ceph/src/rgw/rgw_realm_watcher.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 "common/errno.h"
   5
   6 #include "rgw_realm_watcher.h"
   7 #include "rgw_rados.h"
   8
   9 #define dout_subsys ceph_subsys_rgw
  10
  11 #undef dout_prefix
  12 #define dout_prefix (*_dout << "rgw realm watcher: ")
  13
  14
  15 RGWRealmWatcher::RGWRealmWatcher(CephContext* cct, RGWRealm& realm)
  16   : cct(cct)
  17 {
  18   // no default realm, nothing to watch
  19   if (realm.get_id().empty()) {
  20     ldout(cct, 4) << "No realm, disabling dynamic reconfiguration." << dendl;
  21     return;
  22   }
  23
  24   // establish the watch on RGWRealm
  25   int r = watch_start(realm);
  26   if (r < 0) {
  27     lderr(cct) << "Failed to establish a watch on RGWRealm, "
  28         "disabling dynamic reconfiguration." << dendl;
  29     return;
  30   }
  31 }
  32
  33 RGWRealmWatcher::~RGWRealmWatcher()
  34 {
  35   watch_stop();
  36 }
  37
  38 void RGWRealmWatcher::add_watcher(RGWRealmNotify type, Watcher& watcher)
  39 {
  40   watchers.emplace(type, watcher);
  41 }
  42
  43 void RGWRealmWatcher::handle_notify(uint64_t notify_id, uint64_t cookie,
  44                                     uint64_t notifier_id, bufferlist& bl)
  45 {
  46   if (cookie != watch_handle)
  47     return;
  48
  49   // send an empty notify ack
  50   bufferlist reply;
  51   pool_ctx.notify_ack(watch_oid, notify_id, cookie, reply);
  52
  53   try {
  54     auto p = bl.begin();
  55     while (!p.end()) {
  56       RGWRealmNotify notify;
  57       ::decode(notify, p);
  58       auto watcher = watchers.find(notify);
  59       if (watcher == watchers.end()) {
  60         lderr(cct) << "Failed to find a watcher for notify type "
  61             << static_cast<int>(notify) << dendl;
  62         break;
  63       }
  64       watcher->second.handle_notify(notify, p);
  65     }
  66   } catch (const buffer::error &e) {
  67     lderr(cct) << "Failed to decode realm notifications." << dendl;
  68   }
  69 }
  70
  71 void RGWRealmWatcher::handle_error(uint64_t cookie, int err)
  72 {
  73   if (cookie != watch_handle)
  74     return;
  75
  76   if (err == -ENOTCONN) {
  77     ldout(cct, 4) << "Disconnected watch on " << watch_oid << dendl;
  78     watch_restart();
  79   }
  80 }
  81
  82 int RGWRealmWatcher::watch_start(RGWRealm& realm)
  83 {
  84   // initialize a Rados client
  85   int r = rados.init_with_context(cct);
  86   if (r < 0) {
  87     lderr(cct) << "Rados client initialization failed with "
  88         << cpp_strerror(-r) << dendl;
  89     return r;
  90   }
  91   r = rados.connect();
  92   if (r < 0) {
  93     lderr(cct) << "Rados client connection failed with "
  94         << cpp_strerror(-r) << dendl;
  95     return r;
  96   }
  97
  98   // open an IoCtx for the realm's pool
  99   rgw_pool pool(realm.get_pool(cct));
 100   r = rgw_init_ioctx(&rados, pool, pool_ctx);
 101   if (r < 0) {
 102     lderr(cct) << "Failed to open pool " << pool
 103         << " with " << cpp_strerror(-r) << dendl;
 104     rados.shutdown();
 105     return r;
 106   }
 107
 108   // register a watch on the realm's control object
 109   auto oid = realm.get_control_oid();
 110   r = pool_ctx.watch2(oid, &watch_handle, this);
 111   if (r < 0) {
 112     lderr(cct) << "Failed to watch " << oid
 113         << " with " << cpp_strerror(-r) << dendl;
 114     pool_ctx.close();
 115     rados.shutdown();
 116     return r;
 117   }
 118
 119   ldout(cct, 10) << "Watching " << oid << dendl;
 120   std::swap(watch_oid, oid);
 121   return 0;
 122 }
 123
 124 int RGWRealmWatcher::watch_restart()
 125 {
 126   assert(!watch_oid.empty());
 127   int r = pool_ctx.unwatch2(watch_handle);
 128   if (r < 0) {
 129     lderr(cct) << "Failed to unwatch on " << watch_oid
 130         << " with " << cpp_strerror(-r) << dendl;
 131   }
 132   r = pool_ctx.watch2(watch_oid, &watch_handle, this);
 133   if (r < 0) {
 134     lderr(cct) << "Failed to restart watch on " << watch_oid
 135         << " with " << cpp_strerror(-r) << dendl;
 136     pool_ctx.close();
 137     watch_oid.clear();
 138   }
 139   return r;
 140 }
 141
 142 void RGWRealmWatcher::watch_stop()
 143 {
 144   if (!watch_oid.empty()) {
 145     pool_ctx.unwatch2(watch_handle);
 146     pool_ctx.close();
 147     watch_oid.clear();
 148   }
 149 }