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// -*- 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;
}
m_locker->entity = iter->first.locker;
m_locker->cookie = iter->first.cookie;
m_locker->address = iter->second.addr.get_legacy_str();
if (m_locker->cookie.empty() || m_locker->address.empty()) {
ldout(m_cct, 20) << "no valid lockers detected" << dendl;
finish(-ENOENT);
return;
}
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>;
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