XArray updates for 4.20-rc4 We found some bugs in the DAX conversion to XArray (and one bug which predated the XArray conversion). There were a couple of bugs in some of the higher-level functions, which aren't actually being called in today's kernel, but surfaced as a result of converting existing radix tree & IDR users over to the XArray. Some of the other changes to how the higher-level APIs work were also motivated by converting various users; again, they're not in use in today's kernel, so changing them has a low probability of introducing a bug. Dan can still trigger a bug in the DAX code with hot-offline/online, and we're working on tracking that down.