[PATCH 02/13] mm: Pass a folio to __swap_writepage()

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Both callers now have a folio, so pass that in instead of the page.
Removes a few hidden calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 mm/page_io.c | 14 +++++++-------
 mm/swap.h    |  2 +-
 mm/zswap.c   |  2 +-
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index cb559ae324c6..e0d59f36b70b 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -201,7 +201,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
 		folio_end_writeback(folio);
 		return 0;
 	}
-	__swap_writepage(&folio->page, wbc);
+	__swap_writepage(folio, wbc);
 	return 0;
 }
 
@@ -368,22 +368,22 @@ static void swap_writepage_bdev_async(struct page *page,
 	submit_bio(bio);
 }
 
-void __swap_writepage(struct page *page, struct writeback_control *wbc)
+void __swap_writepage(struct folio *folio, struct writeback_control *wbc)
 {
-	struct swap_info_struct *sis = page_swap_info(page);
+	struct swap_info_struct *sis = swp_swap_info(folio->swap);
 
-	VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+	VM_BUG_ON_FOLIO(!folio_test_swapcache(folio), folio);
 	/*
 	 * ->flags can be updated non-atomicially (scan_swap_map_slots),
 	 * but that will never affect SWP_FS_OPS, so the data_race
 	 * is safe.
 	 */
 	if (data_race(sis->flags & SWP_FS_OPS))
-		swap_writepage_fs(page, wbc);
+		swap_writepage_fs(&folio->page, wbc);
 	else if (sis->flags & SWP_SYNCHRONOUS_IO)
-		swap_writepage_bdev_sync(page, wbc, sis);
+		swap_writepage_bdev_sync(&folio->page, wbc, sis);
 	else
-		swap_writepage_bdev_async(page, wbc, sis);
+		swap_writepage_bdev_async(&folio->page, wbc, sis);
 }
 
 void swap_write_unplug(struct swap_iocb *sio)
diff --git a/mm/swap.h b/mm/swap.h
index a60ab1cfcaf2..b81587740cf1 100644
--- a/mm/swap.h
+++ b/mm/swap.h
@@ -19,7 +19,7 @@ static inline void swap_read_unplug(struct swap_iocb *plug)
 }
 void swap_write_unplug(struct swap_iocb *sio);
 int swap_writepage(struct page *page, struct writeback_control *wbc);
-void __swap_writepage(struct page *page, struct writeback_control *wbc);
+void __swap_writepage(struct folio *folio, struct writeback_control *wbc);
 
 /* linux/mm/swap_state.c */
 /* One swap address space for each 64M swap space */
diff --git a/mm/zswap.c b/mm/zswap.c
index 08b5212aa6b8..0aa3b434d9b5 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1485,7 +1485,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
 	}
 
 	/* start writeback */
-	__swap_writepage(&folio->page, &wbc);
+	__swap_writepage(folio, &wbc);
 	folio_put(folio);
 
 	return ret;
-- 
2.42.0