[BlobStorage] Enabling disk paging and direct storage.

storage/browser/blob/blob_memory_controller.cc

 // Copyright 2016 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.
 
 #include "storage/browser/blob/blob_memory_controller.h"
 
 #include <algorithm>
 #include <numeric>
 
+#include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/containers/small_map.h"
 #include "base/files/file_util.h"
 #include "base/guid.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/numerics/safe_math.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/sys_info.h"
 #include "base/task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
-#include "base/tuple.h"
 #include "storage/browser/blob/blob_data_builder.h"
 #include "storage/browser/blob/blob_data_item.h"
 #include "storage/browser/blob/shareable_blob_data_item.h"
 #include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/common/data_element.h"
 
 using base::File;
 using base::FilePath;
 
 namespace storage {
 namespace {
+const int64_t kUnknownDiskAvailability = -1ll;
+
 using FileCreationInfo = BlobMemoryController::FileCreationInfo;
 using MemoryAllocation = BlobMemoryController::MemoryAllocation;
 using QuotaAllocationTask = BlobMemoryController::QuotaAllocationTask;
 
+// CrOS:

[pwnall, 2016/12/08 21:59:24]

Can you please add explanations of where (which media / disk partition) this
space resides, and note whether filling up the space would result in system
instability or not?

[dmurph, 2016/12/20 02:21:36]

Done.

+// * Ram -  20%
+// * Disk - 50%
+// Android:
+// * RAM -  20%
+// * Disk -  5%
+// Desktop:
+// * Ram -  20%, or 2 gigs if x64.
+// * Disk - 10%
+BlobStorageLimits CalculateBlobStorageLimitsImpl(const FilePath& storage_dir,
+                                                 bool disk_enabled) {
+  BlobStorageLimits output;
+
+  int64_t disk_size =
+      disk_enabled ? base::SysInfo::AmountOfTotalDiskSpace(storage_dir) : 0ull;
+  int64_t memory_size = base::SysInfo::AmountOfPhysicalMemory();
+
+  BlobStorageLimits limits;
+
+  if (memory_size > 0) {
+#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID) && defined(ARCH_CPU_64_BITS)
+    static const size_t kTwoGigabytes = 2ull * 1024 * 1024 * 1024;
+    limits.max_blob_in_memory_space = kTwoGigabytes;
+#else
+    limits.max_blob_in_memory_space = static_cast<size_t>(memory_size / 5ll);
+#endif
+  }
+
+  if (disk_size > 0) {
+#if defined(OS_CHROMEOS)
+    limits.max_blob_disk_space = static_cast<size_t>(disk_size / 2ll);
+#elif defined(OS_ANDROID)
+    limits.max_blob_disk_space = static_cast<size_t>(disk_size / 20ll);
+#else
+    limits.max_blob_disk_space = static_cast<size_t>(disk_size / 10ll);
+#endif
+  }
+
+  return limits;
+}
+
 File::Error CreateBlobDirectory(const FilePath& blob_storage_dir) {
   File::Error error = File::FILE_OK;
   base::CreateDirectoryAndGetError(blob_storage_dir, &error);
   UMA_HISTOGRAM_ENUMERATION("Storage.Blob.CreateDirectoryResult", -error,
                             -File::FILE_ERROR_MAX);
   DLOG_IF(ERROR, error != File::FILE_OK)
       << "Error creating blob storage directory: " << error;
   return error;
 }
 
 void DestructFile(File infos_without_references) {}
 
+void DeleteFiles(std::vector<FileCreationInfo> files) {
+  for (FileCreationInfo& file_info : files) {
+    file_info.file.Close();
+    base::DeleteFile(file_info.path, false);
+  }
+}
+
 // Used for new unpopulated file items. Caller must populate file reference in
-// returned FileCreationInfos.
-std::pair<std::vector<FileCreationInfo>, File::Error> CreateEmptyFiles(
-    const FilePath& blob_storage_dir,
-    scoped_refptr<base::TaskRunner> file_task_runner,
-    std::vector<base::FilePath> file_paths) {
+// returned FileCreationInfos. Also returns the current available disk space
+// (without the future size of these files).
+std::tuple<std::vector<FileCreationInfo>, File::Error, int64_t>
+CreateEmptyFiles(const FilePath& blob_storage_dir,
+                 scoped_refptr<base::TaskRunner> file_task_runner,
+                 std::vector<base::FilePath> file_paths) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   File::Error dir_create_status = CreateBlobDirectory(blob_storage_dir);
-  if (dir_create_status != File::FILE_OK)
-    return std::make_pair(std::vector<FileCreationInfo>(), dir_create_status);
+  if (dir_create_status != File::FILE_OK) {
+    return std::make_tuple(std::vector<FileCreationInfo>(), dir_create_status,
+                           kUnknownDiskAvailability);
+  }
+
+  int64_t free_disk_space =
+      base::SysInfo::AmountOfFreeDiskSpace(blob_storage_dir);
 
   std::vector<FileCreationInfo> result;
   for (const base::FilePath& file_path : file_paths) {
     FileCreationInfo creation_info;
     // Try to open our file.
     File file(file_path, File::FLAG_CREATE_ALWAYS | File::FLAG_WRITE);
     creation_info.path = std::move(file_path);
     creation_info.file_deletion_runner = file_task_runner;
     creation_info.error = file.error_details();
     if (creation_info.error != File::FILE_OK) {
-      return std::make_pair(std::vector<FileCreationInfo>(),
-                            creation_info.error);
+      return std::make_tuple(std::vector<FileCreationInfo>(),
+                             creation_info.error, free_disk_space);
     }
     creation_info.file = std::move(file);
 
     result.push_back(std::move(creation_info));
   }
-  return std::make_pair(std::move(result), File::FILE_OK);
+  return std::make_tuple(std::move(result), File::FILE_OK, free_disk_space);
 }
 
 // Used to evict multiple memory items out to a single file. Caller must
-// populate file reference in returned FileCreationInfo.
-FileCreationInfo CreateFileAndWriteItems(
+// populate file reference in returned FileCreationInfo. Also returns the disk
+// space AFTER creating this file.
+std::pair<FileCreationInfo, int64_t> CreateFileAndWriteItems(
     const FilePath& blob_storage_dir,
     const FilePath& file_path,
     scoped_refptr<base::TaskRunner> file_task_runner,
     std::vector<DataElement*> items,
     size_t total_size_bytes) {
   DCHECK_NE(0u, total_size_bytes);
   UMA_HISTOGRAM_MEMORY_KB("Storage.Blob.PageFileSize", total_size_bytes / 1024);
   base::ThreadRestrictions::AssertIOAllowed();
 
   FileCreationInfo creation_info;
   creation_info.file_deletion_runner = std::move(file_task_runner);
   creation_info.error = CreateBlobDirectory(blob_storage_dir);
   if (creation_info.error != File::FILE_OK)
-    return creation_info;
+    return std::make_pair(std::move(creation_info), kUnknownDiskAvailability);
+
+  int64_t free_disk_space =
+      base::SysInfo::AmountOfFreeDiskSpace(blob_storage_dir);
+
+  // Fail early instead of creating the files if we fill the disk.
+  if (free_disk_space != kUnknownDiskAvailability &&
+      free_disk_space < static_cast<int64_t>(total_size_bytes)) {
+    creation_info.error = File::FILE_ERROR_NO_SPACE;
+    return std::make_pair(std::move(creation_info), kUnknownDiskAvailability);

[michaeln, 2016/12/08 21:17:33]

why say 'unkwonwavail' here, we know what it is, why not let it thru

[dmurph, 2016/12/20 02:21:36]

Done.

+  }
+  int64_t disk_availability =
+      free_disk_space == kUnknownDiskAvailability
+          ? kUnknownDiskAvailability
+          : free_disk_space - static_cast<int64_t>(total_size_bytes);
 
   // Create the page file.
   File file(file_path, File::FLAG_CREATE_ALWAYS | File::FLAG_WRITE);
   creation_info.path = file_path;
   creation_info.error = file.error_details();
   if (creation_info.error != File::FILE_OK)
-    return creation_info;
+    return std::make_pair(std::move(creation_info), disk_availability);

[michaeln, 2016/12/08 21:17:33]

since we failed to create the file and won't be writing any data to disk, should
pair.second be actual |free_disk_space|?

[dmurph, 2016/12/20 02:21:36]

Done.

 
   // Write data.
   file.SetLength(total_size_bytes);
   int bytes_written = 0;
   for (DataElement* element : items) {
     DCHECK_EQ(DataElement::TYPE_BYTES, element->type());
     size_t length = base::checked_cast<size_t>(element->length());
     size_t bytes_left = length;
     while (bytes_left > 0) {
       bytes_written =
           file.WriteAtCurrentPos(element->bytes() + (length - bytes_left),
                                  base::saturated_cast<int>(bytes_left));
       if (bytes_written < 0)
         break;
       DCHECK_LE(static_cast<size_t>(bytes_written), bytes_left);
       bytes_left -= bytes_written;
     }
     if (bytes_written < 0)
       break;
   }
   if (!file.Flush()) {
     creation_info.error = File::FILE_ERROR_FAILED;
-    return creation_info;
+    return std::make_pair(std::move(creation_info), disk_availability);

[michaeln, 2016/12/08 21:17:33]

similar question about |free_disk| vs the locally adjusted number, but also
would it make sense to delete the borked file prior to return?

[dmurph, 2016/12/20 02:21:36]

Done.

   }
 
   File::Info info;
   bool success = file.GetInfo(&info);
   creation_info.error =
       bytes_written < 0 || !success ? File::FILE_ERROR_FAILED : File::FILE_OK;
   creation_info.last_modified = info.last_modified;
-  return creation_info;
+  return std::make_pair(std::move(creation_info), disk_availability);
 }
 
 uint64_t GetTotalSizeAndFileSizes(
     const std::vector<scoped_refptr<ShareableBlobDataItem>>&
         unreserved_file_items,
     std::vector<uint64_t>* file_sizes_output) {
   uint64_t total_size_output = 0;
   base::SmallMap<std::map<uint64_t, uint64_t>> file_id_to_sizes;
   for (const auto& item : unreserved_file_items) {
     const DataElement& element = item->item()->data_element();
@@ skipping 136 matching lines @@
           base::Bind(&BlobMemoryController::OnBlobFileDelete,
                      controller_->weak_factory_.GetWeakPtr(), file_sizes[i]));
     }
 
     // Send file creation task to file thread.
     base::PostTaskAndReplyWithResult(
         controller_->file_runner_.get(), FROM_HERE,
         base::Bind(&CreateEmptyFiles, controller_->blob_storage_dir_,
                    controller_->file_runner_, base::Passed(&file_paths)),
         base::Bind(&FileQuotaAllocationTask::OnCreateEmptyFiles,
-                   weak_factory_.GetWeakPtr(), base::Passed(&references)));
+                   weak_factory_.GetWeakPtr(), base::Passed(&references),
+                   allocation_size_));
     controller_->RecordTracingCounters();
   }
   ~FileQuotaAllocationTask() override {}
 
   void RunDoneCallback(std::vector<FileCreationInfo> file_info, bool success) {
     // Make sure we clear the weak pointers we gave to the caller beforehand.
     weak_factory_.InvalidateWeakPtrs();
 
     // We want to destroy this object on the exit of this method if we were
     // successful.
@@ skipping 14 matching lines @@
   }
 
   void Cancel() override {
     // This call destroys this object. We rely on ShareableFileReference's
     // final release callback for disk_usage_ accounting.
     controller_->pending_file_quota_tasks_.erase(my_list_position_);
   }
 
   void OnCreateEmptyFiles(
       std::vector<scoped_refptr<ShareableFileReference>> references,
-      std::pair<std::vector<FileCreationInfo>, File::Error> files_and_error) {
-    auto& files = files_and_error.first;
+      uint64_t new_files_total_size,
+      std::tuple<std::vector<FileCreationInfo>, File::Error, int64_t> result) {
+    std::vector<FileCreationInfo> files = std::move(std::get<0>(result));
+    File::Error error = std::get<1>(result);
+    int64_t avail_disk_space = std::get<2>(result);
     if (files.empty()) {
+      DCHECK_NE(error, File::FILE_OK);
       DCHECK_GE(controller_->disk_used_, allocation_size_);
       controller_->disk_used_ -= allocation_size_;
       // This will call our callback and delete the object correctly.
-      controller_->DisableFilePaging(files_and_error.second);
+      controller_->DisableFilePaging(error);
       return;
     }
+    // The allocation won't fit at all. Freeze the disk and cancel this request.
+    if (avail_disk_space != kUnknownDiskAvailability &&
+        base::checked_cast<uint64_t>(avail_disk_space) < new_files_total_size) {
+      DCHECK_GE(controller_->disk_used_, allocation_size_);
+      controller_->disk_used_ -= allocation_size_;
+      controller_->FreezeDiskUsage(static_cast<uint64_t>(avail_disk_space));
+      file_runner_->PostTask(FROM_HERE,
+                             base::Bind(&DeleteFiles, base::Passed(&files)));
+      std::unique_ptr<FileQuotaAllocationTask> this_object =
+          std::move(*my_list_position_);
+      controller_->pending_file_quota_tasks_.erase(my_list_position_);
+      RunDoneCallback(std::vector<FileCreationInfo>(), false);
+      return;
+    }
+    // Freeze disk if we're getting close.
+    if (avail_disk_space != kUnknownDiskAvailability &&
+        avail_disk_space - new_files_total_size <=
+            controller_->limits().min_available_disk_space()) {
+      controller_->FreezeDiskUsage(base::checked_cast<uint64_t>(
+          avail_disk_space - new_files_total_size));
+    }
     DCHECK_EQ(files.size(), references.size());
     for (size_t i = 0; i < files.size(); i++) {
       files[i].file_reference = std::move(references[i]);
     }
     RunDoneCallback(std::move(files), true);
   }
 
   // The my_list_position_ iterator is stored so that we can remove ourself
   // from the task list when we are cancelled.
   void set_my_list_position(
@@ skipping 58 matching lines @@
     uint64_t total_transportation_bytes) const {
   if (total_transportation_bytes == 0)
     return Strategy::NONE_NEEDED;
   if (!CanReserveQuota(total_transportation_bytes))
     return Strategy::TOO_LARGE;
 
   // Handle the case where we have all the bytes preemptively transported, and
   // we can also fit them.
   if (preemptive_transported_bytes == total_transportation_bytes &&
       pending_memory_quota_tasks_.empty() &&
-      preemptive_transported_bytes < GetAvailableMemoryForBlobs()) {
+      preemptive_transported_bytes <= GetAvailableMemoryForBlobs()) {
     return Strategy::NONE_NEEDED;
   }
   if (file_paging_enabled_ &&
-      (total_transportation_bytes > limits_.memory_limit_before_paging())) {
+      total_transportation_bytes <= GetAvailableFileSpaceForBlobs() &&
+      total_transportation_bytes > limits_.memory_limit_before_paging()) {
     return Strategy::FILE;
   }
   if (total_transportation_bytes > limits_.max_ipc_memory_size)
     return Strategy::SHARED_MEMORY;
   return Strategy::IPC;
 }
 
 bool BlobMemoryController::CanReserveQuota(uint64_t size) const {
   // We check each size independently as a blob can't be constructed in both
   // disk and memory.
@@ skipping 74 matching lines @@
     auto iterator = populated_memory_items_.Get(item->item_id());
     if (iterator == populated_memory_items_.end()) {
       populated_memory_items_bytes_ +=
           static_cast<size_t>(item->item()->length());
       populated_memory_items_.Put(item->item_id(), item.get());
     }
   }
   MaybeScheduleEvictionUntilSystemHealthy();
 }
 
+void BlobMemoryController::CalculateBlobStorageLimits() {
+  if (file_runner_) {
+    PostTaskAndReplyWithResult(
+        file_runner_.get(), FROM_HERE,
+        base::Bind(&CalculateBlobStorageLimitsImpl, blob_storage_dir_, true),
+        base::Bind(&BlobMemoryController::OnStorageLimitsCalculated,
+                   weak_factory_.GetWeakPtr()));
+  } else {
+    OnStorageLimitsCalculated(
+        CalculateBlobStorageLimitsImpl(blob_storage_dir_, false));
+  }
+}
+
+base::WeakPtr<BlobMemoryController> BlobMemoryController::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
+void BlobMemoryController::OnStorageLimitsCalculated(BlobStorageLimits limits) {
+  if (!limits.IsValid() || manual_limits_set_)
+    return;
+  limits_ = limits;
+}
+
+void BlobMemoryController::FreezeDiskUsage(uint64_t avail_disk) {

[michaeln, 2016/12/08 21:17:33]

Is "Freeze" a misnomer? If i'm understanding the CL properly the max_disk limit
is adjusted in light of the actual availability but additional disk space can
still be allocated, either when avail is not below the min_avail mark, or as
disk_used_ comes down.

If i'm getting it right, I think AdjustMaxDiskLimit(avail_disk) might be more
clear.

Also, when avail increases (say the user deletes a giant pile of non-blob junk
from disk), should max_disk restore itself to its larger nominally desired
value? In which case 'adjust' could mean decrease or increase.

limits_.desired_max_disk 
vs
limits_.effective_max_disk (taking availability into account)

[dmurph, 2016/12/20 02:21:36]

As per our offline discussion, this is a great idea. Changed.

+  limits_.max_blob_disk_space = disk_used_;
+  if (avail_disk > limits_.min_available_disk_space()) {
+    limits_.max_blob_disk_space +=
+        avail_disk - limits_.min_available_disk_space();
+  }
+}
+
 base::WeakPtr<QuotaAllocationTask> BlobMemoryController::AppendMemoryTask(
     uint64_t total_bytes_needed,
     std::vector<scoped_refptr<ShareableBlobDataItem>> unreserved_memory_items,
     const MemoryQuotaRequestCallback& done_callback) {
   DCHECK(file_paging_enabled_)
       << "Caller tried to reserve memory when CanReserveQuota("
       << total_bytes_needed << ") would have returned false.";
 
   pending_memory_quota_total_size_ += total_bytes_needed;
   pending_memory_quota_tasks_.push_back(
@@ skipping 38 matching lines @@
   return total_items_size.ValueOrDie();
 }
 
 void BlobMemoryController::MaybeScheduleEvictionUntilSystemHealthy() {
   // Don't do eviction when others are happening, as we don't change our
   // pending_memory_quota_total_size_ value until after the paging files have
   // been written.
   if (pending_evictions_ != 0 || !file_paging_enabled_)
     return;
 
+  uint64_t total_memory_usage =
+      static_cast<uint64_t>(pending_memory_quota_total_size_) +
+      blob_memory_used_;
+
   // We try to page items to disk until our current system size + requested
   // memory is below our size limit.
-  while (pending_memory_quota_total_size_ + blob_memory_used_ >
-         limits_.memory_limit_before_paging()) {
+  // Size limit is a lower |memory_limit_before_paging()| if we have disk space.
+  while (total_memory_usage > limits_.max_blob_disk_space ||
+         (disk_used_ < limits_.max_blob_disk_space &&
+          total_memory_usage > limits_.memory_limit_before_paging())) {
     // We only page when we have enough items to fill a whole page file.
     if (populated_memory_items_bytes_ < limits_.min_page_file_size)
       break;
     DCHECK_LE(limits_.min_page_file_size,
               static_cast<uint64_t>(blob_memory_used_));
 
     std::vector<scoped_refptr<ShareableBlobDataItem>> items_to_swap;
     size_t total_items_size = CollectItemsForEviction(&items_to_swap);
     if (total_items_size == 0)
       break;
@@ skipping 31 matching lines @@
                    weak_factory_.GetWeakPtr(), base::Passed(&file_reference),
                    base::Passed(&items_to_swap), total_items_size));
   }
   RecordTracingCounters();
 }
 
 void BlobMemoryController::OnEvictionComplete(
     scoped_refptr<ShareableFileReference> file_reference,
     std::vector<scoped_refptr<ShareableBlobDataItem>> items,
     size_t total_items_size,
-    FileCreationInfo result) {
+    std::pair<FileCreationInfo, int64_t> result) {
   if (!file_paging_enabled_)
     return;
 
-  if (result.error != File::FILE_OK) {
-    DisableFilePaging(result.error);
+  FileCreationInfo& file_info = std::get<0>(result);
+  int64_t avail_disk_space = std::get<1>(result);
+
+  if (file_info.error != File::FILE_OK) {
+    DisableFilePaging(file_info.error);
     return;
   }
 
+  if (avail_disk_space != kUnknownDiskAvailability &&
+      base::checked_cast<uint64_t>(avail_disk_space) <=
+          limits_.min_available_disk_space()) {
+    FreezeDiskUsage(static_cast<uint64_t>(avail_disk_space));
+  }
+
   DCHECK_LT(0, pending_evictions_);
   pending_evictions_--;
 
   // Switch item from memory to the new file.
   uint64_t offset = 0;
   for (const scoped_refptr<ShareableBlobDataItem>& shareable_item : items) {
     scoped_refptr<BlobDataItem> new_item(
         new BlobDataItem(base::WrapUnique(new DataElement()), file_reference));
     new_item->data_element_ptr()->SetToFilePathRange(
         file_reference->path(), offset, shareable_item->item()->length(),
-        result.last_modified);
+        file_info.last_modified);
     DCHECK(shareable_item->memory_allocation_);
     shareable_item->set_memory_allocation(nullptr);
     shareable_item->set_item(new_item);
     items_paging_to_file_.erase(shareable_item->item_id());
     offset += shareable_item->item()->length();
   }
   in_flight_memory_used_ -= total_items_size;
 
   // We want callback on blobs up to the amount we've freed.
   MaybeGrantPendingMemoryRequests();
@@ skipping 79 matching lines @@
   MaybeGrantPendingMemoryRequests();
 }
 
 void BlobMemoryController::OnBlobFileDelete(uint64_t size,
                                             const FilePath& path) {
   DCHECK_LE(size, disk_used_);
   disk_used_ -= size;
 }
 
 }  // namespace storage