src/traced/probes/filesystem/inode_file_data_source.cc - third_party/perfetto - Git at Google

 /*
  * Copyright (C) 2018 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "src/traced/probes/filesystem/inode_file_data_source.h"

 #include <dirent.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <queue>
 #include <unordered_map>

 #include "perfetto/base/logging.h"
 #include "perfetto/base/scoped_file.h"
 #include "perfetto/tracing/core/trace_packet.h"
 #include "perfetto/tracing/core/trace_writer.h"

 #include "perfetto/trace/trace_packet.pbzero.h"

 namespace perfetto {

 void ScanFilesDFS(
     const std::string& root_directory,
     const std::function<bool(BlockDeviceID block_device_id,
                              Inode inode_number,
                              const std::string& path,
                              protos::pbzero::InodeFileMap_Entry_Type type)>&
         fn) {
   std::vector<std::string> queue{root_directory};
   while (!queue.empty()) {
     struct dirent* entry;
     std::string directory = queue.back();
     queue.pop_back();
     base::ScopedDir dir(opendir(directory.c_str()));
     directory += "/";
     if (!dir)
       continue;

     struct stat buf;
     if (lstat(directory.c_str(), &buf) != 0) {
       PERFETTO_DPLOG("lstat %s", directory.c_str());
       continue;
     }
     if (S_ISLNK(buf.st_mode))
       continue;

     BlockDeviceID block_device_id = buf.st_dev;

     while ((entry = readdir(dir.get())) != nullptr) {
       std::string filename = entry->d_name;
       if (filename == "." || filename == "..")
         continue;
       std::string filepath = directory + filename;

       Inode inode_number = entry->d_ino;

       protos::pbzero::InodeFileMap_Entry_Type type =
           protos::pbzero::InodeFileMap_Entry_Type_UNKNOWN;
       // Readdir and stat not guaranteed to have directory info for all systems
       if (entry->d_type == DT_DIR) {
         // Continue iterating through files if current entry is a directory
         queue.push_back(filepath);
         type = protos::pbzero::InodeFileMap_Entry_Type_DIRECTORY;
       } else if (entry->d_type == DT_REG) {
         type = protos::pbzero::InodeFileMap_Entry_Type_FILE;
       }

       if (!fn(block_device_id, inode_number, filepath, type))
         return;
     }
     if (errno != 0)
       PERFETTO_DPLOG("readdir %s", directory.c_str());
   }
 }

 void CreateStaticDeviceToInodeMap(
     const std::string& root_directory,
     std::map<BlockDeviceID, std::unordered_map<Inode, InodeMapValue>>*
         static_file_map) {
   ScanFilesDFS(root_directory,
                [static_file_map](BlockDeviceID block_device_id,
                                  Inode inode_number, const std::string& path,
                                  protos::pbzero::InodeFileMap_Entry_Type type) {
                  std::unordered_map<Inode, InodeMapValue>& inode_map =
                      (*static_file_map)[block_device_id];
                  inode_map[inode_number].SetType(type);
                  inode_map[inode_number].AddPath(path);
                  return true;
                });
 }

 void FillInodeEntry(InodeFileMap* destination,
                     Inode inode_number,
                     const InodeMapValue& inode_map_value) {
   auto* entry = destination->add_entries();
   entry->set_inode_number(inode_number);
   entry->set_type(inode_map_value.type());
   for (const auto& path : inode_map_value.paths())
     entry->add_paths(path.c_str());
 }

 InodeFileDataSource::InodeFileDataSource(
     TracingSessionID id,
     std::map<BlockDeviceID, std::unordered_map<Inode, InodeMapValue>>*
         static_file_map,
     LRUInodeCache* cache,
     std::unique_ptr<TraceWriter> writer)
     : session_id_(id),
       static_file_map_(static_file_map),
       cache_(cache),
       writer_(std::move(writer)),
       weak_factory_(this) {}

 void InodeFileDataSource::AddInodesFromFilesystemScan(
     const std::string& root_directory,
     BlockDeviceID provided_block_device_id,
     std::set<Inode>* inode_numbers,
     LRUInodeCache* cache,
     InodeFileMap* destination) {
   if (inode_numbers->empty())
     return;
   ScanFilesDFS(
       root_directory,
       [provided_block_device_id, inode_numbers, cache, destination](
           BlockDeviceID block_device_id, Inode inode_number,
           const std::string& path,
           protos::pbzero::InodeFileMap_Entry_Type type) {
         if (provided_block_device_id != block_device_id)
           return true;
         if (inode_numbers->find(inode_number) == inode_numbers->end())
           return true;
         std::pair<BlockDeviceID, Inode> key{block_device_id, inode_number};
         auto cur_val = cache->Get(key);
         if (cur_val != nullptr) {
           cur_val->AddPath(path);
           FillInodeEntry(destination, inode_number, *cur_val);
         } else {
           InodeMapValue new_val(InodeMapValue(type, {path}));
           cache->Insert(key, new_val);
           FillInodeEntry(destination, inode_number, new_val);
         }
         inode_numbers->erase(inode_number);
         if (inode_numbers->empty())
           return false;
         return true;
       });

   // Could not be found, just add the inode number
   if (inode_numbers->size() != 0)
     PERFETTO_DLOG("%zu inodes not found", inode_numbers->size());
   for (const auto& unresolved_inode : *inode_numbers) {
     auto* entry = destination->add_entries();
     entry->set_inode_number(unresolved_inode);
   }
 }

 void InodeFileDataSource::AddInodesFromStaticMap(BlockDeviceID block_device_id,
                                                  std::set<Inode>* inode_numbers,
                                                  InodeFileMap* destination) {
   // Check if block device id exists in static file map
   auto static_map_entry = static_file_map_->find(block_device_id);
   if (static_map_entry == static_file_map_->end())
     return;

   uint64_t system_found_count = 0;
   for (auto it = inode_numbers->begin(); it != inode_numbers->end();) {
     Inode inode_number = *it;
     // Check if inode number exists in static file map for given block device id
     auto inode_it = static_map_entry->second.find(inode_number);
     if (inode_it == static_map_entry->second.end()) {
       ++it;
       continue;
     }
     system_found_count++;
     it = inode_numbers->erase(it);
     FillInodeEntry(destination, inode_number, inode_it->second);
   }
   PERFETTO_DLOG("%" PRIu64 " inodes found in static file map",
                 system_found_count);
 }

 void InodeFileDataSource::AddInodesFromLRUCache(BlockDeviceID block_device_id,
                                                 std::set<Inode>* inode_numbers,
                                                 InodeFileMap* destination) {
   uint64_t cache_found_count = 0;
   for (auto it = inode_numbers->begin(); it != inode_numbers->end();) {
     Inode inode_number = *it;
     auto value = cache_->Get(std::make_pair(block_device_id, inode_number));
     if (value == nullptr) {
       ++it;
       continue;
     }
     cache_found_count++;
     it = inode_numbers->erase(it);
     FillInodeEntry(destination, inode_number, *value);
   }
   if (cache_found_count > 0)
     PERFETTO_DLOG("%" PRIu64 " inodes found in cache", cache_found_count);
 }

 void InodeFileDataSource::OnInodes(
     const std::vector<std::pair<Inode, BlockDeviceID>>& inodes) {
   if (mount_points_.empty()) {
     mount_points_ = ParseMounts();
   }
   // Group inodes from FtraceMetadata by block device
   std::map<BlockDeviceID, std::set<Inode>> inode_file_maps;
   for (const auto& inodes_pair : inodes) {
     Inode inode_number = inodes_pair.first;
     BlockDeviceID block_device_id = inodes_pair.second;
     inode_file_maps[block_device_id].emplace(inode_number);
   }
   PERFETTO_DLOG("Saw %zu block devices.", inode_file_maps.size());

   // Write a TracePacket with an InodeFileMap proto for each block device id
   for (const auto& inode_file_map_data : inode_file_maps) {
     BlockDeviceID block_device_id = inode_file_map_data.first;
     std::set<Inode> inode_numbers = inode_file_map_data.second;
     PERFETTO_DLOG("Saw %zu unique inode numbers.", inode_numbers.size());

     // New TracePacket for each InodeFileMap
     auto trace_packet = writer_->NewTracePacket();
     auto inode_file_map = trace_packet->set_inode_file_map();

     // Add block device id to InodeFileMap
     inode_file_map->set_block_device_id(block_device_id);

     // Add mount points to InodeFileMap
     auto range = mount_points_.equal_range(block_device_id);
     for (std::multimap<BlockDeviceID, std::string>::iterator it = range.first;
          it != range.second; ++it)
       inode_file_map->add_mount_points(it->second.c_str());

     // Add entries to InodeFileMap as inodes are found and resolved to their
     // paths/type
     AddInodesFromStaticMap(block_device_id, &inode_numbers, inode_file_map);
     AddInodesFromLRUCache(block_device_id, &inode_numbers, inode_file_map);
     // TODO(azappone): Make root directory a mount point
     std::string root_directory = "/data";
     AddInodesFromFilesystemScan(root_directory, block_device_id, &inode_numbers,
                                 cache_, inode_file_map);
     trace_packet->Finalize();
   }
 }

 base::WeakPtr<InodeFileDataSource> InodeFileDataSource::GetWeakPtr() const {
   return weak_factory_.GetWeakPtr();
 }

 }  // namespace perfetto
	/*
	* Copyright (C) 2018 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "src/traced/probes/filesystem/inode_file_data_source.h"

	#include <dirent.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <unistd.h>
	#include <queue>
	#include <unordered_map>

	#include "perfetto/base/logging.h"
	#include "perfetto/base/scoped_file.h"
	#include "perfetto/tracing/core/trace_packet.h"
	#include "perfetto/tracing/core/trace_writer.h"

	#include "perfetto/trace/trace_packet.pbzero.h"

	namespace perfetto {

	void ScanFilesDFS(
	const std::string& root_directory,
	const std::function<bool(BlockDeviceID block_device_id,
	Inode inode_number,
	const std::string& path,
	protos::pbzero::InodeFileMap_Entry_Type type)>&
	fn) {
	std::vector<std::string> queue{root_directory};
	while (!queue.empty()) {
	struct dirent* entry;
	std::string directory = queue.back();
	queue.pop_back();
	base::ScopedDir dir(opendir(directory.c_str()));
	directory += "/";
	if (!dir)
	continue;

	struct stat buf;
	if (lstat(directory.c_str(), &buf) != 0) {
	PERFETTO_DPLOG("lstat %s", directory.c_str());
	continue;
	}
	if (S_ISLNK(buf.st_mode))
	continue;

	BlockDeviceID block_device_id = buf.st_dev;

	while ((entry = readdir(dir.get())) != nullptr) {
	std::string filename = entry->d_name;
	if (filename == "." \|\| filename == "..")
	continue;
	std::string filepath = directory + filename;

	Inode inode_number = entry->d_ino;

	protos::pbzero::InodeFileMap_Entry_Type type =
	protos::pbzero::InodeFileMap_Entry_Type_UNKNOWN;
	// Readdir and stat not guaranteed to have directory info for all systems
	if (entry->d_type == DT_DIR) {
	// Continue iterating through files if current entry is a directory
	queue.push_back(filepath);
	type = protos::pbzero::InodeFileMap_Entry_Type_DIRECTORY;
	} else if (entry->d_type == DT_REG) {
	type = protos::pbzero::InodeFileMap_Entry_Type_FILE;
	}

	if (!fn(block_device_id, inode_number, filepath, type))
	return;
	}
	if (errno != 0)
	PERFETTO_DPLOG("readdir %s", directory.c_str());
	}
	}

	void CreateStaticDeviceToInodeMap(
	const std::string& root_directory,
	std::map<BlockDeviceID, std::unordered_map<Inode, InodeMapValue>>*
	static_file_map) {
	ScanFilesDFS(root_directory,
	[static_file_map](BlockDeviceID block_device_id,
	Inode inode_number, const std::string& path,
	protos::pbzero::InodeFileMap_Entry_Type type) {
	std::unordered_map<Inode, InodeMapValue>& inode_map =
	(*static_file_map)[block_device_id];
	inode_map[inode_number].SetType(type);
	inode_map[inode_number].AddPath(path);
	return true;
	});
	}

	void FillInodeEntry(InodeFileMap* destination,
	Inode inode_number,
	const InodeMapValue& inode_map_value) {
	auto* entry = destination->add_entries();
	entry->set_inode_number(inode_number);
	entry->set_type(inode_map_value.type());
	for (const auto& path : inode_map_value.paths())
	entry->add_paths(path.c_str());
	}

	InodeFileDataSource::InodeFileDataSource(
	TracingSessionID id,
	std::map<BlockDeviceID, std::unordered_map<Inode, InodeMapValue>>*
	static_file_map,
	LRUInodeCache* cache,
	std::unique_ptr<TraceWriter> writer)
	: session_id_(id),
	static_file_map_(static_file_map),
	cache_(cache),
	writer_(std::move(writer)),
	weak_factory_(this) {}

	void InodeFileDataSource::AddInodesFromFilesystemScan(
	const std::string& root_directory,
	BlockDeviceID provided_block_device_id,
	std::set<Inode>* inode_numbers,
	LRUInodeCache* cache,
	InodeFileMap* destination) {
	if (inode_numbers->empty())
	return;
	ScanFilesDFS(
	root_directory,
	[provided_block_device_id, inode_numbers, cache, destination](
	BlockDeviceID block_device_id, Inode inode_number,
	const std::string& path,
	protos::pbzero::InodeFileMap_Entry_Type type) {
	if (provided_block_device_id != block_device_id)
	return true;
	if (inode_numbers->find(inode_number) == inode_numbers->end())
	return true;
	std::pair<BlockDeviceID, Inode> key{block_device_id, inode_number};
	auto cur_val = cache->Get(key);
	if (cur_val != nullptr) {
	cur_val->AddPath(path);
	FillInodeEntry(destination, inode_number, *cur_val);
	} else {
	InodeMapValue new_val(InodeMapValue(type, {path}));
	cache->Insert(key, new_val);
	FillInodeEntry(destination, inode_number, new_val);
	}
	inode_numbers->erase(inode_number);
	if (inode_numbers->empty())
	return false;
	return true;
	});

	// Could not be found, just add the inode number
	if (inode_numbers->size() != 0)
	PERFETTO_DLOG("%zu inodes not found", inode_numbers->size());
	for (const auto& unresolved_inode : *inode_numbers) {
	auto* entry = destination->add_entries();
	entry->set_inode_number(unresolved_inode);
	}
	}

	void InodeFileDataSource::AddInodesFromStaticMap(BlockDeviceID block_device_id,
	std::set<Inode>* inode_numbers,
	InodeFileMap* destination) {
	// Check if block device id exists in static file map
	auto static_map_entry = static_file_map_->find(block_device_id);
	if (static_map_entry == static_file_map_->end())
	return;

	uint64_t system_found_count = 0;
	for (auto it = inode_numbers->begin(); it != inode_numbers->end();) {
	Inode inode_number = *it;
	// Check if inode number exists in static file map for given block device id
	auto inode_it = static_map_entry->second.find(inode_number);
	if (inode_it == static_map_entry->second.end()) {
	++it;
	continue;
	}
	system_found_count++;
	it = inode_numbers->erase(it);
	FillInodeEntry(destination, inode_number, inode_it->second);
	}
	PERFETTO_DLOG("%" PRIu64 " inodes found in static file map",
	system_found_count);
	}

	void InodeFileDataSource::AddInodesFromLRUCache(BlockDeviceID block_device_id,
	std::set<Inode>* inode_numbers,
	InodeFileMap* destination) {
	uint64_t cache_found_count = 0;
	for (auto it = inode_numbers->begin(); it != inode_numbers->end();) {
	Inode inode_number = *it;
	auto value = cache_->Get(std::make_pair(block_device_id, inode_number));
	if (value == nullptr) {
	++it;
	continue;
	}
	cache_found_count++;
	it = inode_numbers->erase(it);
	FillInodeEntry(destination, inode_number, *value);
	}
	if (cache_found_count > 0)
	PERFETTO_DLOG("%" PRIu64 " inodes found in cache", cache_found_count);
	}

	void InodeFileDataSource::OnInodes(
	const std::vector<std::pair<Inode, BlockDeviceID>>& inodes) {
	if (mount_points_.empty()) {
	mount_points_ = ParseMounts();
	}
	// Group inodes from FtraceMetadata by block device
	std::map<BlockDeviceID, std::set<Inode>> inode_file_maps;
	for (const auto& inodes_pair : inodes) {
	Inode inode_number = inodes_pair.first;
	BlockDeviceID block_device_id = inodes_pair.second;
	inode_file_maps[block_device_id].emplace(inode_number);
	}
	PERFETTO_DLOG("Saw %zu block devices.", inode_file_maps.size());

	// Write a TracePacket with an InodeFileMap proto for each block device id
	for (const auto& inode_file_map_data : inode_file_maps) {
	BlockDeviceID block_device_id = inode_file_map_data.first;
	std::set<Inode> inode_numbers = inode_file_map_data.second;
	PERFETTO_DLOG("Saw %zu unique inode numbers.", inode_numbers.size());

	// New TracePacket for each InodeFileMap
	auto trace_packet = writer_->NewTracePacket();
	auto inode_file_map = trace_packet->set_inode_file_map();

	// Add block device id to InodeFileMap
	inode_file_map->set_block_device_id(block_device_id);

	// Add mount points to InodeFileMap
	auto range = mount_points_.equal_range(block_device_id);
	for (std::multimap<BlockDeviceID, std::string>::iterator it = range.first;
	it != range.second; ++it)
	inode_file_map->add_mount_points(it->second.c_str());

	// Add entries to InodeFileMap as inodes are found and resolved to their
	// paths/type
	AddInodesFromStaticMap(block_device_id, &inode_numbers, inode_file_map);
	AddInodesFromLRUCache(block_device_id, &inode_numbers, inode_file_map);
	// TODO(azappone): Make root directory a mount point
	std::string root_directory = "/data";
	AddInodesFromFilesystemScan(root_directory, block_device_id, &inode_numbers,
	cache_, inode_file_map);
	trace_packet->Finalize();
	}
	}

	base::WeakPtr<InodeFileDataSource> InodeFileDataSource::GetWeakPtr() const {
	return weak_factory_.GetWeakPtr();
	}

	} // namespace perfetto