service/fsp_srv: Implement CleanDirectoryRecursively

This is the same behavior-wise as DeleteDirectoryRecursively, with the
only difference being that it doesn't delete the top level directory in
the hierarchy, so given:

root_dir/
  - some_dir/
    - File.txt
  - OtherFile.txt

The end result is just:

root_dir/

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

@@ -113,6 +113,18 @@ ResultCode VfsDirectoryServiceWrapper::DeleteDirectoryRecursively(const std::str
     return RESULT_SUCCESS;
 }
 
+ResultCode VfsDirectoryServiceWrapper::CleanDirectoryRecursively(const std::string& path) const {
+    const std::string sanitized_path(FileUtil::SanitizePath(path));
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(sanitized_path));
+
+    if (!dir->CleanSubdirectoryRecursive(FileUtil::GetFilename(sanitized_path))) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+
+    return RESULT_SUCCESS;
+}
+
 ResultCode VfsDirectoryServiceWrapper::RenameFile(const std::string& src_path_,
                                                   const std::string& dest_path_) const {
     std::string src_path(FileUtil::SanitizePath(src_path_));

src/core/hle/service/filesystem/filesystem.h

@@ -113,6 +113,18 @@ public:
      */
     ResultCode DeleteDirectoryRecursively(const std::string& path) const;
 
+    /**
+     * Cleans the specified directory. This is similar to DeleteDirectoryRecursively,
+     * in that it deletes all the contents of the specified directory, however, this
+     * function does *not* delete the directory itself. It only deletes everything
+     * within it.
+     *
+     * @param path Path relative to the archive.
+     *
+     * @return Result of the operation.
+     */
+    ResultCode CleanDirectoryRecursively(const std::string& path) const;
+
     /**
      * Rename a File specified by its path
      * @param src_path Source path relative to the archive

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

@@ -291,7 +291,7 @@ public:
             {10, &IFileSystem::Commit, "Commit"},
             {11, nullptr, "GetFreeSpaceSize"},
             {12, nullptr, "GetTotalSpaceSize"},
-            {13, nullptr, "CleanDirectoryRecursively"},
+            {13, &IFileSystem::CleanDirectoryRecursively, "CleanDirectoryRecursively"},
             {14, nullptr, "GetFileTimeStampRaw"},
             {15, nullptr, "QueryEntry"},
         };
@@ -361,6 +361,16 @@ public:
         rb.Push(backend.DeleteDirectoryRecursively(name));
     }
 
+    void CleanDirectoryRecursively(Kernel::HLERequestContext& ctx) {
+        const auto file_buffer = ctx.ReadBuffer();
+        const std::string name = Common::StringFromBuffer(file_buffer);
+
+        LOG_DEBUG(Service_FS, "called. Directory: {}", name);
+
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(backend.CleanDirectoryRecursively(name));
+    }
+
     void RenameFile(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};