Re: [PATCH RFC v4 2/3] iomap: use BIO_COMPLETE_IN_TASK for dropbehind writeback

[Christoph Hellwig]

On Wed, Mar 25, 2026 at 08:21:28PM +0000, Matthew Wilcox wrote:
> > +	if (ioend_flags & IOMAP_IOEND_DONTCACHE)
> > +		bio_set_flag(bio, BIO_COMPLETE_IN_TASK);
> >  	wbc_init_bio(wpc->wbc, bio);
> >  	wpc->nr_folios = 0;
> >  	return iomap_init_ioend(wpc->inode, bio, pos, ioend_flags);
> 
> Can't we delete IOMAP_IOEND_DONTCACHE, and just do:
> 
> 	if (folio_test_dropbehind(folio))
> 		bio_set_flag(&ioend->io_bio, BIO_COMPLETE_IN_TASK);
> 
> It'd need to move down a few lines in iomap_add_to_ioend() to after
> bio_add_folio() succeeds.

Yes, that sounds sensible.