Virtual File System MTT

Brilliant, incredible, amazing plan:

Part 0:

1. Setup environment (not to break computers) --> cygwin(?) or VirtualBox

Part 1: File System Setup and Initialization

1. File System Initialization:
   • Create executable file
   • Interpret console commands (parser)
   • Initialize the file system structures and metadata for managing the single file within the VFS (Connect VFS and FS + buffer cache)
   • Structure which filled with pointers to corresponding FS driver functions (esp_vfs_t)
   • File Descriptors: mapping global file descriptors to VFS driver indexes registered in the array.
   • Master File Table: Contains metadata of file
   • Registration - we should register FS we work with. Kinda:

esp_vfs_t myfs = {
            .flags = ESP_VFS_FLAG_DEFAULT,
            .write = &myfs_write,
            .open = &myfs_open,
            .fstat = &myfs_fstat,
            .close = &myfs_close,
            .read = &myfs_read,
            };
ESP_ERROR_CHECK(esp_vfs_register("/data", &myfs, NULL));

2. File System Read and Write Operations:
   • Operations: read and write operations (to interact with the single file).
   • Functions: opening, closing, and modifying the file content.

Part 2: File System Operations and Management

1. File Manipulation Operations:

   • Operations: creating, deleting, copying, moving, and renaming the single file.
   • Functions: modifying file properties and contents.

2. File System Security and Permissions:

   • Security mechanisms: file access control (security descriptor), permissions, and ownership settings.

3. File System Navigation and Search:

   • Functions: navigating, accessing, and searching.
   • Maybe retrieval mechanisms.

TODO:

1. Error Handling and Logging:

   • Handle exceptions, errors.
   • Log file system activities.

2. User Interface and Interaction:

   • UI.
   • Should it be like Far? idk.

Optional:

1. File Metadata Handling:

   • Manage file metadata (file attributes, permissions etc).
   • Mechanisms to store and update file metadata.
   • Possible entities for metadata:
     • Superblock
     • inode
     • file
     • dentry
   • Metadata interact using (maybe) next subsystems:
     • dentry cache
     • inode cache
     • buffer cache

2. The structure includes several main components that allow you to abstract from a specific system and provide a unified interface for working with files and directories. These include:

   • interfaces;
   • file table;
   • file descriptor table;
   • drivers;
   • cache;
   • system calls.

Nice and useful links:

1. OSDev: https://wiki.osdev.org/VFS

2. Wikipedia: https://en.wikipedia.org/wiki/Virtual_file_system

3. LINUX LAB WITH EXAMPLES!!!!: https://linux-kernel-labs.github.io/refs/pull/165/merge/labs/filesystems_part1.html https://linux-kernel-labs.github.io/refs/pull/165/merge/labs/filesystems_part2.html

4. How to write custom vfs: https://support.kaspersky.ru/help/KCE/1.1/en-US/vfs_backends.htm

5. Really useful: https://www.quora.com/How-can-I-implement-a-virtual-file-system-using-C-or-C++-Can-you-please-share-some-code

6. Our google file: https://docs.google.com/document/d/1NtjZ_1by78jzoXFTpV_xjDl8-KFVUTvta4vsJ2M6H_U/edit?pli=1