[LU-14177] PCC: Invalidate PCC-RO cache when access from the old client

Related — Fri, 22 Oct 2021 16:47:39 +0000

For the purpose of the compatibility and interoperability, we have already added a PCC-RO connection flag;
To avoid inconsistent data access, MDT does not (try to) grant layout lock to the client at the time of getattr() or open(). when an old client without PCC-RO support requests a layout lock via intent request on the file that is in L.rdonly state on MDT, MDT needs to clear the L.rdonly flag on the layout first (this maybe invalidate all PCC-RO cached copies on clients), and then return the layout to the old client.

Whamcloud Community JIRA

[LU-14177] PCC: Invalidate PCC-RO cache when access from the old client