Design documents and specification of Ext4 ?

[quanganht]

Seems like there are so few documents about this file system around the Internet. And the one that I got (named ext4-foss) is not detailed enough to makke an implementation. Any idea?

[f2]

The "ext4" article on Wikipedia has some useful links: http://en.wikipedia.org/wiki/Ext4.

[quanganht]

Looked at some of those

[Love4Boobies]

The official web page can be found here. However, as with Linux-related projects in general, the code is the documentation.

Read the documentation!

But there is none...

Read it anyway!

[quanganht]

But the code in Linux will have dependencies on Linux. Spliting it out is a PITA

[pcmattman]

But the code in Linux will have dependencies on Linux.

There's a difference between reading and outright copying code.

You can easily read code and take the algorithms and concepts and apply them to your own, manually-written code. Copying it directly is much harder (and you don't learn anything).

If you're looking for code to copy directly, that's why you can't find anything useful.

[quanganht]

well I don't plan to copy any ****. But consider that I will have to read, say, half a kernel to understand how the file system work. It is bloody stupid. I want to do my own implementation, based on the design of ext4.

[Brynet-Inc]

well I don't plan to copy any ****. But consider that I will have to read, say, half a kernel to understand how the file system work. It is bloody stupid. I want to do my own implementation, based on the design of ext4.

Well I vana toilet made out of solid gold, but it's just not in the cards now is it?

[Love4Boobies]

well I don't plan to copy any ****. But consider that I will have to read, say, half a kernel to understand how the file system work. It is bloody stupid. I want to do my own implementation, based on the design of ext4.

Erm. Have you ever read any source code before?

[quanganht]

Erm. Have you ever read any source code before?

Yes

[Combuster]

At least you didn't seem to have tried this particular case.

I know of Linux (and X.org) that you do not need to see anything beyond the driver itself to know how it works. I didn't read the entire source code to the kernel to know what hardware registers are responsible for what bit of 3D... Its none of the core kernel's business.

[Love4Boobies]

That's a lie! You actually need to read everything and even the sources of some unrelated projects (it doesn't matter which, though).

[Combuster]

What things do you think I read to reverse engineer enough to write my current Verite code?

Answer: only what was in the xf86-video-rendition package
For Ati Mach64, it was only linux/drivers/video/aty

I win.

[quanganht]

Unfortunately I'm not that genius

[Love4Boobies]

Again, Combuster lies! He also read the unreleased source code for Minesweeper.

Ok, but jokes aside, I've looked a little through the ext4 code. You'll manage easily.