6 files changed, 202 insertions, 371 deletions

diff --git a/src/core/hle/service/filesystem/fsp/fs_i_directory.cpp b/src/core/hle/service/filesystem/fsp/fs_i_directory.cpp
index 39690018b..8483394d0 100644
--- a/src/core/hle/service/filesystem/fsp/fs_i_directory.cpp
+++ b/src/core/hle/service/filesystem/fsp/fs_i_directory.cpp
@@ -3,82 +3,34 @@
 
 #include "core/file_sys/fs_filesystem.h"
 #include "core/file_sys/savedata_factory.h"
+#include "core/hle/service/cmif_serialization.h"
 #include "core/hle/service/filesystem/fsp/fs_i_directory.h"
-#include "core/hle/service/ipc_helpers.h"
 
 namespace Service::FileSystem {
 
-template <typename T>
-static void BuildEntryIndex(std::vector<FileSys::DirectoryEntry>& entries,
-                            const std::vector<T>& new_data, FileSys::DirectoryEntryType type) {
-    entries.reserve(entries.size() + new_data.size());
-
-    for (const auto& new_entry : new_data) {
-        auto name = new_entry->GetName();
-
-        if (type == FileSys::DirectoryEntryType::File &&
-            name == FileSys::GetSaveDataSizeFileName()) {
-            continue;
-        }
-
-        entries.emplace_back(name, static_cast<s8>(type),
-                             type == FileSys::DirectoryEntryType::Directory ? 0
-                                                                            : new_entry->GetSize());
-    }
-}
-
-IDirectory::IDirectory(Core::System& system_, FileSys::VirtualDir backend_,
+IDirectory::IDirectory(Core::System& system_, FileSys::VirtualDir directory_,
                        FileSys::OpenDirectoryMode mode)
-    : ServiceFramework{system_, "IDirectory"}, backend(std::move(backend_)) {
+    : ServiceFramework{system_, "IDirectory"},
+      backend(std::make_unique<FileSys::Fsa::IDirectory>(directory_, mode)) {
     static const FunctionInfo functions[] = {
-        {0, &IDirectory::Read, "Read"},
-        {1, &IDirectory::GetEntryCount, "GetEntryCount"},
+        {0, D<&IDirectory::Read>, "Read"},
+        {1, D<&IDirectory::GetEntryCount>, "GetEntryCount"},
     };
     RegisterHandlers(functions);
-
-    // TODO(DarkLordZach): Verify that this is the correct behavior.
-    // Build entry index now to save time later.
-    if (True(mode & FileSys::OpenDirectoryMode::Directory)) {
-        BuildEntryIndex(entries, backend->GetSubdirectories(),
-                        FileSys::DirectoryEntryType::Directory);
-    }
-    if (True(mode & FileSys::OpenDirectoryMode::File)) {
-        BuildEntryIndex(entries, backend->GetFiles(), FileSys::DirectoryEntryType::File);
-    }
 }
 
-void IDirectory::Read(HLERequestContext& ctx) {
+Result IDirectory::Read(
+    Out<s64> out_count,
+    const OutArray<FileSys::DirectoryEntry, BufferAttr_HipcMapAlias> out_entries) {
     LOG_DEBUG(Service_FS, "called.");
 
-    // Calculate how many entries we can fit in the output buffer
-    const u64 count_entries = ctx.GetWriteBufferNumElements<FileSys::DirectoryEntry>();
-
-    // Cap at total number of entries.
-    const u64 actual_entries = std::min(count_entries, entries.size() - next_entry_index);
-
-    // Determine data start and end
-    const auto* begin = reinterpret_cast<u8*>(entries.data() + next_entry_index);
-    const auto* end = reinterpret_cast<u8*>(entries.data() + next_entry_index + actual_entries);
-    const auto range_size = static_cast<std::size_t>(std::distance(begin, end));
-
-    next_entry_index += actual_entries;
-
-    // Write the data to memory
-    ctx.WriteBuffer(begin, range_size);
-
-    IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(ResultSuccess);
-    rb.Push(actual_entries);
+    R_RETURN(backend->Read(out_count, out_entries.data(), out_entries.size()));
 }
 
-void IDirectory::GetEntryCount(HLERequestContext& ctx) {
+Result IDirectory::GetEntryCount(Out<s64> out_count) {
     LOG_DEBUG(Service_FS, "called");
 
-    u64 count = entries.size() - next_entry_index;
-
-    IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(ResultSuccess);
-    rb.Push(count);
+    R_RETURN(backend->GetEntryCount(out_count));
 }
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/fsp/fs_i_directory.h b/src/core/hle/service/filesystem/fsp/fs_i_directory.h
index 793ecfcd7..b6251f7fd 100644
--- a/src/core/hle/service/filesystem/fsp/fs_i_directory.h
+++ b/src/core/hle/service/filesystem/fsp/fs_i_directory.h
@@ -3,7 +3,9 @@
 
 #pragma once
 
+#include "core/file_sys/fsa/fs_i_directory.h"
 #include "core/file_sys/vfs/vfs.h"
+#include "core/hle/service/cmif_types.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/service.h"
 
@@ -15,16 +17,15 @@ namespace Service::FileSystem {
 
 class IDirectory final : public ServiceFramework<IDirectory> {
 public:
-    explicit IDirectory(Core::System& system_, FileSys::VirtualDir backend_,
+    explicit IDirectory(Core::System& system_, FileSys::VirtualDir directory_,
                         FileSys::OpenDirectoryMode mode);
 
 private:
-    FileSys::VirtualDir backend;
-    std::vector<FileSys::DirectoryEntry> entries;
-    u64 next_entry_index = 0;
+    std::unique_ptr<FileSys::Fsa::IDirectory> backend;
 
-    void Read(HLERequestContext& ctx);
-    void GetEntryCount(HLERequestContext& ctx);
+    Result Read(Out<s64> out_count,
+                const OutArray<FileSys::DirectoryEntry, BufferAttr_HipcMapAlias> out_entries);
+    Result GetEntryCount(Out<s64> out_count);
 };
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/fsp/fs_i_file.cpp b/src/core/hle/service/filesystem/fsp/fs_i_file.cpp
index 9a18f6ec5..a355d46ae 100644
--- a/src/core/hle/service/filesystem/fsp/fs_i_file.cpp
+++ b/src/core/hle/service/filesystem/fsp/fs_i_file.cpp
@@ -2,126 +2,64 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "core/file_sys/errors.h"
+#include "core/hle/service/cmif_serialization.h"
 #include "core/hle/service/filesystem/fsp/fs_i_file.h"
-#include "core/hle/service/ipc_helpers.h"
 
 namespace Service::FileSystem {
 
-IFile::IFile(Core::System& system_, FileSys::VirtualFile backend_)
-    : ServiceFramework{system_, "IFile"}, backend(std::move(backend_)) {
+IFile::IFile(Core::System& system_, FileSys::VirtualFile file_)
+    : ServiceFramework{system_, "IFile"}, backend{std::make_unique<FileSys::Fsa::IFile>(file_)} {
+    // clang-format off
     static const FunctionInfo functions[] = {
-        {0, &IFile::Read, "Read"},
-        {1, &IFile::Write, "Write"},
-        {2, &IFile::Flush, "Flush"},
-        {3, &IFile::SetSize, "SetSize"},
-        {4, &IFile::GetSize, "GetSize"},
+        {0, D<&IFile::Read>, "Read"},
+        {1, D<&IFile::Write>, "Write"},
+        {2, D<&IFile::Flush>, "Flush"},
+        {3, D<&IFile::SetSize>, "SetSize"},
+        {4, D<&IFile::GetSize>, "GetSize"},
         {5, nullptr, "OperateRange"},
         {6, nullptr, "OperateRangeWithBuffer"},
     };
+    // clang-format on
     RegisterHandlers(functions);
 }
 
-void IFile::Read(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-    const u64 option = rp.Pop<u64>();
-    const s64 offset = rp.Pop<s64>();
-    const s64 length = rp.Pop<s64>();
-
-    LOG_DEBUG(Service_FS, "called, option={}, offset=0x{:X}, length={}", option, offset, length);
-
-    // Error checking
-    if (length < 0) {
-        LOG_ERROR(Service_FS, "Length is less than 0, length={}", length);
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(FileSys::ResultInvalidSize);
-        return;
-    }
-    if (offset < 0) {
-        LOG_ERROR(Service_FS, "Offset is less than 0, offset={}", offset);
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(FileSys::ResultInvalidOffset);
-        return;
-    }
+Result IFile::Read(
+    FileSys::ReadOption option, Out<s64> out_size, s64 offset,
+    const OutBuffer<BufferAttr_HipcMapAlias | BufferAttr_HipcMapTransferAllowsNonSecure> out_buffer,
+    s64 size) {
+    LOG_DEBUG(Service_FS, "called, option={}, offset=0x{:X}, length={}", option.value, offset,
+              size);
 
     // Read the data from the Storage backend
-    std::vector<u8> output = backend->ReadBytes(length, offset);
-
-    // Write the data to memory
-    ctx.WriteBuffer(output);
-
-    IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(ResultSuccess);
-    rb.Push(static_cast<u64>(output.size()));
+    R_RETURN(
+        backend->Read(reinterpret_cast<size_t*>(out_size.Get()), offset, out_buffer.data(), size));
 }
 
-void IFile::Write(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-    const u64 option = rp.Pop<u64>();
-    const s64 offset = rp.Pop<s64>();
-    const s64 length = rp.Pop<s64>();
-
-    LOG_DEBUG(Service_FS, "called, option={}, offset=0x{:X}, length={}", option, offset, length);
-
-    // Error checking
-    if (length < 0) {
-        LOG_ERROR(Service_FS, "Length is less than 0, length={}", length);
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(FileSys::ResultInvalidSize);
-        return;
-    }
-    if (offset < 0) {
-        LOG_ERROR(Service_FS, "Offset is less than 0, offset={}", offset);
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(FileSys::ResultInvalidOffset);
-        return;
-    }
-
-    const auto data = ctx.ReadBuffer();
+Result IFile::Write(
+    const InBuffer<BufferAttr_HipcMapAlias | BufferAttr_HipcMapTransferAllowsNonSecure> buffer,
+    FileSys::WriteOption option, s64 offset, s64 size) {
+    LOG_DEBUG(Service_FS, "called, option={}, offset=0x{:X}, length={}", option.value, offset,
+              size);
 
-    ASSERT_MSG(static_cast<s64>(data.size()) <= length,
-               "Attempting to write more data than requested (requested={:016X}, actual={:016X}).",
-               length, data.size());
-
-    // Write the data to the Storage backend
-    const auto write_size =
-        static_cast<std::size_t>(std::distance(data.begin(), data.begin() + length));
-    const std::size_t written = backend->Write(data.data(), write_size, offset);
-
-    ASSERT_MSG(static_cast<s64>(written) == length,
-               "Could not write all bytes to file (requested={:016X}, actual={:016X}).", length,
-               written);
-
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    R_RETURN(backend->Write(offset, buffer.data(), size, option));
 }
 
-void IFile::Flush(HLERequestContext& ctx) {
+Result IFile::Flush() {
     LOG_DEBUG(Service_FS, "called");
 
-    // Exists for SDK compatibiltity -- No need to flush file.
-
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    R_RETURN(backend->Flush());
 }
 
-void IFile::SetSize(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-    const u64 size = rp.Pop<u64>();
+Result IFile::SetSize(s64 size) {
     LOG_DEBUG(Service_FS, "called, size={}", size);
 
-    backend->Resize(size);
-
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    R_RETURN(backend->SetSize(size));
 }
 
-void IFile::GetSize(HLERequestContext& ctx) {
-    const u64 size = backend->GetSize();
-    LOG_DEBUG(Service_FS, "called, size={}", size);
+Result IFile::GetSize(Out<s64> out_size) {
+    LOG_DEBUG(Service_FS, "called");
 
-    IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(ResultSuccess);
-    rb.Push<u64>(size);
+    R_RETURN(backend->GetSize(out_size));
 }
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/fsp/fs_i_file.h b/src/core/hle/service/filesystem/fsp/fs_i_file.h
index 5e5430c67..e8599ee2f 100644
--- a/src/core/hle/service/filesystem/fsp/fs_i_file.h
+++ b/src/core/hle/service/filesystem/fsp/fs_i_file.h
@@ -3,6 +3,8 @@
 
 #pragma once
 
+#include "core/file_sys/fsa/fs_i_file.h"
+#include "core/hle/service/cmif_types.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/service.h"
 
@@ -10,16 +12,21 @@ namespace Service::FileSystem {
 
 class IFile final : public ServiceFramework<IFile> {
 public:
-    explicit IFile(Core::System& system_, FileSys::VirtualFile backend_);
+    explicit IFile(Core::System& system_, FileSys::VirtualFile file_);
 
 private:
-    FileSys::VirtualFile backend;
+    std::unique_ptr<FileSys::Fsa::IFile> backend;
 
-    void Read(HLERequestContext& ctx);
-    void Write(HLERequestContext& ctx);
-    void Flush(HLERequestContext& ctx);
-    void SetSize(HLERequestContext& ctx);
-    void GetSize(HLERequestContext& ctx);
+    Result Read(FileSys::ReadOption option, Out<s64> out_size, s64 offset,
+                const OutBuffer<BufferAttr_HipcMapAlias | BufferAttr_HipcMapTransferAllowsNonSecure>
+                    out_buffer,
+                s64 size);
+    Result Write(
+        const InBuffer<BufferAttr_HipcMapAlias | BufferAttr_HipcMapTransferAllowsNonSecure> buffer,
+        FileSys::WriteOption option, s64 offset, s64 size);
+    Result Flush();
+    Result SetSize(s64 size);
+    Result GetSize(Out<s64> out_size);
 };
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/fsp/fs_i_filesystem.cpp b/src/core/hle/service/filesystem/fsp/fs_i_filesystem.cpp
index efa394dd1..d881e144d 100644
--- a/src/core/hle/service/filesystem/fsp/fs_i_filesystem.cpp
+++ b/src/core/hle/service/filesystem/fsp/fs_i_filesystem.cpp
@@ -2,261 +2,172 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "common/string_util.h"
+#include "core/file_sys/fssrv/fssrv_sf_path.h"
+#include "core/hle/service/cmif_serialization.h"
 #include "core/hle/service/filesystem/fsp/fs_i_directory.h"
 #include "core/hle/service/filesystem/fsp/fs_i_file.h"
 #include "core/hle/service/filesystem/fsp/fs_i_filesystem.h"
-#include "core/hle/service/ipc_helpers.h"
 
 namespace Service::FileSystem {
 
-IFileSystem::IFileSystem(Core::System& system_, FileSys::VirtualDir backend_, SizeGetter size_)
-    : ServiceFramework{system_, "IFileSystem"}, backend{std::move(backend_)}, size{std::move(
-                                                                                  size_)} {
+IFileSystem::IFileSystem(Core::System& system_, FileSys::VirtualDir dir_, SizeGetter size_getter_)
+    : ServiceFramework{system_, "IFileSystem"}, backend{std::make_unique<FileSys::Fsa::IFileSystem>(
+                                                    dir_)},
+      size_getter{std::move(size_getter_)} {
     static const FunctionInfo functions[] = {
-        {0, &IFileSystem::CreateFile, "CreateFile"},
-        {1, &IFileSystem::DeleteFile, "DeleteFile"},
-        {2, &IFileSystem::CreateDirectory, "CreateDirectory"},
-        {3, &IFileSystem::DeleteDirectory, "DeleteDirectory"},
-        {4, &IFileSystem::DeleteDirectoryRecursively, "DeleteDirectoryRecursively"},
-        {5, &IFileSystem::RenameFile, "RenameFile"},
+        {0, D<&IFileSystem::CreateFile>, "CreateFile"},
+        {1, D<&IFileSystem::DeleteFile>, "DeleteFile"},
+        {2, D<&IFileSystem::CreateDirectory>, "CreateDirectory"},
+        {3, D<&IFileSystem::DeleteDirectory>, "DeleteDirectory"},
+        {4, D<&IFileSystem::DeleteDirectoryRecursively>, "DeleteDirectoryRecursively"},
+        {5, D<&IFileSystem::RenameFile>, "RenameFile"},
         {6, nullptr, "RenameDirectory"},
-        {7, &IFileSystem::GetEntryType, "GetEntryType"},
-        {8, &IFileSystem::OpenFile, "OpenFile"},
-        {9, &IFileSystem::OpenDirectory, "OpenDirectory"},
-        {10, &IFileSystem::Commit, "Commit"},
-        {11, &IFileSystem::GetFreeSpaceSize, "GetFreeSpaceSize"},
-        {12, &IFileSystem::GetTotalSpaceSize, "GetTotalSpaceSize"},
-        {13, &IFileSystem::CleanDirectoryRecursively, "CleanDirectoryRecursively"},
-        {14, &IFileSystem::GetFileTimeStampRaw, "GetFileTimeStampRaw"},
+        {7, D<&IFileSystem::GetEntryType>, "GetEntryType"},
+        {8, D<&IFileSystem::OpenFile>, "OpenFile"},
+        {9, D<&IFileSystem::OpenDirectory>, "OpenDirectory"},
+        {10, D<&IFileSystem::Commit>, "Commit"},
+        {11, D<&IFileSystem::GetFreeSpaceSize>, "GetFreeSpaceSize"},
+        {12, D<&IFileSystem::GetTotalSpaceSize>, "GetTotalSpaceSize"},
+        {13, D<&IFileSystem::CleanDirectoryRecursively>, "CleanDirectoryRecursively"},
+        {14, D<&IFileSystem::GetFileTimeStampRaw>, "GetFileTimeStampRaw"},
         {15, nullptr, "QueryEntry"},
-        {16, &IFileSystem::GetFileSystemAttribute, "GetFileSystemAttribute"},
+        {16, D<&IFileSystem::GetFileSystemAttribute>, "GetFileSystemAttribute"},
     };
     RegisterHandlers(functions);
 }
 
-void IFileSystem::CreateFile(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
+Result IFileSystem::CreateFile(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path,
+                               s32 option, s64 size) {
+    LOG_DEBUG(Service_FS, "called. file={}, option=0x{:X}, size=0x{:08X}", path->str, option, size);
 
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-
-    const u64 file_mode = rp.Pop<u64>();
-    const u32 file_size = rp.Pop<u32>();
-
-    LOG_DEBUG(Service_FS, "called. file={}, mode=0x{:X}, size=0x{:08X}", name, file_mode,
-              file_size);
-
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.CreateFile(name, file_size));
+    R_RETURN(backend->CreateFile(FileSys::Path(path->str), size));
 }
 
-void IFileSystem::DeleteFile(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
+Result IFileSystem::DeleteFile(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_DEBUG(Service_FS, "called. file={}", path->str);
 
-    LOG_DEBUG(Service_FS, "called. file={}", name);
-
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.DeleteFile(name));
+    R_RETURN(backend->DeleteFile(FileSys::Path(path->str)));
 }
 
-void IFileSystem::CreateDirectory(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-
-    LOG_DEBUG(Service_FS, "called. directory={}", name);
+Result IFileSystem::CreateDirectory(
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_DEBUG(Service_FS, "called. directory={}", path->str);
 
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.CreateDirectory(name));
+    R_RETURN(backend->CreateDirectory(FileSys::Path(path->str)));
 }
 
-void IFileSystem::DeleteDirectory(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-
-    LOG_DEBUG(Service_FS, "called. directory={}", name);
+Result IFileSystem::DeleteDirectory(
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_DEBUG(Service_FS, "called. directory={}", path->str);
 
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.DeleteDirectory(name));
+    R_RETURN(backend->DeleteDirectory(FileSys::Path(path->str)));
 }
 
-void IFileSystem::DeleteDirectoryRecursively(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
+Result IFileSystem::DeleteDirectoryRecursively(
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_DEBUG(Service_FS, "called. directory={}", path->str);
 
-    LOG_DEBUG(Service_FS, "called. directory={}", name);
-
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.DeleteDirectoryRecursively(name));
+    R_RETURN(backend->DeleteDirectoryRecursively(FileSys::Path(path->str)));
 }
 
-void IFileSystem::CleanDirectoryRecursively(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-
-    LOG_DEBUG(Service_FS, "called. Directory: {}", name);
+Result IFileSystem::CleanDirectoryRecursively(
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_DEBUG(Service_FS, "called. Directory: {}", path->str);
 
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.CleanDirectoryRecursively(name));
+    R_RETURN(backend->CleanDirectoryRecursively(FileSys::Path(path->str)));
 }
 
-void IFileSystem::RenameFile(HLERequestContext& ctx) {
-    const std::string src_name = Common::StringFromBuffer(ctx.ReadBuffer(0));
-    const std::string dst_name = Common::StringFromBuffer(ctx.ReadBuffer(1));
-
-    LOG_DEBUG(Service_FS, "called. file '{}' to file '{}'", src_name, dst_name);
+Result IFileSystem::RenameFile(
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> old_path,
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> new_path) {
+    LOG_DEBUG(Service_FS, "called. file '{}' to file '{}'", old_path->str, new_path->str);
 
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(backend.RenameFile(src_name, dst_name));
+    R_RETURN(backend->RenameFile(FileSys::Path(old_path->str), FileSys::Path(new_path->str)));
 }
 
-void IFileSystem::OpenFile(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-
-    const auto mode = static_cast<FileSys::OpenMode>(rp.Pop<u32>());
-
-    LOG_DEBUG(Service_FS, "called. file={}, mode={}", name, mode);
+Result IFileSystem::OpenFile(OutInterface<IFile> out_interface,
+                             const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path,
+                             u32 mode) {
+    LOG_DEBUG(Service_FS, "called. file={}, mode={}", path->str, mode);
 
     FileSys::VirtualFile vfs_file{};
-    auto result = backend.OpenFile(&vfs_file, name, mode);
-    if (result != ResultSuccess) {
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(result);
-        return;
-    }
-
-    auto file = std::make_shared<IFile>(system, vfs_file);
-
-    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
-    rb.Push(ResultSuccess);
-    rb.PushIpcInterface<IFile>(std::move(file));
-}
-
-void IFileSystem::OpenDirectory(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
+    R_TRY(backend->OpenFile(&vfs_file, FileSys::Path(path->str),
+                            static_cast<FileSys::OpenMode>(mode)));
 
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-    const auto mode = rp.PopRaw<FileSys::OpenDirectoryMode>();
+    *out_interface = std::make_shared<IFile>(system, vfs_file);
+    R_SUCCEED();
+}
 
-    LOG_DEBUG(Service_FS, "called. directory={}, mode={}", name, mode);
+Result IFileSystem::OpenDirectory(OutInterface<IDirectory> out_interface,
+                                  const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path,
+                                  u32 mode) {
+    LOG_DEBUG(Service_FS, "called. directory={}, mode={}", path->str, mode);
 
     FileSys::VirtualDir vfs_dir{};
-    auto result = backend.OpenDirectory(&vfs_dir, name);
-    if (result != ResultSuccess) {
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(result);
-        return;
-    }
-
-    auto directory = std::make_shared<IDirectory>(system, vfs_dir, mode);
-
-    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
-    rb.Push(ResultSuccess);
-    rb.PushIpcInterface<IDirectory>(std::move(directory));
-}
+    R_TRY(backend->OpenDirectory(&vfs_dir, FileSys::Path(path->str),
+                                 static_cast<FileSys::OpenDirectoryMode>(mode)));
 
-void IFileSystem::GetEntryType(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
+    *out_interface = std::make_shared<IDirectory>(system, vfs_dir,
+                                                  static_cast<FileSys::OpenDirectoryMode>(mode));
+    R_SUCCEED();
+}
 
-    LOG_DEBUG(Service_FS, "called. file={}", name);
+Result IFileSystem::GetEntryType(
+    Out<u32> out_type, const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_DEBUG(Service_FS, "called. file={}", path->str);
 
     FileSys::DirectoryEntryType vfs_entry_type{};
-    auto result = backend.GetEntryType(&vfs_entry_type, name);
-    if (result != ResultSuccess) {
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(result);
-        return;
-    }
-
-    IPC::ResponseBuilder rb{ctx, 3};
-    rb.Push(ResultSuccess);
-    rb.Push<u32>(static_cast<u32>(vfs_entry_type));
+    R_TRY(backend->GetEntryType(&vfs_entry_type, FileSys::Path(path->str)));
+
+    *out_type = static_cast<u32>(vfs_entry_type);
+    R_SUCCEED();
 }
 
-void IFileSystem::Commit(HLERequestContext& ctx) {
+Result IFileSystem::Commit() {
     LOG_WARNING(Service_FS, "(STUBBED) called");
 
-    IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    R_SUCCEED();
 }
 
-void IFileSystem::GetFreeSpaceSize(HLERequestContext& ctx) {
+Result IFileSystem::GetFreeSpaceSize(
+    Out<s64> out_size, const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
     LOG_DEBUG(Service_FS, "called");
 
-    IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(ResultSuccess);
-    rb.Push(size.get_free_size());
+    *out_size = size_getter.get_free_size();
+    R_SUCCEED();
 }
 
-void IFileSystem::GetTotalSpaceSize(HLERequestContext& ctx) {
+Result IFileSystem::GetTotalSpaceSize(
+    Out<s64> out_size, const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
     LOG_DEBUG(Service_FS, "called");
 
-    IPC::ResponseBuilder rb{ctx, 4};
-    rb.Push(ResultSuccess);
-    rb.Push(size.get_total_size());
+    *out_size = size_getter.get_total_size();
+    R_SUCCEED();
 }
 
-void IFileSystem::GetFileTimeStampRaw(HLERequestContext& ctx) {
-    const auto file_buffer = ctx.ReadBuffer();
-    const std::string name = Common::StringFromBuffer(file_buffer);
-
-    LOG_WARNING(Service_FS, "(Partial Implementation) called. file={}", name);
+Result IFileSystem::GetFileTimeStampRaw(
+    Out<FileSys::FileTimeStampRaw> out_timestamp,
+    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path) {
+    LOG_WARNING(Service_FS, "(Partial Implementation) called. file={}", path->str);
 
     FileSys::FileTimeStampRaw vfs_timestamp{};
-    auto result = backend.GetFileTimeStampRaw(&vfs_timestamp, name);
-    if (result != ResultSuccess) {
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(result);
-        return;
-    }
-
-    IPC::ResponseBuilder rb{ctx, 10};
-    rb.Push(ResultSuccess);
-    rb.PushRaw(vfs_timestamp);
+    R_TRY(backend->GetFileTimeStampRaw(&vfs_timestamp, FileSys::Path(path->str)));
+
+    *out_timestamp = vfs_timestamp;
+    R_SUCCEED();
 }
 
-void IFileSystem::GetFileSystemAttribute(HLERequestContext& ctx) {
+Result IFileSystem::GetFileSystemAttribute(Out<FileSys::FileSystemAttribute> out_attribute) {
     LOG_WARNING(Service_FS, "(STUBBED) called");
 
-    struct FileSystemAttribute {
-        u8 dir_entry_name_length_max_defined;
-        u8 file_entry_name_length_max_defined;
-        u8 dir_path_name_length_max_defined;
-        u8 file_path_name_length_max_defined;
-        INSERT_PADDING_BYTES_NOINIT(0x5);
-        u8 utf16_dir_entry_name_length_max_defined;
-        u8 utf16_file_entry_name_length_max_defined;
-        u8 utf16_dir_path_name_length_max_defined;
-        u8 utf16_file_path_name_length_max_defined;
-        INSERT_PADDING_BYTES_NOINIT(0x18);
-        s32 dir_entry_name_length_max;
-        s32 file_entry_name_length_max;
-        s32 dir_path_name_length_max;
-        s32 file_path_name_length_max;
-        INSERT_PADDING_WORDS_NOINIT(0x5);
-        s32 utf16_dir_entry_name_length_max;
-        s32 utf16_file_entry_name_length_max;
-        s32 utf16_dir_path_name_length_max;
-        s32 utf16_file_path_name_length_max;
-        INSERT_PADDING_WORDS_NOINIT(0x18);
-        INSERT_PADDING_WORDS_NOINIT(0x1);
-    };
-    static_assert(sizeof(FileSystemAttribute) == 0xc0, "FileSystemAttribute has incorrect size");
-
-    FileSystemAttribute savedata_attribute{};
+    FileSys::FileSystemAttribute savedata_attribute{};
     savedata_attribute.dir_entry_name_length_max_defined = true;
     savedata_attribute.file_entry_name_length_max_defined = true;
     savedata_attribute.dir_entry_name_length_max = 0x40;
     savedata_attribute.file_entry_name_length_max = 0x40;
 
-    IPC::ResponseBuilder rb{ctx, 50};
-    rb.Push(ResultSuccess);
-    rb.PushRaw(savedata_attribute);
+    *out_attribute = savedata_attribute;
+    R_SUCCEED();
 }
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/fsp/fs_i_filesystem.h b/src/core/hle/service/filesystem/fsp/fs_i_filesystem.h
index b06b3ef0e..113369203 100644
--- a/src/core/hle/service/filesystem/fsp/fs_i_filesystem.h
+++ b/src/core/hle/service/filesystem/fsp/fs_i_filesystem.h
@@ -3,36 +3,58 @@
 
 #pragma once
 
+#include "common/common_funcs.h"
+#include "core/file_sys/fs_filesystem.h"
+#include "core/file_sys/fsa/fs_i_filesystem.h"
 #include "core/file_sys/vfs/vfs.h"
+#include "core/hle/service/cmif_types.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/filesystem/fsp/fsp_util.h"
 #include "core/hle/service/service.h"
 
+namespace FileSys::Sf {
+struct Path;
+}
+
 namespace Service::FileSystem {
 
+class IFile;
+class IDirectory;
+
 class IFileSystem final : public ServiceFramework<IFileSystem> {
 public:
-    explicit IFileSystem(Core::System& system_, FileSys::VirtualDir backend_, SizeGetter size_);
-
-    void CreateFile(HLERequestContext& ctx);
-    void DeleteFile(HLERequestContext& ctx);
-    void CreateDirectory(HLERequestContext& ctx);
-    void DeleteDirectory(HLERequestContext& ctx);
-    void DeleteDirectoryRecursively(HLERequestContext& ctx);
-    void CleanDirectoryRecursively(HLERequestContext& ctx);
-    void RenameFile(HLERequestContext& ctx);
-    void OpenFile(HLERequestContext& ctx);
-    void OpenDirectory(HLERequestContext& ctx);
-    void GetEntryType(HLERequestContext& ctx);
-    void Commit(HLERequestContext& ctx);
-    void GetFreeSpaceSize(HLERequestContext& ctx);
-    void GetTotalSpaceSize(HLERequestContext& ctx);
-    void GetFileTimeStampRaw(HLERequestContext& ctx);
-    void GetFileSystemAttribute(HLERequestContext& ctx);
+    explicit IFileSystem(Core::System& system_, FileSys::VirtualDir dir_, SizeGetter size_getter_);
+
+    Result CreateFile(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path, s32 option,
+                      s64 size);
+    Result DeleteFile(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result CreateDirectory(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result DeleteDirectory(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result DeleteDirectoryRecursively(
+        const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result CleanDirectoryRecursively(
+        const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result RenameFile(const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> old_path,
+                      const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> new_path);
+    Result OpenFile(OutInterface<IFile> out_interface,
+                    const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path, u32 mode);
+    Result OpenDirectory(OutInterface<IDirectory> out_interface,
+                         const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path,
+                         u32 mode);
+    Result GetEntryType(Out<u32> out_type,
+                        const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result Commit();
+    Result GetFreeSpaceSize(Out<s64> out_size,
+                            const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result GetTotalSpaceSize(Out<s64> out_size,
+                             const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result GetFileTimeStampRaw(Out<FileSys::FileTimeStampRaw> out_timestamp,
+                               const InLargeData<FileSys::Sf::Path, BufferAttr_HipcPointer> path);
+    Result GetFileSystemAttribute(Out<FileSys::FileSystemAttribute> out_attribute);
 
 private:
-    VfsDirectoryServiceWrapper backend;
-    SizeGetter size;
+    std::unique_ptr<FileSys::Fsa::IFileSystem> backend;
+    SizeGetter size_getter;
 };
 
 } // namespace Service::FileSystem