Re: [PATCH 02/17] writeback: also update wbc->nr_to_write on writeback failure

From: Jan Kara
Date: Tue Dec 19 2023 - 12:36:48 EST


On Mon 18-12-23 16:35:38, Christoph Hellwig wrote:
> When exiting write_cache_pages early due to a non-integrity write
> failure, wbc->nr_to_write currently doesn't account for the folio
> we just failed to write. This doesn't matter because the callers
> always ingore the value on a failure, but moving the update to
> common code will allow to simply the code, so do it.
^^^ simplify

> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Otherwise the patch looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> mm/page-writeback.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index b13ea243edb6b2..8e312d73475646 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -2473,6 +2473,7 @@ int write_cache_pages(struct address_space *mapping,
> trace_wbc_writepage(wbc, inode_to_bdi(mapping->host));
> error = writepage(folio, wbc, data);
> nr = folio_nr_pages(folio);
> + wbc->nr_to_write -= nr;
> if (unlikely(error)) {
> /*
> * Handle errors according to the type of
> @@ -2506,7 +2507,6 @@ int write_cache_pages(struct address_space *mapping,
> * we tagged for writeback prior to entering this loop.
> */
> done_index = folio->index + nr;
> - wbc->nr_to_write -= nr;
> if (wbc->nr_to_write <= 0 &&
> wbc->sync_mode == WB_SYNC_NONE) {
> done = 1;
> --
> 2.39.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR