Re: [PATCH 7/7] dm: call dm_zone_endio after the target endio callback for zoned devices

[Christoph Hellwig]

On Fri, Jan 06, 2023 at 09:33:17AM +0100, Pankaj Raghav wrote:
> dm_zone_endio() updates the bi_sector of orig bio for zoned devices that
> uses either native append or append emulation, and it is called before the
> endio of the target. But target endio can still update the clone bio
> after dm_zone_endio is called, thereby, the orig bio does not contain
> the updated information anymore.
> 
> Currently, this is not a problem as the targets that support zoned devices
> such as dm-zoned, dm-linear, and dm-crypt do not have an endio function,
> and even if they do (such as dm-flakey), they don't modify the
> bio->bi_iter.bi_sector of the cloned bio that is used to update the
> orig_bio's bi_sector in dm_zone_endio function.
> 
> Call dm_zone_endio for zoned devices after calling the target's endio
> function.

This looks sensible, but I fail to see why we need this or how it fits
into the earlier block layer part of the series.