[RFC PATCH v1 02/10] mm: pass number of pages to __folio_end_writeback()

[Joanne Koong <joannelkoong@gmail.com>]

Add an additional arg to __folio_end_writeback() that takes in the
number of pages that were written back.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
 mm/filemap.c        |  2 +-
 mm/internal.h       |  2 +-
 mm/page-writeback.c | 13 ++++++-------
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index bada249b9fb7..b69ba95746f0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1657,7 +1657,7 @@ void folio_end_writeback(struct folio *folio)
 	 * reused before the folio_wake_bit().
 	 */
 	folio_get(folio);
-	if (__folio_end_writeback(folio))
+	if (__folio_end_writeback(folio, folio_nr_pages(folio)))
 		folio_wake_bit(folio, PG_writeback);
 
 	filemap_end_dropbehind_write(folio);
diff --git a/mm/internal.h b/mm/internal.h
index 6b8ed2017743..d94f3d40cc66 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -416,7 +416,7 @@ static inline vm_fault_t vmf_anon_prepare(struct vm_fault *vmf)
 
 vm_fault_t do_swap_page(struct vm_fault *vmf);
 void folio_rotate_reclaimable(struct folio *folio);
-bool __folio_end_writeback(struct folio *folio);
+bool __folio_end_writeback(struct folio *folio, long nr_pages);
 void deactivate_file_folio(struct folio *folio);
 void folio_activate(struct folio *folio);
 
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2e6b132f7ac2..2afdfaa285a6 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -3008,9 +3008,8 @@ static void wb_inode_writeback_end(struct bdi_writeback *wb)
 	spin_unlock_irqrestore(&wb->work_lock, flags);
 }
 
-bool __folio_end_writeback(struct folio *folio)
+bool __folio_end_writeback(struct folio *folio, long nr_pages)
 {
-	long nr = folio_nr_pages(folio);
 	struct address_space *mapping = folio_mapping(folio);
 	bool ret;
 
@@ -3024,8 +3023,8 @@ bool __folio_end_writeback(struct folio *folio)
 		__xa_clear_mark(&mapping->i_pages, folio_index(folio),
 					PAGECACHE_TAG_WRITEBACK);
 
-		wb_stat_mod(wb, WB_WRITEBACK, -nr);
-		__wb_writeout_add(wb, nr);
+		wb_stat_mod(wb, WB_WRITEBACK, -nr_pages);
+		__wb_writeout_add(wb, nr_pages);
 		if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) {
 			wb_inode_writeback_end(wb);
 			if (mapping->host)
@@ -3037,9 +3036,9 @@ bool __folio_end_writeback(struct folio *folio)
 		ret = folio_xor_flags_has_waiters(folio, 1 << PG_writeback);
 	}
 
-	lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
-	zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
-	node_stat_mod_folio(folio, NR_WRITTEN, nr);
+	lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr_pages);
+	zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr_pages);
+	node_stat_mod_folio(folio, NR_WRITTEN, nr_pages);
 
 	return ret;
 }
-- 
2.47.3