f2fs: refactor f2fs_move_node_folio function

This patch refactor the f2fs_move_node_folio() function. No logical
changes.

Cc: stable@kernel.org
Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: Yongpeng Yang

fs/f2fs/node.c

@@ -1841,41 +1841,51 @@ static bool __write_node_folio(struct folio *folio, bool atomic, bool *submitted
 	return false;
 }
 
-int f2fs_move_node_folio(struct folio *node_folio, int gc_type)
+static int f2fs_write_single_node_folio(struct folio *node_folio, int sync_mode,
+			bool mark_dirty, enum iostat_type io_type)
 {
 	int err = 0;
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = 1,
+	};
 
-	if (gc_type == FG_GC) {
-		struct writeback_control wbc = {
-			.sync_mode = WB_SYNC_ALL,
-			.nr_to_write = 1,
-		};
+	if (!sync_mode) {
+		/* set page dirty and write it */
+		if (!folio_test_writeback(node_folio))
+			folio_mark_dirty(node_folio);
+		goto out_folio;
+	}
 
-		f2fs_folio_wait_writeback(node_folio, NODE, true, true);
+	f2fs_folio_wait_writeback(node_folio, NODE, true, true);
 
+	if (mark_dirty)
 		folio_mark_dirty(node_folio);
+	else if (!folio_test_dirty(node_folio))
+		goto out_folio;
 
-		if (!folio_clear_dirty_for_io(node_folio)) {
-			err = -EAGAIN;
-			goto out_page;
-		}
-
-		if (!__write_node_folio(node_folio, false, NULL,
-					&wbc, false, FS_GC_NODE_IO, NULL))
-			err = -EAGAIN;
-		goto release_page;
-	} else {
-		/* set page dirty and write it */
-		if (!folio_test_writeback(node_folio))
-			folio_mark_dirty(node_folio);
+	if (!folio_clear_dirty_for_io(node_folio)) {
+		err = -EAGAIN;
+		goto out_folio;
 	}
-out_page:
+
+	if (!__write_node_folio(node_folio, false, NULL,
+				&wbc, false, FS_GC_NODE_IO, NULL))
+		err = -EAGAIN;
+	goto release_folio;
+out_folio:
 	folio_unlock(node_folio);
-release_page:
+release_folio:
 	f2fs_folio_put(node_folio, false);
 	return err;
 }
 
+int f2fs_move_node_folio(struct folio *node_folio, int gc_type)
+{
+	return f2fs_write_single_node_folio(node_folio, gc_type == FG_GC,
+			true, FS_GC_NODE_IO);
+}
+
 int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
 			struct writeback_control *wbc, bool atomic,
 			unsigned int *seq_id)