On 2/19/22 9:38 PM, Jens Axboe wrote: > On 2/19/22 9:23 PM, Matthew Wilcox wrote: >> On Fri, Feb 18, 2022 at 11:35:10PM -0800, Christoph Hellwig wrote: >>> Err, hell no. Please do not add any new functionality to the legacy >>> buffer head code. If you want new features do that on the >>> non-bufferhead iomap code path only please. >> >> I think "first convert the block device code from buffer_heads to >> iomap" might be a bit much of a prerequisite. I think running ext4 on >> top of a > > Yes, that's exactly what Christoph was trying to say, but failing to > state in an appropriate manner. And we did actually discuss that, I'm > not against doing something like that. Just to be clear, I do agree with you that it's an unfair ask for this change. And as you mentioned, ext4 would require the buffer_head code to be touched anyway, just layering on top of the necessary changes for the bdev code. -- Jens Axboe