Re: I wish Linux would support the Apple File System (APFS)
Just think practically:
Unless someone takes the time to code it up, port it over, test its implementation, keeps synced with all the iOS updates and features they throw into it (probably without announcement, code or assistance as this is Apple we're talking about), tests it to the extent that you're happy with putting your data on it, fight the patent fight with Apple, and then works to integrate it into the Linux kernel, it ain't gonna happen.
"Linux" isn't about a team of guys just putting in your wishlist. The central people do nothing more than approve and critique stuff other people have made. If nobody's made it, it won't get in. I think there's precisely ZIP in terms of Apple code contributions in the kernel, and even MS has huge chunks of their code in HyperV etc. compatibility modules.
So, if Apple aren't going to do it, and there's no open-source implementation of it (even NTFS had several competing implementations, one utilising the original Windows NTFS.SYS binary via a shim layer!), where's this code going to come from?
The closest I can find is this:
Which is read-only (like NTFS drivers were for years). I have no idea about Mac version numbers for compatibility so you're on your own there, but it appears to be a wrote-from-scratch, reverse-engineered module using FUSE. It's also a handful of months old. You're going to be several years down the path before that's even close to CaptiveNTFS's standard, which never made it to the kernel.
And who would benefit? People putting an Apple-formatted disk into a machine that runs Linux. That's a tiny portion of even the most techy of users.
And, looking at the code in that archive, there's literally nothing in there that's shocking or new or complicated or whole-new-levels of filesystem. It's just a bog-standard bit of coding. Sure, that's not the write-logic, including all the data-safety-guarantees and atomicity required for that (because that's the hard part), but that code is pretty indicative that APFS is really nothing very special at all.