On Fri, Jun 23, 2023 at 03:08:52PM +0000, Song Liu wrote:

Please let me know if you need set #1 (deprecate file bitmap) to 
unblock other work. Otherwise, we will delay it until 6.6. 

It was intended so that we don't have to make all of md depend on
the new config option for buffers heads I plan to introduce.  So it's
a bit of a pity that we won't have it for 6.5, but not a deal breaker.