Merge pull request ceph#58882 from idryomov/wip-native-format-dispatch

librbd/migration: don't instantiate NativeFormat, handle it via dispatch

Reviewed-by: Ramana Raja <[email protected]>
Reviewed-by: N Balachandran <[email protected]>

Author: idryomov

src/librbd/api/Migration.cc

@@ -540,7 +540,6 @@ int Migration<I>::prepare_import(
     return r;
   }
 
-  auto asio_engine = src_image_ctx->asio_engine;
   BOOST_SCOPE_EXIT_TPL(src_image_ctx) {
     src_image_ctx->state->close();
   } BOOST_SCOPE_EXIT_END;
@@ -581,11 +580,6 @@ int Migration<I>::prepare_import(
   Migration migration(src_image_ctx, dst_image_ctx, dst_migration_spec,
                       opts, nullptr);
   return migration.prepare_import();
-  if (r < 0) {
-    return r;
-  }
-
-  return 0;
 }
 
 template <typename I>

src/librbd/migration/FileStream.cc

@@ -74,7 +74,7 @@ struct FileStream<I>::ReadRequest {
     auto offset = lseek64(file_stream->m_file_no, byte_extent.first, SEEK_SET);
     if (offset == -1) {
       r = -errno;
-      lderr(cct) << "failed to seek file stream: " << cpp_strerror(r) << dendl;
+      lderr(cct) << "failed to seek file: " << cpp_strerror(r) << dendl;
       finish(r);
       return;
     }
@@ -149,7 +149,7 @@ void FileStream<I>::open(Context* on_finish) {
   m_file_no = ::open(file_path.c_str(), O_RDONLY);
   if (m_file_no < 0) {
     int r = -errno;
-    lderr(m_cct) << "failed to open file stream '" << file_path << "': "
+    lderr(m_cct) << "failed to open file '" << file_path << "': "
                  << cpp_strerror(r) << dendl;
     on_finish->complete(r);
     return;

src/librbd/migration/FormatInterface.h

@@ -35,7 +35,7 @@ struct FormatInterface {
   virtual void get_image_size(uint64_t snap_id, uint64_t* size,
                               Context* on_finish) = 0;
 
-  virtual bool read(io::AioCompletion* aio_comp, uint64_t snap_id,
+  virtual 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) = 0;

src/librbd/migration/HttpClient.cc

@@ -283,7 +283,7 @@ class HttpClient<I>::HttpSession : public HttpSessionInterface {
     ldout(cct, 15) << "r=" << r << dendl;
 
     if (r < 0) {
-      lderr(cct) << "failed to disconnect stream: '" << cpp_strerror(r)
+      lderr(cct) << "failed to disconnect stream: " << cpp_strerror(r)
                  << dendl;
     }
 
@@ -350,7 +350,7 @@ class HttpClient<I>::HttpSession : public HttpSessionInterface {
     ldout(cct, 15) << "r=" << r << dendl;
 
     if (r < 0) {
-      lderr(cct) << "failed to disconnect stream: '" << cpp_strerror(r)
+      lderr(cct) << "failed to disconnect stream: " << cpp_strerror(r)
                  << dendl;
     }
 

src/librbd/migration/ImageDispatch.cc

@@ -43,10 +43,17 @@ bool ImageDispatch<I>::read(
   auto cct = m_image_ctx->cct;
   ldout(cct, 20) << dendl;
 
+  // let io::ImageDispatch layer (IMAGE_DISPATCH_LAYER_CORE) handle
+  // native format
+  if (!m_format) {
+    return false;
+  }
+
   *dispatch_result = io::DISPATCH_RESULT_COMPLETE;
-  return m_format->read(aio_comp, io_context->get_read_snap(),
-                        std::move(image_extents), std::move(read_result),
-                        op_flags, read_flags, parent_trace);
+  m_format->read(aio_comp, io_context->get_read_snap(),
+                 std::move(image_extents), std::move(read_result),
+                 op_flags, read_flags, parent_trace);
+  return true;
 }
 
 template <typename I>
@@ -132,6 +139,12 @@ bool ImageDispatch<I>::list_snaps(
   auto cct = m_image_ctx->cct;
   ldout(cct, 20) << dendl;
 
+  // let io::ImageDispatch layer (IMAGE_DISPATCH_LAYER_CORE) handle
+  // native format
+  if (!m_format) {
+    return false;
+  }
+
   *dispatch_result = io::DISPATCH_RESULT_COMPLETE;
 
   aio_comp->set_request_count(1);

src/librbd/migration/ImageDispatch.h

@@ -86,6 +86,8 @@ class ImageDispatch : public io::ImageDispatchInterface {
 
 private:
   ImageCtxT* m_image_ctx;
+
+  // empty (nullptr) for native format
   std::unique_ptr<FormatInterface> m_format;
 
   void fail_io(int r, io::AioCompletion* aio_comp,