1 files changed, 244 insertions, 0 deletions
diff --git a/src/librbd/image/RefreshParentRequest.cc b/src/librbd/image/RefreshParentRequest.cc
new file mode 100644
index 000000000..348226c39
--- /dev/null
+++ b/src/librbd/image/RefreshParentRequest.cc
@@ -0,0 +1,244 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/image/RefreshParentRequest.h"
+#include "include/rados/librados.hpp"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ImageState.h"
+#include "librbd/Utils.h"
+#include "librbd/asio/ContextWQ.h"
+#include "librbd/io/ObjectDispatcherInterface.h"
+#include "librbd/migration/OpenSourceImageRequest.h"
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::image::RefreshParentRequest: "
+
+namespace librbd {
+namespace image {
+
+using util::create_async_context_callback;
+using util::create_context_callback;
+
+template <typename I>
+RefreshParentRequest<I>::RefreshParentRequest(
+    I &child_image_ctx, const ParentImageInfo &parent_md,
+    const MigrationInfo &migration_info, Context *on_finish)
+  : m_child_image_ctx(child_image_ctx), m_parent_md(parent_md),
+    m_migration_info(migration_info), m_on_finish(on_finish),
+    m_parent_image_ctx(nullptr), m_parent_snap_id(CEPH_NOSNAP),
+    m_error_result(0) {
+}
+
+template <typename I>
+bool RefreshParentRequest<I>::is_refresh_required(
+    I &child_image_ctx, const ParentImageInfo &parent_md,
+    const MigrationInfo &migration_info) {
+  ceph_assert(ceph_mutex_is_locked(child_image_ctx.image_lock));
+  return (is_open_required(child_image_ctx, parent_md, migration_info) ||
+          is_close_required(child_image_ctx, parent_md, migration_info));
+}
+
+template <typename I>
+bool RefreshParentRequest<I>::is_close_required(
+    I &child_image_ctx, const ParentImageInfo &parent_md,
+    const MigrationInfo &migration_info) {
+  return (child_image_ctx.parent != nullptr &&
+          !does_parent_exist(child_image_ctx, parent_md, migration_info));
+}
+
+template <typename I>
+bool RefreshParentRequest<I>::is_open_required(
+    I &child_image_ctx, const ParentImageInfo &parent_md,
+    const MigrationInfo &migration_info) {
+  return (does_parent_exist(child_image_ctx, parent_md, migration_info) &&
+          (child_image_ctx.parent == nullptr ||
+           child_image_ctx.parent->md_ctx.get_id() != parent_md.spec.pool_id ||
+           child_image_ctx.parent->md_ctx.get_namespace() !=
+             parent_md.spec.pool_namespace ||
+           child_image_ctx.parent->id != parent_md.spec.image_id ||
+           child_image_ctx.parent->snap_id != parent_md.spec.snap_id));
+}
+
+template <typename I>
+bool RefreshParentRequest<I>::does_parent_exist(
+    I &child_image_ctx, const ParentImageInfo &parent_md,
+    const MigrationInfo &migration_info) {
+  if (child_image_ctx.child != nullptr &&
+      child_image_ctx.child->migration_info.empty() && parent_md.overlap == 0) {
+    // intermediate, non-migrating images should only open their parent if they
+    // overlap
+    return false;
+  }
+
+  return (parent_md.spec.pool_id > -1 && parent_md.overlap > 0) ||
+          !migration_info.empty();
+}
+
+template <typename I>
+void RefreshParentRequest<I>::send() {
+  if (is_open_required(m_child_image_ctx, m_parent_md, m_migration_info)) {
+    send_open_parent();
+  } else {
+    // parent will be closed (if necessary) during finalize
+    send_complete(0);
+  }
+}
+
+template <typename I>
+void RefreshParentRequest<I>::apply() {
+  ceph_assert(ceph_mutex_is_wlocked(m_child_image_ctx.image_lock));
+  std::swap(m_child_image_ctx.parent, m_parent_image_ctx);
+}
+
+template <typename I>
+void RefreshParentRequest<I>::finalize(Context *on_finish) {
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << dendl;
+
+  m_on_finish = on_finish;
+  if (m_parent_image_ctx != nullptr) {
+    send_close_parent();
+  } else {
+    send_complete(0);
+  }
+}
+
+template <typename I>
+void RefreshParentRequest<I>::send_open_parent() {
+  ceph_assert(m_parent_md.spec.pool_id >= 0);
+
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << dendl;
+
+  if (!m_migration_info.empty()) {
+    auto ctx = create_async_context_callback(
+      m_child_image_ctx, create_context_callback<
+        RefreshParentRequest<I>,
+        &RefreshParentRequest<I>::handle_open_parent, false>(this));
+    auto req = migration::OpenSourceImageRequest<I>::create(
+      m_child_image_ctx.md_ctx, &m_child_image_ctx, m_parent_md.spec.snap_id,
+      m_migration_info, &m_parent_image_ctx, ctx);
+    req->send();
+    return;
+  }
+
+  librados::IoCtx parent_io_ctx;
+  int r = util::create_ioctx(m_child_image_ctx.md_ctx, "parent image",
+                             m_parent_md.spec.pool_id,
+                             m_parent_md.spec.pool_namespace, &parent_io_ctx);
+  if (r < 0) {
+    send_complete(r);
+    return;
+  }
+
+  m_parent_image_ctx = new I("", m_parent_md.spec.image_id,
+                             m_parent_md.spec.snap_id, parent_io_ctx, true);
+  m_parent_image_ctx->child = &m_child_image_ctx;
+
+  // set rados flags for reading the parent image
+  if (m_child_image_ctx.config.template get_val<bool>("rbd_balance_parent_reads")) {
+    m_parent_image_ctx->set_read_flag(librados::OPERATION_BALANCE_READS);
+  } else if (m_child_image_ctx.config.template get_val<bool>("rbd_localize_parent_reads")) {
+    m_parent_image_ctx->set_read_flag(librados::OPERATION_LOCALIZE_READS);
+  }
+
+  auto ctx = create_async_context_callback(
+    m_child_image_ctx, create_context_callback<
+      RefreshParentRequest<I>,
+      &RefreshParentRequest<I>::handle_open_parent, false>(this));
+  m_parent_image_ctx->state->open(0U, ctx);
+}
+
+template <typename I>
+Context *RefreshParentRequest<I>::handle_open_parent(int *result) {
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << " r=" << *result << dendl;
+
+  save_result(result);
+  if (*result < 0) {
+    lderr(cct) << "failed to open parent image: " << cpp_strerror(*result)
+               << dendl;
+
+    // image already closed by open state machine
+    m_parent_image_ctx = nullptr;
+  }
+
+  return m_on_finish;
+}
+
+template <typename I>
+void RefreshParentRequest<I>::send_close_parent() {
+  ceph_assert(m_parent_image_ctx != nullptr);
+
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << dendl;
+
+  auto ctx = create_async_context_callback(
+    m_child_image_ctx, create_context_callback<
+      RefreshParentRequest<I>,
+      &RefreshParentRequest<I>::handle_close_parent, false>(this));
+  m_parent_image_ctx->state->close(ctx);
+}
+
+template <typename I>
+Context *RefreshParentRequest<I>::handle_close_parent(int *result) {
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << " r=" << *result << dendl;
+
+  m_parent_image_ctx = nullptr;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to close parent image: " << cpp_strerror(*result)
+               << dendl;
+  }
+
+  send_reset_existence_cache();
+  return nullptr;
+}
+
+template <typename I>
+void RefreshParentRequest<I>::send_reset_existence_cache() {
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << dendl;
+
+  Context *ctx = create_async_context_callback(
+    m_child_image_ctx, create_context_callback<
+      RefreshParentRequest<I>,
+      &RefreshParentRequest<I>::handle_reset_existence_cache, false>(this));
+  m_child_image_ctx.io_object_dispatcher->reset_existence_cache(ctx);
+}
+
+template <typename I>
+Context *RefreshParentRequest<I>::handle_reset_existence_cache(int *result) {
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << " r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to reset object existence cache: "
+               << cpp_strerror(*result) << dendl;
+  }
+
+  if (m_error_result < 0) {
+    // propagate errors from opening the image
+    *result = m_error_result;
+  } else {
+    *result = 0;
+  }
+  return m_on_finish;
+}
+
+template <typename I>
+void RefreshParentRequest<I>::send_complete(int r) {
+  CephContext *cct = m_child_image_ctx.cct;
+  ldout(cct, 10) << this << " " << __func__ << dendl;
+
+  m_on_finish->complete(r);
+}
+
+} // namespace image
+} // namespace librbd
+
+template class librbd::image::RefreshParentRequest<librbd::ImageCtx>;