On Fri, Dec 17, 2021 at 10:48:22AM +1100, NeilBrown wrote:

Some caller currently call blk_finish_plug() *before* the final call to
swap_readpage(), so the last page cannot be included.  This patch moves
blk_finish_plug() to after the last call, and calls swap_read_unplug()
there too.

Can you move this fix into a separate prep patch, preferably with a
Fixes tag so that it gets picked up for backports?

Otherwise this looks sensible to me.