librbd: state machine for snapshot based mirror promote/demote

Signed-off-by: Mykola Golub <mgolub@suse.com>

diff --git a/src/librbd/CMakeLists.txt b/src/librbd/CMakeLists.txt
index 9bf456f87811b86d18193f00af52aae7713eaf81..8de8dbe0b579b19d84b4fddd6c720c6b1bf73fde 100644 (file)
--- a/src/librbd/CMakeLists.txt
+++ b/src/librbd/CMakeLists.txt
@@ -106,6 +106,8 @@ set(librbd_internal_srcs
   mirror/PromoteRequest.cc
   mirror/snapshot/CreateNonPrimaryRequest.cc
   mirror/snapshot/CreatePrimaryRequest.cc
+  mirror/snapshot/DemoteRequest.cc
+  mirror/snapshot/PromoteRequest.cc
   mirror/snapshot/UnlinkPeerRequest.cc
   object_map/CreateRequest.cc
   object_map/InvalidateRequest.cc

diff --git a/src/librbd/mirror/snapshot/DemoteRequest.cc b/src/librbd/mirror/snapshot/DemoteRequest.cc
new file mode 100644 (file)
index 0000000..18481b2
--- /dev/null
+++ b/src/librbd/mirror/snapshot/DemoteRequest.cc
@@ -0,0 +1,100 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/mirror/snapshot/DemoteRequest.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "cls/rbd/cls_rbd_client.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ImageState.h"
+#include "librbd/Operations.h"
+#include "librbd/Utils.h"
+#include "librbd/mirror/snapshot/CreatePrimaryRequest.h"
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::mirror::snapshot::DemoteRequest: " \
+                           << this << " " << __func__ << ": "
+
+namespace librbd {
+namespace mirror {
+namespace snapshot {
+
+using librbd::util::create_context_callback;
+
+template <typename I>
+void DemoteRequest<I>::send() {
+  refresh_image();
+}
+
+template <typename I>
+void DemoteRequest<I>::refresh_image() {
+  if (!m_image_ctx->state->is_refresh_required()) {
+    create_snapshot();
+    return;
+  }
+
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << dendl;
+
+  auto ctx = create_context_callback<
+    DemoteRequest<I>, &DemoteRequest<I>::handle_refresh_image>(this);
+  m_image_ctx->state->refresh(ctx);
+}
+
+template <typename I>
+void DemoteRequest<I>::handle_refresh_image(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << "r=" << r << dendl;
+
+  if (r < 0) {
+    lderr(cct) << "failed to refresh image: " << cpp_strerror(r) << dendl;
+    finish(r);
+    return;
+  }
+
+  create_snapshot();
+}
+
+template <typename I>
+void DemoteRequest<I>::create_snapshot() {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << dendl;
+
+  auto ctx = create_context_callback<
+    DemoteRequest<I>, &DemoteRequest<I>::handle_create_snapshot>(this);
+
+  auto req = CreatePrimaryRequest<I>::create(m_image_ctx, true, false, nullptr,
+                                             ctx);
+  req->send();
+}
+
+template <typename I>
+void DemoteRequest<I>::handle_create_snapshot(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << "r=" << r << dendl;
+
+  if (r < 0) {
+    lderr(cct) << "failed to create mirror snapshot: " << cpp_strerror(r)
+               << dendl;
+    finish(r);
+    return;
+  }
+
+  finish(0);
+}
+
+template <typename I>
+void DemoteRequest<I>::finish(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << "r=" << r << dendl;
+
+  m_on_finish->complete(r);
+  delete this;
+}
+
+} // namespace snapshot
+} // namespace mirror
+} // namespace librbd
+
+template class librbd::mirror::snapshot::DemoteRequest<librbd::ImageCtx>;

diff --git a/src/librbd/mirror/snapshot/DemoteRequest.h b/src/librbd/mirror/snapshot/DemoteRequest.h
new file mode 100644 (file)
index 0000000..054a9dc
--- /dev/null
+++ b/src/librbd/mirror/snapshot/DemoteRequest.h
@@ -0,0 +1,73 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_MIRROR_SNAPSHOT_DEMOTE_REQUEST_H
+#define CEPH_LIBRBD_MIRROR_SNAPSHOT_DEMOTE_REQUEST_H
+
+#include "include/buffer.h"
+
+#include <string>
+#include <set>
+
+struct Context;
+
+namespace librbd {
+
+struct ImageCtx;
+
+namespace mirror {
+namespace snapshot {
+
+template <typename ImageCtxT = librbd::ImageCtx>
+class DemoteRequest {
+public:
+  static DemoteRequest *create(ImageCtxT *image_ctx, bool force,
+                               Context *on_finish) {
+    return new DemoteRequest(image_ctx, force, on_finish);
+  }
+
+  DemoteRequest(ImageCtxT *image_ctx, bool force, Context *on_finish)
+    : m_image_ctx(image_ctx), m_force(force), m_on_finish(on_finish) {
+  }
+
+  void send();
+
+private:
+  /**
+   * @verbatim
+   *
+   * <start>
+   *    |
+   *    v
+   * REFRESH_IMAGE
+   *    |
+   *    v
+   * CREATE_SNAPSHOT
+   *    |
+   *    v
+   * <finish>
+   *
+   * @endverbatim
+   */
+
+  ImageCtxT *m_image_ctx;
+  bool m_force;
+  Context *m_on_finish;
+
+  void refresh_image();
+  void handle_refresh_image(int r);
+
+  void create_snapshot();
+  void handle_create_snapshot(int r);
+
+  void finish(int r);
+
+};
+
+} // namespace snapshot
+} // namespace mirror
+} // namespace librbd
+
+extern template class librbd::mirror::snapshot::DemoteRequest<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_MIRROR_SNAPSHOT_DEMOTE_REQUEST_H

diff --git a/src/librbd/mirror/snapshot/PromoteRequest.cc b/src/librbd/mirror/snapshot/PromoteRequest.cc
new file mode 100644 (file)
index 0000000..c9e59e0
--- /dev/null
+++ b/src/librbd/mirror/snapshot/PromoteRequest.cc
@@ -0,0 +1,100 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/mirror/snapshot/PromoteRequest.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "cls/rbd/cls_rbd_client.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ImageState.h"
+#include "librbd/Operations.h"
+#include "librbd/Utils.h"
+#include "librbd/mirror/snapshot/CreatePrimaryRequest.h"
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::mirror::snapshot::PromoteRequest: " \
+                           << this << " " << __func__ << ": "
+
+namespace librbd {
+namespace mirror {
+namespace snapshot {
+
+using librbd::util::create_context_callback;
+
+template <typename I>
+void PromoteRequest<I>::send() {
+  refresh_image();
+}
+
+template <typename I>
+void PromoteRequest<I>::refresh_image() {
+  if (!m_image_ctx->state->is_refresh_required()) {
+    create_snapshot();
+    return;
+  }
+
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << dendl;
+
+  auto ctx = create_context_callback<
+    PromoteRequest<I>, &PromoteRequest<I>::handle_refresh_image>(this);
+  m_image_ctx->state->refresh(ctx);
+}
+
+template <typename I>
+void PromoteRequest<I>::handle_refresh_image(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << "r=" << r << dendl;
+
+  if (r < 0) {
+    lderr(cct) << "failed to refresh image: " << cpp_strerror(r) << dendl;
+    finish(r);
+    return;
+  }
+
+  create_snapshot();
+}
+
+template <typename I>
+void PromoteRequest<I>::create_snapshot() {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << dendl;
+
+  auto ctx = create_context_callback<
+    PromoteRequest<I>, &PromoteRequest<I>::handle_create_snapshot>(this);
+
+  auto req = CreatePrimaryRequest<I>::create(m_image_ctx, false, true, nullptr,
+                                             ctx);
+  req->send();
+}
+
+template <typename I>
+void PromoteRequest<I>::handle_create_snapshot(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << "r=" << r << dendl;
+
+  if (r < 0) {
+    lderr(cct) << "failed to create mirror snapshot: " << cpp_strerror(r)
+               << dendl;
+    finish(r);
+    return;
+  }
+
+  finish(0);
+}
+
+template <typename I>
+void PromoteRequest<I>::finish(int r) {
+  CephContext *cct = m_image_ctx->cct;
+  ldout(cct, 20) << "r=" << r << dendl;
+
+  m_on_finish->complete(r);
+  delete this;
+}
+
+} // namespace snapshot
+} // namespace mirror
+} // namespace librbd
+
+template class librbd::mirror::snapshot::PromoteRequest<librbd::ImageCtx>;

diff --git a/src/librbd/mirror/snapshot/PromoteRequest.h b/src/librbd/mirror/snapshot/PromoteRequest.h
new file mode 100644 (file)
index 0000000..ef6e933
--- /dev/null
+++ b/src/librbd/mirror/snapshot/PromoteRequest.h
@@ -0,0 +1,73 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_MIRROR_SNAPSHOT_PROMOTE_REQUEST_H
+#define CEPH_LIBRBD_MIRROR_SNAPSHOT_PROMOTE_REQUEST_H
+
+#include "include/buffer.h"
+
+#include <string>
+#include <set>
+
+struct Context;
+
+namespace librbd {
+
+struct ImageCtx;
+
+namespace mirror {
+namespace snapshot {
+
+template <typename ImageCtxT = librbd::ImageCtx>
+class PromoteRequest {
+public:
+  static PromoteRequest *create(ImageCtxT *image_ctx, bool force,
+                                Context *on_finish) {
+    return new PromoteRequest(image_ctx, force, on_finish);
+  }
+
+  PromoteRequest(ImageCtxT *image_ctx, bool force, Context *on_finish)
+    : m_image_ctx(image_ctx), m_force(force), m_on_finish(on_finish) {
+  }
+
+  void send();
+
+private:
+  /**
+   * @verbatim
+   *
+   * <start>
+   *    |
+   *    v
+   * REFRESH_IMAGE
+   *    |
+   *    v
+   * CREATE_SNAPSHOT
+   *    |
+   *    v
+   * <finish>
+   *
+   * @endverbatim
+   */
+
+  ImageCtxT *m_image_ctx;
+  bool m_force;
+  Context *m_on_finish;
+
+  void refresh_image();
+  void handle_refresh_image(int r);
+
+  void create_snapshot();
+  void handle_create_snapshot(int r);
+
+  void finish(int r);
+
+};
+
+} // namespace snapshot
+} // namespace mirror
+} // namespace librbd
+
+extern template class librbd::mirror::snapshot::PromoteRequest<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_MIRROR_SNAPSHOT_PROMOTE_REQUEST_H