Re: [PATCH] xfs: Remove i_rwsem lock in buffered read

[Christoph Hellwig]

On Sat, Jan 18, 2025 at 09:19:15AM +1100, Dave Chinner wrote:
> And, quite frankly, the fact the bcachefs solution also covers AIO
> DIO in flight (which i_rwsem based locking does not!) means it is a
> more robust solution than trying to rely on racy i_dio_count hacks
> and folio residency in the page cache...

The original i_rwsem (still i_iolock then) scheme did that, but the
core locking maintainers asked us to remove the non-owner unlocks,
so I did that.  It turns out later we got officially sanctioned
non-owner unlocks, so we could have easily add this back.  I did that
5 years ago, but reception was lukewarm:

http://git.infradead.org/?p=users/hch/xfs.git;a=shortlog;h=refs/heads/i_rwsem-non_owner