VFS: Add documentation for Virtual File System Part 1

[sigmanature]

Description

Hello! I am an undergraduate student passionate about the Linux kernel. I have previously contributed an RFC patch for large folios to the f2fs community.

This is my first pull request to linux-insides. My goal is to start writing a new series of articles for the Virtual File System (VFS) section. This first article serves as an introduction to VFS, explaining its role as an abstraction layer that provides a unified interface for filesystems, and introduces its core data structures.

Changes proposed in this pull request:

• Add the new VFS/ directory.
• Add the new article VFS/linux-vfs-1.md.
• Add a VFS/README.md for future planning.

Questions for the Maintainer

Before I proceed with further work, I have a few questions about the project's contribution style and direction. I would greatly appreciate your guidance:

1. Writing Style: I've noticed that most linux-insides articles focus on code and flow analysis. Do you have any specific style guidelines? Would you encourage the use of more diagrams to aid explanation?
2. External Links: I'd like to cite some high-quality technical articles from the Chinese community, especially if my work is inspired by or references them. Is this acceptable?
3. Modifying Existing Content: Is it permissible to modify existing articles? Some changes might be substantial.
4. Chapter Structure: Some complex topics (like mount in VFS) might be best explained in several sub-parts. This structure doesn't seem to be used in existing articles. What are your thoughts on this approach?
5. Code Evolution: Many kernel subsystems (like swap in the mm subsystem) have undergone significant changes since kernel 3.18. I think it could be valuable to analyze the code from different versions to show the evolution and motivation. What do you think of this idea for future articles?

Thank you for your time and for reviewing my contribution. I look forward to your feedback!

Related issues
N/A

[0xAX]

Hello @sigmanature. First of all thank you for your work!

Writing Style: I've noticed that most linux-insides articles focus on code and flow analysis. Do you have any specific style guidelines? Would you encourage the use of more diagrams to aid explanation?

There is no any guidelines since somewhen I started to write it for myself mostly. Actually any information about the kernel and its parts is appreciated. For the start it is ok I think if you will more-less follow the common structure that each part has - short introduction, main part, conclusion, links.

External Links: I'd like to cite some high-quality technical articles from the Chinese community, especially if my work is inspired by or references them. Is this acceptable?

It is ok in general but may look somewhat strange if the articles themselves are written in Chinese. Usually each part as you probably have seen ends with links, I think it is pretty ok to have a small note that in addition these links were used.

Modifying Existing Content: Is it permissible to modify existing articles? Some changes might be substantial.

Of course, if you see something wrong, outdated or just you have better phrasing feel free to open PR.

Chapter Structure: Some complex topics (like mount in VFS) might be best explained in several sub-parts. This structure doesn't seem to be used in existing articles. What are your thoughts on this approach?

In this case I'd usally go with 'Main title. Part 1'

Code Evolution: Many kernel subsystems (like swap in the mm subsystem) have undergone significant changes since kernel 3.18. I think it could be valuable to analyze the code from different versions to show the evolution and motivation. What do you think of this idea for future articles?

It is always interesting from the historical perspective especially with description why it was changed. But of course it is always good to have the latest code despite any previous. I know and understand how hard it can be since the kernel is constantly developed.

The very first thing related to the review could you please add an annotation to each code snippet in your article. The examples you can find in any .md file in Booting. For example:

<!-- https://raw.githubusercontent.com/coreboot/coreboot/refs/heads/main/src/cpu/x86/entry16.S#L155-L159 -->

they are visible only in raw format - https://raw.githubusercontent.com/0xAX/linux-insides/refs/heads/master/Booting/linux-bootstrap-1.md. They are used by the script https://github.com/0xAX/linux-insides/blob/master/scripts/check_code_snippets.py that checks that the code snippets are valid and exist in the current kernel master branch. If I was not clear or you need help please let me know.

The content itself I will review at this week. Thank you again very much.