Re: [PATCH v7 3/5] iomap: use BIO_COMPLETE_IN_TASK for dropbehind writeback

[Christoph Hellwig <hch@infradead.org>]

On Thu, Jul 30, 2026 at 04:39:03PM -0400, Tal Zussman wrote:
> Sorry, I misunderstood and assumed you'd take care of it in a follow-up.
> I'll adjust it as below and send v8.

My plan was to move from the version you had to something better in a
follow-up.  Anyway, Jens merged it as-is so I'll look into a fixup.
Travelling for two conferences this week might make this a bit slow,
though.

> > And move setting the flag to iomap_ioend_writeback_submit, and only
> > for the case where no io_bio.bi_end_io is already assigned.
> > 
> 
> To confirm, this would only work because XFS provides its own task context
> and is the only consumer of iomap that sets its own io_bio.bi_end_io.
> If another filesystem set it and didn't provide task context, this would
> break, right? I can add a comment about this requirement, but I want to
> confirm the intent, as it feels a little fragile as-is.

Yes.  And I think this might be a good time to actually open code
iomap_ioend_writeback_submit in XFS and remove the "accept an overriden
bi_io_end" thing entirely.  Back in the original code that was required,
but now that the submission happens from a file system methods there is
no good reason for keeping it.