[LU-6582] Wireshark fails to parse LDLM_ENQUEUE RPC - likely for layout lock

Related — Sat, 3 Jun 2017 04:45:05 +0000

It looks to me like there is a least one bug in the Wireshark parsing. What I see is an LDLM_ENQUEUE that I think is wanting to do RQF_LDLM_INTENT_GETXATTR in order to establish a layout lock on the MDT. Some of the structures/fields appear to be missing in the parsed output,
the LDLM_ENQUEUE request appears in the output with ³LustreBUG² in place
of ³LUSTRE², and the LDLM_ENQUEUE reply says ³malformed packet².

A simple experiment that will replicate this behavior is to run the shell command 'touch -c file'. I do it from a client that has not previously visited the file or directory, so I know that nothing is cached. I also have the file precreated from a separate client, so that there really is a file to 'touch'. The '-c' suppresses any file create/file open that otherwise might be attempted, so you just get the simple 'setattr' behaviour. After the resulting MDS_REINT:REINT_SETATTR RPCs are exchanged, and before the subsequent MDS_GETXATTR:trusted.lov that get the actual layout, there is an LDLM_ENQUEUE exchanged that exhibits the problem. It's a good guess that it is trying to get a layout lock. The actual activities appear to be working fine, it is just the Wireshark parsing that appears to be a problem.

Whamcloud Community JIRA

[LU-6582] Wireshark fails to parse LDLM_ENQUEUE RPC - likely for layout lock