific_info()->mutable_cache_state()->
 403           clear_md5();
 404       if (storage_->PutEntry(new_entry) != FILE_ERROR_OK)
 405         return false;
 406     }
 407   }
 408   if (it->HasError())
 409     return false;
 410
 411   if (!RenameCacheFilesToNewFormat())
 412     return false;
 413   return true;
 414 }
 415
 416 void FileCache::Destroy() {
 417   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 418
 419   // Destroy myself on the blocking pool.
 420   // Note that base::DeletePointer<> cannot be used as the destructor of this
 421   // class is private.
 422   blocking_task_runner_->PostTask(
 423       FROM_HERE,
 424       base::Bind(&FileCache::DestroyOnBlockingPool, base::Unretained(this)));
 425 }
 426
 427 void FileCache::DestroyOnBlockingPool() {
 428   AssertOnSequencedWorkerPool();
 429   delete this;
 430 }
 431
 432 bool FileCache::RecoverFilesFromCacheDirectory(
 433     const base::FilePath& dest_directory,
 434     const ResourceMetadataStorage::RecoveredCacheInfoMap&
 435         recovered_cache_info) {
 436   int file_number = 1;
 437
 438   base::FileEnumerator enumerator(cache_file_directory_,
 439                                   false,  // not recursive
 440                                   base::FileEnumerator::FILES);
 441   for (base::FilePath current = enumerator.Next(); !current.empty();
 442        current = enumerator.Next()) {
 443     const std::string& id = GetIdFromPath(current);
 444     ResourceEntry entry;
 445     FileError error = storage_->GetEntry(id, &entry);
 446     if (error != FILE_ERROR_OK && error != FILE_ERROR_NOT_FOUND)
 447       return false;
 448     if (error == FILE_ERROR_OK &&
 449         entry.file_specific_info().cache_state().is_present()) {
 450       // This file is managed by FileCache, no need to recover it.
 451       continue;
 452     }
 453
 454     // If a cache entry which is non-dirty and has matching MD5 is found in
 455     // |recovered_cache_entries|, it means the current file is already uploaded
 456     // to the server. Just delete it instead of recovering it.
 457     ResourceMetadataStorage::RecoveredCacheInfoMap::const_iterator it =
 458         recovered_cache_info.find(id);
 459     if (it != recovered_cache_info.end()) {
 460       // Due to the DB corruption, cache info might be recovered from old
 461       // revision. Perform MD5 check even when is_dirty is false just in case.
 462       if (!it->second.is_dirty &&
 463           it->second.md5 == util::GetMd5Digest(current)) {
 464         base::DeleteFile(current, false /* recursive */);
 465         continue;
 466       }
 467     }
 468
 469     // Read file contents to sniff mime type.
 470     std::vector<char> content(net::kMaxBytesToSniff);
 471     const int read_result =
 472         base::ReadFile(current, &content[0], content.size());
 473     if (read_result < 0) {
 474       LOG(WARNING) << "Cannot read: " << current.value();
 475       return false;
 476     }
 477     if (read_result == 0)  // Skip empty files.
 478       continue;
 479
 480     // Use recovered file name if available, otherwise decide file name with
 481     // sniffed mime type.
 482     base::FilePath dest_base_name(FILE_PATH_LITERAL("file"));
 483     std::string mime_type;
 484     if (it != recovered_cache_info.end() && !it->second.title.empty()) {
 485       // We can use a file name recovered from the trashed DB.
 486       dest_base_name = base::FilePath::FromUTF8Unsafe(it->second.title);
 487     } else if (net::SniffMimeType(&content[0], read_result,
 488                                   net::FilePathToFileURL(current),
 489                                   std::string(), &mime_type) ||
 490                net::SniffMimeTypeFromLocalData(&content[0], read_result,
 491                                                &mime_type)) {
 492       // Change base name for common mime types.
 493       if (net::MatchesMimeType("image/*", mime_type)) {
 494         dest_base_name = base::FilePath(FILE_PATH_LITERAL("image"));
 495       } else if (net::MatchesMimeType("video/*", mime_type)) {
 496         dest_base_name = base::FilePath(FILE_PATH_LITERAL("video"));
 497       } else if (net::MatchesMimeType("audio/*", mime_type)) {
 498         dest_base_name = base::FilePath(FILE_PATH_LITERAL("audio"));
 499       }
 500
 501       // Estimate extension from mime type.
 502       std::vector<base::FilePath::StringType> extensions;
 503       base::FilePath::StringType extension;
 504       if (net::GetPreferredExtensionForMimeType(mime_type, &extension))
 505         extensions.push_back(extension);
 506       else
 507         net::GetExtensionsForMimeType(mime_type, &extensions);
 508
 509       // Add extension if possible.
 510       if (!extensions.empty())
 511         dest_base_name = dest_base_name.AddExtension(extensions[0]);
 512     }
 513
 514     // Add file number to the file name and move.
 515     const base::FilePath& dest_path = dest_directory.Append(dest_base_name)
 516         .InsertBeforeExtensionASCII(base::StringPrintf("%08d", file_number++));
 517     if (!base::CreateDirectory(dest_directory) ||
 518         !base::Move(current, dest_path)) {
 519       LOG(WARNING) << "Failed to move: " << current.value()
 520                    << " to " << dest_path.value();
 521       return false;
 522     }
 523   }
 524   UMA_HISTOGRAM_COUNTS("Drive.NumberOfCacheFilesRecoveredAfterDBCorruption",
 525                        file_number - 1);
 526   return true;
 527 }
 528
 529 FileError FileCache::MarkAsUnmounted(const base::FilePath& file_path) {
 530   AssertOnSequencedWorkerPool();
 531   DCHECK(IsUnderFileCacheDirectory(file_path));
 532
 533   std::string id = GetIdFromPath(file_path);
 534
 535   // Get the entry associated with the id.
 536   ResourceEntry entry;
 537   FileError error = storage_->GetEntry(id, &entry);
 538   if (error != FILE_ERROR_OK)
 539     return error;
 540
 541   std::set<std::string>::iterator it = mounted_files_.find(id);
 542   if (it == mounted_files_.end())
 543     return FILE_ERROR_INVALID_OPERATION;
 544
 545   mounted_files_.erase(it);
 546   return FILE_ERROR_OK;
 547 }
 548
 549 bool FileCache::HasEnoughSpaceFor(int64 num_bytes,
 550                                   const base::FilePath& path) {
 551   int64 free_space = 0;
 552   if (free_disk_space_getter_)
 553     free_space = free_disk_space_getter_->AmountOfFreeDiskSpace();
 554   else
 555     free_space = base::SysInfo::AmountOfFreeDiskSpace(path);
 556
 557   // Subtract this as if this portion does not exist.
 558   free_space -= cryptohome::kMinFreeSpaceInBytes;
 559   return (free_space >= num_bytes);
 560 }
 561
 562 bool FileCache::RenameCacheFilesToNewFormat() {
 563   base::FileEnumerator enumerator(cache_file_directory_,
 564                                   false,  // not recursive
 565                                   base::FileEnumerator::FILES);
 566   for (base::FilePath current = enumerator.Next(); !current.empty();
 567        current = enumerator.Next()) {
 568     base::FilePath new_path = current.RemoveExtension();
 569     if (!new_path.Extension().empty()) {
 570       // Delete files with multiple extensions.
 571       if (!base::DeleteFile(current, false /* recursive */))
 572         return false;
 573       continue;
 574     }
 575     const std::string& id = GetIdFromPath(new_path);
 576     new_path = GetCacheFilePath(util::CanonicalizeResourceId(id));
 577     if (new_path != current && !base::Move(current, new_path))
 578       return false;
 579   }
 580   return true;
 581 }
 582
 583 void FileCache::CloseForWrite(const std::string& id) {
 584   AssertOnSequencedWorkerPool();
 585
 586   std::map<std::string, int>::iterator it = write_opened_files_.find(id);
 587   if (it == write_opened_files_.end())
 588     return;
 589
 590   DCHECK_LT(0, it->second);
 591   --it->second;
 592   if (it->second == 0)
 593     write_opened_files_.erase(it);
 594
 595   // Update last modified date.
 596   ResourceEntry entry;
 597   FileError error = storage_->GetEntry(id, &entry);
 598   if (error != FILE_ERROR_OK) {
 599     LOG(ERROR) << "Failed to get entry: " << id << ", "
 600                << FileErrorToString(error);
 601     return;
 602   }
 603   entry.mutable_file_info()->set_last_modified(
 604       base::Time::Now().ToInternalValue());
 605   error = storage_->PutEntry(entry);
 606   if (error != FILE_ERROR_OK) {
 607     LOG(ERROR) << "Failed to put entry: " << id << ", "
 608                << FileErrorToString(error);
 609   }
 610 }
 611
 612 }  // namespace internal
 613 }  // namespace drive