Re: [RFC v2 0/8] add support for blocksize > PAGE_SIZE

From: Matthew Wilcox
Date: Fri May 26 2023 - 09:54:25 EST

On Fri, May 26, 2023 at 12:55:44AM -0700, Luis Chamberlain wrote:
> This is an initial attempt to add support for block size > PAGE_SIZE for tmpfs.
> Why would you want this? It helps us experiment with higher order folio uses
> with fs APIS and helps us test out corner cases which would likely need
> to be accounted for sooner or later if and when filesystems enable support
> for this. Better review early and burn early than continue on in the wrong
> direction so looking for early feedback.

I think this is entirely the wrong direction to go in.

You're coming at this from a block layer perspective, and we have two
ways of doing large block devices -- qemu nvme and brd. tmpfs should
be like other filesystems and opportunistically use folios of whatever
size makes sense.

Don't add a mount option to specify what size folios to use.