[PATCH 2/6] mm: merge writeout into pageout

[Christoph Hellwig <hch@lst.de>]

writeout is only called from pageout, and a straight flow at the end, so
merge the two functions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/vmscan.c | 63 ++++++++++++++++++++++++-----------------------------
 1 file changed, 29 insertions(+), 34 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bd1b1aa12581..dc0d4312ac6c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -614,45 +614,14 @@ typedef enum {
 	PAGE_CLEAN,
 } pageout_t;
 
-static pageout_t writeout(struct folio *folio, struct address_space *mapping,
-		struct swap_iocb **plug, struct list_head *folio_list)
-{
-	int res;
-
-	folio_set_reclaim(folio);
-
-	/*
-	 * The large shmem folio can be split if CONFIG_THP_SWAP is not enabled
-	 * or we failed to allocate contiguous swap entries, in which case
-	 * the split out folios get added back to folio_list.
-	 */
-	if (shmem_mapping(mapping))
-		res = shmem_writeout(folio, plug, folio_list);
-	else
-		res = swap_writeout(folio, plug);
-
-	if (res < 0)
-		handle_write_error(mapping, folio, res);
-	if (res == AOP_WRITEPAGE_ACTIVATE) {
-		folio_clear_reclaim(folio);
-		return PAGE_ACTIVATE;
-	}
-
-	/* synchronous write? */
-	if (!folio_test_writeback(folio))
-		folio_clear_reclaim(folio);
-
-	trace_mm_vmscan_write_folio(folio);
-	node_stat_add_folio(folio, NR_VMSCAN_WRITE);
-	return PAGE_SUCCESS;
-}
-
 /*
  * pageout is called by shrink_folio_list() for each dirty folio.
  */
 static pageout_t pageout(struct folio *folio, struct address_space *mapping,
 			 struct swap_iocb **plug, struct list_head *folio_list)
 {
+	int res;
+
 	/*
 	 * We no longer attempt to writeback filesystem folios here, other
 	 * than tmpfs/shmem.  That's taken care of in page-writeback.
@@ -676,7 +645,33 @@ static pageout_t pageout(struct folio *folio, struct address_space *mapping,
 		return PAGE_ACTIVATE;
 	if (!folio_clear_dirty_for_io(folio))
 		return PAGE_CLEAN;
-	return writeout(folio, mapping, plug, folio_list);
+
+	folio_set_reclaim(folio);
+
+	/*
+	 * The large shmem folio can be split if CONFIG_THP_SWAP is not enabled
+	 * or we failed to allocate contiguous swap entries, in which case
+	 * the split out folios get added back to folio_list.
+	 */
+	if (shmem_mapping(mapping))
+		res = shmem_writeout(folio, plug, folio_list);
+	else
+		res = swap_writeout(folio, plug);
+
+	if (res < 0)
+		handle_write_error(mapping, folio, res);
+	if (res == AOP_WRITEPAGE_ACTIVATE) {
+		folio_clear_reclaim(folio);
+		return PAGE_ACTIVATE;
+	}
+
+	/* synchronous write? */
+	if (!folio_test_writeback(folio))
+		folio_clear_reclaim(folio);
+
+	trace_mm_vmscan_write_folio(folio);
+	node_stat_add_folio(folio, NR_VMSCAN_WRITE);
+	return PAGE_SUCCESS;
 }
 
 /*
-- 
2.53.0