diff options
Diffstat (limited to 'src/librbd/Watcher.cc')
| -rw-r--r-- | src/librbd/Watcher.cc | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/src/librbd/Watcher.cc b/src/librbd/Watcher.cc new file mode 100644 index 00000000..9f866f25 --- /dev/null +++ b/src/librbd/Watcher.cc @@ -0,0 +1,367 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab + +#include "librbd/Watcher.h" +#include "librbd/watcher/RewatchRequest.h" +#include "librbd/Utils.h" +#include "librbd/TaskFinisher.h" +#include "include/encoding.h" +#include "common/errno.h" +#include "common/WorkQueue.h" +#include <boost/bind.hpp> + +// re-include our assert to clobber the system one; fix dout: +#include "include/ceph_assert.h" + +#define dout_subsys ceph_subsys_rbd + +namespace librbd { + +using namespace watcher; + +using util::create_context_callback; +using util::create_rados_callback; +using std::string; + +namespace { + +struct C_UnwatchAndFlush : public Context { + librados::Rados rados; + Context *on_finish; + bool flushing = false; + int ret_val = 0; + + C_UnwatchAndFlush(librados::IoCtx &io_ctx, Context *on_finish) + : rados(io_ctx), on_finish(on_finish) { + } + + void complete(int r) override { + if (ret_val == 0 && r < 0) { + ret_val = r; + } + + if (!flushing) { + flushing = true; + + librados::AioCompletion *aio_comp = create_rados_callback(this); + r = rados.aio_watch_flush(aio_comp); + ceph_assert(r == 0); + aio_comp->release(); + return; + } + + // ensure our reference to the RadosClient is released prior + // to completing the callback to avoid racing an explicit + // librados shutdown + Context *ctx = on_finish; + r = ret_val; + delete this; + + ctx->complete(r); + } + + void finish(int r) override { + } +}; + +} // anonymous namespace + +#undef dout_prefix +#define dout_prefix *_dout << "librbd::Watcher::C_NotifyAck " << this << " " \ + << __func__ << ": " + +Watcher::C_NotifyAck::C_NotifyAck(Watcher *watcher, uint64_t notify_id, + uint64_t handle) + : watcher(watcher), cct(watcher->m_cct), notify_id(notify_id), + handle(handle) { + ldout(cct, 10) << "id=" << notify_id << ", " << "handle=" << handle << dendl; +} + +void Watcher::C_NotifyAck::finish(int r) { + ldout(cct, 10) << "r=" << r << dendl; + ceph_assert(r == 0); + watcher->acknowledge_notify(notify_id, handle, out); +} + +#undef dout_prefix +#define dout_prefix *_dout << "librbd::Watcher: " << this << " " << __func__ \ + << ": " + +Watcher::Watcher(librados::IoCtx& ioctx, ContextWQ *work_queue, + const string& oid) + : m_ioctx(ioctx), m_work_queue(work_queue), m_oid(oid), + m_cct(reinterpret_cast<CephContext *>(ioctx.cct())), + m_watch_lock(util::unique_lock_name("librbd::Watcher::m_watch_lock", this)), + m_watch_handle(0), m_notifier(work_queue, ioctx, oid), + m_watch_state(WATCH_STATE_IDLE), m_watch_ctx(*this) { +} + +Watcher::~Watcher() { + RWLock::RLocker l(m_watch_lock); + ceph_assert(is_unregistered(m_watch_lock)); +} + +void Watcher::register_watch(Context *on_finish) { + ldout(m_cct, 10) << dendl; + + RWLock::WLocker watch_locker(m_watch_lock); + ceph_assert(is_unregistered(m_watch_lock)); + m_watch_state = WATCH_STATE_REGISTERING; + m_watch_blacklisted = false; + + librados::AioCompletion *aio_comp = create_rados_callback( + new C_RegisterWatch(this, on_finish)); + int r = m_ioctx.aio_watch(m_oid, aio_comp, &m_watch_handle, &m_watch_ctx); + ceph_assert(r == 0); + aio_comp->release(); +} + +void Watcher::handle_register_watch(int r, Context *on_finish) { + ldout(m_cct, 10) << "r=" << r << dendl; + + bool watch_error = false; + Context *unregister_watch_ctx = nullptr; + { + RWLock::WLocker watch_locker(m_watch_lock); + ceph_assert(m_watch_state == WATCH_STATE_REGISTERING); + + m_watch_state = WATCH_STATE_IDLE; + if (r < 0) { + lderr(m_cct) << "failed to register watch: " << cpp_strerror(r) + << dendl; + m_watch_handle = 0; + } + + if (m_unregister_watch_ctx != nullptr) { + std::swap(unregister_watch_ctx, m_unregister_watch_ctx); + } else if (r == 0 && m_watch_error) { + lderr(m_cct) << "re-registering watch after error" << dendl; + m_watch_state = WATCH_STATE_REWATCHING; + watch_error = true; + } else { + m_watch_blacklisted = (r == -EBLACKLISTED); + } + } + + on_finish->complete(r); + + if (unregister_watch_ctx != nullptr) { + unregister_watch_ctx->complete(0); + } else if (watch_error) { + rewatch(); + } +} + +void Watcher::unregister_watch(Context *on_finish) { + ldout(m_cct, 10) << dendl; + + { + RWLock::WLocker watch_locker(m_watch_lock); + if (m_watch_state != WATCH_STATE_IDLE) { + ldout(m_cct, 10) << "delaying unregister until register completed" + << dendl; + + ceph_assert(m_unregister_watch_ctx == nullptr); + m_unregister_watch_ctx = new FunctionContext([this, on_finish](int r) { + unregister_watch(on_finish); + }); + return; + } else if (is_registered(m_watch_lock)) { + librados::AioCompletion *aio_comp = create_rados_callback( + new C_UnwatchAndFlush(m_ioctx, on_finish)); + int r = m_ioctx.aio_unwatch(m_watch_handle, aio_comp); + ceph_assert(r == 0); + aio_comp->release(); + + m_watch_handle = 0; + m_watch_blacklisted = false; + return; + } + } + + on_finish->complete(0); +} + +bool Watcher::notifications_blocked() const { + RWLock::RLocker locker(m_watch_lock); + + bool blocked = (m_blocked_count > 0); + ldout(m_cct, 5) << "blocked=" << blocked << dendl; + return blocked; +} + +void Watcher::block_notifies(Context *on_finish) { + { + RWLock::WLocker locker(m_watch_lock); + ++m_blocked_count; + ldout(m_cct, 5) << "blocked_count=" << m_blocked_count << dendl; + } + m_async_op_tracker.wait_for_ops(on_finish); +} + +void Watcher::unblock_notifies() { + RWLock::WLocker locker(m_watch_lock); + ceph_assert(m_blocked_count > 0); + --m_blocked_count; + ldout(m_cct, 5) << "blocked_count=" << m_blocked_count << dendl; +} + +void Watcher::flush(Context *on_finish) { + m_notifier.flush(on_finish); +} + +std::string Watcher::get_oid() const { + RWLock::RLocker locker(m_watch_lock); + return m_oid; +} + +void Watcher::set_oid(const string& oid) { + RWLock::WLocker watch_locker(m_watch_lock); + ceph_assert(is_unregistered(m_watch_lock)); + + m_oid = oid; +} + +void Watcher::handle_error(uint64_t handle, int err) { + lderr(m_cct) << "handle=" << handle << ": " << cpp_strerror(err) << dendl; + + RWLock::WLocker watch_locker(m_watch_lock); + m_watch_error = true; + + if (is_registered(m_watch_lock)) { + m_watch_state = WATCH_STATE_REWATCHING; + if (err == -EBLACKLISTED) { + m_watch_blacklisted = true; + } + + FunctionContext *ctx = new FunctionContext( + boost::bind(&Watcher::rewatch, this)); + m_work_queue->queue(ctx); + } +} + +void Watcher::acknowledge_notify(uint64_t notify_id, uint64_t handle, + bufferlist &out) { + m_ioctx.notify_ack(m_oid, notify_id, handle, out); +} + +void Watcher::rewatch() { + ldout(m_cct, 10) << dendl; + + Context *unregister_watch_ctx = nullptr; + { + RWLock::WLocker watch_locker(m_watch_lock); + ceph_assert(m_watch_state == WATCH_STATE_REWATCHING); + + if (m_unregister_watch_ctx != nullptr) { + m_watch_state = WATCH_STATE_IDLE; + std::swap(unregister_watch_ctx, m_unregister_watch_ctx); + } else { + m_watch_error = false; + auto ctx = create_context_callback< + Watcher, &Watcher::handle_rewatch>(this); + auto req = RewatchRequest::create(m_ioctx, m_oid, m_watch_lock, + &m_watch_ctx, &m_watch_handle, ctx); + req->send(); + return; + } + } + + unregister_watch_ctx->complete(0); +} + +void Watcher::handle_rewatch(int r) { + ldout(m_cct, 10) << "r=" << r << dendl; + + bool watch_error = false; + Context *unregister_watch_ctx = nullptr; + { + RWLock::WLocker watch_locker(m_watch_lock); + ceph_assert(m_watch_state == WATCH_STATE_REWATCHING); + + m_watch_blacklisted = false; + if (m_unregister_watch_ctx != nullptr) { + ldout(m_cct, 10) << "image is closing, skip rewatch" << dendl; + m_watch_state = WATCH_STATE_IDLE; + std::swap(unregister_watch_ctx, m_unregister_watch_ctx); + } else if (r == -EBLACKLISTED) { + lderr(m_cct) << "client blacklisted" << dendl; + m_watch_blacklisted = true; + } else if (r == -ENOENT) { + ldout(m_cct, 5) << "object does not exist" << dendl; + } else if (r < 0) { + lderr(m_cct) << "failed to rewatch: " << cpp_strerror(r) << dendl; + watch_error = true; + } else if (m_watch_error) { + lderr(m_cct) << "re-registering watch after error" << dendl; + watch_error = true; + } + } + + if (unregister_watch_ctx != nullptr) { + unregister_watch_ctx->complete(0); + return; + } else if (watch_error) { + rewatch(); + return; + } + + auto ctx = create_context_callback< + Watcher, &Watcher::handle_rewatch_callback>(this); + m_work_queue->queue(ctx, r); +} + +void Watcher::handle_rewatch_callback(int r) { + ldout(m_cct, 10) << "r=" << r << dendl; + handle_rewatch_complete(r); + + bool watch_error = false; + Context *unregister_watch_ctx = nullptr; + { + RWLock::WLocker watch_locker(m_watch_lock); + ceph_assert(m_watch_state == WATCH_STATE_REWATCHING); + + if (m_unregister_watch_ctx != nullptr) { + m_watch_state = WATCH_STATE_IDLE; + std::swap(unregister_watch_ctx, m_unregister_watch_ctx); + } else if (r == -EBLACKLISTED || r == -ENOENT) { + m_watch_state = WATCH_STATE_IDLE; + } else if (r < 0 || m_watch_error) { + watch_error = true; + } else { + m_watch_state = WATCH_STATE_IDLE; + } + } + + if (unregister_watch_ctx != nullptr) { + unregister_watch_ctx->complete(0); + } else if (watch_error) { + rewatch(); + } +} + +void Watcher::send_notify(bufferlist& payload, + watcher::NotifyResponse *response, + Context *on_finish) { + m_notifier.notify(payload, response, on_finish); +} + +void Watcher::WatchCtx::handle_notify(uint64_t notify_id, uint64_t handle, + uint64_t notifier_id, bufferlist& bl) { + // if notifications are blocked, finish the notification w/o + // bubbling the notification up to the derived class + watcher.m_async_op_tracker.start_op(); + if (watcher.notifications_blocked()) { + bufferlist bl; + watcher.acknowledge_notify(notify_id, handle, bl); + } else { + watcher.handle_notify(notify_id, handle, notifier_id, bl); + } + watcher.m_async_op_tracker.finish_op(); +} + +void Watcher::WatchCtx::handle_error(uint64_t handle, int err) { + watcher.handle_error(handle, err); +} + +} // namespace librbd |