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  1. Lustre
  2. LU-6648

Wireshark 1.8.10 does not correctly parse LDLM_ENQUEUE intent : getxattr

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Details

    • Bug
    • Resolution: Fixed
    • Minor
    • Lustre 2.10.0
    • None
    • 3
    • 9223372036854775807

    Description

      Running the experiment 'multiop <file> Oac' to generate a getxattr VFS method call results in a tcpdump trace that the Lustre Wireshark extension fails to parse correctly.

      wireshark-1.8.10 was used built against a fairly recent checkout of Lustre HEAD (as of May 26, 2015). The tcpdump file it failed to parse is attached. Look for the "LDLM_ENQUEUE request [Protected Read][ intent : getxattr ]" and its reply. The tcpdump itself is taken from the client that ran the 'mulitop' command.

      A followup experiment that does the complimentary 'setxattr' ('multiop <file> OAc') also shows a LustreBUG in the summary output for the client that does the operation (2015-05-26_14-55-43_c20.tcpdump). When I look at the detailed output for both of these ('tshark -v ...') neither of them shows the LustreBUG output from the summary view. Not sure if that means it's just a reporting problem or a real failure to parse.

      For the 'getxattr' experiment the header says there are four buffers with non-zero length, but only three get displayed:
      Lm Buflens: 184 => ptlrpc_body
      Lm Buflens: 104 => ldlm_request
      Lm Buflens: 8 => intent opcode
      Lm Buflens: 216 => nothing
      Lm Buflens: 0

      For the 'setxattr' case thingsare a litle different:
      Lm Buflens: 184 => ptlrpc_body
      Lm Buflens: 136 => mdt_rec_reint
      Lm Buflens: 0
      Lm Buflens: 13 => "user.multiop"
      <extra padding>
      Lm Buflens: 8 => "mds xattr eadata"
      Lm Buflens: 104 => llog_cookie

      The "mds xattr eadata" is not interpreted. I'd be interested to know if there's anything in there I should know about.

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              utopiabound Nathaniel Clark
              uselton Andrew Uselton (Inactive)
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