NILFS: the New Implementation of a Log-structured File System

NILFS: the New Implementation of a Log-structured File System

[amagai]

Hello,

We are developing an LFS for Linux 2.6, named Nilfs (the New
Implementation of a Log-structured File System).  We implemented NILFS
using modern technology, for example, file and inode blocks are
managed by B-trees, internal data is processed in 64 bit wide word
size.  The NILFS also supports snapshots.  The snapshots are
automatically hold without any explicit requests, snapshot can be mounted
as a read-only file system.

The latest version is available on the NILFS WEB site  http://www.nilfs.org/
Comments are welcome!

Thank you!

AMAGAI Yoshiji
Nippon Telegraph and Telephone Corporation
NTT Cyber Space Laboratories
Open Source Software Computing Project
Kernel Team

nilfs@osrg.net

Re: NILFS: the New Implementation of a Log-structured File System

[Jörn Engel]

On Mon, 26 September 2005 15:20:26 +0900, amagai@osrg.net wrote:
> 
> We are developing an LFS for Linux 2.6, named Nilfs (the New
> Implementation of a Log-structured File System).  We implemented NILFS
> using modern technology, for example, file and inode blocks are
> managed by B-trees, internal data is processed in 64 bit wide word
> size.  The NILFS also supports snapshots.  The snapshots are
> automatically hold without any explicit requests, snapshot can be mounted
> as a read-only file system.
> 
> The latest version is available on the NILFS WEB site  http://www.nilfs.org/
> Comments are welcome!

o The spagetti in nilfs_check_page() might want a cleanup. :)
o nilfs_type_by_mode is a strange concept.  Do you really want to
  compress the 4 bits for file types to 3 bits?  With union mount,
  you'd already need whiteouts, so you have used all 8 possible file
  types.  Not sure if anything else could come up in the future.

Interesting stuff.  When do you aim for kernel inclusion?

Jörn

-- 
Admonish your friends privately, but praise them openly.
-- Publilius Syrus 
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Re: [nilfs] Re: NILFS: the New Implementation of a Log-structured File System

[Seiji Kihara]

Hello,

Thank you for comments!  The message below are from Amagai.
Regards,

Seiji

==================================================================
Joern, thank you for comments!

> o The spagetti in nilfs_check_page() might want a cleanup. :)
> o nilfs_type_by_mode is a strange concept.  Do you really want to

The nilfs_check_page() and nilfs_type_by_mode(), or fs/dir.c itself
are modified version of linux/fs/ext2/dir.c.  Current NILFS directory
implementation is a tentative version.

We have a plan to rewrite the NILFS directory mechanism using B-tree
structures.

> Interesting stuff.  When do you aim for kernel inclusion?

There are too many things to do to stabilize the NILFS, and we have
not discussed the attractive theme yet.

================
AMAGAI Yoshiji
Nippon Telegraph and Telephone Corporation
NTT Cyber Space Laboratories
Open Source Software Computing Project
Kernel Team

Re: NILFS: the New Implementation of a Log-structured File System

[Pradeep Padala]

Hi Amagai,

> We are developing an LFS for Linux 2.6, named Nilfs (the New
> Implementation of a Log-structured File System).  We implemented NILFS
> using modern technology, for example, file and inode blocks are
> managed by B-trees, internal data is processed in 64 bit wide word
> size.  The NILFS also supports snapshots.  The snapshots are
> automatically hold without any explicit requests, snapshot can be mounted
> as a read-only file system.

I will have a closer look at the code, and see how we can merge our work
(I am assuming that you are interested in merging). Did you get a chance
to look at my code at http://logfs.sourceforge.net?

-- 
Pradeep Padala
http://ppadala.blogspot.com