ceph/src/rgw/rgw_period_puller.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include "rgw_rados.h"
   5 #include "rgw_rest_conn.h"
   6 #include "common/ceph_json.h"
   7 #include "common/errno.h"
   8
   9 #define dout_subsys ceph_subsys_rgw
  10
  11 #undef dout_prefix
  12 #define dout_prefix (*_dout << "rgw period puller: ")
  13
  14 namespace {
  15
  16 // pull the given period over the connection
  17 int pull_period(RGWRESTConn* conn, const std::string& period_id,
  18                 const std::string& realm_id, RGWPeriod& period)
  19 {
  20   rgw_user user;
  21   RGWEnv env;
  22   req_info info(conn->get_ctx(), &env);
  23   info.method = "GET";
  24   info.request_uri = "/admin/realm/period";
  25
  26   auto& params = info.args.get_params();
  27   params["realm_id"] = realm_id;
  28   params["period_id"] = period_id;
  29
  30   bufferlist data;
  31 #define MAX_REST_RESPONSE (128 * 1024)
  32   int r = conn->forward(user, info, nullptr, MAX_REST_RESPONSE, nullptr, &data);
  33   if (r < 0) {
  34     return r;
  35   }
  36
  37   JSONParser parser;
  38   r = parser.parse(data.c_str(), data.length());
  39   if (r < 0) {
  40     lderr(conn->get_ctx()) << "request failed: " << cpp_strerror(-r) << dendl;
  41     return r;
  42   }
  43
  44   try {
  45     decode_json_obj(period, &parser);
  46   } catch (JSONDecoder::err& e) {
  47     lderr(conn->get_ctx()) << "failed to decode JSON input: "
  48         << e.message << dendl;
  49     return -EINVAL;
  50   }
  51   return 0;
  52 }
  53
  54 } // anonymous namespace
  55
  56 int RGWPeriodPuller::pull(const std::string& period_id, RGWPeriod& period)
  57 {
  58   // try to read the period from rados
  59   period.set_id(period_id);
  60   period.set_epoch(0);
  61   int r = period.init(store->ctx(), store);
  62   if (r < 0) {
  63     if (store->is_meta_master()) {
  64       // can't pull if we're the master
  65       ldout(store->ctx(), 1) << "metadata master failed to read period "
  66           << period_id << " from local storage: " << cpp_strerror(r) << dendl;
  67       return r;
  68     }
  69     ldout(store->ctx(), 14) << "pulling period " << period_id
  70         << " from master" << dendl;
  71     // request the period from the master zone
  72     r = pull_period(store->rest_master_conn, period_id,
  73                     store->realm.get_id(), period);
  74     if (r < 0) {
  75       lderr(store->ctx()) << "failed to pull period " << period_id << dendl;
  76       return r;
  77     }
  78     // write the period to rados
  79     r = period.store_info(true);
  80     if (r == -EEXIST) {
  81       r = 0;
  82     } else if (r < 0) {
  83       lderr(store->ctx()) << "failed to store period " << period_id << dendl;
  84       return r;
  85     }
  86     // update latest epoch
  87     r = period.update_latest_epoch(period.get_epoch());
  88     if (r == -EEXIST) {
  89       // already have this epoch (or a more recent one)
  90       return 0;
  91     }
  92     if (r < 0) {
  93       lderr(store->ctx()) << "failed to update latest_epoch for period "
  94           << period_id << dendl;
  95       return r;
  96     }
  97     // reflect period objects if this is the latest version
  98     if (store->realm.get_current_period() == period_id) {
  99       r = period.reflect();
 100       if (r < 0) {
 101         return r;
 102       }
 103     }
 104     ldout(store->ctx(), 14) << "period " << period_id
 105         << " pulled and written to local storage" << dendl;
 106   } else {
 107     ldout(store->ctx(), 14) << "found period " << period_id
 108         << " in local storage" << dendl;
 109   }
 110   return 0;
 111 }