[PATCH 03/14] writeback: fix done_index when hitting the wbc->nr_to_write

From: Christoph Hellwig
Date: Mon Feb 12 2024 - 02:15:07 EST


When write_cache_pages finishes writing out a folio, it fails to update
done_index to account for the number of pages in the folio just written.
That means when range_cyclic writeback is restarted, it will be
restarted at this folio instead of after it as it should. Fix that
by updating done_index before breaking out of the loop.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Acked-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
mm/page-writeback.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 62901fa905f01e..aa3b432f77e37a 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2505,6 +2505,7 @@ int write_cache_pages(struct address_space *mapping,
* keep going until we have written all the pages
* 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) {
--
2.39.2