src/storage/fshost/inspect-manager.cc - fuchsia - Git at Google

 // Copyright 2020 The Fuchsia 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 "inspect-manager.h"

 #include <lib/inspect/service/cpp/service.h>
 #include <sys/stat.h>

 #include <fs/service.h>

 namespace fio = ::llcpp::fuchsia::io;

 namespace devmgr {

 zx_status_t OpenNode(zx::unowned_channel root, const std::string& path, uint32_t mode,
                      zx::channel* result) {
   zx::channel dir_chan, server;
   zx_status_t status = zx::channel::create(0, &dir_chan, &server);
   if (status != ZX_OK) {
     return status;
   }

   fidl::StringView path_view(fidl::unowned_ptr(&path[0]), strlen(&path[0]));
   status = fio::Directory::Call::Open(std::move(root),
                                       fs::VnodeConnectionOptions::ReadOnly().ToIoV1Flags(), mode,
                                       std::move(path_view), std::move(server))
                .status();
   if (status != ZX_OK) {
     return status;
   }
   *result = std::move(dir_chan);
   return ZX_OK;
 }

 InspectManager::InspectManager() = default;
 InspectManager::~InspectManager() = default;

 fbl::RefPtr<fs::PseudoDir> InspectManager::Initialize(async_dispatcher* dispatcher) {
   auto diagnostics_dir = fbl::MakeRefCounted<fs::PseudoDir>();
   diagnostics_dir->AddEntry(
       fuchsia::inspect::Tree::Name_,
       fbl::MakeRefCounted<fs::Service>([connector = inspect::MakeTreeHandler(
                                             &inspector_, dispatcher)](zx::channel chan) mutable {
         connector(fidl::InterfaceRequest<fuchsia::inspect::Tree>(std::move(chan)));
         return ZX_OK;
       }));
   return diagnostics_dir;
 }

 void InspectManager::ServeStats(const std::string& name, fbl::RefPtr<fs::Vnode> root) {
   inspector_.GetRoot().CreateLazyNode(
       name + "_stats",
       [this, name = std::move(name), root = std::move(root)] {
         inspect::Inspector insp;
         zx::channel root_chan;
         zx_status_t status =
             devmgr::OpenNode(zx::unowned_channel(root->GetRemote()), "/", S_IFDIR, &root_chan);
         if (status != ZX_OK) {
           return fit::make_result_promise(fit::ok(std::move(insp)));
         }
         FillFileTreeSizes(std::move(root_chan), insp.GetRoot().CreateChild(name), &insp);
         FillStats(zx::unowned_channel(root->GetRemote()), &insp);
         return fit::make_result_promise(fit::ok(std::move(insp)));
       },
       &inspector_);
 }

 void InspectManager::FillStats(zx::unowned_channel dir_chan, inspect::Inspector* inspector) {
   auto result = fio::DirectoryAdmin::Call::QueryFilesystem(std::move(dir_chan));
   inspect::Node stats = inspector->GetRoot().CreateChild("stats");
   if (result.status() == ZX_OK) {
     fio::DirectoryAdmin::QueryFilesystemResponse* response = result.Unwrap();
     fio::FilesystemInfo* info = response->info.get();
     if (info != nullptr) {
       stats.CreateUint("total_bytes", info->total_bytes + info->free_shared_pool_bytes, inspector);
       stats.CreateUint("used_bytes", info->used_bytes, inspector);
     } else {
       stats.CreateString("error", "Query failed", inspector);
     }
   } else {
     stats.CreateString("error", "Query failed", inspector);
   }
   inspector->emplace(std::move(stats));
 }

 void InspectManager::FillFileTreeSizes(zx::channel current_dir, inspect::Node node,
                                        inspect::Inspector* inspector) {
   struct PendingDirectory {
     std::unique_ptr<DirectoryEntriesIterator> entries_iterator;
     inspect::Node node;
     size_t total_size;
   };

   // Keeps track of entries in the stack, the entry at N+1 will always be a child of the entry at N
   // to be able to update the parent `total_size` and propaget the sizes up. We use the lazy
   // iterator to have a single child connection at a time per node.
   std::vector<PendingDirectory> work_stack;
   auto current = PendingDirectory{
       .entries_iterator = std::make_unique<DirectoryEntriesIterator>(std::move(current_dir)),
       .node = std::move(node),
       .total_size = 0,
   };
   work_stack.push_back(std::move(current));

   while (!work_stack.empty()) {
     auto& current = work_stack.back();

     // If we have finished with this node then pop it from the stack, save it in inspect and
     // continue.
     if (current.entries_iterator->finished()) {
       // Maintain this node alive in inspect by adding it to the inspector value list and delete the
       // stack item.
       current.node.CreateUint("size", current.total_size, inspector);
       inspector->emplace(std::move(current.node));
       size_t size = current.total_size;

       work_stack.pop_back();

       // The next node in the stack is the parent of this node. Increment its size by the total size
       // of this node. If the work stack is emtpy, then `current` is the root.
       if (!work_stack.empty()) {
         work_stack.back().total_size += size;
       }

       continue;
     }

     // Get the next entry.
     while (auto entry = current.entries_iterator->GetNext()) {
       // If the entry is a directory, push it to the stack and continue the stack loop.
       if (entry->is_dir) {
         work_stack.push_back(PendingDirectory{
             .entries_iterator = std::make_unique<DirectoryEntriesIterator>(std::move(entry->node)),
             .node = current.node.CreateChild(entry->name),
             .total_size = 0,
         });
         break;
       } else {
         // If the entry is a file, record its size.
         inspect::Node child_node = current.node.CreateChild(entry->name);
         child_node.CreateUint("size", entry->size, inspector);
         inspector->emplace(std::move(child_node));
         current.total_size += entry->size;
       }
     }
   }
 }

 // Create a new lazy iterator.
 DirectoryEntriesIterator::DirectoryEntriesIterator(zx::channel directory)
     : directory_(std::move(directory)), finished_(false) {}

 // Get the next entry. If there's no more entries left, this method will return std::nullopt
 // forever.
 std::optional<DirectoryEntry> DirectoryEntriesIterator::GetNext() {
   // Loop until we can return an entry or there are none left.
   while (true) {
     // If we have pending entries to return, take one and return it. If for some reason, we fail
     // to make a result out of the pending entry (it may not exist anymore) then keep trying until
     // we can return one.
     while (!pending_entries_.empty()) {
       auto entry_name = pending_entries_.front();
       pending_entries_.pop();
       if (auto result = MaybeMakeEntry(entry_name)) {
         return result;
       }
     }

     // When there are no pending entries and we have already finished, return.
     if (finished_) {
       return std::nullopt;
     }

     // Load the next set of dirents.
     RefreshPendingEntries();

     // If we didn't find any pending entries in this batch of dirents, then we have finished.
     if (pending_entries_.empty()) {
       finished_ = true;
       return std::nullopt;
     }
   }
 }

 std::optional<DirectoryEntry> DirectoryEntriesIterator::MaybeMakeEntry(
     const std::string& entry_name) {
   // Open child of the current node with the given entry name.
   zx::channel child_chan;
   zx_status_t status =
       OpenNode(zx::unowned_channel(directory_), entry_name, S_IFREG | S_IFDIR, &child_chan);
   if (status != ZX_OK) {
     return std::nullopt;
   }

   // Get child attributes to know whether the child is a directory or not.
   auto result = fio::Directory::Call::GetAttr(zx::unowned_channel(child_chan));
   if (result.status() != ZX_OK) {
     return std::nullopt;
   }
   fio::Directory::GetAttrResponse* response = result.Unwrap();

   bool is_dir = response->attributes.mode & fio::MODE_TYPE_DIRECTORY;
   return std::optional<DirectoryEntry>{{
       .name = entry_name,
       .node = std::move(child_chan),
       .size = (is_dir) ? 0 : response->attributes.content_size,
       .is_dir = is_dir,
   }};
 }

 // Reads the next set of dirents and loads them into `pending_entries_`.
 void DirectoryEntriesIterator::RefreshPendingEntries() {
   auto result = fio::Directory::Call::ReadDirents(zx::unowned_channel(directory_), fio::MAX_BUF);
   if (result.status() != ZX_OK) {
     return;
   }
   fio::Directory::ReadDirentsResponse* response = result.Unwrap();
   if (response->dirents.count() == 0) {
     return;
   }

   size_t offset = 0;
   auto data_ptr = response->dirents.data();

   while (sizeof(vdirent_t) < response->dirents.count() - offset) {
     const vdirent_t* entry = reinterpret_cast<const vdirent_t*>(data_ptr + offset);
     std::string entry_name(entry->name, entry->size);
     offset += sizeof(vdirent_t) + entry->size;
     if (entry_name == "." || entry_name == "..") {
       continue;
     }
     pending_entries_.push(std::move(entry_name));
   }
 }

 }  // namespace devmgr
	// Copyright 2020 The Fuchsia 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 "inspect-manager.h"

	#include <lib/inspect/service/cpp/service.h>
	#include <sys/stat.h>

	#include <fs/service.h>

	namespace fio = ::llcpp::fuchsia::io;

	namespace devmgr {

	zx_status_t OpenNode(zx::unowned_channel root, const std::string& path, uint32_t mode,
	zx::channel* result) {
	zx::channel dir_chan, server;
	zx_status_t status = zx::channel::create(0, &dir_chan, &server);
	if (status != ZX_OK) {
	return status;
	}

	fidl::StringView path_view(fidl::unowned_ptr(&path[0]), strlen(&path[0]));
	status = fio::Directory::Call::Open(std::move(root),
	fs::VnodeConnectionOptions::ReadOnly().ToIoV1Flags(), mode,
	std::move(path_view), std::move(server))
	.status();
	if (status != ZX_OK) {
	return status;
	}
	*result = std::move(dir_chan);
	return ZX_OK;
	}

	InspectManager::InspectManager() = default;
	InspectManager::~InspectManager() = default;

	fbl::RefPtr<fs::PseudoDir> InspectManager::Initialize(async_dispatcher* dispatcher) {
	auto diagnostics_dir = fbl::MakeRefCounted<fs::PseudoDir>();
	diagnostics_dir->AddEntry(
	fuchsia::inspect::Tree::Name_,
	fbl::MakeRefCounted<fs::Service>([connector = inspect::MakeTreeHandler(
	&inspector_, dispatcher)](zx::channel chan) mutable {
	connector(fidl::InterfaceRequest<fuchsia::inspect::Tree>(std::move(chan)));
	return ZX_OK;
	}));
	return diagnostics_dir;
	}

	void InspectManager::ServeStats(const std::string& name, fbl::RefPtr<fs::Vnode> root) {
	inspector_.GetRoot().CreateLazyNode(
	name + "_stats",
	[this, name = std::move(name), root = std::move(root)] {
	inspect::Inspector insp;
	zx::channel root_chan;
	zx_status_t status =
	devmgr::OpenNode(zx::unowned_channel(root->GetRemote()), "/", S_IFDIR, &root_chan);
	if (status != ZX_OK) {
	return fit::make_result_promise(fit::ok(std::move(insp)));
	}
	FillFileTreeSizes(std::move(root_chan), insp.GetRoot().CreateChild(name), &insp);
	FillStats(zx::unowned_channel(root->GetRemote()), &insp);
	return fit::make_result_promise(fit::ok(std::move(insp)));
	},
	&inspector_);
	}

	void InspectManager::FillStats(zx::unowned_channel dir_chan, inspect::Inspector* inspector) {
	auto result = fio::DirectoryAdmin::Call::QueryFilesystem(std::move(dir_chan));
	inspect::Node stats = inspector->GetRoot().CreateChild("stats");
	if (result.status() == ZX_OK) {
	fio::DirectoryAdmin::QueryFilesystemResponse* response = result.Unwrap();
	fio::FilesystemInfo* info = response->info.get();
	if (info != nullptr) {
	stats.CreateUint("total_bytes", info->total_bytes + info->free_shared_pool_bytes, inspector);
	stats.CreateUint("used_bytes", info->used_bytes, inspector);
	} else {
	stats.CreateString("error", "Query failed", inspector);
	}
	} else {
	stats.CreateString("error", "Query failed", inspector);
	}
	inspector->emplace(std::move(stats));
	}

	void InspectManager::FillFileTreeSizes(zx::channel current_dir, inspect::Node node,
	inspect::Inspector* inspector) {
	struct PendingDirectory {
	std::unique_ptr<DirectoryEntriesIterator> entries_iterator;
	inspect::Node node;
	size_t total_size;
	};

	// Keeps track of entries in the stack, the entry at N+1 will always be a child of the entry at N
	// to be able to update the parent `total_size` and propaget the sizes up. We use the lazy
	// iterator to have a single child connection at a time per node.
	std::vector<PendingDirectory> work_stack;
	auto current = PendingDirectory{
	.entries_iterator = std::make_unique<DirectoryEntriesIterator>(std::move(current_dir)),
	.node = std::move(node),
	.total_size = 0,
	};
	work_stack.push_back(std::move(current));

	while (!work_stack.empty()) {
	auto& current = work_stack.back();

	// If we have finished with this node then pop it from the stack, save it in inspect and
	// continue.
	if (current.entries_iterator->finished()) {
	// Maintain this node alive in inspect by adding it to the inspector value list and delete the
	// stack item.
	current.node.CreateUint("size", current.total_size, inspector);
	inspector->emplace(std::move(current.node));
	size_t size = current.total_size;

	work_stack.pop_back();

	// The next node in the stack is the parent of this node. Increment its size by the total size
	// of this node. If the work stack is emtpy, then `current` is the root.
	if (!work_stack.empty()) {
	work_stack.back().total_size += size;
	}

	continue;
	}

	// Get the next entry.
	while (auto entry = current.entries_iterator->GetNext()) {
	// If the entry is a directory, push it to the stack and continue the stack loop.
	if (entry->is_dir) {
	work_stack.push_back(PendingDirectory{
	.entries_iterator = std::make_unique<DirectoryEntriesIterator>(std::move(entry->node)),
	.node = current.node.CreateChild(entry->name),
	.total_size = 0,
	});
	break;
	} else {
	// If the entry is a file, record its size.
	inspect::Node child_node = current.node.CreateChild(entry->name);
	child_node.CreateUint("size", entry->size, inspector);
	inspector->emplace(std::move(child_node));
	current.total_size += entry->size;
	}
	}
	}
	}

	// Create a new lazy iterator.
	DirectoryEntriesIterator::DirectoryEntriesIterator(zx::channel directory)
	: directory_(std::move(directory)), finished_(false) {}

	// Get the next entry. If there's no more entries left, this method will return std::nullopt
	// forever.
	std::optional<DirectoryEntry> DirectoryEntriesIterator::GetNext() {
	// Loop until we can return an entry or there are none left.
	while (true) {
	// If we have pending entries to return, take one and return it. If for some reason, we fail
	// to make a result out of the pending entry (it may not exist anymore) then keep trying until
	// we can return one.
	while (!pending_entries_.empty()) {
	auto entry_name = pending_entries_.front();
	pending_entries_.pop();
	if (auto result = MaybeMakeEntry(entry_name)) {
	return result;
	}
	}

	// When there are no pending entries and we have already finished, return.
	if (finished_) {
	return std::nullopt;
	}

	// Load the next set of dirents.
	RefreshPendingEntries();

	// If we didn't find any pending entries in this batch of dirents, then we have finished.
	if (pending_entries_.empty()) {
	finished_ = true;
	return std::nullopt;
	}
	}
	}

	std::optional<DirectoryEntry> DirectoryEntriesIterator::MaybeMakeEntry(
	const std::string& entry_name) {
	// Open child of the current node with the given entry name.
	zx::channel child_chan;
	zx_status_t status =
	OpenNode(zx::unowned_channel(directory_), entry_name, S_IFREG \| S_IFDIR, &child_chan);
	if (status != ZX_OK) {
	return std::nullopt;
	}

	// Get child attributes to know whether the child is a directory or not.
	auto result = fio::Directory::Call::GetAttr(zx::unowned_channel(child_chan));
	if (result.status() != ZX_OK) {
	return std::nullopt;
	}
	fio::Directory::GetAttrResponse* response = result.Unwrap();

	bool is_dir = response->attributes.mode & fio::MODE_TYPE_DIRECTORY;
	return std::optional<DirectoryEntry>{{
	.name = entry_name,
	.node = std::move(child_chan),
	.size = (is_dir) ? 0 : response->attributes.content_size,
	.is_dir = is_dir,
	}};
	}

	// Reads the next set of dirents and loads them into `pending_entries_`.
	void DirectoryEntriesIterator::RefreshPendingEntries() {
	auto result = fio::Directory::Call::ReadDirents(zx::unowned_channel(directory_), fio::MAX_BUF);
	if (result.status() != ZX_OK) {
	return;
	}
	fio::Directory::ReadDirentsResponse* response = result.Unwrap();
	if (response->dirents.count() == 0) {
	return;
	}

	size_t offset = 0;
	auto data_ptr = response->dirents.data();

	while (sizeof(vdirent_t) < response->dirents.count() - offset) {
	const vdirent_t* entry = reinterpret_cast<const vdirent_t*>(data_ptr + offset);
	std::string entry_name(entry->name, entry->size);
	offset += sizeof(vdirent_t) + entry->size;
	if (entry_name == "." \|\| entry_name == "..") {
	continue;
	}
	pending_entries_.push(std::move(entry_name));
	}
	}

	} // namespace devmgr