[LU-6349] remove old protocol compatibility

Related — Wed, 19 Dec 2018 16:33:44 +0000

It seems that there are some old protocol compatibility workarounds that are still present in master that should have been removed when LUSTRE_MSG_MAGIC_V1 was removed.

In particular, the process for upgrading LUSTRE_MSG_MAGIC_V1 to LUSTRE_MSG_MAGIC_V2 required the client to connect to the server using the V1 protocol first with the MSG_CONNECT_NEXT_VER op_flag set, and if the server supported the V2 protocol it would reply with LUSTRE_MSG_MAGIC_V2. However, even with V1 protocol support removed, the 2.x clients are still always connecting with NEXT_VER set. In b1_8 this flag was contingent on LUSTRE_MSG_MAGIC_V1 being used.

A few other cleanups can be done at the same time:

disallow 1.8 clients (or at least those that don't understand OBD_CONNECT_FULL20 features so we can remove workarounds for those old clients
remove support for pre-2.1 DLM flock lock handling
don't workaround the lack of MDS_ATTR_xTIME_SET flags in setattr
always set MSGHDR_CKSUM_INCOMPAT18 (it can eventually be removed)

There are also a lot of places that pretend to allow LUSTRE_MSG_MAGIC_V1 RPCs, but they don't do anything but print an error. They can be cleaned up in a second patch, but i don't want them mixed in with the MSG_CONNECT_NEXT_VER cleanup, since that is important and would prevent us from using this functionality again in the future should we need to upgrade the protocol again.

Whamcloud Community JIRA

[LU-6349] remove old protocol compatibility