On Tue, Aug 27, 2024 at 04:45:14PM -0400, Josef Bacik wrote:
>
> +/*
> + * Wait for page writeback in the range to be completed. This will work for
> + * folio_size() > PAGE_SIZE, even tho we don't currently allow that.
> + */
> +static void fuse_wait_on_folio_writeback(struct inode *inode,
> + struct folio *folio)
> +{
> + for (pgoff_t index = folio_index(folio);
> + index < folio_next_index(folio); index++)
> + fuse_wait_on_page_writeback(inode, index);
> +}
Would it be better to write this as:
struct fuse_inode *fi = get_fuse_inode(inode);
pgoff_t last = folio_next_index(folio) - 1;
wait_event(fi->page_waitq, !fuse_range_is_writeback(inode,
folio->index, last));
> @@ -1015,13 +1036,14 @@ static void fuse_readahead(struct readahead_control *rac)
> if (!ia)
> return;
> ap = &ia->ap;
> - nr_pages = __readahead_batch(rac, ap->pages, nr_pages);
> - for (i = 0; i < nr_pages; i++) {
> - fuse_wait_on_page_writeback(inode,
> - readahead_index(rac) + i);
> - ap->descs[i].length = PAGE_SIZE;
> +
> + while (nr_folios < nr_pages &&
> + (folio = readahead_folio(rac)) != NULL) {
> + fuse_wait_on_folio_writeback(inode, folio);
Oh. Even easier, we should hoist the whole thing to here. Before
this loop,
pgoff_t first = readahead_index(rac);
pgoff_t last = first + readahead_count(rac) - 1;
wait_event(fi->page_waitq, !fuse_range_is_writeback(inode,
first, last);
(I'm not quite sure how we might have pending writeback still when we're
doing readahead, but fuse is a funny creature and if somebody explains
why to me, I'll probably forget again)
> + ap->pages[i] = &folio->page;
> + ap->descs[i].length = folio_size(folio);
> + ap->num_pages++;
I do want to turn __readahead_batch into working on folios, but that
involves working on fuse & squashfs at the same time ... I see you
got rid of the readahead_page_batch() in btrfs recently; that'll help.
