Re: [PATCH v3 11/28] iomap: pass readpage operation to read path

Andrey Albershteyn
2023-10-16T12:33:18Z

On 2023-10-16 02:15:00, Christoph Hellwig wrote:
> Looking at the entire series, it seems like the only XFS-specific
> part of the fsverity processing in iomap is the per-sb workqueue
> now that the fsverity interfaces were cleaned up.
>
> Based on that it seems like we'd be much better just doing all the
> work inside iomap, and just allow XFS to pass the workqueue to
> iomap_read_folio and iomap_readahead. The patch below does that
> as an untested WIP on top of your branch.
>
> If we go down that way I suspect the better interface would be
> to allocate the iomap_readpage_ctx in the callers of these functions
> instead of passing an extra argument, but I'm not entirely sure
> about that yet.

From the discussion in v2 [1] I understood that btrfs would like to
have this bio_set/submit_io interface for iomap transition; and any
other filesystem deferrals would also be possible. Is it no more the
case with btrfs? Would fs-verity verification in iomap_read_end_io
combine both solutions (fs-verity verification in iomap +
submit_io/bio_set interface).

[1]: https://lore.kernel.org/linux-xfs/ZCxEHkWayQyGqnxL@infradead.org/#t

--
- Andrey