nilfs2: convert nilfs_empty_dir() to use a folio

Remove three calls to compound_head() by using the folio API.

Link: https://lkml.kernel.org/r/20231127143036.2425-15-konishi.ryusuke@gmail.comSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/nilfs2/dir.c

@@ -203,17 +203,6 @@ static void *nilfs_get_folio(struct inode *dir, unsigned long n,
 	return ERR_PTR(-EIO);
 }
 
-static void *nilfs_get_page(struct inode *dir, unsigned long n,
-		struct page **pagep)
-{
-	struct folio *folio;
-	void *kaddr = nilfs_get_folio(dir, n, &folio);
-
-	if (!IS_ERR(kaddr))
-		*pagep = &folio->page;
-	return kaddr;
-}
-
 /*
  * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure.
  *
@@ -611,14 +600,14 @@ int nilfs_make_empty(struct inode *inode, struct inode *parent)
  */
 int nilfs_empty_dir(struct inode *inode)
 {
-	struct page *page = NULL;
+	struct folio *folio = NULL;
 	char *kaddr;
 	unsigned long i, npages = dir_pages(inode);
 
 	for (i = 0; i < npages; i++) {
 		struct nilfs_dir_entry *de;
 
-		kaddr = nilfs_get_page(inode, i, &page);
+		kaddr = nilfs_get_folio(inode, i, &folio);
 		if (IS_ERR(kaddr))
 			continue;
 
@@ -647,12 +636,12 @@ int nilfs_empty_dir(struct inode *inode)
 			}
 			de = nilfs_next_entry(de);
 		}
-		unmap_and_put_page(page, kaddr);
+		folio_release_kmap(folio, kaddr);
 	}
 	return 1;
 
 not_empty:
-	unmap_and_put_page(page, kaddr);
+	folio_release_kmap(folio, kaddr);
 	return 0;
 }