--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_RBD_MIRROR_LEADER_WATCHER_H
+#define CEPH_RBD_MIRROR_LEADER_WATCHER_H
+
+#include <list>
+#include <memory>
+#include <string>
+
+#include "common/AsyncOpTracker.h"
+#include "librbd/ManagedLock.h"
+#include "librbd/Watcher.h"
+#include "librbd/managed_lock/Types.h"
+#include "librbd/watcher/Types.h"
+#include "Instances.h"
+#include "MirrorStatusWatcher.h"
+#include "tools/rbd_mirror/leader_watcher/Types.h"
+
+namespace librbd { class ImageCtx; }
+
+namespace rbd {
+namespace mirror {
+
+template <typename> struct Threads;
+
+template <typename ImageCtxT = librbd::ImageCtx>
+class LeaderWatcher : protected librbd::Watcher {
+public:
+ struct Listener {
+ virtual ~Listener() {
+ }
+
+ virtual void post_acquire_handler(Context *on_finish) = 0;
+ virtual void pre_release_handler(Context *on_finish) = 0;
+
+ virtual void update_leader_handler(
+ const std::string &leader_instance_id) = 0;
+ };
+
+ LeaderWatcher(Threads<ImageCtxT> *threads, librados::IoCtx &io_ctx,
+ Listener *listener);
+ ~LeaderWatcher() override;
+
+ int init();
+ void shut_down();
+
+ void init(Context *on_finish);
+ void shut_down(Context *on_finish);
+
+ bool is_leader() const;
+ bool is_releasing_leader() const;
+ bool get_leader_instance_id(std::string *instance_id) const;
+ void release_leader();
+ void list_instances(std::vector<std::string> *instance_ids);
+
+ std::string get_instance_id();
+
+private:
+ /**
+ * @verbatim
+ *
+ * <uninitialized> <------------------------------ WAIT_FOR_TASKS
+ * | (init) ^ ^
+ * v * |
+ * CREATE_OBJECT * * (error) UNREGISTER_WATCH
+ * | * ^
+ * v * |
+ * REGISTER_WATCH * * SHUT_DOWN_LEADER_LOCK
+ * | ^
+ * | (no leader heartbeat and acquire failed) |
+ * | BREAK_LOCK <-------------------------------------\ |
+ * | | (no leader heartbeat) | | (shut down)
+ * | | /----------------------------------------\ | |
+ * | | | (lock_released received) | |
+ * | | | /-------------------------------------\ | |
+ * | | | | (lock_acquired or | | |
+ * | | | | heartbeat received) | | |
+ * | | | | (ENOENT) /-----------\ | | |
+ * | | | | * * * * * * * * * * | | | | |
+ * v v v v v (error) * v | | | |
+ * ACQUIRE_LEADER_LOCK * * * * *> GET_LOCKER ---> <secondary>
+ * | * ^
+ * ....|...................*.................... .....|.....................
+ * . v * . . | post_release .
+ * .INIT_STATUS_WATCHER * * (error) . .NOTIFY_LOCK_RELEASED .
+ * . | ^ . .....^.....................
+ * . v (error) | . |
+ * .INIT_INSTANCES *> SHUT_DOWN_STATUS_WATCHER . RELEASE_LEADER_LOCK
+ * . | . ^
+ * . v . .....|.....................
+ * .NOTIFY_LISTENER . .SHUT_DOWN_STATUS_WATCHER .
+ * . | . . ^ .
+ * . v . . | .
+ * .NOTIFY_LOCK_ACQUIRED post_acquire . .SHUT_DOWN_INSTANCES .
+ * ....|........................................ . ^ .
+ * v . | .
+ * <leader> -----------------------------------> .NOTIFY_LISTENER .
+ * (shut_down, release_leader, . pre_release .
+ * notify error) ...........................
+ * @endverbatim
+ */
+
+ class LeaderLock : public librbd::ManagedLock<ImageCtxT> {
+ public:
+ typedef librbd::ManagedLock<ImageCtxT> Parent;
+
+ LeaderLock(librados::IoCtx& ioctx, ContextWQ *work_queue,
+ const std::string& oid, LeaderWatcher *watcher,
+ bool blacklist_on_break_lock,
+ uint32_t blacklist_expire_seconds)
+ : Parent(ioctx, work_queue, oid, watcher, librbd::managed_lock::EXCLUSIVE,
+ blacklist_on_break_lock, blacklist_expire_seconds),
+ watcher(watcher) {
+ }
+
+ bool is_leader() const {
+ Mutex::Locker locker(Parent::m_lock);
+ return Parent::is_state_post_acquiring() || Parent::is_state_locked();
+ }
+
+ bool is_releasing_leader() const {
+ Mutex::Locker locker(Parent::m_lock);
+ return Parent::is_state_pre_releasing();
+ }
+
+ protected:
+ void post_acquire_lock_handler(int r, Context *on_finish) {
+ if (r == 0) {
+ // lock is owned at this point
+ Mutex::Locker locker(Parent::m_lock);
+ Parent::set_state_post_acquiring();
+ }
+ watcher->handle_post_acquire_leader_lock(r, on_finish);
+ }
+ void pre_release_lock_handler(bool shutting_down,
+ Context *on_finish) {
+ watcher->handle_pre_release_leader_lock(on_finish);
+ }
+ void post_release_lock_handler(bool shutting_down, int r,
+ Context *on_finish) {
+ watcher->handle_post_release_leader_lock(r, on_finish);
+ }
+ private:
+ LeaderWatcher *watcher;
+ };
+
+ struct HandlePayloadVisitor : public boost::static_visitor<void> {
+ LeaderWatcher *leader_watcher;
+ Context *on_notify_ack;
+
+ HandlePayloadVisitor(LeaderWatcher *leader_watcher, Context *on_notify_ack)
+ : leader_watcher(leader_watcher), on_notify_ack(on_notify_ack) {
+ }
+
+ template <typename Payload>
+ inline void operator()(const Payload &payload) const {
+ leader_watcher->handle_payload(payload, on_notify_ack);
+ }
+ };
+
+ struct C_GetLocker : public Context {
+ LeaderWatcher *leader_watcher;
+ librbd::managed_lock::Locker locker;
+
+ C_GetLocker(LeaderWatcher *leader_watcher)
+ : leader_watcher(leader_watcher) {
+ }
+
+ void finish(int r) override {
+ leader_watcher->handle_get_locker(r, locker);
+ }
+ };
+
+ typedef void (LeaderWatcher<ImageCtxT>::*TimerCallback)();
+
+ struct C_TimerGate : public Context {
+ LeaderWatcher *leader_watcher;
+
+ bool leader = false;
+ TimerCallback timer_callback = nullptr;
+
+ C_TimerGate(LeaderWatcher *leader_watcher)
+ : leader_watcher(leader_watcher) {
+ }
+
+ void finish(int r) override {
+ leader_watcher->m_timer_gate = nullptr;
+ leader_watcher->execute_timer_task(leader, timer_callback);
+ }
+ };
+
+ Threads<ImageCtxT> *m_threads;
+ Listener *m_listener;
+
+ mutable Mutex m_lock;
+ uint64_t m_notifier_id;
+ LeaderLock *m_leader_lock;
+ Context *m_on_finish = nullptr;
+ Context *m_on_shut_down_finish = nullptr;
+ int m_acquire_attempts = 0;
+ int m_ret_val = 0;
+ MirrorStatusWatcher<ImageCtxT> *m_status_watcher = nullptr;
+ Instances<ImageCtxT> *m_instances = nullptr;
+ librbd::managed_lock::Locker m_locker;
+
+ AsyncOpTracker m_timer_op_tracker;
+ Context *m_timer_task = nullptr;
+ C_TimerGate *m_timer_gate = nullptr;
+
+ librbd::watcher::NotifyResponse m_heartbeat_response;
+
+ bool is_leader(Mutex &m_lock) const;
+ bool is_releasing_leader(Mutex &m_lock) const;
+
+ void cancel_timer_task();
+ void schedule_timer_task(const std::string &name,
+ int delay_factor, bool leader,
+ TimerCallback callback, bool shutting_down);
+ void execute_timer_task(bool leader, TimerCallback timer_callback);
+
+ void create_leader_object();
+ void handle_create_leader_object(int r);
+
+ void register_watch();
+ void handle_register_watch(int r);
+
+ void shut_down_leader_lock();
+ void handle_shut_down_leader_lock(int r);
+
+ void unregister_watch();
+ void handle_unregister_watch(int r);
+
+ void wait_for_tasks();
+ void handle_wait_for_tasks();
+
+ void break_leader_lock();
+ void handle_break_leader_lock(int r);
+
+ void schedule_get_locker(bool reset_leader, uint32_t delay_factor);
+ void get_locker();
+ void handle_get_locker(int r, librbd::managed_lock::Locker& locker);
+
+ void schedule_acquire_leader_lock(uint32_t delay_factor);
+ void acquire_leader_lock();
+ void handle_acquire_leader_lock(int r);
+
+ void release_leader_lock();
+ void handle_release_leader_lock(int r);
+
+ void init_status_watcher();
+ void handle_init_status_watcher(int r);
+
+ void shut_down_status_watcher();
+ void handle_shut_down_status_watcher(int r);
+
+ void init_instances();
+ void handle_init_instances(int r);
+
+ void shut_down_instances();
+ void handle_shut_down_instances(int r);
+
+ void notify_listener();
+ void handle_notify_listener(int r);
+
+ void notify_lock_acquired();
+ void handle_notify_lock_acquired(int r);
+
+ void notify_lock_released();
+ void handle_notify_lock_released(int r);
+
+ void notify_heartbeat();
+ void handle_notify_heartbeat(int r);
+
+ void get_instances();
+ void handle_get_instances(int r);
+
+ void handle_post_acquire_leader_lock(int r, Context *on_finish);
+ void handle_pre_release_leader_lock(Context *on_finish);
+ void handle_post_release_leader_lock(int r, Context *on_finish);
+
+ void handle_notify(uint64_t notify_id, uint64_t handle,
+ uint64_t notifier_id, bufferlist &bl) override;
+
+ void handle_heartbeat(Context *on_ack);
+ void handle_lock_acquired(Context *on_ack);
+ void handle_lock_released(Context *on_ack);
+
+ void handle_payload(const leader_watcher::HeartbeatPayload &payload,
+ Context *on_notify_ack);
+ void handle_payload(const leader_watcher::LockAcquiredPayload &payload,
+ Context *on_notify_ack);
+ void handle_payload(const leader_watcher::LockReleasedPayload &payload,
+ Context *on_notify_ack);
+ void handle_payload(const leader_watcher::UnknownPayload &payload,
+ Context *on_notify_ack);
+};
+
+} // namespace mirror
+} // namespace rbd
+
+#endif // CEPH_RBD_MIRROR_LEADER_WATCHER_H
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