Re: [PATCH v3] fs/buffer.c: update per-CPU bh_lru cache via RCU

[Christoph Hellwig]

On Fri, Feb 03, 2023 at 09:36:53AM +1100, Dave Chinner wrote:
> Rather than adding more complexity to the legacy bufferhead code,
> wouldn't it be better to switch the block device mapping to use
> iomap+folios and get rid of the use of bufferheads altogether?

It's not that simple unfortunately :(  All file systems that use
buffer heads also use them on the block device for metadata.  I have
a WIP block device iomap conversion, but it still has to offer
buffer_heads similar to the legacy path in iomap to make all that
work.