"performant", it's still slow if you actually use any of the advanced features like copy on write.

Every CoW filesystem is just as slow. There's no magic pill to fix performance but it's a known tradeoff.

	▲	koverstreet a day ago \| parent [-]
		Not inherently. Early bcachefs was ridiculously fast, it's gotten slower as we've grown all the features to compete with ZFS. All the database stuff that gives us amazing flexibility adds overhead (the btree iterator code has gotten fat), backpointers and modern accounting blew up our journalling overhead. A lot things that we needed for scalability, or hardening/self healing, have added overhead. COW really isn't the main thing, it's cramming all the features in that we want these days while keeping the fastpaths fast that's the tricky part. But, a lot of this stuff is fixable - performance just hasn't been the priority, since the actual users aren't complaining about performance and are instead clamoring for things like erasure coding. (and, the performance numbers that I've seen comparing us to ZFS still put us _significantly faster)