hugetlb: Convert huge_add_to_page_cache() to use a folio

Remove the last caller of add_to_page_cache()
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>

fs/hugetlbfs/inode.c

@@ -759,7 +759,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 
 		SetHPageMigratable(page);
 		/*
-		 * unlock_page because locked by add_to_page_cache()
+		 * unlock_page because locked by huge_add_to_page_cache()
 		 * put_page() due to reference from alloc_huge_page()
 		 */
 		unlock_page(page);

mm/hugetlb.c

@@ -5414,19 +5414,25 @@ static bool hugetlbfs_pagecache_present(struct hstate *h,
 int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
 			   pgoff_t idx)
 {
+	struct folio *folio = page_folio(page);
 	struct inode *inode = mapping->host;
 	struct hstate *h = hstate_inode(inode);
-	int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
+	int err;
 
-	if (err)
+	__folio_set_locked(folio);
+	err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL);
+
+	if (unlikely(err)) {
+		__folio_clear_locked(folio);
 		return err;
+	}
 	ClearHPageRestoreReserve(page);
 
 	/*
-	 * set page dirty so that it will not be removed from cache/file
+	 * mark folio dirty so that it will not be removed from cache/file
 	 * by non-hugetlbfs specific code paths.
 	 */
-	set_page_dirty(page);
+	folio_mark_dirty(folio);
 
 	spin_lock(&inode->i_lock);
 	inode->i_blocks += blocks_per_huge_page(h);