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
