1 files changed, 131 insertions, 0 deletions
diff --git a/src/librbd/managed_lock/GetLockerRequest.cc b/src/librbd/managed_lock/GetLockerRequest.cc
new file mode 100644
index 000000000..ea898ab96
--- /dev/null
+++ b/src/librbd/managed_lock/GetLockerRequest.cc
@@ -0,0 +1,131 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/managed_lock/GetLockerRequest.h"
+#include "cls/lock/cls_lock_client.h"
+#include "cls/lock/cls_lock_types.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "include/stringify.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/Utils.h"
+#include "librbd/managed_lock/Types.h"
+#include "librbd/managed_lock/Utils.h"
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::managed_lock::GetLockerRequest: " \
+                           << this << " " << __func__ << ": "
+
+namespace librbd {
+namespace managed_lock {
+
+using librbd::util::create_rados_callback;
+
+template <typename I>
+GetLockerRequest<I>::GetLockerRequest(librados::IoCtx& ioctx,
+				      const std::string& oid, bool exclusive,
+                                      Locker *locker, Context *on_finish)
+  : m_ioctx(ioctx), m_cct(reinterpret_cast<CephContext *>(m_ioctx.cct())),
+    m_oid(oid), m_exclusive(exclusive), m_locker(locker),
+    m_on_finish(on_finish) {
+}
+
+template <typename I>
+void GetLockerRequest<I>::send() {
+  send_get_lockers();
+}
+
+template <typename I>
+void GetLockerRequest<I>::send_get_lockers() {
+  ldout(m_cct, 10) << dendl;
+
+  librados::ObjectReadOperation op;
+  rados::cls::lock::get_lock_info_start(&op, RBD_LOCK_NAME);
+
+  using klass = GetLockerRequest<I>;
+  librados::AioCompletion *rados_completion =
+    create_rados_callback<klass, &klass::handle_get_lockers>(this);
+  m_out_bl.clear();
+  int r = m_ioctx.aio_operate(m_oid, rados_completion, &op, &m_out_bl);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+template <typename I>
+void GetLockerRequest<I>::handle_get_lockers(int r) {
+  ldout(m_cct, 10) << "r=" << r << dendl;
+
+  std::map<rados::cls::lock::locker_id_t,
+           rados::cls::lock::locker_info_t> lockers;
+  ClsLockType lock_type = ClsLockType::NONE;
+  std::string lock_tag;
+  if (r == 0) {
+    auto it = m_out_bl.cbegin();
+    r = rados::cls::lock::get_lock_info_finish(&it, &lockers, &lock_type,
+                                               &lock_tag);
+  }
+
+  if (r < 0) {
+    lderr(m_cct) << "failed to retrieve lockers: " << cpp_strerror(r) << dendl;
+    finish(r);
+    return;
+  }
+
+  if (lockers.empty()) {
+    ldout(m_cct, 20) << "no lockers detected" << dendl;
+    finish(-ENOENT);
+    return;
+  }
+
+  if (lock_tag != util::get_watcher_lock_tag()) {
+    ldout(m_cct, 5) <<"locked by external mechanism: tag=" << lock_tag << dendl;
+    finish(-EBUSY);
+    return;
+  }
+
+  if (m_exclusive && lock_type == ClsLockType::SHARED) {
+    ldout(m_cct, 5) << "incompatible shared lock type detected" << dendl;
+    finish(-EBUSY);
+    return;
+  } else if (!m_exclusive && lock_type == ClsLockType::EXCLUSIVE) {
+    ldout(m_cct, 5) << "incompatible exclusive lock type detected" << dendl;
+    finish(-EBUSY);
+    return;
+  }
+
+  std::map<rados::cls::lock::locker_id_t,
+           rados::cls::lock::locker_info_t>::iterator iter = lockers.begin();
+  if (!util::decode_lock_cookie(iter->first.cookie, &m_locker->handle)) {
+    ldout(m_cct, 5) << "locked by external mechanism: "
+		    << "cookie=" << iter->first.cookie << dendl;
+    finish(-EBUSY);
+    return;
+  }
+
+  if (iter->second.addr.is_blank_ip()) {
+    ldout(m_cct, 5) << "locker has a blank address" << dendl;
+    finish(-EBUSY);
+    return;
+  }
+  m_locker->entity = iter->first.locker;
+  m_locker->cookie = iter->first.cookie;
+  m_locker->address = iter->second.addr.get_legacy_str();
+
+  ldout(m_cct, 10) << "retrieved exclusive locker: "
+                 << m_locker->entity << "@" << m_locker->address << dendl;
+  finish(0);
+}
+
+template <typename I>
+void GetLockerRequest<I>::finish(int r) {
+  ldout(m_cct, 10) << "r=" << r << dendl;
+
+  m_on_finish->complete(r);
+  delete this;
+}
+
+} // namespace managed_lock
+} // namespace librbd
+
+template class librbd::managed_lock::GetLockerRequest<librbd::ImageCtx>;