On Mon 18-12-23 16:35:48, Christoph Hellwig wrote:
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
>
> Make it return the first folio in the batch so that we can use it
> in a typical for() pattern.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> mm/page-writeback.c | 39 ++++++++++++++++++++-------------------
> 1 file changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 70f42fd9a95b5d..efcfffa800884d 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -2442,6 +2442,22 @@ static bool should_writeback_folio(struct address_space *mapping,
> return true;
> }
>
> +static struct folio *writeback_iter_init(struct address_space *mapping,
> + struct writeback_control *wbc)
> +{
> + if (wbc->range_cyclic)
> + wbc->index = mapping->writeback_index; /* prev offset */
> + else
> + wbc->index = wbc->range_start >> PAGE_SHIFT;
> +
> + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
> + tag_pages_for_writeback(mapping, wbc->index, wbc_end(wbc));
> +
> + wbc->err = 0;
> + folio_batch_init(&wbc->fbatch);
> + return writeback_get_next(mapping, wbc);
> +}
> +
> /**
> * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
> * @mapping: address space structure to write
> @@ -2477,29 +2493,14 @@ int write_cache_pages(struct address_space *mapping,
> struct writeback_control *wbc, writepage_t writepage,
> void *data)
> {
> + struct folio *folio;
> int error;
> - pgoff_t end; /* Inclusive */
>
> - if (wbc->range_cyclic) {
> - wbc->index = mapping->writeback_index; /* prev offset */
> - end = -1;
> - } else {
> - wbc->index = wbc->range_start >> PAGE_SHIFT;
> - end = wbc->range_end >> PAGE_SHIFT;
> - }
> - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
> - tag_pages_for_writeback(mapping, wbc->index, end);
> -
> - folio_batch_init(&wbc->fbatch);
> - wbc->err = 0;
> -
> - for (;;) {
> - struct folio *folio = writeback_get_next(mapping, wbc);
> + for (folio = writeback_iter_init(mapping, wbc);
> + folio;
> + folio = writeback_get_next(mapping, wbc)) {
> unsigned long nr;
>
> - if (!folio)
> - break;
> -
> folio_lock(folio);
> if (!should_writeback_folio(mapping, wbc, folio)) {
> folio_unlock(folio);
> --
> 2.39.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
