ceph/src/librbd/managed_lock/BreakRequest.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 "librbd/managed_lock/BreakRequest.h"
   5 #include "common/dout.h"
   6 #include "common/errno.h"
   7 #include "common/WorkQueue.h"
   8 #include "include/stringify.h"
   9 #include "cls/lock/cls_lock_client.h"
  10 #include "cls/lock/cls_lock_types.h"
  11 #include "librbd/ImageCtx.h"
  12 #include "librbd/Utils.h"
  13
  14 #define dout_subsys ceph_subsys_rbd
  15 #undef dout_prefix
  16 #define dout_prefix *_dout << "librbd::managed_lock::BreakRequest: " << this \
  17                            << " " << __func__ << ": "
  18
  19 namespace librbd {
  20 namespace managed_lock {
  21
  22 using util::create_context_callback;
  23 using util::create_rados_callback;
  24
  25 namespace {
  26
  27 struct C_BlacklistClient : public Context {
  28   librados::IoCtx &ioctx;
  29   std::string locker_address;
  30   uint32_t expire_seconds;
  31   Context *on_finish;
  32
  33   C_BlacklistClient(librados::IoCtx &ioctx, const std::string &locker_address,
  34                     uint32_t expire_seconds, Context *on_finish)
  35     : ioctx(ioctx), locker_address(locker_address),
  36       expire_seconds(expire_seconds), on_finish(on_finish) {
  37   }
  38
  39   void finish(int r) override {
  40     librados::Rados rados(ioctx);
  41     r = rados.blacklist_add(locker_address, expire_seconds);
  42     on_finish->complete(r);
  43   }
  44 };
  45
  46 } // anonymous namespace
  47
  48 template <typename I>
  49 BreakRequest<I>::BreakRequest(librados::IoCtx& ioctx, ContextWQ *work_queue,
  50                               const std::string& oid, const Locker &locker,
  51                               bool blacklist_locker,
  52                               uint32_t blacklist_expire_seconds,
  53                               bool force_break_lock, Context *on_finish)
  54   : m_ioctx(ioctx), m_cct(reinterpret_cast<CephContext *>(m_ioctx.cct())),
  55     m_work_queue(work_queue), m_oid(oid), m_locker(locker),
  56     m_blacklist_locker(blacklist_locker),
  57     m_blacklist_expire_seconds(blacklist_expire_seconds),
  58     m_force_break_lock(force_break_lock), m_on_finish(on_finish) {
  59 }
  60
  61 template <typename I>
  62 void BreakRequest<I>::send() {
  63   send_get_watchers();
  64 }
  65
  66 template <typename I>
  67 void BreakRequest<I>::send_get_watchers() {
  68   ldout(m_cct, 10) << dendl;
  69
  70   librados::ObjectReadOperation op;
  71   op.list_watchers(&m_watchers, &m_watchers_ret_val);
  72
  73   using klass = BreakRequest<I>;
  74   librados::AioCompletion *rados_completion =
  75     create_rados_callback<klass, &klass::handle_get_watchers>(this);
  76   m_out_bl.clear();
  77   int r = m_ioctx.aio_operate(m_oid, rados_completion, &op, &m_out_bl);
  78   assert(r == 0);
  79   rados_completion->release();
  80 }
  81
  82 template <typename I>
  83 void BreakRequest<I>::handle_get_watchers(int r) {
  84   ldout(m_cct, 10) << "r=" << r << dendl;
  85
  86   if (r == 0) {
  87     r = m_watchers_ret_val;
  88   }
  89   if (r < 0) {
  90     lderr(m_cct) << "failed to retrieve watchers: " << cpp_strerror(r)
  91                  << dendl;
  92     finish(r);
  93     return;
  94   }
  95
  96   bool found_alive_locker = false;
  97   for (auto &watcher : m_watchers) {
  98     ldout(m_cct, 20) << "watcher=["
  99                      << "addr=" << watcher.addr << ", "
 100                      << "entity=client." << watcher.watcher_id << "]" << dendl;
 101
 102     if ((strncmp(m_locker.address.c_str(),
 103                  watcher.addr, sizeof(watcher.addr)) == 0) &&
 104         (m_locker.handle == watcher.cookie)) {
 105       ldout(m_cct, 10) << "lock owner is still alive" << dendl;
 106       found_alive_locker = true;
 107     }
 108   }
 109
 110   if (!m_force_break_lock && found_alive_locker) {
 111     finish(-EAGAIN);
 112     return;
 113   }
 114
 115   send_blacklist();
 116 }
 117
 118 template <typename I>
 119 void BreakRequest<I>::send_blacklist() {
 120   if (!m_blacklist_locker) {
 121     send_break_lock();
 122     return;
 123   }
 124
 125   entity_name_t entity_name = entity_name_t::CLIENT(m_ioctx.get_instance_id());
 126   ldout(m_cct, 10) << "local entity=" << entity_name << ", "
 127                    << "locker entity=" << m_locker.entity << dendl;
 128
 129   if (m_locker.entity == entity_name) {
 130     lderr(m_cct) << "attempting to self-blacklist" << dendl;
 131     finish(-EINVAL);
 132     return;
 133   }
 134
 135   // TODO: need async version of RadosClient::blacklist_add
 136   using klass = BreakRequest<I>;
 137   Context *ctx = create_context_callback<klass, &klass::handle_blacklist>(
 138     this);
 139   m_work_queue->queue(new C_BlacklistClient(m_ioctx, m_locker.address,
 140                                             m_blacklist_expire_seconds, ctx),
 141                       0);
 142 }
 143
 144 template <typename I>
 145 void BreakRequest<I>::handle_blacklist(int r) {
 146   ldout(m_cct, 10) << "r=" << r << dendl;
 147
 148   if (r < 0) {
 149     lderr(m_cct) << "failed to blacklist lock owner: " << cpp_strerror(r)
 150                  << dendl;
 151     finish(r);
 152     return;
 153   }
 154   send_break_lock();
 155 }
 156
 157 template <typename I>
 158 void BreakRequest<I>::send_break_lock() {
 159   ldout(m_cct, 10) << dendl;
 160
 161   librados::ObjectWriteOperation op;
 162   rados::cls::lock::break_lock(&op, RBD_LOCK_NAME, m_locker.cookie,
 163                                m_locker.entity);
 164
 165   using klass = BreakRequest<I>;
 166   librados::AioCompletion *rados_completion =
 167     create_rados_callback<klass, &klass::handle_break_lock>(this);
 168   int r = m_ioctx.aio_operate(m_oid, rados_completion, &op);
 169   assert(r == 0);
 170   rados_completion->release();
 171 }
 172
 173 template <typename I>
 174 void BreakRequest<I>::handle_break_lock(int r) {
 175   ldout(m_cct, 10) << "r=" << r << dendl;
 176
 177   if (r < 0 && r != -ENOENT) {
 178     lderr(m_cct) << "failed to break lock: " << cpp_strerror(r) << dendl;
 179     finish(r);
 180     return;
 181   }
 182
 183   finish(0);
 184 }
 185
 186 template <typename I>
 187 void BreakRequest<I>::finish(int r) {
 188   ldout(m_cct, 10) << "r=" << r << dendl;
 189
 190   m_on_finish->complete(r);
 191   delete this;
 192 }
 193
 194 } // namespace managed_lock
 195 } // namespace librbd
 196
 197 template class librbd::managed_lock::BreakRequest<librbd::ImageCtx>;