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

[Pankaj Raghav]

On 2023-09-15 20:50, Matthew Wilcox wrote:
> 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.
> 

Got it! Probably I will stick to Large block size and explain what it means
at the start of the patchset.

> 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.
> 

I remember some patches from you trying to avoid the stack limitation while working
with bh. Thanks for the clarification!