On Fri, Aug 29, 2025 at 4:58 PM Joanne Koong <joannelkoong@xxxxxxxxx> wrote:
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index bdfb13cdee4b..1659603f4cb6 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> +
> +static int fuse_handle_readahead(struct folio *folio,
> + struct fuse_fill_read_data *data, loff_t pos,
> + size_t len)
> +{
> + struct fuse_io_args *ia = data->ia;
> + size_t off = offset_in_folio(folio, pos);
> + struct fuse_conn *fc = data->fc;
> + struct fuse_args_pages *ap;
> +
> + if (ia && fuse_folios_need_send(fc, pos, len, &ia->ap, data->nr_bytes,
> + false)) {
> + fuse_send_readpages(ia, data->file, data->nr_bytes,
> + fc->async_read);
> + data->nr_bytes = 0;
> + ia = NULL;
> + }
> + if (!ia) {
> + struct readahead_control *rac = data->rac;
> + unsigned nr_pages = min(fc->max_pages, readahead_count(rac));
This should also be constrained by "fc->max_read / PAGE_SIZE". Will
fix this up for v2.
> +
> + if (fc->num_background >= fc->congestion_threshold &&
> + rac->ra->async_size >= readahead_count(rac))
> + /*
> + * Congested and only async pages left, so skip the
> + * rest.
> + */
> + return -EAGAIN;
> +
> + data->ia = fuse_io_alloc(NULL, nr_pages);
> + if (!data->ia)
> + return -ENOMEM;
> + ia = data->ia;
> + }
> + folio_get(folio);
> + ap = &ia->ap;
> + ap->folios[ap->num_folios] = folio;
> + ap->descs[ap->num_folios].offset = off;
> + ap->descs[ap->num_folios].length = len;
> + data->nr_bytes += len;
> + ap->num_folios++;
> +
> + return 0;
> +}
> +
