Re: RFC: iomap patches for zoned XFS

[Brian Foster <bfoster@redhat.com>]

On Wed, Dec 11, 2024 at 09:53:40AM +0100, Christoph Hellwig wrote:
> Hi all,
> 
> this series contains the iomap prep work to support zoned XFS.
> 
> The biggest changes are:
> 
>  - an option to reuse the ioend code for direct writes in addition to the
>    current use for buffered writeback, which allows the file system to
>    track completions on a per-bio basis instead of the current end_io
>    callback which operates on the entire I/O.
>    Note that it might make sense to split the ioend code from
>    buffered-io.c into its own file with this.  Let me know what you think
>    of that and I can include it in the next version
>  - change of the writeback_ops so that the submit_bio call can be done by
>    the file system.  Note that btrfs will also need this eventually when
>    it starts using iomap
>  - helpers to split ioend to the zone append queue_limits that plug
>    into the previous item above.
>  - a bunch of changes for slightly different merge conditions when using
>    zone append.  Note that btrfs wants something similar also for
>    compressed I/O, which might be able to share some code.  For now
>    the flags use zone append naming, but we can change that if it gets
>    used elsewhere.
>  - passing private data to a few more helper
> 
> The XFS changes to use this will be posted to the xfs list only to not
> spam fsdevel too much.
> 

Orthogonal to the couple or so questions inline, the series LGTM:

Reviewed-by: Brian Foster <bfoster@redhat.com>