From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Wrap up the iterator with a nice bit of syntactic sugar. Now the caller doesn't need to know about wbc->err and can just return error, not knowing that the iterator took care of storing errors correctly. Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- include/linux/writeback.h | 10 ++++++++++ mm/page-writeback.c | 8 +++----- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 195393981ccb5c..1c1a543070c17b 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -368,6 +368,16 @@ int balance_dirty_pages_ratelimited_flags(struct address_space *mapping, bool wb_over_bg_thresh(struct bdi_writeback *wb); +struct folio *writeback_iter_init(struct address_space *mapping, + struct writeback_control *wbc); +struct folio *writeback_iter_next(struct address_space *mapping, + struct writeback_control *wbc, struct folio *folio, int error); + +#define for_each_writeback_folio(mapping, wbc, folio, error) \ + for (folio = writeback_iter_init(mapping, wbc); \ + folio || ((error = wbc->err), false); \ + folio = writeback_iter_next(mapping, wbc, folio, error)) + typedef int (*writepage_t)(struct folio *folio, struct writeback_control *wbc, void *data); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0771f19950081f..fbffd30a9cc93f 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2463,7 +2463,7 @@ static struct folio *writeback_get_folio(struct address_space *mapping, return folio; } -static struct folio *writeback_iter_init(struct address_space *mapping, +struct folio *writeback_iter_init(struct address_space *mapping, struct writeback_control *wbc) { if (wbc->range_cyclic) @@ -2479,7 +2479,7 @@ static struct folio *writeback_iter_init(struct address_space *mapping, return writeback_get_folio(mapping, wbc); } -static struct folio *writeback_iter_next(struct address_space *mapping, +struct folio *writeback_iter_next(struct address_space *mapping, struct writeback_control *wbc, struct folio *folio, int error) { unsigned long nr = folio_nr_pages(folio); @@ -2557,9 +2557,7 @@ int write_cache_pages(struct address_space *mapping, struct folio *folio; int error; - for (folio = writeback_iter_init(mapping, wbc); - folio; - folio = writeback_iter_next(mapping, wbc, folio, error)) + for_each_writeback_folio(mapping, wbc, folio, error) error = writepage(folio, wbc, data); return wbc->err; -- 2.39.2