[PATCH v4 3/7] fs/dax: Use free_zone_device_folio_prepare() helper

[Francois Dugast]

From: Matthew Brost <matthew.brost@xxxxxxxxx>

Use free_zone_device_folio_prepare() to restore fsdax ZONE_DEVICE folios
to a sane initial state upon the final put.

Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Balbir Singh <balbirs@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: nvdimm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Suggested-by: Alistair Popple <apopple@xxxxxxxxxx>
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Signed-off-by: Francois Dugast <francois.dugast@xxxxxxxxx>
---
 fs/dax.c | 24 +-----------------------
 1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 289e6254aa30..d998f7615abb 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -391,29 +391,7 @@ static inline unsigned long dax_folio_put(struct folio *folio)
 	if (ref)
 		return ref;
 
-	folio->mapping = NULL;
-	order = folio_order(folio);
-	if (!order)
-		return 0;
-	folio_reset_order(folio);
-
-	for (i = 0; i < (1UL << order); i++) {
-		struct dev_pagemap *pgmap = page_pgmap(&folio->page);
-		struct page *page = folio_page(folio, i);
-		struct folio *new_folio = (struct folio *)page;
-
-		ClearPageHead(page);
-		clear_compound_head(page);
-
-		new_folio->mapping = NULL;
-		/*
-		 * Reset pgmap which was over-written by
-		 * prep_compound_page().
-		 */
-		new_folio->pgmap = pgmap;
-		new_folio->share = 0;
-		WARN_ON_ONCE(folio_ref_count(new_folio));
-	}
+	free_zone_device_folio_prepare(folio);
 
 	return ref;
 }
-- 
2.43.0