diff options
Diffstat (limited to 'src/librbd/ImageState.cc')
| -rw-r--r-- | src/librbd/ImageState.cc | 741 |
1 files changed, 741 insertions, 0 deletions
diff --git a/src/librbd/ImageState.cc b/src/librbd/ImageState.cc new file mode 100644 index 00000000..1f0535e2 --- /dev/null +++ b/src/librbd/ImageState.cc @@ -0,0 +1,741 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab + +#include "librbd/ImageState.h" +#include "include/rbd/librbd.hpp" +#include "common/dout.h" +#include "common/errno.h" +#include "common/Cond.h" +#include "common/WorkQueue.h" +#include "librbd/ImageCtx.h" +#include "librbd/Utils.h" +#include "librbd/image/CloseRequest.h" +#include "librbd/image/OpenRequest.h" +#include "librbd/image/RefreshRequest.h" +#include "librbd/image/SetSnapRequest.h" + +#define dout_subsys ceph_subsys_rbd +#undef dout_prefix +#define dout_prefix *_dout << "librbd::ImageState: " << this << " " + +namespace librbd { + +using util::create_async_context_callback; +using util::create_context_callback; + +class ImageUpdateWatchers { +public: + + explicit ImageUpdateWatchers(CephContext *cct) : m_cct(cct), + m_lock(util::unique_lock_name("librbd::ImageUpdateWatchers::m_lock", this)) { + } + + ~ImageUpdateWatchers() { + ceph_assert(m_watchers.empty()); + ceph_assert(m_in_flight.empty()); + ceph_assert(m_pending_unregister.empty()); + ceph_assert(m_on_shut_down_finish == nullptr); + + destroy_work_queue(); + } + + void flush(Context *on_finish) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ << dendl; + { + Mutex::Locker locker(m_lock); + if (!m_in_flight.empty()) { + Context *ctx = new FunctionContext( + [this, on_finish](int r) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ + << ": completing flush" << dendl; + on_finish->complete(r); + }); + m_work_queue->queue(ctx, 0); + return; + } + } + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ + << ": completing flush" << dendl; + on_finish->complete(0); + } + + void shut_down(Context *on_finish) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ << dendl; + { + Mutex::Locker locker(m_lock); + ceph_assert(m_on_shut_down_finish == nullptr); + m_watchers.clear(); + if (!m_in_flight.empty()) { + m_on_shut_down_finish = on_finish; + return; + } + } + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ + << ": completing shut down" << dendl; + on_finish->complete(0); + } + + void register_watcher(UpdateWatchCtx *watcher, uint64_t *handle) { + ldout(m_cct, 20) << __func__ << ": watcher=" << watcher << dendl; + + Mutex::Locker locker(m_lock); + ceph_assert(m_on_shut_down_finish == nullptr); + + create_work_queue(); + + *handle = m_next_handle++; + m_watchers.insert(std::make_pair(*handle, watcher)); + } + + void unregister_watcher(uint64_t handle, Context *on_finish) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ << ": handle=" + << handle << dendl; + int r = 0; + { + Mutex::Locker locker(m_lock); + auto it = m_watchers.find(handle); + if (it == m_watchers.end()) { + r = -ENOENT; + } else { + if (m_in_flight.find(handle) != m_in_flight.end()) { + ceph_assert(m_pending_unregister.find(handle) == m_pending_unregister.end()); + m_pending_unregister[handle] = on_finish; + on_finish = nullptr; + } + m_watchers.erase(it); + } + } + + if (on_finish) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ + << ": completing unregister" << dendl; + on_finish->complete(r); + } + } + + void notify() { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ << dendl; + + Mutex::Locker locker(m_lock); + for (auto it : m_watchers) { + send_notify(it.first, it.second); + } + } + + void send_notify(uint64_t handle, UpdateWatchCtx *watcher) { + ceph_assert(m_lock.is_locked()); + + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ << ": handle=" + << handle << ", watcher=" << watcher << dendl; + + m_in_flight.insert(handle); + + Context *ctx = new FunctionContext( + [this, handle, watcher](int r) { + handle_notify(handle, watcher); + }); + + m_work_queue->queue(ctx, 0); + } + + void handle_notify(uint64_t handle, UpdateWatchCtx *watcher) { + + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ << ": handle=" + << handle << ", watcher=" << watcher << dendl; + + watcher->handle_notify(); + + Context *on_unregister_finish = nullptr; + Context *on_shut_down_finish = nullptr; + + { + Mutex::Locker locker(m_lock); + + auto in_flight_it = m_in_flight.find(handle); + ceph_assert(in_flight_it != m_in_flight.end()); + m_in_flight.erase(in_flight_it); + + // If there is no more in flight notifications for this watcher + // and it is pending unregister, complete it now. + if (m_in_flight.find(handle) == m_in_flight.end()) { + auto it = m_pending_unregister.find(handle); + if (it != m_pending_unregister.end()) { + on_unregister_finish = it->second; + m_pending_unregister.erase(it); + } + } + + if (m_in_flight.empty()) { + ceph_assert(m_pending_unregister.empty()); + if (m_on_shut_down_finish != nullptr) { + std::swap(m_on_shut_down_finish, on_shut_down_finish); + } + } + } + + if (on_unregister_finish != nullptr) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ + << ": completing unregister" << dendl; + on_unregister_finish->complete(0); + } + + if (on_shut_down_finish != nullptr) { + ldout(m_cct, 20) << "ImageUpdateWatchers::" << __func__ + << ": completing shut down" << dendl; + on_shut_down_finish->complete(0); + } + } + +private: + class ThreadPoolSingleton : public ThreadPool { + public: + explicit ThreadPoolSingleton(CephContext *cct) + : ThreadPool(cct, "librbd::ImageUpdateWatchers::thread_pool", "tp_librbd", + 1) { + start(); + } + ~ThreadPoolSingleton() override { + stop(); + } + }; + + CephContext *m_cct; + Mutex m_lock; + ContextWQ *m_work_queue = nullptr; + std::map<uint64_t, UpdateWatchCtx*> m_watchers; + uint64_t m_next_handle = 0; + std::multiset<uint64_t> m_in_flight; + std::map<uint64_t, Context*> m_pending_unregister; + Context *m_on_shut_down_finish = nullptr; + + void create_work_queue() { + if (m_work_queue != nullptr) { + return; + } + auto& thread_pool = m_cct->lookup_or_create_singleton_object< + ThreadPoolSingleton>("librbd::ImageUpdateWatchers::thread_pool", + false, m_cct); + m_work_queue = new ContextWQ("librbd::ImageUpdateWatchers::op_work_queue", + m_cct->_conf.get_val<uint64_t>("rbd_op_thread_timeout"), + &thread_pool); + } + + void destroy_work_queue() { + if (m_work_queue == nullptr) { + return; + } + m_work_queue->drain(); + delete m_work_queue; + } +}; + +template <typename I> +ImageState<I>::ImageState(I *image_ctx) + : m_image_ctx(image_ctx), m_state(STATE_UNINITIALIZED), + m_lock(util::unique_lock_name("librbd::ImageState::m_lock", this)), + m_last_refresh(0), m_refresh_seq(0), + m_update_watchers(new ImageUpdateWatchers(image_ctx->cct)) { +} + +template <typename I> +ImageState<I>::~ImageState() { + ceph_assert(m_state == STATE_UNINITIALIZED || m_state == STATE_CLOSED); + delete m_update_watchers; +} + +template <typename I> +int ImageState<I>::open(uint64_t flags) { + C_SaferCond ctx; + open(flags, &ctx); + + int r = ctx.wait(); + if (r < 0) { + delete m_image_ctx; + } + return r; +} + +template <typename I> +void ImageState<I>::open(uint64_t flags, Context *on_finish) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << dendl; + + m_lock.Lock(); + ceph_assert(m_state == STATE_UNINITIALIZED); + m_open_flags = flags; + + Action action(ACTION_TYPE_OPEN); + action.refresh_seq = m_refresh_seq; + + execute_action_unlock(action, on_finish); +} + +template <typename I> +int ImageState<I>::close() { + C_SaferCond ctx; + close(&ctx); + + int r = ctx.wait(); + delete m_image_ctx; + return r; +} + +template <typename I> +void ImageState<I>::close(Context *on_finish) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << dendl; + + m_lock.Lock(); + ceph_assert(!is_closed()); + + Action action(ACTION_TYPE_CLOSE); + action.refresh_seq = m_refresh_seq; + execute_action_unlock(action, on_finish); +} + +template <typename I> +void ImageState<I>::handle_update_notification() { + Mutex::Locker locker(m_lock); + ++m_refresh_seq; + + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << ": refresh_seq = " << m_refresh_seq << ", " + << "last_refresh = " << m_last_refresh << dendl; + + if (m_state == STATE_OPEN) { + m_update_watchers->notify(); + } +} + +template <typename I> +bool ImageState<I>::is_refresh_required() const { + Mutex::Locker locker(m_lock); + return (m_last_refresh != m_refresh_seq || find_pending_refresh() != nullptr); +} + +template <typename I> +int ImageState<I>::refresh() { + C_SaferCond refresh_ctx; + refresh(&refresh_ctx); + return refresh_ctx.wait(); +} + +template <typename I> +void ImageState<I>::refresh(Context *on_finish) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << dendl; + + m_lock.Lock(); + if (is_closed()) { + m_lock.Unlock(); + on_finish->complete(-ESHUTDOWN); + return; + } + + Action action(ACTION_TYPE_REFRESH); + action.refresh_seq = m_refresh_seq; + execute_action_unlock(action, on_finish); +} + +template <typename I> +int ImageState<I>::refresh_if_required() { + C_SaferCond ctx; + { + m_lock.Lock(); + Action action(ACTION_TYPE_REFRESH); + action.refresh_seq = m_refresh_seq; + + auto refresh_action = find_pending_refresh(); + if (refresh_action != nullptr) { + // if a refresh is in-flight, delay until it is finished + action = *refresh_action; + } else if (m_last_refresh == m_refresh_seq) { + m_lock.Unlock(); + return 0; + } else if (is_closed()) { + m_lock.Unlock(); + return -ESHUTDOWN; + } + + execute_action_unlock(action, &ctx); + } + + return ctx.wait(); +} + +template <typename I> +const typename ImageState<I>::Action * +ImageState<I>::find_pending_refresh() const { + ceph_assert(m_lock.is_locked()); + + auto it = std::find_if(m_actions_contexts.rbegin(), + m_actions_contexts.rend(), + [](const ActionContexts& action_contexts) { + return (action_contexts.first == ACTION_TYPE_REFRESH); + }); + if (it != m_actions_contexts.rend()) { + return &it->first; + } + return nullptr; +} + +template <typename I> +void ImageState<I>::snap_set(uint64_t snap_id, Context *on_finish) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << ": snap_id=" << snap_id << dendl; + + Action action(ACTION_TYPE_SET_SNAP); + action.snap_id = snap_id; + + m_lock.Lock(); + execute_action_unlock(action, on_finish); +} + +template <typename I> +void ImageState<I>::prepare_lock(Context *on_ready) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << __func__ << dendl; + + m_lock.Lock(); + if (is_closed()) { + m_lock.Unlock(); + on_ready->complete(-ESHUTDOWN); + return; + } + + Action action(ACTION_TYPE_LOCK); + action.on_ready = on_ready; + execute_action_unlock(action, nullptr); +} + +template <typename I> +void ImageState<I>::handle_prepare_lock_complete() { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << __func__ << dendl; + + m_lock.Lock(); + if (m_state != STATE_PREPARING_LOCK) { + m_lock.Unlock(); + return; + } + + complete_action_unlock(STATE_OPEN, 0); +} + +template <typename I> +int ImageState<I>::register_update_watcher(UpdateWatchCtx *watcher, + uint64_t *handle) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << dendl; + + m_update_watchers->register_watcher(watcher, handle); + + ldout(cct, 20) << __func__ << ": handle=" << *handle << dendl; + return 0; +} + +template <typename I> +int ImageState<I>::unregister_update_watcher(uint64_t handle) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << ": handle=" << handle << dendl; + + C_SaferCond ctx; + m_update_watchers->unregister_watcher(handle, &ctx); + return ctx.wait(); +} + +template <typename I> +void ImageState<I>::flush_update_watchers(Context *on_finish) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << dendl; + + m_update_watchers->flush(on_finish); +} + +template <typename I> +void ImageState<I>::shut_down_update_watchers(Context *on_finish) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 20) << __func__ << dendl; + + m_update_watchers->shut_down(on_finish); +} + +template <typename I> +bool ImageState<I>::is_transition_state() const { + switch (m_state) { + case STATE_UNINITIALIZED: + case STATE_OPEN: + case STATE_CLOSED: + return false; + case STATE_OPENING: + case STATE_CLOSING: + case STATE_REFRESHING: + case STATE_SETTING_SNAP: + case STATE_PREPARING_LOCK: + break; + } + return true; +} + +template <typename I> +bool ImageState<I>::is_closed() const { + ceph_assert(m_lock.is_locked()); + + return ((m_state == STATE_CLOSED) || + (!m_actions_contexts.empty() && + m_actions_contexts.back().first.action_type == ACTION_TYPE_CLOSE)); +} + +template <typename I> +void ImageState<I>::append_context(const Action &action, Context *context) { + ceph_assert(m_lock.is_locked()); + + ActionContexts *action_contexts = nullptr; + for (auto &action_ctxs : m_actions_contexts) { + if (action == action_ctxs.first) { + action_contexts = &action_ctxs; + break; + } + } + + if (action_contexts == nullptr) { + m_actions_contexts.push_back({action, {}}); + action_contexts = &m_actions_contexts.back(); + } + + if (context != nullptr) { + action_contexts->second.push_back(context); + } +} + +template <typename I> +void ImageState<I>::execute_next_action_unlock() { + ceph_assert(m_lock.is_locked()); + ceph_assert(!m_actions_contexts.empty()); + switch (m_actions_contexts.front().first.action_type) { + case ACTION_TYPE_OPEN: + send_open_unlock(); + return; + case ACTION_TYPE_CLOSE: + send_close_unlock(); + return; + case ACTION_TYPE_REFRESH: + send_refresh_unlock(); + return; + case ACTION_TYPE_SET_SNAP: + send_set_snap_unlock(); + return; + case ACTION_TYPE_LOCK: + send_prepare_lock_unlock(); + return; + } + ceph_abort(); +} + +template <typename I> +void ImageState<I>::execute_action_unlock(const Action &action, + Context *on_finish) { + ceph_assert(m_lock.is_locked()); + + append_context(action, on_finish); + if (!is_transition_state()) { + execute_next_action_unlock(); + } else { + m_lock.Unlock(); + } +} + +template <typename I> +void ImageState<I>::complete_action_unlock(State next_state, int r) { + ceph_assert(m_lock.is_locked()); + ceph_assert(!m_actions_contexts.empty()); + + ActionContexts action_contexts(std::move(m_actions_contexts.front())); + m_actions_contexts.pop_front(); + + m_state = next_state; + m_lock.Unlock(); + + for (auto ctx : action_contexts.second) { + ctx->complete(r); + } + + if (next_state != STATE_UNINITIALIZED && next_state != STATE_CLOSED) { + m_lock.Lock(); + if (!is_transition_state() && !m_actions_contexts.empty()) { + execute_next_action_unlock(); + } else { + m_lock.Unlock(); + } + } +} + +template <typename I> +void ImageState<I>::send_open_unlock() { + ceph_assert(m_lock.is_locked()); + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << dendl; + + m_state = STATE_OPENING; + + Context *ctx = create_async_context_callback( + *m_image_ctx, create_context_callback< + ImageState<I>, &ImageState<I>::handle_open>(this)); + image::OpenRequest<I> *req = image::OpenRequest<I>::create( + m_image_ctx, m_open_flags, ctx); + + m_lock.Unlock(); + req->send(); +} + +template <typename I> +void ImageState<I>::handle_open(int r) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << ": r=" << r << dendl; + + if (r < 0 && r != -ENOENT) { + lderr(cct) << "failed to open image: " << cpp_strerror(r) << dendl; + } + + m_lock.Lock(); + complete_action_unlock(r < 0 ? STATE_UNINITIALIZED : STATE_OPEN, r); +} + +template <typename I> +void ImageState<I>::send_close_unlock() { + ceph_assert(m_lock.is_locked()); + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << dendl; + + m_state = STATE_CLOSING; + + Context *ctx = create_context_callback< + ImageState<I>, &ImageState<I>::handle_close>(this); + image::CloseRequest<I> *req = image::CloseRequest<I>::create( + m_image_ctx, ctx); + + m_lock.Unlock(); + req->send(); +} + +template <typename I> +void ImageState<I>::handle_close(int r) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << ": r=" << r << dendl; + + if (r < 0) { + lderr(cct) << "error occurred while closing image: " << cpp_strerror(r) + << dendl; + } + + m_lock.Lock(); + complete_action_unlock(STATE_CLOSED, r); +} + +template <typename I> +void ImageState<I>::send_refresh_unlock() { + ceph_assert(m_lock.is_locked()); + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << dendl; + + m_state = STATE_REFRESHING; + ceph_assert(!m_actions_contexts.empty()); + auto &action_context = m_actions_contexts.front().first; + ceph_assert(action_context.action_type == ACTION_TYPE_REFRESH); + + Context *ctx = create_async_context_callback( + *m_image_ctx, create_context_callback< + ImageState<I>, &ImageState<I>::handle_refresh>(this)); + image::RefreshRequest<I> *req = image::RefreshRequest<I>::create( + *m_image_ctx, false, false, ctx); + + m_lock.Unlock(); + req->send(); +} + +template <typename I> +void ImageState<I>::handle_refresh(int r) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << ": r=" << r << dendl; + + m_lock.Lock(); + ceph_assert(!m_actions_contexts.empty()); + + ActionContexts &action_contexts(m_actions_contexts.front()); + ceph_assert(action_contexts.first.action_type == ACTION_TYPE_REFRESH); + ceph_assert(m_last_refresh <= action_contexts.first.refresh_seq); + + if (r == -ERESTART) { + ldout(cct, 5) << "incomplete refresh: not updating sequence" << dendl; + r = 0; + } else { + m_last_refresh = action_contexts.first.refresh_seq; + } + + complete_action_unlock(STATE_OPEN, r); +} + +template <typename I> +void ImageState<I>::send_set_snap_unlock() { + ceph_assert(m_lock.is_locked()); + + m_state = STATE_SETTING_SNAP; + + ceph_assert(!m_actions_contexts.empty()); + ActionContexts &action_contexts(m_actions_contexts.front()); + ceph_assert(action_contexts.first.action_type == ACTION_TYPE_SET_SNAP); + + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << ": " + << "snap_id=" << action_contexts.first.snap_id << dendl; + + Context *ctx = create_async_context_callback( + *m_image_ctx, create_context_callback< + ImageState<I>, &ImageState<I>::handle_set_snap>(this)); + image::SetSnapRequest<I> *req = image::SetSnapRequest<I>::create( + *m_image_ctx, action_contexts.first.snap_id, ctx); + + m_lock.Unlock(); + req->send(); +} + +template <typename I> +void ImageState<I>::handle_set_snap(int r) { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << " r=" << r << dendl; + + if (r < 0 && r != -ENOENT) { + lderr(cct) << "failed to set snapshot: " << cpp_strerror(r) << dendl; + } + + m_lock.Lock(); + complete_action_unlock(STATE_OPEN, r); +} + +template <typename I> +void ImageState<I>::send_prepare_lock_unlock() { + CephContext *cct = m_image_ctx->cct; + ldout(cct, 10) << this << " " << __func__ << dendl; + + ceph_assert(m_lock.is_locked()); + m_state = STATE_PREPARING_LOCK; + + ceph_assert(!m_actions_contexts.empty()); + ActionContexts &action_contexts(m_actions_contexts.front()); + ceph_assert(action_contexts.first.action_type == ACTION_TYPE_LOCK); + + Context *on_ready = action_contexts.first.on_ready; + m_lock.Unlock(); + + if (on_ready == nullptr) { + complete_action_unlock(STATE_OPEN, 0); + return; + } + + // wake up the lock handler now that its safe to proceed + on_ready->complete(0); +} + +} // namespace librbd + +template class librbd::ImageState<librbd::ImageCtx>; |