ceph/src/librbd/managed_lock/AcquireRequest.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/AcquireRequest.h"
   5 #include "librbd/Watcher.h"
   6 #include "cls/lock/cls_lock_client.h"
   7 #include "cls/lock/cls_lock_types.h"
   8 #include "common/dout.h"
   9 #include "common/errno.h"
  10 #include "common/WorkQueue.h"
  11 #include "include/stringify.h"
  12 #include "librbd/ImageCtx.h"
  13 #include "librbd/Utils.h"
  14 #include "librbd/managed_lock/BreakRequest.h"
  15 #include "librbd/managed_lock/GetLockerRequest.h"
  16 #include "librbd/managed_lock/Utils.h"
  17
  18 #define dout_subsys ceph_subsys_rbd
  19 #undef dout_prefix
  20 #define dout_prefix *_dout << "librbd::managed_lock::AcquireRequest: " << this \
  21                            << " " << __func__ << ": "
  22
  23 using std::string;
  24
  25 namespace librbd {
  26
  27 using librbd::util::detail::C_AsyncCallback;
  28 using librbd::util::create_context_callback;
  29 using librbd::util::create_rados_callback;
  30
  31 namespace managed_lock {
  32
  33 template <typename I>
  34 AcquireRequest<I>* AcquireRequest<I>::create(librados::IoCtx& ioctx,
  35                                              Watcher *watcher,
  36                                              ContextWQ *work_queue,
  37                                              const string& oid,
  38                                              const string& cookie,
  39                                              bool exclusive,
  40                                              bool blacklist_on_break_lock,
  41                                              uint32_t blacklist_expire_seconds,
  42                                              Context *on_finish) {
  43     return new AcquireRequest(ioctx, watcher, work_queue, oid, cookie,
  44                               exclusive, blacklist_on_break_lock,
  45                               blacklist_expire_seconds, on_finish);
  46 }
  47
  48 template <typename I>
  49 AcquireRequest<I>::AcquireRequest(librados::IoCtx& ioctx, Watcher *watcher,
  50                                   ContextWQ *work_queue, const string& oid,
  51                                   const string& cookie, bool exclusive,
  52                                   bool blacklist_on_break_lock,
  53                                   uint32_t blacklist_expire_seconds,
  54                                   Context *on_finish)
  55   : m_ioctx(ioctx), m_watcher(watcher),
  56     m_cct(reinterpret_cast<CephContext *>(m_ioctx.cct())),
  57     m_work_queue(work_queue), m_oid(oid), m_cookie(cookie),
  58     m_exclusive(exclusive),
  59     m_blacklist_on_break_lock(blacklist_on_break_lock),
  60     m_blacklist_expire_seconds(blacklist_expire_seconds),
  61     m_on_finish(new C_AsyncCallback<ContextWQ>(work_queue, on_finish)) {
  62 }
  63
  64 template <typename I>
  65 AcquireRequest<I>::~AcquireRequest() {
  66 }
  67
  68 template <typename I>
  69 void AcquireRequest<I>::send() {
  70   send_get_locker();
  71 }
  72
  73 template <typename I>
  74 void AcquireRequest<I>::send_get_locker() {
  75   ldout(m_cct, 10) << dendl;
  76
  77   Context *ctx = create_context_callback<
  78     AcquireRequest<I>, &AcquireRequest<I>::handle_get_locker>(this);
  79   auto req = GetLockerRequest<I>::create(m_ioctx, m_oid, m_exclusive,
  80                                          &m_locker, ctx);
  81   req->send();
  82 }
  83
  84 template <typename I>
  85 void AcquireRequest<I>::handle_get_locker(int r) {
  86   ldout(m_cct, 10) << "r=" << r << dendl;
  87
  88   if (r == -ENOENT) {
  89     ldout(m_cct, 20) << "no lockers detected" << dendl;
  90     m_locker = {};
  91   } else if (r == -EBUSY) {
  92     ldout(m_cct, 5) << "incompatible lock detected" << dendl;
  93     finish(r);
  94     return;
  95   } else if (r < 0) {
  96     lderr(m_cct) << "failed to retrieve lockers: " << cpp_strerror(r) << dendl;
  97     finish(r);
  98     return;
  99   }
 100
 101   send_lock();
 102 }
 103
 104 template <typename I>
 105 void AcquireRequest<I>::send_lock() {
 106   ldout(m_cct, 10) << "entity=client." << m_ioctx.get_instance_id() << ", "
 107                    << "cookie=" << m_cookie << dendl;
 108
 109   librados::ObjectWriteOperation op;
 110   rados::cls::lock::lock(&op, RBD_LOCK_NAME,
 111                          m_exclusive ? LOCK_EXCLUSIVE : LOCK_SHARED, m_cookie,
 112                          util::get_watcher_lock_tag(), "", utime_t(), 0);
 113
 114   using klass = AcquireRequest;
 115   librados::AioCompletion *rados_completion =
 116     create_rados_callback<klass, &klass::handle_lock>(this);
 117   int r = m_ioctx.aio_operate(m_oid, rados_completion, &op);
 118   ceph_assert(r == 0);
 119   rados_completion->release();
 120 }
 121
 122 template <typename I>
 123 void AcquireRequest<I>::handle_lock(int r) {
 124   ldout(m_cct, 10) << "r=" << r << dendl;
 125
 126   if (r == 0) {
 127     finish(0);
 128     return;
 129   } else if (r == -EBUSY && m_locker.cookie.empty()) {
 130     ldout(m_cct, 5) << "already locked, refreshing locker" << dendl;
 131     send_get_locker();
 132     return;
 133   } else if (r != -EBUSY) {
 134     lderr(m_cct) << "failed to lock: " << cpp_strerror(r) << dendl;
 135     finish(r);
 136     return;
 137   }
 138
 139   send_break_lock();
 140 }
 141
 142 template <typename I>
 143 void AcquireRequest<I>::send_break_lock() {
 144   ldout(m_cct, 10) << dendl;
 145
 146   Context *ctx = create_context_callback<
 147     AcquireRequest<I>, &AcquireRequest<I>::handle_break_lock>(this);
 148   auto req = BreakRequest<I>::create(
 149     m_ioctx, m_work_queue, m_oid, m_locker, m_exclusive,
 150     m_blacklist_on_break_lock, m_blacklist_expire_seconds, false, ctx);
 151   req->send();
 152 }
 153
 154 template <typename I>
 155 void AcquireRequest<I>::handle_break_lock(int r) {
 156   ldout(m_cct, 10) << "r=" << r << dendl;
 157
 158   if (r == -EAGAIN) {
 159     ldout(m_cct, 5) << "lock owner is still alive" << dendl;
 160     finish(r);
 161     return;
 162   } else if (r < 0) {
 163     lderr(m_cct) << "failed to break lock : " << cpp_strerror(r) << dendl;
 164     finish(r);
 165     return;
 166   }
 167
 168   m_locker = {};
 169   send_lock();
 170 }
 171
 172 template <typename I>
 173 void AcquireRequest<I>::finish(int r) {
 174   m_on_finish->complete(r);
 175   delete this;
 176 }
 177
 178 } // namespace managed_lock
 179 } // namespace librbd
 180
 181 template class librbd::managed_lock::AcquireRequest<librbd::ImageCtx>;