tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: unhooking lfs from ufs


Eduardo Horvath wrote:
On Sun, 7 Feb 2010, David Holland wrote:

Anyhow, it seems to me that isolating it from changes to ffs is likely
to result in less breakage over time, not more. Can you expand on your
reasoning some?

The most significant parts that are shared are the directory ops and the read/write routeines.

The directory ops are essentially FFS code with an LFS wrapper around it. Right now any ffs bugfixes for those used directly by LFS. The read/write routines also share about 80% of the code. I suppose there is a better case for separating these out if it makes code maintenance easier.

If we were to separate them out then every time someone fixes a problem with FFS, the same changes would be required to be made for LFS. Historically this has not happened. When you look at UVM or UBC integration, there were long periods of time when LFS was unusable because that filesystem has been considered of secondary importance.

So, the fact that the code was shared did indeed *not* make FFS fixes also flow over into LFS? (I assume that FFS was fixed for those things in short order.)
That would, in my eyes, mean that this argument isn't valid.

LFS has a rather small user base since it's historically been considered experimental and most machines can't boot from it. Few people use it and fewer still work on it.

Indeed. I tried LFS a few times many years ago, but had some problems with it, along with the "experimenal" status of it, which made me stop trying.

I would love to hear someone allay my fears, but I think segregating the LFS code from the FFS code will accelerate the bitrot and the final result will be removal of the LFS code.

I can't alleviate your fears, however, it appears to me that the assumption that LFS benefits from sharing code with FFS is wrong, or atleast exaggerated. Looking at how the LFS code have had problems for extended periods, even with shared code with FFS suggests that LFS have not really gained much from that sharing.

Having the code split, and then possibly getting it leaner and cleaner, looks like a potential gain atleast.


Home | Main Index | Thread Index | Old Index