nilfs2: convert nilfs_clear_dirty_pages() to use filemap_get_folios_tag()

Convert function to use folios throughout.  This is in preparation for the
removal of find_get_pages_range_tag().  This change removes 2 calls to
compound_head().

Link: https://lkml.kernel.org/r/20230104211448.4804-23-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/nilfs2/page.c

@@ -358,22 +358,22 @@ void nilfs_copy_back_pages(struct address_space *dmap,
  */
 void nilfs_clear_dirty_pages(struct address_space *mapping, bool silent)
 {
-	struct pagevec pvec;
+	struct folio_batch fbatch;
 	unsigned int i;
 	pgoff_t index = 0;
 
-	pagevec_init(&pvec);
+	folio_batch_init(&fbatch);
 
-	while (pagevec_lookup_tag(&pvec, mapping, &index,
-					PAGECACHE_TAG_DIRTY)) {
-		for (i = 0; i < pagevec_count(&pvec); i++) {
-			struct page *page = pvec.pages[i];
+	while (filemap_get_folios_tag(mapping, &index, (pgoff_t)-1,
+				PAGECACHE_TAG_DIRTY, &fbatch)) {
+		for (i = 0; i < folio_batch_count(&fbatch); i++) {
+			struct folio *folio = fbatch.folios[i];
 
-			lock_page(page);
-			nilfs_clear_dirty_page(page, silent);
-			unlock_page(page);
+			folio_lock(folio);
+			nilfs_clear_dirty_page(&folio->page, silent);
+			folio_unlock(folio);
 		}
-		pagevec_release(&pvec);
+		folio_batch_release(&fbatch);
 		cond_resched();
 	}
 }