Where Is Dirty Data Flushed During NFSv4 Delegation Recall?

["Zhou Jifeng" <zhoujifeng@kylinsec.com.cn>]

Hello everyone, I have a question that has been bothering me for a long
 time. I would like to ask a familiar friend to help explain it. In the NFSv4
 protocol, it is clearly defined that during the delegation RECALL 
processing, the client needs to write the modified cache to the server
side. However, throughout the process, I have not found the code for
flushing dirty data in the kernel NFS client. I have repeatedly reviewed
the code logic of nfs4_callback_recall and nfs4_state_manager, but still
cannot understand where the dirty data is flushed.

My question is: When the client is handling the RECALL operation, where
does the process of flushing the dirty data take place?

Best regards