On Mon, Dec 07, 2020 at 03:13:52PM +0800, Qu Wenruo wrote: > >From the initial merge of btrfs, there is always the mystery cow fixup. For the record, the code needs to stay for because it's still needed. Though finding the exact point where it happens on intel architectures is not easy, it's required on s390 because of the separate page bits tracking at least. How exactly it works and why the code exists is left as an exercise to the reader.
