--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/ExclusiveLock.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ImageWatcher.h"
+#include "librbd/ImageState.h"
+#include "librbd/exclusive_lock/PreAcquireRequest.h"
+#include "librbd/exclusive_lock/PostAcquireRequest.h"
+#include "librbd/exclusive_lock/PreReleaseRequest.h"
+#include "librbd/io/ImageRequestWQ.h"
+#include "librbd/Utils.h"
+#include "common/Mutex.h"
+#include "common/dout.h"
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::ExclusiveLock: " << this << " " \
+ << __func__
+
+namespace librbd {
+
+using namespace exclusive_lock;
+
+template <typename I>
+using ML = ManagedLock<I>;
+
+template <typename I>
+ExclusiveLock<I>::ExclusiveLock(I &image_ctx)
+ : ML<I>(image_ctx.md_ctx, image_ctx.op_work_queue, image_ctx.header_oid,
+ image_ctx.image_watcher, managed_lock::EXCLUSIVE,
+ image_ctx.blacklist_on_break_lock,
+ image_ctx.blacklist_expire_seconds),
+ m_image_ctx(image_ctx) {
+ Mutex::Locker locker(ML<I>::m_lock);
+ ML<I>::set_state_uninitialized();
+}
+
+template <typename I>
+bool ExclusiveLock<I>::accept_requests(int *ret_val) const {
+ Mutex::Locker locker(ML<I>::m_lock);
+
+ bool accept_requests = (!ML<I>::is_state_shutdown() &&
+ ML<I>::is_state_locked() &&
+ m_request_blocked_count == 0);
+ if (ret_val != nullptr) {
+ *ret_val = m_request_blocked_ret_val;
+ }
+
+ ldout(m_image_ctx.cct, 20) << "=" << accept_requests << dendl;
+ return accept_requests;
+}
+
+template <typename I>
+bool ExclusiveLock<I>::accept_ops() const {
+ Mutex::Locker locker(ML<I>::m_lock);
+ bool accept = accept_ops(ML<I>::m_lock);
+ ldout(m_image_ctx.cct, 20) << "=" << accept << dendl;
+ return accept;
+}
+
+template <typename I>
+bool ExclusiveLock<I>::accept_ops(const Mutex &lock) const {
+ return (!ML<I>::is_state_shutdown() &&
+ (ML<I>::is_state_locked() || ML<I>::is_state_post_acquiring()));
+}
+
+template <typename I>
+void ExclusiveLock<I>::block_requests(int r) {
+ Mutex::Locker locker(ML<I>::m_lock);
+
+ m_request_blocked_count++;
+ if (m_request_blocked_ret_val == 0) {
+ m_request_blocked_ret_val = r;
+ }
+
+ ldout(m_image_ctx.cct, 20) << dendl;
+}
+
+template <typename I>
+void ExclusiveLock<I>::unblock_requests() {
+ Mutex::Locker locker(ML<I>::m_lock);
+
+ assert(m_request_blocked_count > 0);
+ m_request_blocked_count--;
+ if (m_request_blocked_count == 0) {
+ m_request_blocked_ret_val = 0;
+ }
+
+ ldout(m_image_ctx.cct, 20) << dendl;
+}
+
+template <typename I>
+void ExclusiveLock<I>::init(uint64_t features, Context *on_init) {
+ assert(m_image_ctx.owner_lock.is_locked());
+ ldout(m_image_ctx.cct, 10) << dendl;
+
+ {
+ Mutex::Locker locker(ML<I>::m_lock);
+ ML<I>::set_state_initializing();
+ }
+
+ m_image_ctx.io_work_queue->block_writes(new C_InitComplete(this, features,
+ on_init));
+}
+
+template <typename I>
+void ExclusiveLock<I>::shut_down(Context *on_shut_down) {
+ ldout(m_image_ctx.cct, 10) << dendl;
+
+ ML<I>::shut_down(on_shut_down);
+
+ // if stalled in request state machine -- abort
+ handle_peer_notification(0);
+}
+
+template <typename I>
+void ExclusiveLock<I>::handle_peer_notification(int r) {
+ Mutex::Locker locker(ML<I>::m_lock);
+ if (!ML<I>::is_state_waiting_for_lock()) {
+ return;
+ }
+
+ ldout(m_image_ctx.cct, 10) << dendl;
+ assert(ML<I>::is_action_acquire_lock());
+
+ m_acquire_lock_peer_ret_val = r;
+ ML<I>::execute_next_action();
+}
+
+template <typename I>
+Context *ExclusiveLock<I>::start_op() {
+ assert(m_image_ctx.owner_lock.is_locked());
+ Mutex::Locker locker(ML<I>::m_lock);
+
+ if (!accept_ops(ML<I>::m_lock)) {
+ return nullptr;
+ }
+
+ m_async_op_tracker.start_op();
+ return new FunctionContext([this](int r) {
+ m_async_op_tracker.finish_op();
+ });
+}
+
+template <typename I>
+void ExclusiveLock<I>::handle_init_complete(uint64_t features) {
+ ldout(m_image_ctx.cct, 10) << ": features=" << features << dendl;
+
+ {
+ RWLock::RLocker owner_locker(m_image_ctx.owner_lock);
+ if (m_image_ctx.clone_copy_on_read ||
+ (features & RBD_FEATURE_JOURNALING) != 0) {
+ m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, true);
+ } else {
+ m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_WRITE, true);
+ }
+ }
+
+ Mutex::Locker locker(ML<I>::m_lock);
+ ML<I>::set_state_unlocked();
+}
+
+template <typename I>
+void ExclusiveLock<I>::shutdown_handler(int r, Context *on_finish) {
+ ldout(m_image_ctx.cct, 10) << dendl;
+
+ {
+ RWLock::WLocker owner_locker(m_image_ctx.owner_lock);
+ m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, false);
+ m_image_ctx.exclusive_lock = nullptr;
+ }
+
+ m_image_ctx.io_work_queue->unblock_writes();
+ m_image_ctx.image_watcher->flush(on_finish);
+}
+
+template <typename I>
+void ExclusiveLock<I>::pre_acquire_lock_handler(Context *on_finish) {
+ ldout(m_image_ctx.cct, 10) << dendl;
+
+ int acquire_lock_peer_ret_val = 0;
+ {
+ Mutex::Locker locker(ML<I>::m_lock);
+ std::swap(acquire_lock_peer_ret_val, m_acquire_lock_peer_ret_val);
+ }
+
+ if (acquire_lock_peer_ret_val == -EROFS) {
+ ldout(m_image_ctx.cct, 10) << ": peer nacked lock request" << dendl;
+ on_finish->complete(acquire_lock_peer_ret_val);
+ return;
+ }
+
+ PreAcquireRequest<I> *req = PreAcquireRequest<I>::create(m_image_ctx,
+ on_finish);
+ m_image_ctx.op_work_queue->queue(new FunctionContext([req](int r) {
+ req->send();
+ }));
+}
+
+template <typename I>
+void ExclusiveLock<I>::post_acquire_lock_handler(int r, Context *on_finish) {
+ ldout(m_image_ctx.cct, 10) << ": r=" << r << dendl;
+
+ if (r == -EROFS) {
+ // peer refused to release the exclusive lock
+ on_finish->complete(r);
+ return;
+ } else if (r < 0) {
+ ML<I>::m_lock.Lock();
+ assert(ML<I>::is_state_acquiring());
+
+ // PostAcquire state machine will not run, so we need complete prepare
+ m_image_ctx.state->handle_prepare_lock_complete();
+
+ // if lock is in-use by another client, request the lock
+ if (ML<I>::is_action_acquire_lock() && (r == -EBUSY || r == -EAGAIN)) {
+ ML<I>::set_state_waiting_for_lock();
+ ML<I>::m_lock.Unlock();
+
+ // request the lock from a peer
+ m_image_ctx.image_watcher->notify_request_lock();
+
+ // inform manage lock that we have interrupted the state machine
+ r = -ECANCELED;
+ } else {
+ ML<I>::m_lock.Unlock();
+
+ // clear error if peer owns lock
+ if (r == -EAGAIN) {
+ r = 0;
+ }
+ }
+
+ on_finish->complete(r);
+ return;
+ }
+
+ Mutex::Locker locker(ML<I>::m_lock);
+ m_pre_post_callback = on_finish;
+ using EL = ExclusiveLock<I>;
+ PostAcquireRequest<I> *req = PostAcquireRequest<I>::create(m_image_ctx,
+ util::create_context_callback<EL, &EL::handle_post_acquiring_lock>(this),
+ util::create_context_callback<EL, &EL::handle_post_acquired_lock>(this));
+
+ m_image_ctx.op_work_queue->queue(new FunctionContext([req](int r) {
+ req->send();
+ }));
+}
+
+template <typename I>
+void ExclusiveLock<I>::handle_post_acquiring_lock(int r) {
+ ldout(m_image_ctx.cct, 10) << dendl;
+
+ Mutex::Locker locker(ML<I>::m_lock);
+
+ assert(r == 0);
+
+ // lock is owned at this point
+ ML<I>::set_state_post_acquiring();
+}
+
+template <typename I>
+void ExclusiveLock<I>::handle_post_acquired_lock(int r) {
+ ldout(m_image_ctx.cct, 10) << ": r=" << r << dendl;
+
+ Context *on_finish = nullptr;
+ {
+ Mutex::Locker locker(ML<I>::m_lock);
+ assert(ML<I>::is_state_acquiring() || ML<I>::is_state_post_acquiring());
+
+ assert (m_pre_post_callback != nullptr);
+ std::swap(m_pre_post_callback, on_finish);
+ }
+
+ if (r >= 0) {
+ m_image_ctx.image_watcher->notify_acquired_lock();
+ m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, false);
+ m_image_ctx.io_work_queue->unblock_writes();
+ }
+
+ on_finish->complete(r);
+}
+
+template <typename I>
+void ExclusiveLock<I>::pre_release_lock_handler(bool shutting_down,
+ Context *on_finish) {
+ ldout(m_image_ctx.cct, 10) << dendl;
+ Mutex::Locker locker(ML<I>::m_lock);
+
+ PreReleaseRequest<I> *req = PreReleaseRequest<I>::create(
+ m_image_ctx, shutting_down, m_async_op_tracker, on_finish);
+ m_image_ctx.op_work_queue->queue(new FunctionContext([req](int r) {
+ req->send();
+ }));
+}
+
+template <typename I>
+void ExclusiveLock<I>::post_release_lock_handler(bool shutting_down, int r,
+ Context *on_finish) {
+ ldout(m_image_ctx.cct, 10) << ": r=" << r << " shutting_down="
+ << shutting_down << dendl;
+ if (!shutting_down) {
+ {
+ Mutex::Locker locker(ML<I>::m_lock);
+ assert(ML<I>::is_state_pre_releasing() || ML<I>::is_state_releasing());
+ }
+
+ if (r >= 0) {
+ m_image_ctx.image_watcher->notify_released_lock();
+ }
+ } else {
+ {
+ RWLock::WLocker owner_locker(m_image_ctx.owner_lock);
+ m_image_ctx.io_work_queue->set_require_lock(io::DIRECTION_BOTH, false);
+ m_image_ctx.exclusive_lock = nullptr;
+ }
+
+ if (r >= 0) {
+ m_image_ctx.io_work_queue->unblock_writes();
+ }
+
+ m_image_ctx.image_watcher->notify_released_lock();
+ }
+
+ on_finish->complete(r);
+}
+
+template <typename I>
+void ExclusiveLock<I>::post_reacquire_lock_handler(int r, Context *on_finish) {
+ ldout(m_image_ctx.cct, 10) << dendl;
+ if (r >= 0) {
+ m_image_ctx.image_watcher->notify_acquired_lock();
+ }
+
+ on_finish->complete(r);
+}
+
+template <typename I>
+struct ExclusiveLock<I>::C_InitComplete : public Context {
+ ExclusiveLock *exclusive_lock;
+ uint64_t features;
+ Context *on_init;
+
+ C_InitComplete(ExclusiveLock *exclusive_lock, uint64_t features,
+ Context *on_init)
+ : exclusive_lock(exclusive_lock), features(features), on_init(on_init) {
+ }
+ void finish(int r) override {
+ if (r == 0) {
+ exclusive_lock->handle_init_complete(features);
+ }
+ on_init->complete(r);
+ }
+};
+
+} // namespace librbd
+
+template class librbd::ExclusiveLock<librbd::ImageCtx>;
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