Re: [PATCH v14 00/74] Convert page cache to XArray

[Matthew Wilcox]

On Fri, Jul 27, 2018 at 11:20:35AM -0600, Ross Zwisler wrote:
> Okay, the next failure I'm hitting is with DAX + XFS + generic/344.  It
> doesn't happen every time, but I can usually recreate it within 10 iterations
> of the test.  Here's the failure:

Thanks.  I've made some progress with this; the WARNing is coming from
a vm_insert_* mkwrite call.  Inserting sufficient debugging code has
let me determine we still have a zero_pfn in the page table when we're
trying to insert a new PFN.