[fs] Preserve guest file open modes in real VFS

src/core/file_sys/fs_filesystem.h

@@ -12,6 +12,7 @@
 namespace FileSys {
 
 enum class OpenMode : u32 {
+    Default = 0,
     Read = (1 << 0),
     Write = (1 << 1),
     AllowAppend = (1 << 2),

src/core/file_sys/vfs/vfs.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
@@ -40,7 +40,7 @@ VfsEntryType VfsFilesystem::GetEntryType(std::string_view path_) const {
 
 VirtualFile VfsFilesystem::OpenFile(std::string_view path_, OpenMode perms) {
     const auto path = Common::FS::SanitizePath(path_);
-    return root->GetFileRelative(path);
+    return root->GetFileRelative(path, perms);
 }
 
 VirtualFile VfsFilesystem::CreateFile(std::string_view path_, OpenMode perms) {
@@ -201,7 +201,7 @@ std::string VfsFile::GetFullPath() const {
     return GetContainingDirectory()->GetFullPath() + '/' + GetName();
 }
 
-VirtualFile VfsDirectory::GetFileRelative(std::string_view path) const {
+VirtualFile VfsDirectory::GetFileRelative(std::string_view path, OpenMode perms) const {
     auto vec = Common::FS::SplitPathComponents(path);
     if (vec.empty()) {
         return nullptr;
@@ -224,7 +224,10 @@ VirtualFile VfsDirectory::GetFileRelative(std::string_view path) const {
         return nullptr;
     }
 
-    return dir->GetFile(vec.back());
+    if (perms == OpenMode::Default) {
+        return dir->GetFile(vec.back());
+    }
+    return dir->GetFileRelative(vec.back(), perms);
 }
 
 VirtualFile VfsDirectory::GetFileAbsolute(std::string_view path) const {

src/core/file_sys/vfs/vfs.h

@@ -201,7 +201,8 @@ public:
 
     // Retrieves the file located at path as if the current directory was root. Returns nullptr if
     // not found.
-    virtual VirtualFile GetFileRelative(std::string_view path) const;
+    virtual VirtualFile GetFileRelative(std::string_view path,
+                                        OpenMode perms = OpenMode::Default) const;
     // Calls GetFileRelative(path) on the root of the current directory.
     virtual VirtualFile GetFileAbsolute(std::string_view path) const;
 

src/core/file_sys/vfs/vfs_layered.cpp

@@ -27,9 +27,9 @@ VirtualDir LayeredVfsDirectory::MakeLayeredDirectory(std::vector<VirtualDir> dir
     return VirtualDir(new LayeredVfsDirectory(std::move(dirs), std::move(name)));
 }
 
-VirtualFile LayeredVfsDirectory::GetFileRelative(std::string_view path) const {
+VirtualFile LayeredVfsDirectory::GetFileRelative(std::string_view path, OpenMode perms) const {
     for (const auto& layer : dirs) {
-        const auto file = layer->GetFileRelative(path);
+        const auto file = layer->GetFileRelative(path, perms);
         if (file != nullptr)
             return file;
     }

src/core/file_sys/vfs/vfs_layered.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
 
@@ -20,7 +23,8 @@ public:
     /// Wrapper function to allow for more efficient handling of dirs.size() == 0, 1 cases.
     static VirtualDir MakeLayeredDirectory(std::vector<VirtualDir> dirs, std::string name = "");
 
-    VirtualFile GetFileRelative(std::string_view path) const override;
+    VirtualFile GetFileRelative(std::string_view path,
+                                OpenMode perms = OpenMode::Default) const override;
     VirtualDir GetDirectoryRelative(std::string_view path) const override;
     VirtualFile GetFile(std::string_view file_name) const override;
     VirtualDir GetSubdirectory(std::string_view subdir_name) const override;

src/core/file_sys/vfs/vfs_real.cpp

@@ -45,17 +45,11 @@ bool IsWithinRoot(std::string_view root, std::string_view full_path) {
 }
 
 constexpr FS::FileAccessMode ModeFlagsToFileAccessMode(OpenMode mode) {
-    switch (mode) {
-    case OpenMode::Read:
-        return FS::FileAccessMode::Read;
-    case OpenMode::Write:
-    case OpenMode::ReadWrite:
-    case OpenMode::AllowAppend:
-    case OpenMode::All:
+    if (True(mode & OpenMode::Write) || True(mode & OpenMode::AllowAppend)) {
         return FS::FileAccessMode::ReadWrite;
-    default:
-        return {};
     }
+
+    return FS::FileAccessMode::Read;
 }
 
 } // Anonymous namespace
@@ -93,9 +87,11 @@ VirtualFile RealVfsFilesystem::OpenFileFromEntry(std::string_view path_, std::op
                                                  std::optional<std::string> parent_path,
                                                  OpenMode perms) {
     const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
+    const auto open_perms = perms == OpenMode::Default ? OpenMode::Read : perms;
     std::scoped_lock lk{list_lock};
 
-    if (auto it = cache.find(path); it != cache.end()) {
+    const CacheKey cache_key{path, open_perms};
+    if (auto it = cache.find(cache_key); it != cache.end()) {
         if (auto file = it->second.lock(); file) {
             return file;
         }
@@ -109,8 +105,9 @@ VirtualFile RealVfsFilesystem::OpenFileFromEntry(std::string_view path_, std::op
     this->InsertReferenceIntoListLocked(*reference);
 
     auto file = std::shared_ptr<RealVfsFile>(
-        new RealVfsFile(*this, std::move(reference), path, perms, size, std::move(parent_path)));
-    cache[path] = file;
+        new RealVfsFile(*this, std::move(reference), path, open_perms, size,
+                        std::move(parent_path)));
+    cache[cache_key] = file;
 
     return file;
 }
@@ -124,7 +121,6 @@ VirtualFile RealVfsFilesystem::CreateFile(std::string_view path_, OpenMode perms
     {
         std::scoped_lock lk{list_lock};
         CloseCachedFileReferenceLocked(path);
-        cache.erase(path);
     }
 
     // Current usages of CreateFile expect to delete the contents of an existing file.
@@ -159,8 +155,6 @@ VirtualFile RealVfsFilesystem::MoveFile(std::string_view old_path_, std::string_
         std::scoped_lock lk{list_lock};
         CloseCachedFileReferenceLocked(old_path);
         CloseCachedFileReferenceLocked(new_path);
-        cache.erase(old_path);
-        cache.erase(new_path);
     }
     if (!FS::RenameFile(old_path, new_path)) {
         return nullptr;
@@ -173,14 +167,14 @@ bool RealVfsFilesystem::DeleteFile(std::string_view path_) {
     {
         std::scoped_lock lk{list_lock};
         CloseCachedFileReferenceLocked(path);
-        cache.erase(path);
     }
     return FS::RemoveFile(path);
 }
 
 VirtualDir RealVfsFilesystem::OpenDirectory(std::string_view path_, OpenMode perms) {
     const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
-    return std::shared_ptr<RealVfsDirectory>(new RealVfsDirectory(*this, path, perms));
+    return std::shared_ptr<RealVfsDirectory>(
+        new RealVfsDirectory(*this, path, perms == OpenMode::Default ? OpenMode::Read : perms));
 }
 
 VirtualDir RealVfsFilesystem::CreateDirectory(std::string_view path_, OpenMode perms) {
@@ -301,26 +295,21 @@ RealVfsFile::~RealVfsFile() {
 }
 
 void RealVfsFilesystem::CloseCachedFileReferenceLocked(const std::string& path) {
-    const auto it = cache.find(path);
-    if (it == cache.end()) {
-        return;
-    }
-
-    const auto cached_file = it->second.lock();
-    if (!cached_file) {
-        return;
-    }
-
-    auto* real_file = static_cast<RealVfsFile*>(cached_file.get());
-    auto& reference = real_file->reference;
-    if (!reference || !reference->file) {
-        return;
+    for (auto it = cache.lower_bound(CacheKey{path, OpenMode::Default});
+         it != cache.end() && it->first.first == path;) {
+        const auto cached_file = it->second.lock();
+        if (cached_file) {
+            auto* const real_file = static_cast<RealVfsFile*>(cached_file.get());
+            auto& reference = real_file->reference;
+            if (reference && reference->file) {
+                RemoveReferenceFromListLocked(*reference);
+                reference->file.reset();
+                num_open_files--;
+                InsertReferenceIntoListLocked(*reference);
+            }
+        }
+        it = cache.erase(it);
     }
-
-    RemoveReferenceFromListLocked(*reference);
-    reference->file.reset();
-    num_open_files--;
-    InsertReferenceIntoListLocked(*reference);
 }
 
 std::string RealVfsFile::GetName() const {
@@ -449,13 +438,14 @@ RealVfsDirectory::RealVfsDirectory(RealVfsFilesystem& base_, const std::string&
 
 RealVfsDirectory::~RealVfsDirectory() = default;
 
-VirtualFile RealVfsDirectory::GetFileRelative(std::string_view relative_path) const {
+VirtualFile RealVfsDirectory::GetFileRelative(std::string_view relative_path,
+                                              OpenMode open_perms) const {
     const auto full_path = FS::SanitizePath(path + '/' + std::string(relative_path));
     if (!FS::Exists(full_path) || FS::IsDir(full_path)
         || !IsWithinRoot(FS::SanitizePath(path), full_path)) {
         return nullptr;
     }
-    return base.OpenFile(full_path, perms);
+    return base.OpenFile(full_path, open_perms == OpenMode::Default ? perms : open_perms);
 }
 
 VirtualDir RealVfsDirectory::GetDirectoryRelative(std::string_view relative_path) const {

src/core/file_sys/vfs/vfs_real.h

@@ -10,6 +10,7 @@
 #include <mutex>
 #include <optional>
 #include <string_view>
+#include <utility>
 #include "common/intrusive_list.h"
 #include "core/file_sys/fs_filesystem.h"
 #include "core/file_sys/vfs/vfs.h"
@@ -49,8 +50,9 @@ public:
     bool DeleteDirectory(std::string_view path) override;
 
 private:
+    using CacheKey = std::pair<std::string, OpenMode>;
     using ReferenceListType = Common::IntrusiveListBaseTraits<FileReference>::ListType;
-    std::map<std::string, std::weak_ptr<VfsFile>, std::less<>> cache;
+    std::map<CacheKey, std::weak_ptr<VfsFile>, std::less<>> cache;
     ReferenceListType open_references;
     ReferenceListType closed_references;
     std::mutex list_lock;
@@ -117,7 +119,8 @@ class RealVfsDirectory : public VfsDirectory {
 public:
     ~RealVfsDirectory() override;
 
-    VirtualFile GetFileRelative(std::string_view relative_path) const override;
+    VirtualFile GetFileRelative(std::string_view relative_path,
+                                OpenMode perms = OpenMode::Default) const override;
     VirtualDir GetDirectoryRelative(std::string_view relative_path) const override;
     VirtualFile GetFile(std::string_view name) const override;
     VirtualDir GetSubdirectory(std::string_view name) const override;

src/core/hle/service/filesystem/filesystem.cpp

@@ -258,7 +258,7 @@ Result VfsDirectoryServiceWrapper::OpenFile(FileSys::VirtualFile* out_file,
         npath.remove_prefix(1);
     }
 
-    auto file = backing->GetFileRelative(npath);
+    auto file = backing->GetFileRelative(npath, mode);
     if (file == nullptr) {
         return FileSys::ResultPathNotFound;
     }