1 files changed, 135 insertions, 0 deletions
diff --git a/src/librbd/io/WriteBlockImageDispatch.h b/src/librbd/io/WriteBlockImageDispatch.h
new file mode 100644
index 000000000..9d200fb97
--- /dev/null
+++ b/src/librbd/io/WriteBlockImageDispatch.h
@@ -0,0 +1,135 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_IO_WRITE_BLOCK_IMAGE_DISPATCH_H
+#define CEPH_LIBRBD_IO_WRITE_BLOCK_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 "common/Throttle.h"
+#include "librbd/io/ReadResult.h"
+#include "librbd/io/Types.h"
+#include <list>
+
+struct Context;
+
+namespace librbd {
+
+struct ImageCtx;
+
+namespace io {
+
+struct AioCompletion;
+
+template <typename ImageCtxT>
+class WriteBlockImageDispatch : public ImageDispatchInterface {
+public:
+  WriteBlockImageDispatch(ImageCtxT* image_ctx);
+
+  ImageDispatchLayer get_dispatch_layer() const override {
+    return IMAGE_DISPATCH_LAYER_WRITE_BLOCK;
+  }
+
+  void shut_down(Context* on_finish) override;
+
+  int block_writes();
+  void block_writes(Context *on_blocked);
+  void unblock_writes();
+
+  inline bool writes_blocked() const {
+    std::shared_lock locker{m_lock};
+    return (m_write_blockers > 0);
+  }
+
+  void wait_on_writes_unblocked(Context *on_unblocked);
+
+  bool read(
+      AioCompletion* aio_comp, Extents &&image_extents,
+      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,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override {
+    return false;
+  }
+  bool write(
+      AioCompletion* aio_comp, 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,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool discard(
+      AioCompletion* aio_comp, 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,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool write_same(
+      AioCompletion* aio_comp, 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,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool compare_and_write(
+      AioCompletion* aio_comp, 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,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+  bool flush(
+      AioCompletion* aio_comp, FlushSource flush_source,
+      const ZTracer::Trace &parent_trace, uint64_t tid,
+      std::atomic<uint32_t>* image_dispatch_flags,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override;
+
+  bool list_snaps(
+      AioCompletion* aio_comp, Extents&& image_extents, SnapIds&& snap_ids,
+      int list_snaps_flags, SnapshotDelta* snapshot_delta,
+      const ZTracer::Trace &parent_trace, uint64_t tid,
+      std::atomic<uint32_t>* image_dispatch_flags,
+      DispatchResult* dispatch_result, Context** on_finish,
+      Context* on_dispatched) override {
+    return false;
+  }
+
+private:
+  struct C_BlockedWrites;
+
+  typedef std::list<Context*> Contexts;
+
+  ImageCtxT* m_image_ctx;
+
+  mutable ceph::shared_mutex m_lock;
+  Contexts m_on_dispatches;
+
+  uint32_t m_write_blockers = 0;
+  Contexts m_write_blocker_contexts;
+  Contexts m_unblocked_write_waiter_contexts;
+  uint64_t m_in_flight_writes = 0;
+
+  void handle_finished(int r, uint64_t tid);
+
+  bool process_io(uint64_t tid, DispatchResult* dispatch_result,
+                  Context** on_finish, Context* on_dispatched);
+  void flush_io(Context* on_finish);
+
+  bool invalidate_cache(Context* on_finish) override {
+    return false;
+  }
+
+  void handle_blocked_writes(int r);
+
+};
+
+} // namespace io
+} // namespace librbd
+
+extern template class librbd::io::WriteBlockImageDispatch<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_IO_WRITE_BLOCK_IMAGE_DISPATCH_H