[RFC PATCH 1/2] mm: remove duplicated flush_dcache_folio()

[Yin Fengwei <fengwei.yin@xxxxxxxxx>]

folio_zero_range() calls the flush_dcache_folio() already. Remove
unnecessary flush_dcache_folio() call.

Signed-off-by: Yin Fengwei <fengwei.yin@xxxxxxxxx>
---
 fs/libfs.c | 1 -
 mm/shmem.c | 7 +------
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index 4eda519c3002..d57370c8e382 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -543,7 +543,6 @@ EXPORT_SYMBOL(simple_setattr);
 static int simple_read_folio(struct file *file, struct folio *folio)
 {
 	folio_zero_range(folio, 0, folio_size(folio));
-	flush_dcache_folio(folio);
 	folio_mark_uptodate(folio);
 	folio_unlock(folio);
 	return 0;
diff --git a/mm/shmem.c b/mm/shmem.c
index 448f393d8ab2..66e50f0a15ab 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1401,7 +1401,6 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
 				goto redirty;
 		}
 		folio_zero_range(folio, 0, folio_size(folio));
-		flush_dcache_folio(folio);
 		folio_mark_uptodate(folio);
 	}
 
@@ -2010,11 +2009,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
 	 * it now, lest undo on failure cancel our earlier guarantee.
 	 */
 	if (sgp != SGP_WRITE && !folio_test_uptodate(folio)) {
-		long i, n = folio_nr_pages(folio);
-
-		for (i = 0; i < n; i++)
-			clear_highpage(folio_page(folio, i));
-		flush_dcache_folio(folio);
+		folio_zero_range(folio, 0, folio_size(folio));
 		folio_mark_uptodate(folio);
 	}
 
-- 
2.30.2