Re: [LSF/MM/BPF TOPIC] Sunsetting buffer_heads

[Hannes Reinecke <hare@suse.de>]

On 4/12/23 15:16, Matthew Wilcox wrote:
> On Wed, Apr 12, 2023 at 12:18:29PM +0200, Hannes Reinecke wrote:
>> Ceterum censeo ...
>>
>> Having looked at implementing large blocksizes I constantly get bogged down
>> by buffer_heads and being as they are intricately linked into filesystems
>> and mm.
>>
>> And also everyone seems to have agreed to phase out buffer_heads eventually.
>>
>> So maybe it's time to start discussing exactly _how_ this could be done.
>> And LSF/MM seems to be the idea location for it.
>>
>> So far I've came across the following issues:
>>
>> - reading superblocks / bread(): maybe convert to ->read_folio() ?
>> - bh_lru and friends (maybe pointless once bread() has been converted)
>> - How to handle legacy filesystems still running on buffer_heads
>>
>> I'm sure this is an incomplete list, and I'm equally sure that several
>> people have their own ideas what should or need to be done.
>>
>> So this BOF will be about collecting these ideas and coming up with a design
>> how we can deprecated buffer_heads.
> 
> Might be worth reviewing this thread:
> 
> https://lore.kernel.org/linux-fsdevel/20230129044645.3cb2ayyxwxvxzhah@garbanzo/

A-ha. So I'm not alone.

Please count me in in that session.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
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