https://arstechnica.com/gadgets/2020/01/linus-torvalds-zfs-statements-arent-right-heres-the-straight-dope/

Last Monday in the "Moderated Discussions" forum at realworldtech.com, Linus Torvalds—founding developer and current supreme maintainer of the Linux kernel—answered a user's question about a year-old kernel maintenance controversy that heavily impacted the ZFS on Linux project. After answering the user's actual question, Torvalds went on to make inaccurate and damaging claims about the ZFS filesystem itself.

Given the massive weight automatically given Torvalds' words due to his status as founding developer and chief maintainer of the Linux kernel, we feel it's a good idea to explain both the controversial kernel change itself, and Torvalds' comments about both the change in question and the ZFS filesystem.