Re: [PATCH v7 04/13] btrfs: add support for inserting raid stripe extents

[Christoph Hellwig <hch@lst.de>]

On Wed, Mar 08, 2023 at 09:11:54AM +0000, Johannes Thumshirn wrote:
> @@ -393,10 +378,12 @@ static void btrfs_orig_write_end_io(struct bio *bio)
>                 stripe->physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
>  
>         if (btrfs_need_stripe_tree_update(bioc->fs_info, bioc->map_type)) {
> +               struct btrfs_ordered_extent *oe;
> +
> +               oe = btrfs_lookup_ordered_extent(bbio->inode, bbio->file_offset);
> +               btrfs_get_bioc(bioc);
> +               oe->bioc = bioc;
> +               btrfs_put_ordered_extent(oe);


> +       } else if (ordered_extent->bioc) {
> +               ret = btrfs_add_ordered_stripe(ordered_extent->bioc);
> +               btrfs_put_bioc(ordered_extent->bioc);
> +               if (ret)
> +                       goto out;

Given that btrfs_add_ordered_stripe only really builds the
btrfs_ordered_stripe structure and inserts it into the tree,
can't we just allocate the btrfs_ordered_stripe structure
in the end_io handler and have the ordered_extent point to it?

Also if you don't to split the ordered_extent for each bio,
you could instead have a list of btrfs_ordered_stripes in the
ordered_extent and then process all of them in the ordered_extent
completion handling.