1 files changed, 134 insertions, 0 deletions
diff --git a/src/librbd/exclusive_lock/ImageDispatch.h b/src/librbd/exclusive_lock/ImageDispatch.h
new file mode 100644
index 000000000..77c101973
--- /dev/null
+++ b/src/librbd/exclusive_lock/ImageDispatch.h
@@ -0,0 +1,134 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_EXCLUSIVE_LOCK_IMAGE_DISPATCH_H
+#define CEPH_LIBRBD_EXCLUSIVE_LOCK_IMAGE_DISPATCH_H
+
+#include "librbd/io/ImageDispatchInterface.h"
+#include "include/int_types.h"
+#include "include/buffer.h"
+#include "common/ceph_mutex.h"
+#include "common/zipkin_trace.h"
+#include "librbd/io/ReadResult.h"
+#include "librbd/io/Types.h"
+#include <atomic>
+#include <list>
+#include <unordered_set>
+
+struct Context;
+
+namespace librbd {
+
+struct ImageCtx;
+
+namespace io {
+struct AioCompletion;
+}
+
+namespace exclusive_lock {
+
+template <typename ImageCtxT>
+class ImageDispatch : public io::ImageDispatchInterface {
+public:
+  static ImageDispatch* create(ImageCtxT* image_ctx) {
+    return new ImageDispatch(image_ctx);
+  }
+  void destroy() {
+    delete this;
+  }
+
+  ImageDispatch(ImageCtxT* image_ctx);
+
+  io::ImageDispatchLayer get_dispatch_layer() const override {
+    return io::IMAGE_DISPATCH_LAYER_EXCLUSIVE_LOCK;
+  }
+
+  void set_require_lock(bool init_shutdown,
+                        io::Direction direction, Context* on_finish);
+  void unset_require_lock(io::Direction direction);
+
+  void shut_down(Context* on_finish) override;
+
+  bool read(
+      io::AioCompletion* aio_comp, io::Extents &&image_extents,
+      io::ReadResult &&read_result, IOContext io_context, int op_flags,
+      int read_flags, const ZTracer::Trace &parent_trace, uint64_t tid,
+      std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool write(
+      io::AioCompletion* aio_comp, io::Extents &&image_extents, bufferlist &&bl,
+      IOContext io_context, int op_flags, const ZTracer::Trace &parent_trace,
+      uint64_t tid, std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool discard(
+      io::AioCompletion* aio_comp, io::Extents &&image_extents,
+      uint32_t discard_granularity_bytes, IOContext io_context,
+      const ZTracer::Trace &parent_trace, uint64_t tid,
+      std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool write_same(
+      io::AioCompletion* aio_comp, io::Extents &&image_extents, bufferlist &&bl,
+      IOContext io_context, int op_flags, const ZTracer::Trace &parent_trace,
+      uint64_t tid, std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool compare_and_write(
+      io::AioCompletion* aio_comp, io::Extents &&image_extents,
+      bufferlist &&cmp_bl, bufferlist &&bl, uint64_t *mismatch_offset,
+      IOContext io_context, int op_flags, const ZTracer::Trace &parent_trace,
+      uint64_t tid, std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool flush(
+      io::AioCompletion* aio_comp, io::FlushSource flush_source,
+      const ZTracer::Trace &parent_trace, uint64_t tid,
+      std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+
+  bool list_snaps(
+      io::AioCompletion* aio_comp, io::Extents&& image_extents,
+      io::SnapIds&& snap_ids, int list_snaps_flags,
+      io::SnapshotDelta* snapshot_delta, const ZTracer::Trace &parent_trace,
+      uint64_t tid, std::atomic<uint32_t>* image_dispatch_flags,
+      io::DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override {
+    return false;
+  }
+
+  bool invalidate_cache(Context* on_finish) override {
+    return false;
+  }
+
+private:
+  typedef std::list<Context*> Contexts;
+  typedef std::unordered_set<uint64_t> Tids;
+
+  ImageCtxT* m_image_ctx;
+  mutable ceph::shared_mutex m_lock;
+
+  bool m_require_lock_on_read = false;
+  bool m_require_lock_on_write = false;
+
+  Contexts m_on_dispatches;
+
+  bool set_require_lock(io::Direction direction, bool enabled);
+
+  bool is_lock_required(bool read_op) const;
+
+  bool needs_exclusive_lock(bool read_op, uint64_t tid,
+                            io::DispatchResult* dispatch_result,
+                            Context* on_dispatched);
+
+  void handle_acquire_lock(int r);
+};
+
+} // namespace exclusiv_lock
+} // namespace librbd
+
+extern template class librbd::exclusive_lock::ImageDispatch<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_EXCLUSIVE_LOCK_IMAGE_DISPATCH_H