Pass simplifiedCustomData to fs mkdir call during slimInit. (#23572)

## Description
Pass simplifiedCustomData to fs mkdir call during slimInit, to support a
particular AFR use case during container creation, which requires
information from simplifiedCustomData.
This is a follow up change of
#23354

server/gitrest/packages/gitrest-base/src/utils/definitions.ts

@@ -4,6 +4,7 @@
  */
 
 import fsPromises from "fs/promises";
+import type { MakeDirectoryOptions } from "fs";
 import * as git from "@fluidframework/gitresources";
 
 export enum Constants {
@@ -104,6 +105,10 @@ export interface IFileSystemManagerFactories {
 	ephemeralFileSystemManagerFactory?: IFileSystemManagerFactory;
 }
 
+export interface IFileSystemMakeDirectoryOptions extends MakeDirectoryOptions {
+	simplifiedCustomData?: string;
+}
+
 export interface IStorageRoutingId {
 	tenantId: string;
 	documentId: string;

server/gitrest/packages/gitrest-base/src/utils/index.ts

@@ -12,6 +12,7 @@ export {
 	IFileSystemManagerFactories,
 	IFileSystemManagerFactory,
 	IFileSystemManagerParams,
+	IFileSystemMakeDirectoryOptions,
 	IFileSystemPromises,
 	IRepoManagerParams,
 	IRepositoryManager,

server/gitrest/packages/gitrest-base/src/utils/isomorphicgitManager.ts

@@ -12,6 +12,8 @@ import {
 	IExternalWriterConfig,
 	IFileSystemManager,
 	IFileSystemManagerFactories,
+	IFileSystemManagerParams,
+	IFileSystemMakeDirectoryOptions,
 	IRepositoryManager,
 	IStorageDirectoryConfig,
 } from "./definitions";
@@ -397,9 +399,13 @@ export class IsomorphicGitManagerFactory extends RepositoryManagerFactoryBase<vo
 		);
 	}
 
-	protected async initGitRepo(fs: IFileSystemManager, gitdir: string): Promise<void> {
+	protected async initGitRepo(
+		fs: IFileSystemManager,
+		gitdir: string,
+		fsParams: IFileSystemManagerParams | undefined,
+	): Promise<void> {
 		return this.enableSlimGitInit
-			? this.slimInit(fs, gitdir)
+			? this.slimInit(fs, gitdir, fsParams)
 			: isomorphicGit.init({
 					fs,
 					gitdir,
@@ -442,7 +448,21 @@ export class IsomorphicGitManagerFactory extends RepositoryManagerFactoryBase<vo
 	 *
 	 * This brings file reads from 1 to 0, and writes from 10 to 3.
 	 */
-	private async slimInit(fs: IFileSystemManager, gitdir: string): Promise<void> {
+	private async slimInit(
+		fs: IFileSystemManager,
+		gitdir: string,
+		fsParams: IFileSystemManagerParams | undefined,
+	): Promise<void> {
+		const splfCustomData = fsParams?.simplifiedCustomData;
+		if (splfCustomData) {
+			// Only pass valid simplifiedCustomData to rootdir in fs mkdir call during slimInit
+			const mkdirOptions: IFileSystemMakeDirectoryOptions = {
+				recursive: false,
+				simplifiedCustomData: splfCustomData,
+			};
+			await fs.promises.mkdir(gitdir, mkdirOptions);
+		}
+
 		const folders = ["objects", "refs/heads"].map((dir) => `${gitdir}/${dir}`);
 		for (const folder of folders) {
 			await fs.promises.mkdir(folder, { recursive: true });

server/gitrest/packages/gitrest-base/src/utils/repositoryManagerFactoryBase.ts

@@ -12,6 +12,7 @@ import {
 	Constants,
 	IFileSystemManager,
 	IFileSystemManagerFactories,
+	IFileSystemManagerParams,
 	IRepoManagerParams,
 	IRepositoryManager,
 	IRepositoryManagerFactory,
@@ -42,7 +43,11 @@ export abstract class RepositoryManagerFactoryBase<TRepo> implements IRepository
 	) => Promise<IRepositoryManager>;
 	// Cache repositories to allow for reuse
 	protected readonly repositoryCache = new Map<string, TRepo>();
-	protected abstract initGitRepo(fs: IFileSystemManager, gitdir: string): Promise<TRepo>;
+	protected abstract initGitRepo(
+		fs: IFileSystemManager,
+		gitdir: string,
+		fsParams: IFileSystemManagerParams | undefined,
+	): Promise<TRepo>;
 	protected abstract openGitRepo(gitdir: string): Promise<TRepo>;
 	protected abstract createRepoManager(
 		fileSystemManager: IFileSystemManager,
@@ -81,7 +86,11 @@ export abstract class RepositoryManagerFactoryBase<TRepo> implements IRepository
 			lumberjackBaseProperties: Record<string, any>,
 		) => {
 			// Create and then cache the repository
-			const repository = await this.initGitRepo(fileSystemManager, gitdir);
+			const repository = await this.initGitRepo(
+				fileSystemManager,
+				gitdir,
+				params.fileSystemManagerParams,
+			);
 			this.repositoryCache.set(repoPath, repository);
 			Lumberjack.info("Created a new repo", {
 				...lumberjackBaseProperties,