f2fs: convert __write_node_page() to use folio

Convert to use folio, so that we can get rid of 'page->index' to
prepare for removal of 'index' field in structure page [1].

[1] https://lore.kernel.org/all/Zp8fgUSIBGQ1TN0D@casper.infradead.org/

Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/node.c

@@ -1608,6 +1608,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 				enum iostat_type io_type, unsigned int *seq_id)
 {
 	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+	struct folio *folio = page_folio(page);
 	nid_t nid;
 	struct node_info ni;
 	struct f2fs_io_info fio = {
@@ -1624,15 +1625,15 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 	};
 	unsigned int seq;
 
-	trace_f2fs_writepage(page_folio(page), NODE);
+	trace_f2fs_writepage(folio, NODE);
 
 	if (unlikely(f2fs_cp_error(sbi))) {
 		/* keep node pages in remount-ro mode */
 		if (F2FS_OPTION(sbi).errors == MOUNT_ERRORS_READONLY)
 			goto redirty_out;
-		ClearPageUptodate(page);
+		folio_clear_uptodate(folio);
 		dec_page_count(sbi, F2FS_DIRTY_NODES);
-		unlock_page(page);
+		folio_unlock(folio);
 		return 0;
 	}
 
@@ -1646,7 +1647,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 
 	/* get old block addr of this node page */
 	nid = nid_of_node(page);
-	f2fs_bug_on(sbi, page->index != nid);
+	f2fs_bug_on(sbi, folio->index != nid);
 
 	if (f2fs_get_node_info(sbi, nid, &ni, !do_balance))
 		goto redirty_out;
@@ -1660,10 +1661,10 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 
 	/* This page is already truncated */
 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
-		ClearPageUptodate(page);
+		folio_clear_uptodate(folio);
 		dec_page_count(sbi, F2FS_DIRTY_NODES);
 		f2fs_up_read(&sbi->node_write);
-		unlock_page(page);
+		folio_unlock(folio);
 		return 0;
 	}
 
@@ -1684,7 +1685,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 			*seq_id = seq;
 	}
 
-	set_page_writeback(page);
+	folio_start_writeback(folio);
 
 	fio.old_blkaddr = ni.blk_addr;
 	f2fs_do_write_node_page(nid, &fio);
@@ -1697,7 +1698,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 		submitted = NULL;
 	}
 
-	unlock_page(page);
+	folio_unlock(folio);
 
 	if (unlikely(f2fs_cp_error(sbi))) {
 		f2fs_submit_merged_write(sbi, NODE);
@@ -1711,7 +1712,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 	return 0;
 
 redirty_out:
-	redirty_page_for_writepage(wbc, page);
+	folio_redirty_for_writepage(wbc, folio);
 	return AOP_WRITEPAGE_ACTIVATE;
 }