Revert "f2fs: no need inc dirty pages under inode lock"

This reverts commit b951a4ec16.

 Conflicts:
	fs/f2fs/checkpoint.c

fs/f2fs/checkpoint.c

@@ -793,13 +793,12 @@ void update_dirty_page(struct inode *inode, struct page *page)
 			!S_ISLNK(inode->i_mode))
 		return;
 
-	if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH)) {
-		spin_lock(&sbi->inode_lock[type]);
+	spin_lock(&sbi->inode_lock[type]);
+	if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH))
 		__add_dirty_inode(inode, type);
-		spin_unlock(&sbi->inode_lock[type]);
-	}
-
 	inode_inc_dirty_pages(inode);
+	spin_unlock(&sbi->inode_lock[type]);
+
 	SetPagePrivate(page);
 	f2fs_trace_pid(page);
 }