Re: [RFC 00/23] Enable block size > page size in XFS

[Matthew Wilcox]

On Fri, Sep 15, 2023 at 08:38:25PM +0200, Pankaj Raghav wrote:
> Only XFS was enabled and tested as a part of this series as it has
> supported block sizes up to 64k and sector sizes up to 32k for years.
> The only thing missing was the page cache magic to enable bs > ps. However any filesystem
> that doesn't depend on buffer-heads and support larger block sizes
> already should be able to leverage this effort to also support LBS,
> bs > ps.

I think you should choose whether you're going to use 'bs > ps' or LBS
and stick to it.  They're both pretty inscrutable and using both
interchanagbly is worse.

But I think filesystems which use buffer_heads should be fine to support
bs > ps.  The problems with the buffer cache are really when you try to
support small block sizes and large folio sizes (eg arrays of bhs on
the stack).  Supporting bs == folio_size shouldn't be a problem.