Re: [RFC PATCH 00/80] Rust PuzzleFS filesystem driver

[Gao Xiang <hsiangkao@linux.alibaba.com>]

On 2023/6/9 20:03, Ariel Miculas (amiculas) wrote:

...

> 
> But aside from the infrastructure discussion:
> 
> This is yet another filesystem for solving the container image problem
> in the kernel with the addition of yet another filesystem. We just went
> through this excercise with another filesystem. So I'd expect some
> reluctance here. Tbh, the container world keeps sending us filesystems
> at an alarming rate. That's two within a few months and that leaves a
> rather disorganized impression.

Just a head up.  Since Rust kernel infrastructure is too premature,
it's impossible to handle page cache / iomap and many useful stuffs.
In the long term, at least (someday) after Rust infrastructure is
mature, I will implement EROFS ino Rust as a try as well.

As for chunk CDC, I don't see it's hard (since we already have some
CDC approach since Linux v6.1) but as an effective disk filesystem
for performance, EROFS on-disk data is all block-aligned to match
storage and page cache alignment.  If it's really needed, I could
update a more complete (but ineffective and slow) index version to
implement unaligned extents (both for decoded and encoded sides).
Yet I really think the main purpose of a kernel filesystem is to
make full use of kernel infrastructure for performance (like page
cache handling) otherwise a FUSE approach is enough.

Finally, as for OCI container image stuffs, I'd like to avoid
saying this topic anymore on the list (too tired about this).  I've
seen _three_ in-kernel approaches already before this one and I tend
to avoid listing the complete names (including FUSE alternatives)
here.  I really suggest if you guys could sit down and plan at least
a complete OCI standard for the next image format (even you don't
want to reuse any exist filesystem for whatever reasons).

Thanks,
Gao Xiang