librbd: migration raw format source

The raw format maps an abstract, fully allocated, raw block device image
to the migration source IO API.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

src/librbd/CMakeLists.txt

@@ -120,6 +120,7 @@ set(librbd_internal_srcs
   migration/ImageDispatch.cc
   migration/NativeFormat.cc
   migration/OpenSourceImageRequest.cc
+  migration/RawFormat.cc
   mirror/DemoteRequest.cc
   mirror/DisableRequest.cc
   mirror/EnableRequest.cc

src/librbd/migration/RawFormat.cc

@@ -0,0 +1,139 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/migration/RawFormat.h"
+#include "common/dout.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/io/AioCompletion.h"
+#include "librbd/io/ReadResult.h"
+#include "librbd/migration/FileStream.h"
+#include "librbd/migration/StreamInterface.h"
+
+static const std::string STREAM{"stream"};
+static const std::string STREAM_TYPE{"type"};
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::migration::RawFormat: " << this \
+                           << " " << __func__ << ": "
+
+namespace librbd {
+namespace migration {
+
+template <typename I>
+RawFormat<I>::RawFormat(
+    I* image_ctx, const json_spirit::mObject& json_object)
+  : m_image_ctx(image_ctx), m_json_object(json_object) {
+}
+
+template <typename I>
+void RawFormat<I>::open(Context* on_finish) {
+  auto cct = m_image_ctx->cct;
+  ldout(cct, 10) << dendl;
+
+  // TODO switch to stream builder when more available
+  auto& stream_value = m_json_object[STREAM];
+  if (stream_value.type() != json_spirit::obj_type) {
+    lderr(cct) << "missing stream section" << dendl;
+    on_finish->complete(-EINVAL);
+    return;
+  }
+
+  auto& stream_obj = stream_value.get_obj();
+  auto& stream_type_value = stream_obj[STREAM_TYPE];
+  if (stream_type_value.type() != json_spirit::str_type) {
+    lderr(cct) << "missing stream type value" << dendl;
+    on_finish->complete(-EINVAL);
+    return;
+  }
+
+  auto& stream_type = stream_type_value.get_str();
+  if (stream_type != "file") {
+    lderr(cct) << "unknown stream type '" << stream_type << "'" << dendl;
+    on_finish->complete(-EINVAL);
+    return;
+  }
+
+  m_stream.reset(FileStream<I>::create(m_image_ctx, stream_obj));
+  m_stream->open(on_finish);
+}
+
+template <typename I>
+void RawFormat<I>::close(Context* on_finish) {
+  auto cct = m_image_ctx->cct;
+  ldout(cct, 10) << dendl;
+
+  if (!m_stream) {
+    on_finish->complete(0);
+    return;
+  }
+
+  m_stream->close(on_finish);
+}
+
+template <typename I>
+void RawFormat<I>::get_snapshots(SnapInfos* snap_infos, Context* on_finish) {
+  auto cct = m_image_ctx->cct;
+  ldout(cct, 10) << dendl;
+
+  snap_infos->clear();
+  on_finish->complete(0);
+}
+
+template <typename I>
+void RawFormat<I>::get_image_size(uint64_t snap_id, uint64_t* size,
+                                  Context* on_finish) {
+  auto cct = m_image_ctx->cct;
+  ldout(cct, 10) << dendl;
+
+  if (snap_id != CEPH_NOSNAP) {
+    on_finish->complete(-EINVAL);
+    return;
+  }
+
+  m_stream->get_size(size, on_finish);
+}
+
+template <typename I>
+void RawFormat<I>::read(
+    io::AioCompletion* aio_comp, uint64_t snap_id, io::Extents&& image_extents,
+    io::ReadResult&& read_result, int op_flags, int read_flags,
+    const ZTracer::Trace &parent_trace) {
+  auto cct = m_image_ctx->cct;
+  ldout(cct, 20) << "image_extents=" << image_extents << dendl;
+
+  if (snap_id != CEPH_NOSNAP) {
+    aio_comp->fail(-EINVAL);
+    return;
+  }
+
+  aio_comp->read_result = std::move(read_result);
+  aio_comp->read_result.set_image_extents(image_extents);
+
+  aio_comp->set_request_count(1);
+  auto ctx = new io::ReadResult::C_ImageReadRequest(aio_comp,
+                                                    image_extents);
+
+  // raw directly maps the image-extent IO down to a byte IO extent
+  m_stream->read(std::move(image_extents), &ctx->bl, ctx);
+}
+
+template <typename I>
+void RawFormat<I>::list_snaps(io::Extents&& image_extents,
+                              io::SnapIds&& snap_ids, int list_snaps_flags,
+                              io::SnapshotDelta* snapshot_delta,
+                              const ZTracer::Trace &parent_trace,
+                              Context* on_finish) {
+  // raw does support snapshots so list the full IO extent as a delta
+  auto& snapshot = (*snapshot_delta)[{CEPH_NOSNAP, CEPH_NOSNAP}];
+  for (auto& image_extent : image_extents) {
+    snapshot.insert(image_extent.first, image_extent.second,
+                    {io::SPARSE_EXTENT_STATE_DATA, image_extent.second});
+  }
+  on_finish->complete(0);
+}
+
+} // namespace migration
+} // namespace librbd
+
+template class librbd::migration::RawFormat<librbd::ImageCtx>;

src/librbd/migration/RawFormat.h

@@ -0,0 +1,66 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_MIGRATION_RAW_FORMAT_H
+#define CEPH_LIBRBD_MIGRATION_RAW_FORMAT_H
+
+#include "include/int_types.h"
+#include "librbd/Types.h"
+#include "librbd/migration/FormatInterface.h"
+#include "json_spirit/json_spirit.h"
+#include <memory>
+
+struct Context;
+
+namespace librbd {
+
+struct AsioEngine;
+struct ImageCtx;
+
+namespace migration {
+
+struct StreamInterface;
+
+template <typename ImageCtxT>
+class RawFormat : public FormatInterface {
+public:
+  static RawFormat* create(ImageCtxT* image_ctx,
+                           const json_spirit::mObject& json_object) {
+    return new RawFormat(image_ctx, json_object);
+  }
+
+  RawFormat(ImageCtxT* image_ctx, const json_spirit::mObject& json_object);
+  RawFormat(const RawFormat&) = delete;
+  RawFormat& operator=(const RawFormat&) = delete;
+
+  void open(Context* on_finish) override;
+  void close(Context* on_finish) override;
+
+  void get_snapshots(SnapInfos* snap_infos, Context* on_finish) override;
+  void get_image_size(uint64_t snap_id, uint64_t* size,
+                      Context* on_finish) override;
+
+  void read(io::AioCompletion* aio_comp, uint64_t snap_id,
+            io::Extents&& image_extents, io::ReadResult&& read_result,
+            int op_flags, int read_flags,
+            const ZTracer::Trace &parent_trace) override;
+
+  void list_snaps(io::Extents&& image_extents, io::SnapIds&& snap_ids,
+                  int list_snaps_flags, io::SnapshotDelta* snapshot_delta,
+                  const ZTracer::Trace &parent_trace,
+                  Context* on_finish) override;
+
+private:
+  ImageCtxT* m_image_ctx;
+  json_spirit::mObject m_json_object;
+
+  std::unique_ptr<StreamInterface> m_stream;
+
+};
+
+} // namespace migration
+} // namespace librbd
+
+extern template class librbd::migration::RawFormat<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_MIGRATION_RAW_FORMAT_H

src/test/librbd/CMakeLists.txt

@@ -90,6 +90,7 @@ set(unittest_librbd_srcs
   managed_lock/test_mock_ReacquireRequest.cc
   managed_lock/test_mock_ReleaseRequest.cc
   migration/test_mock_FileStream.cc
+  migration/test_mock_RawFormat.cc
   mirror/snapshot/test_mock_CreateNonPrimaryRequest.cc
   mirror/snapshot/test_mock_CreatePrimaryRequest.cc
   mirror/snapshot/test_mock_ImageMeta.cc