On Thu, Aug 12, 2021 at 09:22:41PM +0100, David Howells wrote:

[!] NOTE: This doesn't work and might damage your disk's contents.

Delete the BIO-generating swap read/write paths and always use
->direct_IO().  This puts the mapping layer in the filesystem.

This doesn't work - probably due to ki_pos being set to
page_file_offset(page) which then gets remapped.

Also because most common block file systems do not actually implement
a ->direct_IO that does anything (noop_direct_IO).