nsresult
GetFileReferencesHelper::DispatchAndReturnFileReferences(int32_t* aMemRefCnt,
                                                         int32_t* aDBRefCnt,
                                                         int32_t* aSliceRefCnt,
                                                         bool* aResult)
{
  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");

  QuotaManager* quotaManager = QuotaManager::Get();
  NS_ASSERTION(quotaManager, "Shouldn't be null!");

  nsresult rv =
    quotaManager->IOThread()->Dispatch(this, NS_DISPATCH_NORMAL);
  NS_ENSURE_SUCCESS(rv, rv);

  mozilla::MutexAutoLock autolock(mMutex);
  while (mWaiting) {
    mCondVar.Wait();
  }

  *aMemRefCnt = mMemRefCnt;
  *aDBRefCnt = mDBRefCnt;
  *aSliceRefCnt = mSliceRefCnt;
  *aResult = mResult;

  return NS_OK;
}
Ejemplo n.º 2
0
nsresult
ParentRunnable::OpenCacheFileForWrite()
{
  AssertIsOnIOThread();
  MOZ_ASSERT(mState == eReadyToReadMetadata);
  MOZ_ASSERT(mOpenMode == eOpenForWrite);

  mFileSize = mWriteParams.mSize;

  // Kick out the oldest entry in the LRU queue in the metadata.
  mModuleIndex = mMetadata.mEntries[Metadata::kLastEntry].mModuleIndex;

  nsCOMPtr<nsIFile> file;
  nsresult rv = GetCacheFile(mDirectory, mModuleIndex, getter_AddRefs(file));
  NS_ENSURE_SUCCESS(rv, rv);

  QuotaManager* qm = QuotaManager::Get();
  MOZ_ASSERT(qm, "We are on the QuotaManager's IO thread");

  // Create the QuotaObject before all file IO and keep it alive until caching
  // completes to get maximum assertion coverage in QuotaManager against
  // concurrent removal, etc.
  mQuotaObject = qm->GetQuotaObject(quota::PERSISTENCE_TYPE_TEMPORARY, mGroup,
                                    mOrigin, file);
  NS_ENSURE_STATE(mQuotaObject);

  if (!mQuotaObject->MaybeUpdateSize(mWriteParams.mSize,
                                     /* aTruncate */ false)) {
    // If the request fails, it might be because mOrigin is using too much
    // space (MaybeUpdateSize will not evict our own origin since it is
    // active). Try to make some space by evicting LRU entries until there is
    // enough space.
    EvictEntries(mDirectory, mGroup, mOrigin, mWriteParams.mSize, mMetadata);
    if (!mQuotaObject->MaybeUpdateSize(mWriteParams.mSize,
                                       /* aTruncate */ false)) {
      mResult = JS::AsmJSCache_QuotaExceeded;
      return NS_ERROR_FAILURE;
    }
  }

  int32_t openFlags = PR_RDWR | PR_TRUNCATE | PR_CREATE_FILE;
  rv = file->OpenNSPRFileDesc(openFlags, 0644, &mFileDesc);
  NS_ENSURE_SUCCESS(rv, rv);

  // Move the mModuleIndex's LRU entry to the recent end of the queue.
  PodMove(mMetadata.mEntries + 1, mMetadata.mEntries, Metadata::kLastEntry);
  Metadata::Entry& entry = mMetadata.mEntries[0];
  entry.mFastHash = mWriteParams.mFastHash;
  entry.mNumChars = mWriteParams.mNumChars;
  entry.mFullHash = mWriteParams.mFullHash;
  entry.mModuleIndex = mModuleIndex;

  rv = WriteMetadataFile(mMetadataFile, mMetadata);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}
Ejemplo n.º 3
0
bool
QuotaObject::MaybeAllocateMoreSpace(int64_t aOffset, int32_t aCount)
{
  int64_t end = aOffset + aCount;

  QuotaManager* quotaManager = QuotaManager::Get();
  NS_ASSERTION(quotaManager, "Shouldn't be null!");

  MutexAutoLock lock(quotaManager->mQuotaMutex);

  if (mSize >= end || !mOriginInfo) {
    return true;
  }

  int64_t newUsage = mOriginInfo->mUsage - mSize + end;
  if (newUsage > mOriginInfo->mLimit) {
    // This will block the thread, but it will also drop the mutex while
    // waiting. The mutex will be reacquired again when the waiting is finished.
    if (!quotaManager->LockedQuotaIsLifted()) {
      return false;
    }

    // Threads raced, the origin info removal has been done by some other
    // thread.
    if (!mOriginInfo) {
      // The other thread could allocate more space.
      if (end > mSize) {
        mSize = end;
      }

      return true;
    }

    nsCString origin = mOriginInfo->mOrigin;

    mOriginInfo->LockedClearOriginInfos();
    NS_ASSERTION(!mOriginInfo,
                 "Should have cleared in LockedClearOriginInfos!");

    quotaManager->mOriginInfos.Remove(origin);

    // Some other thread could increase the size without blocking (increasing
    // the origin usage without hitting the limit), but no more than this one.
    NS_ASSERTION(mSize < end, "This shouldn't happen!");

    mSize = end;

    return true;
  }

  mOriginInfo->mUsage = newUsage;
  mSize = end;

  return true;
}
Ejemplo n.º 4
0
NS_IMETHODIMP
AbortOperationsRunnable::Run()
{
  AssertIsOnBackgroundThread();

  if (QuotaManager::IsShuttingDown()) {
    return NS_OK;
  }

  QuotaManager* quotaManager = QuotaManager::Get();
  if (!quotaManager) {
    return NS_OK;
  }

  quotaManager->AbortOperationsForProcess(mContentParentId);

  return NS_OK;
}
Ejemplo n.º 5
0
  void
  DispatchToIOThread()
  {
    AssertIsOnOwningThread();

    // If shutdown just started, the QuotaManager may have been deleted.
    QuotaManager* qm = QuotaManager::Get();
    if (!qm) {
      FailOnNonOwningThread();
      return;
    }

    nsresult rv = qm->IOThread()->Dispatch(this, NS_DISPATCH_NORMAL);
    if (NS_FAILED(rv)) {
      FailOnNonOwningThread();
      return;
    }
  }
Ejemplo n.º 6
0
nsresult
ParentRunnable::OpenCacheFileForRead()
{
  AssertIsOnIOThread();
  MOZ_ASSERT(mState == eReadyToOpenCacheFileForRead);
  MOZ_ASSERT(mOpenMode == eOpenForRead);

  nsCOMPtr<nsIFile> file;
  nsresult rv = GetCacheFile(mDirectory, mModuleIndex, getter_AddRefs(file));
  NS_ENSURE_SUCCESS(rv, rv);

  QuotaManager* qm = QuotaManager::Get();
  MOZ_ASSERT(qm, "We are on the QuotaManager's IO thread");

  // Even though it's not strictly necessary, create the QuotaObject before all
  // file IO and keep it alive until caching completes to get maximum assertion
  // coverage in QuotaManager against concurrent removal, etc.
  mQuotaObject = qm->GetQuotaObject(quota::PERSISTENCE_TYPE_TEMPORARY, mGroup,
                                    mOrigin, file);
  NS_ENSURE_STATE(mQuotaObject);

  rv = file->GetFileSize(&mFileSize);
  NS_ENSURE_SUCCESS(rv, rv);

  int32_t openFlags = PR_RDONLY | nsIFile::OS_READAHEAD;
  rv = file->OpenNSPRFileDesc(openFlags, 0644, &mFileDesc);
  NS_ENSURE_SUCCESS(rv, rv);

  // Move the mModuleIndex's LRU entry to the recent end of the queue.
  unsigned lruIndex = 0;
  while (mMetadata.mEntries[lruIndex].mModuleIndex != mModuleIndex) {
    if (++lruIndex == Metadata::kNumEntries) {
      return NS_ERROR_UNEXPECTED;
    }
  }
  Metadata::Entry entry = mMetadata.mEntries[lruIndex];
  PodMove(mMetadata.mEntries + 1, mMetadata.mEntries, lruIndex);
  mMetadata.mEntries[0] = entry;

  rv = WriteMetadataFile(mMetadataFile, mMetadata);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}
Ejemplo n.º 7
0
nsresult
Client::GetDirectory(const nsACString& aOrigin, nsIFile** aDirectory)
{
  QuotaManager* quotaManager = QuotaManager::Get();
  NS_ASSERTION(quotaManager, "This should never fail!");

  nsCOMPtr<nsIFile> directory;
  nsresult rv =
    quotaManager->GetDirectoryForOrigin(aOrigin, getter_AddRefs(directory));
  NS_ENSURE_SUCCESS(rv, rv);

  NS_ASSERTION(directory, "What?");

  rv = directory->Append(NS_LITERAL_STRING(IDB_DIRECTORY_NAME));
  NS_ENSURE_SUCCESS(rv, rv);

  directory.forget(aDirectory);
  return NS_OK;
}
Ejemplo n.º 8
0
nsresult
FileQuotaStream<FileStreamBase>::DoOpen()
{
  QuotaManager* quotaManager = QuotaManager::Get();
  NS_ASSERTION(quotaManager, "Shouldn't be null!");

  NS_ASSERTION(!mQuotaObject, "Creating quota object more than once?");
  mQuotaObject = quotaManager->GetQuotaObject(mPersistenceType, mGroup, mOrigin,
    FileStreamBase::mOpenParams.localFile);

  nsresult rv = FileStreamBase::DoOpen();
  NS_ENSURE_SUCCESS(rv, rv);

  if (mQuotaObject && (FileStreamBase::mOpenParams.ioFlags & PR_TRUNCATE)) {
    mQuotaObject->MaybeUpdateSize(0, /* aTruncate */ true);
  }

  return NS_OK;
}
Ejemplo n.º 9
0
void
DeleteFilesRunnable::DirectoryLockAcquired(DirectoryLock* aLock)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(mState == State_DirectoryOpenPending);
  MOZ_ASSERT(!mDirectoryLock);

  mDirectoryLock = aLock;

  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  // Must set this before dispatching otherwise we will race with the IO thread
  mState = State_DatabaseWorkOpen;

  nsresult rv = quotaManager->IOThread()->Dispatch(this, NS_DISPATCH_NORMAL);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    Finish();
    return;
  }
}
Ejemplo n.º 10
0
nsresult
DeleteFilesRunnable::Open()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(mState == State_Initial);

  QuotaManager* quotaManager = QuotaManager::Get();
  if (NS_WARN_IF(!quotaManager)) {
    return NS_ERROR_FAILURE;
  }

  mState = State_DirectoryOpenPending;

  quotaManager->OpenDirectory(mFileManager->Type(),
                              mFileManager->Group(),
                              mFileManager->Origin(),
                              mFileManager->IsApp(),
                              Client::IDB,
                              /* aExclusive */ false,
                              this);

  return NS_OK;
}
Ejemplo n.º 11
0
nsresult
DeleteFilesRunnable::DeleteFile(int64_t aFileId)
{
  MOZ_ASSERT(mDirectory);
  MOZ_ASSERT(mJournalDirectory);

  nsCOMPtr<nsIFile> file = mFileManager->GetFileForId(mDirectory, aFileId);
  NS_ENSURE_TRUE(file, NS_ERROR_FAILURE);

  nsresult rv;
  int64_t fileSize;

  if (mFileManager->EnforcingQuota()) {
    rv = file->GetFileSize(&fileSize);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
  }

  rv = file->Remove(false);
  NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

  if (mFileManager->EnforcingQuota()) {
    QuotaManager* quotaManager = QuotaManager::Get();
    NS_ASSERTION(quotaManager, "Shouldn't be null!");

    quotaManager->DecreaseUsageForOrigin(mFileManager->Type(),
                                         mFileManager->Group(),
                                         mFileManager->Origin(), fileSize);
  }

  file = mFileManager->GetFileForId(mJournalDirectory, aFileId);
  NS_ENSURE_TRUE(file, NS_ERROR_FAILURE);

  rv = file->Remove(false);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}
Ejemplo n.º 12
0
bool
QuotaObject::MaybeAllocateMoreSpace(int64_t aOffset, int32_t aCount)
{
  int64_t end = aOffset + aCount;

  QuotaManager* quotaManager = QuotaManager::Get();
  NS_ASSERTION(quotaManager, "Shouldn't be null!");

  MutexAutoLock lock(quotaManager->mQuotaMutex);

  if (mSize >= end || !mOriginInfo) {
    return true;
  }

  GroupInfo* groupInfo = mOriginInfo->mGroupInfo;

  if (groupInfo->IsForPersistentStorage()) {
    uint64_t newUsage = mOriginInfo->mUsage - mSize + end;

    if (newUsage > mOriginInfo->mLimit) {
      // This will block the thread, but it will also drop the mutex while
      // waiting. The mutex will be reacquired again when the waiting is
      // finished.
      if (!quotaManager->LockedQuotaIsLifted()) {
        return false;
      }

      // Threads raced, the origin info removal has been done by some other
      // thread.
      if (!mOriginInfo) {
        // The other thread could allocate more space.
        if (end > mSize) {
          mSize = end;
        }

        return true;
      }

      nsCString group = mOriginInfo->mGroupInfo->mGroup;
      nsCString origin = mOriginInfo->mOrigin;

      mOriginInfo->LockedClearOriginInfos();
      NS_ASSERTION(!mOriginInfo,
                   "Should have cleared in LockedClearOriginInfos!");

      quotaManager->LockedRemoveQuotaForOrigin(PERSISTENCE_TYPE_PERSISTENT,
                                               group, origin);

      // Some other thread could increase the size without blocking (increasing
      // the origin usage without hitting the limit), but no more than this one.
      NS_ASSERTION(mSize < end, "This shouldn't happen!");

      mSize = end;

      return true;
    }

    mOriginInfo->mUsage = newUsage;

    groupInfo->mUsage = groupInfo->mUsage - mSize + end;

    mSize = end;

    return true;
  }

  NS_ASSERTION(groupInfo->mPersistenceType == PERSISTENCE_TYPE_TEMPORARY,
               "Huh?");

  uint64_t delta = end - mSize;

  uint64_t newUsage = mOriginInfo->mUsage + delta;

  // Temporary storage has no limit for origin usage (there's a group and the
  // global limit though).

  uint64_t newGroupUsage = groupInfo->mUsage + delta;

  // Temporary storage has a hard limit for group usage (20 % of the global
  // limit).
  if (newGroupUsage > quotaManager->GetGroupLimit()) {
    return false;
  }

  uint64_t newTemporaryStorageUsage = quotaManager->mTemporaryStorageUsage +
                                      delta;

  if (newTemporaryStorageUsage > quotaManager->mTemporaryStorageLimit) {
    // This will block the thread without holding the lock while waitting.

    nsAutoTArray<OriginInfo*, 10> originInfos;
    uint64_t sizeToBeFreed =
      quotaManager->LockedCollectOriginsForEviction(delta, originInfos);

    if (!sizeToBeFreed) {
      return false;
    }

    NS_ASSERTION(sizeToBeFreed >= delta, "Huh?");

    {
      MutexAutoUnlock autoUnlock(quotaManager->mQuotaMutex);

      for (uint32_t i = 0; i < originInfos.Length(); i++) {
        quotaManager->DeleteTemporaryFilesForOrigin(originInfos[i]->mOrigin);
      }
    }

    // Relocked.

    NS_ASSERTION(mOriginInfo, "How come?!");

    nsTArray<nsCString> origins;
    for (uint32_t i = 0; i < originInfos.Length(); i++) {
      OriginInfo* originInfo = originInfos[i];

      NS_ASSERTION(originInfo != mOriginInfo, "Deleted itself!");

      nsCString group = originInfo->mGroupInfo->mGroup;
      nsCString origin = originInfo->mOrigin;
      quotaManager->LockedRemoveQuotaForOrigin(PERSISTENCE_TYPE_TEMPORARY,
                                               group, origin);

#ifdef DEBUG
      originInfos[i] = nullptr;
#endif

      origins.AppendElement(origin);
    }

    // We unlocked and relocked several times so we need to recompute all the
    // essential variables and recheck the group limit.

    delta = end - mSize;

    newUsage = mOriginInfo->mUsage + delta;

    newGroupUsage = groupInfo->mUsage + delta;

    if (newGroupUsage > quotaManager->GetGroupLimit()) {
      // Unfortunately some other thread increased the group usage in the
      // meantime and we are not below the group limit anymore.

      // However, the origin eviction must be finalized in this case too.
      MutexAutoUnlock autoUnlock(quotaManager->mQuotaMutex);

      quotaManager->FinalizeOriginEviction(origins);

      return false;
    }

    newTemporaryStorageUsage = quotaManager->mTemporaryStorageUsage + delta;

    NS_ASSERTION(newTemporaryStorageUsage <=
                 quotaManager->mTemporaryStorageLimit, "How come?!");

    // Ok, we successfully freed enough space and the operation can continue
    // without throwing the quota error.

    mOriginInfo->mUsage = newUsage;
    groupInfo->mUsage = newGroupUsage;
    quotaManager->mTemporaryStorageUsage = newTemporaryStorageUsage;;

    // Some other thread could increase the size in the meantime, but no more
    // than this one.
    NS_ASSERTION(mSize < end, "This shouldn't happen!");
    mSize = end;

    // Finally, release IO thread only objects and allow next synchronized
    // ops for the evicted origins.
    MutexAutoUnlock autoUnlock(quotaManager->mQuotaMutex);

    quotaManager->FinalizeOriginEviction(origins);

    return true;
  }

  mOriginInfo->mUsage = newUsage;
  groupInfo->mUsage = newGroupUsage;
  quotaManager->mTemporaryStorageUsage = newTemporaryStorageUsage;

  mSize = end;

  return true;
}
Ejemplo n.º 13
0
bool
QuotaObject::MaybeUpdateSize(int64_t aSize, bool aTruncate)
{
  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  MutexAutoLock lock(quotaManager->mQuotaMutex);

  if (mSize == aSize) {
    return true;
  }

  if (!mOriginInfo) {
    mSize = aSize;
    return true;
  }

  GroupInfo* groupInfo = mOriginInfo->mGroupInfo;
  MOZ_ASSERT(groupInfo);

  if (mSize > aSize) {
    if (aTruncate) {
      const int64_t delta = mSize - aSize;

      AssertNoUnderflow(quotaManager->mTemporaryStorageUsage, delta);
      quotaManager->mTemporaryStorageUsage -= delta;

      AssertNoUnderflow(groupInfo->mUsage, delta);
      groupInfo->mUsage -= delta;

      AssertNoUnderflow(mOriginInfo->mUsage, delta);
      mOriginInfo->mUsage -= delta;

      mSize = aSize;
    }
    return true;
  }

  MOZ_ASSERT(mSize < aSize);

  nsRefPtr<GroupInfo> complementaryGroupInfo =
    groupInfo->mGroupInfoPair->LockedGetGroupInfo(
      ComplementaryPersistenceType(groupInfo->mPersistenceType));

  uint64_t delta = aSize - mSize;

  AssertNoOverflow(mOriginInfo->mUsage, delta);
  uint64_t newUsage = mOriginInfo->mUsage + delta;

  // Temporary storage has no limit for origin usage (there's a group and the
  // global limit though).

  AssertNoOverflow(groupInfo->mUsage, delta);
  uint64_t newGroupUsage = groupInfo->mUsage + delta;

  uint64_t groupUsage = groupInfo->mUsage;
  if (complementaryGroupInfo) {
    AssertNoOverflow(groupUsage, complementaryGroupInfo->mUsage);
    groupUsage += complementaryGroupInfo->mUsage;
  }

  // Temporary storage has a hard limit for group usage (20 % of the global
  // limit).
  AssertNoOverflow(groupUsage, delta);
  if (groupUsage + delta > quotaManager->GetGroupLimit()) {
    return false;
  }

  AssertNoOverflow(quotaManager->mTemporaryStorageUsage, delta);
  uint64_t newTemporaryStorageUsage = quotaManager->mTemporaryStorageUsage +
                                      delta;

  if (newTemporaryStorageUsage > quotaManager->mTemporaryStorageLimit) {
    // This will block the thread without holding the lock while waitting.

    nsAutoTArray<OriginInfo*, 10> originInfos;
    uint64_t sizeToBeFreed =
      quotaManager->LockedCollectOriginsForEviction(delta, originInfos);

    if (!sizeToBeFreed) {
      return false;
    }

    NS_ASSERTION(sizeToBeFreed >= delta, "Huh?");

    {
      MutexAutoUnlock autoUnlock(quotaManager->mQuotaMutex);

      for (uint32_t i = 0; i < originInfos.Length(); i++) {
        OriginInfo* originInfo = originInfos[i];

        quotaManager->DeleteFilesForOrigin(
                                       originInfo->mGroupInfo->mPersistenceType,
                                       originInfo->mOrigin);
      }
    }

    // Relocked.

    NS_ASSERTION(mOriginInfo, "How come?!");

    nsTArray<OriginParams> origins;
    for (uint32_t i = 0; i < originInfos.Length(); i++) {
      OriginInfo* originInfo = originInfos[i];

      NS_ASSERTION(originInfo != mOriginInfo, "Deleted itself!");

      PersistenceType persistenceType =
        originInfo->mGroupInfo->mPersistenceType;
      nsCString group = originInfo->mGroupInfo->mGroup;
      nsCString origin = originInfo->mOrigin;
      bool isApp = originInfo->mIsApp;
      quotaManager->LockedRemoveQuotaForOrigin(persistenceType, group, origin);

#ifdef DEBUG
      originInfos[i] = nullptr;
#endif

      origins.AppendElement(OriginParams(persistenceType, origin, isApp));
    }

    // We unlocked and relocked several times so we need to recompute all the
    // essential variables and recheck the group limit.

    AssertNoUnderflow(aSize, mSize);
    delta = aSize - mSize;

    AssertNoOverflow(mOriginInfo->mUsage, delta);
    newUsage = mOriginInfo->mUsage + delta;

    AssertNoOverflow(groupInfo->mUsage, delta);
    newGroupUsage = groupInfo->mUsage + delta;

    groupUsage = groupInfo->mUsage;
    if (complementaryGroupInfo) {
      AssertNoOverflow(groupUsage, complementaryGroupInfo->mUsage);
      groupUsage += complementaryGroupInfo->mUsage;
    }

    AssertNoOverflow(groupUsage, delta);
    if (groupUsage + delta > quotaManager->GetGroupLimit()) {
      // Unfortunately some other thread increased the group usage in the
      // meantime and we are not below the group limit anymore.

      // However, the origin eviction must be finalized in this case too.
      MutexAutoUnlock autoUnlock(quotaManager->mQuotaMutex);

      quotaManager->FinalizeOriginEviction(origins);

      return false;
    }

    AssertNoOverflow(quotaManager->mTemporaryStorageUsage, delta);
    newTemporaryStorageUsage = quotaManager->mTemporaryStorageUsage + delta;

    NS_ASSERTION(newTemporaryStorageUsage <=
                 quotaManager->mTemporaryStorageLimit, "How come?!");

    // Ok, we successfully freed enough space and the operation can continue
    // without throwing the quota error.
    mOriginInfo->mUsage = newUsage;
    groupInfo->mUsage = newGroupUsage;
    quotaManager->mTemporaryStorageUsage = newTemporaryStorageUsage;;

    // Some other thread could increase the size in the meantime, but no more
    // than this one.
    MOZ_ASSERT(mSize < aSize);
    mSize = aSize;

    // Finally, release IO thread only objects and allow next synchronized
    // ops for the evicted origins.
    MutexAutoUnlock autoUnlock(quotaManager->mQuotaMutex);

    quotaManager->FinalizeOriginEviction(origins);

    return true;
  }

  mOriginInfo->mUsage = newUsage;
  groupInfo->mUsage = newGroupUsage;
  quotaManager->mTemporaryStorageUsage = newTemporaryStorageUsage;

  mSize = aSize;

  return true;
}
Ejemplo n.º 14
0
nsresult
ParentRunnable::ReadMetadata()
{
  AssertIsOnIOThread();
  MOZ_ASSERT(mState == eReadyToReadMetadata);

  QuotaManager* qm = QuotaManager::Get();
  MOZ_ASSERT(qm, "We are on the QuotaManager's IO thread");

  nsresult rv =
    qm->EnsureOriginIsInitialized(quota::PERSISTENCE_TYPE_TEMPORARY, mSuffix,
                                  mGroup, mOrigin, getter_AddRefs(mDirectory));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    mResult = JS::AsmJSCache_StorageInitFailure;
    return rv;
  }

  rv = mDirectory->Append(NS_LITERAL_STRING(ASMJSCACHE_DIRECTORY_NAME));
  NS_ENSURE_SUCCESS(rv, rv);

  bool exists;
  rv = mDirectory->Exists(&exists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!exists) {
    rv = mDirectory->Create(nsIFile::DIRECTORY_TYPE, 0755);
    NS_ENSURE_SUCCESS(rv, rv);
  } else {
    DebugOnly<bool> isDirectory;
    MOZ_ASSERT(NS_SUCCEEDED(mDirectory->IsDirectory(&isDirectory)));
    MOZ_ASSERT(isDirectory, "Should have caught this earlier!");
  }

  rv = mDirectory->Clone(getter_AddRefs(mMetadataFile));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mMetadataFile->Append(NS_LITERAL_STRING(ASMJSCACHE_METADATA_FILE_NAME));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mMetadataFile->Exists(&exists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (exists && NS_FAILED(ReadMetadataFile(mMetadataFile, mMetadata))) {
    exists = false;
  }

  if (!exists) {
    // If we are reading, we can't possibly have a cache hit.
    if (mOpenMode == eOpenForRead) {
      return NS_ERROR_FILE_NOT_FOUND;
    }

    // Initialize Metadata with a valid empty state for the LRU cache.
    for (unsigned i = 0; i < Metadata::kNumEntries; i++) {
      Metadata::Entry& entry = mMetadata.mEntries[i];
      entry.mModuleIndex = i;
      entry.clear();
    }
  }

  return NS_OK;
}