My naive implementation (as shown in the linked question) in Rust was mind boggling slow. C could do around 150MiB/s, while Rust could only do 10MiB/s. A simple `objdump -d` shows Rust is generating a lot more code. I'm not sure how much of that is relevant though.
At that point my coffee time ran out. I wish I had more time to figure out why. :-(
> Btrfs has had no real work done on it since then, and anyone that is actually serious about data storage has moved to ZFS, or has left POSIX filesystems entirely.
I'm not very familiar with this space, but if this were true why would Fedora use Btrfs by default?
Also on Fedora wiki [0] -- Btrfs is a mature, well-understood, and battle-tested file system, used on both desktop/container and server/cloud use-cases -- which seems to contradict what you said.
Linux is well funded in the sense that corporations put big money looking after their own interest in the kernel. Anything outside of their respective areas of interest? Good luck.
Paragon, for better or worse, is just yet another corporation. They shouldn't really expect other corporations or volunteers to care much about their code, other than the fact that their code may break others'.
Now that they have Linus' blessing, they can just send a pull request. The work paid off in the end.
At that point my coffee time ran out. I wish I had more time to figure out why. :-(