From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Pull the post-processing of the writepage_t callback into a
separate function. That means changing writeback_finish() to
return NULL, and writeback_get_next() to call writeback_finish()
when we naturally run out of folios.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
mm/page-writeback.c | 89 +++++++++++++++++++++++----------------------
1 file changed, 46 insertions(+), 43 deletions(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index b0accca1f4bfa7..4fae912f7a86e2 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2360,7 +2360,7 @@ void tag_pages_for_writeback(struct address_space *mapping,
}
EXPORT_SYMBOL(tag_pages_for_writeback);
-static int writeback_finish(struct address_space *mapping,
+static struct folio *writeback_finish(struct address_space *mapping,
struct writeback_control *wbc, bool done)
{
folio_batch_release(&wbc->fbatch);
@@ -2375,7 +2375,7 @@ static int writeback_finish(struct address_space *mapping,
if (wbc->range_cyclic || (wbc->range_whole && wbc->nr_to_write > 0))
mapping->writeback_index = wbc->done_index;
- return wbc->err;
+ return NULL;
}
static struct folio *writeback_get_next(struct address_space *mapping,
@@ -2437,7 +2437,7 @@ static struct folio *writeback_get_folio(struct address_space *mapping,
for (;;) {
folio = writeback_get_next(mapping, wbc);
if (!folio)
- return NULL;
+ return writeback_finish(mapping, wbc, false);
wbc->done_index = folio->index;
folio_lock(folio);
@@ -2472,6 +2472,47 @@ 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 writeback_control *wbc, struct folio *folio, int error)
+{
+ unsigned long nr = folio_nr_pages(folio);
+
+ if (unlikely(error)) {
+ /*
+ * Handle errors according to the type of writeback.
+ * There's no need to continue for background writeback.
+ * Just push done_index past this folio so media
+ * errors won't choke writeout for the entire file.
+ * For integrity writeback, we must process the entire
+ * dirty set regardless of errors because the fs may
+ * still have state to clear for each folio. In that
+ * case we continue processing and return the first error.
+ */
+ if (error == AOP_WRITEPAGE_ACTIVATE) {
+ folio_unlock(folio);
+ error = 0;
+ } else if (wbc->sync_mode != WB_SYNC_ALL) {
+ wbc->err = error;
+ wbc->done_index = folio->index + nr;
+ return writeback_finish(mapping, wbc, true);
+ }
+ if (!wbc->err)
+ wbc->err = error;
+ }
+
+ /*
+ * We stop writing back only if we are not doing integrity
+ * sync. In case of integrity sync we have to keep going until
+ * we have written all the folios we tagged for writeback prior
+ * to entering this loop.
+ */
+ wbc->nr_to_write -= nr;
+ if (wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE)
+ return writeback_finish(mapping, wbc, true);
+
+ return writeback_get_folio(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
@@ -2512,49 +2553,11 @@ int write_cache_pages(struct address_space *mapping,
for (folio = writeback_iter_init(mapping, wbc);
folio;
- folio = writeback_get_folio(mapping, wbc)) {
- unsigned long nr;
-
+ folio = writeback_iter_next(mapping, wbc, folio, error)) {
error = writepage(folio, wbc, data);
- nr = folio_nr_pages(folio);
- if (unlikely(error)) {
- /*
- * Handle errors according to the type of
- * writeback. There's no need to continue for
- * background writeback. Just push done_index
- * past this page so media errors won't choke
- * writeout for the entire file. For integrity
- * writeback, we must process the entire dirty
- * set regardless of errors because the fs may
- * still have state to clear for each page. In
- * that case we continue processing and return
- * the first error.
- */
- if (error == AOP_WRITEPAGE_ACTIVATE) {
- folio_unlock(folio);
- error = 0;
- } else if (wbc->sync_mode != WB_SYNC_ALL) {
- wbc->err = error;
- wbc->done_index = folio->index + nr;
- return writeback_finish(mapping, wbc, true);
- }
- if (!wbc->err)
- wbc->err = error;
- }
-
- /*
- * We stop writing back only if we are not doing
- * integrity sync. In case of integrity sync we have to
- * keep going until we have written all the pages
- * we tagged for writeback prior to entering this loop.
- */
- wbc->nr_to_write -= nr;
- if (wbc->nr_to_write <= 0 &&
- wbc->sync_mode == WB_SYNC_NONE)
- return writeback_finish(mapping, wbc, true);
}
- return writeback_finish(mapping, wbc, false);
+ return wbc->err;
}
EXPORT_SYMBOL(write_cache_pages);
--
2.39.2
