Lets forget the licensing entirely. ZFS was built ontop of the Solaris VFS layer (virtual file system), which is entirely different than the Linux VFS. Taking the code in the Solaris kernel that provides ZFS and porting it to the Linux VFS is a massive undertaking that would require rewriting most of the "stable" guts of ZFS.
Honestly other than the fuse stuff, I doubt ZFS will ever be in Linux as it would require a rewrite of such a large portion of code, it would be impractical.
> Taking the code in the Solaris kernel that provides ZFS and porting it to the Linux VFS is a massive undertaking that would require rewriting most of the "stable" guts of ZFS.
And it's been done and working quite well considering. There still are improvements to be made, but progress is happening.
I don't mean adding solaris / illumos interfaces (see slide 8 on your link) into the Linux kernel. That will simply never be accepted upstream. I mean properly porting it from the Solaris to the Linux VFS without a shim ie a native port.
That still has not been done. It is a ridiculous amount of work.
Wait, if the current Linux ZFS module doesn't interface with the Linux VFS, then how does the filesystem even work? Did they write a Solaris VFS -> Linux VFS bridge?
"""
Solaris Porting Layer
- Adds stable Solaris/Illumos interfaces
* Tasqs, lists, condition variables, rwlocks, memory allocators, etc
- Layers ontop of Linux equivalents if available
- Solaris specific interfaces were implemented from scratch
"""
It doesn't (currently) use the Linux page cache, which causes quite a few ancillary issues. The idea is awesome, but this will simply never be able to be "natively" in linux without a rewrite of much of the core.
Honestly other than the fuse stuff, I doubt ZFS will ever be in Linux as it would require a rewrite of such a large portion of code, it would be impractical.