[leo_storage][read-repair] unnecessary check happen

[mocchira]

like this with N=2.
now leo_storage_read_repairer:compare called twice (one of that is check oneself) but should be only once.

(storage_0@127.0.0.1)1> recon_trace:calls({leo_storage_read_repairer, compare, fun(_) -> return_trace() end}, 10, [{scope, local}]).
1

4:42:26.519992 <0.1716.2> leo_storage_read_repairer:compare(#Ref<0.0.1.207799>, <0.1715.2>, <0.1718.2>, '[email protected]', {state,0,undefined,2,
       [{redundant_node,'[email protected]',true,true,'L'},
        {redundant_node,'[email protected]',true,true,'FL'}],
       {metadata_2,<<"test/README.md">>,
                   259282365037923196831115620348746724776,14,12487,<<>>,0,0,
                   0,0,194,1481769775994683,63648988975,
                   111724457788928492841190877856378396241,2133482811,
                   undefined,0,0,0},
       undefined,6653868})

4:42:26.520437 <0.1717.2> leo_storage_read_repairer:compare(#Ref<0.0.1.207799>, <0.1715.2>, <0.1719.2>, '[email protected]', {state,0,undefined,2,
       [{redundant_node,'[email protected]',true,true,'L'},
        {redundant_node,'[email protected]',true,true,'FL'}],
       {metadata_2,<<"test/README.md">>,
                   259282365037923196831115620348746724776,14,12487,<<>>,0,0,
                   0,0,194,1481769775994683,63648988975,
                   111724457788928492841190877856378396241,2133482811,
                   undefined,0,0,0},
       undefined,6653868})

4:42:26.521782 <0.1716.2> leo_storage_read_repairer:compare/5 --> {#Ref<0.0.1.207799>,
                                                                   ok}

4:42:26.522153 <0.1717.2> leo_storage_read_repairer:compare/5 --> {#Ref<0.0.1.207799>,
                                                                   ok}

[yosukehara]

Fixed

LeoFS' environment

$ leofs-adm status
 [System Confiuration]
-----------------------------------+----------
 Item                              | Value
-----------------------------------+----------
 Basic/Consistency level
-----------------------------------+----------
                    system version | 1.3.1
                        cluster Id | leofs_1
                             DC Id | dc_1
                    Total replicas | 2
          number of successes of R | 1
          number of successes of W | 1
          number of successes of D | 1
 number of rack-awareness replicas | 0
                         ring size | 2^128
-----------------------------------+----------
 Multi DC replication settings
-----------------------------------+----------
        max number of joinable DCs | 2
           number of replicas a DC | 1
-----------------------------------+----------
 Manager RING hash
-----------------------------------+----------
                 current ring-hash | 3923d007
                previous ring-hash | 3923d007
-----------------------------------+----------

 [State of Node(s)]
-------+--------------------------+--------------+----------------+----------------+----------------------------
 type  |           node           |    state     |  current ring  |   prev ring    |          updated at
-------+--------------------------+--------------+----------------+----------------+----------------------------
  S    | [email protected]      | running      | 3923d007       | 3923d007       | 2016-12-19 13:32:52 +0900
  S    | [email protected]      | running      | 3923d007       | 3923d007       | 2016-12-19 13:32:52 +0900
  S    | [email protected]      | running      | 3923d007       | 3923d007       | 2016-12-19 13:32:52 +0900
  S    | [email protected]      | running      | 3923d007       | 3923d007       | 2016-12-19 13:32:52 +0900
  G    | [email protected]      | running      | 3923d007       | 3923d007       | 2016-12-19 13:32:56 +0900
-------+--------------------------+--------------+----------------+----------------+----------------------------

Test result

$ ./package/leo_storage/bin/leo_storage remote_console
Erlang/OTP 18 [erts-7.3] [source] [64-bit halfword] [smp:4:4] [async-threads:10] [kernel-poll:false]

Eshell V7.3  (abort with ^G)

(storage_1@127.0.0.1)1> recon_trace:calls({leo_storage_read_repairer, compare, fun(_) -> 
                          return_trace() end}, 10, [{scope, local}]).
1

13:23:41.110822 <0.2115.0> leo_storage_read_repairer:compare(#Ref<0.0.1.10994>, 
                             <0.2114.0>, <0.2116.0>, '[email protected]', {state,0,undefined,1,
       [{redundant_node,'[email protected]',true,true,'L'},
        {redundant_node,'[email protected]',true,true,'FL'}],
       {metadata_2,<<"test/rebar.config">>,
                   321741514302956045863620177719282422959,17,1591,
                   <<131,108,0,0,0,1,104,2,109,0,0,0,22,120,45,97,109,122,45,
                     109,101,116,97,45,115,51,99,109,100,45,97,116,116,114,115,
                     109,0,0,0,142,117,105,100,58,49,48,48,48,47,103,110,97,
                     109,101,58,121,111,115,117,107,101,47,117,110,97,109,101,
                     58,121,111,115,117,107,101,47,103,105,100,58,49,48,48,48,
                     47,109,111,100,101,58,51,51,50,48,52,47,109,116,105,109,
                     101,58,49,52,56,49,49,54,48,57,56,54,47,97,116,105,109,
                     101,58,49,52,56,50,49,49,48,54,49,49,47,109,100,53,58,101,
                     56,49,100,100,50,100,97,101,102,100,57,97,54,48,97,51,101,
                     102,99,56,97,101,48,100,56,57,100,102,52,57,57,47,99,116,
                     105,109,101,58,49,52,56,49,49,54,48,57,56,54,106>>,
                   183,0,0,0,194,1482121366679264,63649340566,
                   308535748282984225827325344971067618457,958648327,
                   undefined,0,0,0},
       undefined,5716950})

13:23:41.113985 <0.2115.0> leo_storage_read_repairer:compare/5 --> {#Ref<0.0.1.10994>, ok}