[fs] share parent resources with bundled programs (#4319)

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Normal games are Applications;
Bundled games are Application + Programs;

We've been treating both as the same thing, calling both programs, and making programs unable to see settings and saves from application.

References:
https://switchbrew.org/wiki/Filesystem_services
https://switchbrew.org/wiki/NCM_services#ApplicationId
https://switchbrew.org/wiki/Super_Mario_3D_All-Stars
Ryujinx.HLE/HOS/ApplicationLoader.cs:GetMultiProgramInfo

UPDATE:

The first version was a big rework to make AppId/ProgId concepts proper, and it was successful in most tests, but it caused a regression with applets, which are programs that breed straight from no application.
In order to simplify things i've reverted all the rework, added a helper to identify whether a program has a parent Application and bounded it to it's proper stores.

Although this is no big deal coz it doesn't have impact on emulation, it permeates to several routines, so it needs to be tested broadly. Applets, Normal games, Bundled games, Blobbed NSPs/XCIs, Mods, Updates, Saves, DLCs,.

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4319
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: lizzie <lizzie@eden-emu.dev>

src/core/file_sys/patch_manager.cpp

@@ -9,6 +9,7 @@
 #include <cstddef>
 #include <cstring>
 
+#include "common/assert.h"
 #include "common/hex_util.h"
 #include "common/logging.h"
 #include "common/settings.h"
@@ -156,12 +157,15 @@ std::string GetUpdateVersionStringFromSlot(const ContentProvider* provider, u64
     NACP nacp{nacp_file};
     return nacp.GetVersionString();
 }
+YUZU_NO_INLINE std::optional<u64> GetParentApplicationId(const ContentProvider* provider, u64 title_id) {
+    return provider == nullptr ? std::nullopt : provider->GetParentApplicationId(title_id);
+}
 } // Anonymous namespace
 
 PatchManager::PatchManager(u64 title_id_,
                            const Service::FileSystem::FileSystemController& fs_controller_,
                            const ContentProvider& content_provider_)
-    : title_id{title_id_}, fs_controller{fs_controller_}, content_provider{content_provider_} {}
+    : title_id{title_id_}, parent_title_id{GetParentApplicationId(std::addressof(content_provider_), title_id_)}, fs_controller{fs_controller_}, content_provider{content_provider_} {}
 
 PatchManager::~PatchManager() = default;
 
@@ -169,13 +173,35 @@ u64 PatchManager::GetTitleID() const {
     return title_id;
 }
 
+VirtualDir PatchManager::GetModificationLoadRoot(bool sdmc) const {
+    const auto get_root = [&](u64 id) {
+        return sdmc ? fs_controller.GetSDMCModificationLoadRoot(id) : fs_controller.GetModificationLoadRoot(id);
+    };
+    auto root = get_root(title_id);
+    if (!parent_title_id) {
+        return root;
+    }
+    std::vector<VirtualDir> roots{std::move(root), get_root(*parent_title_id)};
+    std::erase(roots, nullptr);
+    return LayeredVfsDirectory::MakeLayeredDirectory(std::move(roots));
+}
+
+std::vector<std::string> PatchManager::GetDisabledAddons() const {
+    auto disabled = Settings::values.disabled_addons[title_id];
+    if (parent_title_id) {
+        const auto& shared = Settings::values.disabled_addons[*parent_title_id];
+        disabled.insert(disabled.end(), shared.begin(), shared.end());
+    }
+    return disabled;
+}
+
 VirtualDir PatchManager::PatchExeFS(VirtualDir exefs) const {
     LOG_INFO(Loader, "Patching ExeFS for title_id={:016X}", title_id);
 
     if (exefs == nullptr)
         return exefs;
 
-    const auto& disabled = Settings::values.disabled_addons[title_id];
+    const auto disabled = GetDisabledAddons();
 
     bool update_disabled = true;
     std::optional<u32> enabled_version;
@@ -303,8 +329,8 @@ VirtualDir PatchManager::PatchExeFS(VirtualDir exefs) const {
     }
 
     // LayeredExeFS
-    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
-    const auto sdmc_load_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);
+    const auto load_dir = GetModificationLoadRoot();
+    const auto sdmc_load_dir = GetModificationLoadRoot(true);
 
     std::vector<VirtualDir> patch_dirs = {sdmc_load_dir};
     if (load_dir != nullptr) {
@@ -346,7 +372,7 @@ VirtualDir PatchManager::PatchExeFS(VirtualDir exefs) const {
 }
 
 std::vector<VirtualFile> PatchManager::CollectPatches(const std::vector<VirtualDir>& patch_dirs, const std::string& build_id) const {
-    const auto& disabled = Settings::values.disabled_addons[title_id];
+    const auto disabled = GetDisabledAddons();
     const auto nso_build_id = fmt::format("{:0<64}", build_id);
 
     std::vector<VirtualFile> out;
@@ -405,7 +431,7 @@ std::vector<u8> PatchManager::PatchNSO(const std::vector<u8>& nso, const std::st
 
     LOG_INFO(Loader, "Patching NSO for name={}, build_id={}", name, build_id);
 
-    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
+    const auto load_dir = GetModificationLoadRoot();
     if (load_dir == nullptr) {
         LOG_ERROR(Loader, "Cannot load mods for invalid title_id={:016X}", title_id);
         return nso;
@@ -448,7 +474,7 @@ bool PatchManager::HasNSOPatch(const BuildID& build_id_, std::string_view name)
 
     LOG_INFO(Loader, "Querying NSO patch existence for build_id={}, name={}", build_id, name);
 
-    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
+    const auto load_dir = GetModificationLoadRoot();
     if (load_dir == nullptr) {
         LOG_ERROR(Loader, "Cannot load mods for invalid title_id={:016X}", title_id);
         return false;
@@ -462,13 +488,13 @@ bool PatchManager::HasNSOPatch(const BuildID& build_id_, std::string_view name)
 }
 
 std::vector<Core::Memory::CheatEntry> PatchManager::CreateCheatList(const BuildID& build_id_) const {
-    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
+    const auto load_dir = GetModificationLoadRoot();
     if (load_dir == nullptr) {
         LOG_ERROR(Loader, "Cannot load mods for invalid title_id={:016X}", title_id);
         return {};
     }
 
-    const auto& disabled = Settings::values.disabled_addons[title_id];
+    const auto disabled = GetDisabledAddons();
     auto patch_dirs = load_dir->GetSubdirectories();
     std::sort(patch_dirs.begin(), patch_dirs.end(), [](auto const& l, auto const& r) { return l->GetName() < r->GetName(); });
 
@@ -502,17 +528,16 @@ std::vector<Core::Memory::CheatEntry> PatchManager::CreateCheatList(const BuildI
     return out;
 }
 
-static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType type,
-                           const Service::FileSystem::FileSystemController& fs_controller) {
-    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
-    const auto sdmc_load_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);
+void PatchManager::ApplyLayeredFS(VirtualFile& romfs, ContentRecordType type) const {
+    const auto load_dir = GetModificationLoadRoot();
+    const auto sdmc_load_dir = GetModificationLoadRoot(true);
     if ((type != ContentRecordType::Program && type != ContentRecordType::Data &&
          type != ContentRecordType::HtmlDocument) ||
         (load_dir == nullptr && sdmc_load_dir == nullptr)) {
         return;
     }
 
-    const auto& disabled = Settings::values.disabled_addons[title_id];
+    const auto disabled = GetDisabledAddons();
     std::vector<VirtualDir> patch_dirs = load_dir->GetSubdirectories();
     if (std::find(disabled.cbegin(), disabled.cend(), "SDMC") == disabled.cend()) {
         patch_dirs.push_back(sdmc_load_dir);
@@ -591,7 +616,7 @@ VirtualFile PatchManager::PatchRomFS(const NCA* base_nca, VirtualFile base_romfs
 
     // Game Updates
     const auto update_tid = GetUpdateTitleID(title_id);
-    const auto& disabled = Settings::values.disabled_addons[title_id];
+    const auto disabled = GetDisabledAddons();
 
     bool update_disabled = true;
     std::optional<u32> enabled_version;
@@ -698,7 +723,7 @@ VirtualFile PatchManager::PatchRomFS(const NCA* base_nca, VirtualFile base_romfs
 
     // LayeredFS
     if (apply_layeredfs) {
-        ApplyLayeredFS(romfs, title_id, type, fs_controller);
+        ApplyLayeredFS(romfs, type);
     }
 
     return romfs;
@@ -1072,15 +1097,22 @@ std::vector<Patch> PatchManager::GetPatches(VirtualFile update_raw) const {
 std::optional<u32> PatchManager::GetGameVersion() const {
     const auto update_tid = GetUpdateTitleID(title_id);
     if (content_provider.HasEntry(update_tid, ContentRecordType::Program)) {
-        return content_provider.GetEntryVersion(update_tid);
+        const auto version = content_provider.GetEntryVersion(update_tid);
+        return version || !parent_title_id ? version : content_provider.GetEntryVersion(GetUpdateTitleID(*parent_title_id));
     }
 
-    return content_provider.GetEntryVersion(title_id);
+    const auto version = content_provider.GetEntryVersion(title_id);
+    return version || !parent_title_id ? version : content_provider.GetEntryVersion(*parent_title_id);
 }
 
 PatchManager::Metadata PatchManager::GetControlMetadata() const {
     const auto base_control_nca = content_provider.GetEntry(title_id, ContentRecordType::Control);
     if (base_control_nca == nullptr) {
+        if (parent_title_id) {
+            const auto control_id = content_provider.HasEntry(*parent_title_id, ContentRecordType::Control) ? *parent_title_id : GetUpdateTitleID(*parent_title_id);
+            const PatchManager parent{control_id, fs_controller, content_provider};
+            return parent.GetControlMetadata();
+        }
         return {};
     }
 

src/core/file_sys/patch_manager.h

@@ -109,10 +109,14 @@ public:
     [[nodiscard]] static PatchManager::Metadata GetMetadataFromBaseOrUpdate(Core::System& system, u64 application_id) noexcept;
 
 private:
+    [[nodiscard]] VirtualDir GetModificationLoadRoot(bool sdmc = false) const;
+    [[nodiscard]] std::vector<std::string> GetDisabledAddons() const;
+    void ApplyLayeredFS(VirtualFile& romfs, ContentRecordType type) const;
     [[nodiscard]] std::vector<VirtualFile> CollectPatches(const std::vector<VirtualDir>& patch_dirs,
                                                           const std::string& build_id) const;
 
     u64 title_id;
+    std::optional<u64> parent_title_id;
     const Service::FileSystem::FileSystemController& fs_controller;
     const ContentProvider& content_provider;
 };

src/core/file_sys/registered_cache.cpp

@@ -5,6 +5,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <algorithm>
+#include <limits>
 #include <random>
 #include <regex>
 #include <openssl/evp.h>
@@ -348,6 +349,22 @@ std::vector<ContentProviderEntry> ContentProvider::ListEntries() const {
     return ListEntriesFilter(std::nullopt, std::nullopt, std::nullopt);
 }
 
+std::optional<u64> ContentProvider::GetParentApplicationId(u64 program_id) const {
+    const auto application_id = GetBaseTitleID(program_id);
+    const auto program_index = program_id - application_id;
+    if (program_index == 0 || program_index > std::numeric_limits<u8>::max()) {
+        return std::nullopt;
+    }
+    if (!ListEntriesFilter(TitleType::Application, ContentRecordType::Meta, program_id).empty()) {
+        return std::nullopt;
+    }
+    if ((!ListEntriesFilter(TitleType::Application, ContentRecordType::Meta, application_id).empty() && HasEntry(program_id, ContentRecordType::Program))
+     || (!ListEntriesFilter(TitleType::Update, ContentRecordType::Meta, GetUpdateTitleID(application_id)).empty() && HasEntry(GetUpdateTitleID(program_id), ContentRecordType::Program))) {
+        return application_id;
+    }
+    return std::nullopt;
+}
+
 PlaceholderCache::PlaceholderCache(VirtualDir dir_) : dir(std::move(dir_)) {}
 
 bool PlaceholderCache::Create(const NcaID& id, u64 size) const {

src/core/file_sys/registered_cache.h

@@ -100,6 +100,8 @@ public:
         std::optional<TitleType> title_type = {}, std::optional<ContentRecordType> record_type = {},
         std::optional<u64> title_id = {}) const = 0;
 
+    [[nodiscard]] std::optional<u64> GetParentApplicationId(u64 program_id) const;
+
 protected:
     // A single instance of KeyManager to be used by GetEntry()
     Core::Crypto::KeyManager& keys = Core::Crypto::KeyManager::Instance();

src/core/file_sys/savedata_factory.cpp

@@ -9,6 +9,7 @@
 #include "common/logging.h"
 #include "common/uuid.h"
 #include "core/core.h"
+#include "core/file_sys/registered_cache.h"
 #include "core/file_sys/savedata_factory.h"
 #include "core/file_sys/vfs/vfs.h"
 
@@ -61,17 +62,24 @@ SaveDataFactory::SaveDataFactory(Core::System& system_, ProgramId program_id_,
 
 SaveDataFactory::~SaveDataFactory() = default;
 
+std::string SaveDataFactory::GetSaveDataPath(SaveDataSpaceId space, SaveDataType type, u64 title_id, u128 user_id, u64 save_id) const {
+    if (type == SaveDataType::Account || type == SaveDataType::Device) {
+        const auto requested_id = title_id != 0 ? title_id : program_id;
+        const auto parent_id = system.GetContentProvider().GetParentApplicationId(requested_id);
+        title_id = parent_id.value_or(requested_id);
+    }
+    return GetFullPath(program_id, dir, space, type, title_id, user_id, save_id);
+}
+
 VirtualDir SaveDataFactory::Create(SaveDataSpaceId space, const SaveDataAttribute& meta) const {
-    const auto save_directory = GetFullPath(program_id, dir, space, meta.type, meta.program_id,
-                                            meta.user_id, meta.system_save_data_id);
+    const auto save_directory = GetSaveDataPath(space, meta.type, meta.program_id, meta.user_id, meta.system_save_data_id);
 
     return dir->CreateDirectoryRelative(save_directory);
 }
 
 VirtualDir SaveDataFactory::Open(SaveDataSpaceId space, const SaveDataAttribute& meta) const {
 
-    const auto save_directory = GetFullPath(program_id, dir, space, meta.type, meta.program_id,
-                                            meta.user_id, meta.system_save_data_id);
+    const auto save_directory = GetSaveDataPath(space, meta.type, meta.program_id, meta.user_id, meta.system_save_data_id);
 
     auto out = dir->GetDirectoryRelative(save_directory);
 
@@ -154,8 +162,7 @@ std::string SaveDataFactory::GetUserGameSaveDataRoot(u128 user_id, bool future)
 
 SaveDataSize SaveDataFactory::ReadSaveDataSize(SaveDataType type, u64 title_id,
                                                u128 user_id) const {
-    const auto path =
-        GetFullPath(program_id, dir, SaveDataSpaceId::User, type, title_id, user_id, 0);
+    const auto path = GetSaveDataPath(SaveDataSpaceId::User, type, title_id, user_id, 0);
     const auto relative_dir = GetOrCreateDirectoryRelative(dir, path);
 
     const auto size_file = relative_dir->GetFile(GetSaveDataSizeFileName());
@@ -173,8 +180,7 @@ SaveDataSize SaveDataFactory::ReadSaveDataSize(SaveDataType type, u64 title_id,
 
 void SaveDataFactory::WriteSaveDataSize(SaveDataType type, u64 title_id, u128 user_id,
                                         SaveDataSize new_value) const {
-    const auto path =
-        GetFullPath(program_id, dir, SaveDataSpaceId::User, type, title_id, user_id, 0);
+    const auto path = GetSaveDataPath(SaveDataSpaceId::User, type, title_id, user_id, 0);
     const auto relative_dir = GetOrCreateDirectoryRelative(dir, path);
 
     const auto size_file = relative_dir->CreateFile(GetSaveDataSizeFileName());

src/core/file_sys/savedata_factory.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -47,6 +50,7 @@ public:
     void SetAutoCreate(bool state);
 
 private:
+    std::string GetSaveDataPath(SaveDataSpaceId space, SaveDataType type, u64 title_id, u128 user_id, u64 save_id) const;
     Core::System& system;
     ProgramId program_id;
     VirtualDir dir;