1 files changed, 392 insertions, 0 deletions
diff --git a/src/librbd/image/DetachChildRequest.cc b/src/librbd/image/DetachChildRequest.cc
new file mode 100644
index 000000000..ab39dbcd7
--- /dev/null
+++ b/src/librbd/image/DetachChildRequest.cc
@@ -0,0 +1,392 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/image/DetachChildRequest.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "cls/rbd/cls_rbd_client.h"
+#include "librbd/ExclusiveLock.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ImageState.h"
+#include "librbd/Operations.h"
+#include "librbd/Utils.h"
+#include "librbd/asio/ContextWQ.h"
+#include "librbd/journal/DisabledPolicy.h"
+#include "librbd/trash/RemoveRequest.h"
+#include <string>
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::image::DetachChildRequest: " << this \
+                           << " " << __func__ << ": "
+
+namespace librbd {
+namespace image {
+
+using util::create_context_callback;
+using util::create_rados_callback;
+
+template <typename I>
+DetachChildRequest<I>::~DetachChildRequest() {
+  ceph_assert(m_parent_image_ctx == nullptr);
+}
+
+template <typename I>
+void DetachChildRequest<I>::send() {
+  {
+    std::shared_lock image_locker{m_image_ctx.image_lock};
+
+    // use oldest snapshot or HEAD for parent spec
+    if (!m_image_ctx.snap_info.empty()) {
+      m_parent_spec = m_image_ctx.snap_info.begin()->second.parent.spec;
+    } else {
+      m_parent_spec = m_image_ctx.parent_md.spec;
+    }
+  }
+
+  if (m_parent_spec.pool_id == -1) {
+    // ignore potential race with parent disappearing
+    m_image_ctx.op_work_queue->queue(create_context_callback<
+      DetachChildRequest<I>,
+      &DetachChildRequest<I>::finish>(this), 0);
+    return;
+  } else if (!m_image_ctx.test_op_features(RBD_OPERATION_FEATURE_CLONE_CHILD)) {
+    clone_v1_remove_child();
+    return;
+  }
+
+  clone_v2_child_detach();
+}
+
+template <typename I>
+void DetachChildRequest<I>::clone_v2_child_detach() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  librados::ObjectWriteOperation op;
+  cls_client::child_detach(&op, m_parent_spec.snap_id,
+                           {m_image_ctx.md_ctx.get_id(),
+                            m_image_ctx.md_ctx.get_namespace(),
+                            m_image_ctx.id});
+
+  int r = util::create_ioctx(m_image_ctx.md_ctx, "parent image",
+                             m_parent_spec.pool_id,
+                             m_parent_spec.pool_namespace, &m_parent_io_ctx);
+  if (r < 0) {
+    if (r == -ENOENT) {
+      r = 0;
+    }
+    finish(r);
+    return;
+  }
+
+  m_parent_header_name = util::header_name(m_parent_spec.image_id);
+
+  auto aio_comp = create_rados_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_child_detach>(this);
+  r = m_parent_io_ctx.aio_operate(m_parent_header_name, aio_comp, &op);
+  ceph_assert(r == 0);
+  aio_comp->release();
+}
+
+template <typename I>
+void DetachChildRequest<I>::handle_clone_v2_child_detach(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r < 0 && r != -ENOENT) {
+    lderr(cct) << "error detaching child from parent: " << cpp_strerror(r)
+               << dendl;
+    finish(r);
+    return;
+  }
+
+  clone_v2_get_snapshot();
+}
+
+template <typename I>
+void DetachChildRequest<I>::clone_v2_get_snapshot() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  librados::ObjectReadOperation op;
+  cls_client::snapshot_get_start(&op, m_parent_spec.snap_id);
+
+  m_out_bl.clear();
+  auto aio_comp = create_rados_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_get_snapshot>(this);
+  int r = m_parent_io_ctx.aio_operate(m_parent_header_name, aio_comp, &op,
+                                      &m_out_bl);
+  ceph_assert(r == 0);
+  aio_comp->release();
+}
+
+template <typename I>
+void DetachChildRequest<I>::handle_clone_v2_get_snapshot(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  bool remove_snapshot = false;
+  if (r == 0) {
+    cls::rbd::SnapshotInfo snap_info;
+    auto it = m_out_bl.cbegin();
+    r = cls_client::snapshot_get_finish(&it, &snap_info);
+    if (r == 0) {
+      m_parent_snap_namespace = snap_info.snapshot_namespace;
+      m_parent_snap_name = snap_info.name;
+
+      if (cls::rbd::get_snap_namespace_type(m_parent_snap_namespace) ==
+            cls::rbd::SNAPSHOT_NAMESPACE_TYPE_TRASH &&
+          snap_info.child_count == 0) {
+        // snapshot is in trash w/ zero children, so remove it
+        remove_snapshot = true;
+      }
+    }
+  }
+
+  if (r < 0 && r != -ENOENT) {
+    ldout(cct, 5) << "failed to retrieve snapshot: " << cpp_strerror(r)
+                  << dendl;
+  }
+
+  if (!remove_snapshot) {
+    finish(0);
+    return;
+  }
+
+  clone_v2_open_parent();
+}
+
+template<typename I>
+void DetachChildRequest<I>::clone_v2_open_parent() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  m_parent_image_ctx = I::create("", m_parent_spec.image_id, nullptr,
+                                 m_parent_io_ctx, false);
+
+  // ensure non-primary images can be modified
+  m_parent_image_ctx->read_only_mask &= ~IMAGE_READ_ONLY_FLAG_NON_PRIMARY;
+
+  auto ctx = create_context_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_open_parent>(this);
+  m_parent_image_ctx->state->open(OPEN_FLAG_SKIP_OPEN_PARENT, ctx);
+}
+
+template<typename I>
+void DetachChildRequest<I>::handle_clone_v2_open_parent(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r < 0) {
+    ldout(cct, 5) << "failed to open parent for read/write: "
+                  << cpp_strerror(r) << dendl;
+    m_parent_image_ctx = nullptr;
+    finish(0);
+    return;
+  }
+
+  // do not attempt to open the parent journal when removing the trash
+  // snapshot, because the parent may be not promoted
+  if (m_parent_image_ctx->test_features(RBD_FEATURE_JOURNALING)) {
+    std::unique_lock image_locker{m_parent_image_ctx->image_lock};
+    m_parent_image_ctx->set_journal_policy(new journal::DisabledPolicy());
+  }
+
+  // disallow any proxied maintenance operations
+  {
+    std::shared_lock owner_locker{m_parent_image_ctx->owner_lock};
+    if (m_parent_image_ctx->exclusive_lock != nullptr) {
+      m_parent_image_ctx->exclusive_lock->block_requests(0);
+    }
+  }
+
+  clone_v2_remove_snapshot();
+}
+
+template<typename I>
+void DetachChildRequest<I>::clone_v2_remove_snapshot() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  auto ctx = create_context_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_remove_snapshot>(this);
+  m_parent_image_ctx->operations->snap_remove(m_parent_snap_namespace,
+                                              m_parent_snap_name, ctx);
+}
+
+template<typename I>
+void DetachChildRequest<I>::handle_clone_v2_remove_snapshot(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r < 0 && r != -ENOENT) {
+    ldout(cct, 5) << "failed to remove trashed clone snapshot: "
+                  << cpp_strerror(r) << dendl;
+    clone_v2_close_parent();
+    return;
+  }
+
+  if (m_parent_image_ctx->snaps.empty()) {
+    clone_v2_get_parent_trash_entry();
+  } else {
+    clone_v2_close_parent();
+  }
+}
+
+template<typename I>
+void DetachChildRequest<I>::clone_v2_get_parent_trash_entry() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  librados::ObjectReadOperation op;
+  cls_client::trash_get_start(&op, m_parent_image_ctx->id);
+
+  m_out_bl.clear();
+  auto aio_comp = create_rados_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_get_parent_trash_entry>(this);
+  int r = m_parent_io_ctx.aio_operate(RBD_TRASH, aio_comp, &op, &m_out_bl);
+  ceph_assert(r == 0);
+  aio_comp->release();
+}
+
+template<typename I>
+void DetachChildRequest<I>::handle_clone_v2_get_parent_trash_entry(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r < 0 && r != -ENOENT) {
+    ldout(cct, 5) << "failed to get parent trash entry: " << cpp_strerror(r)
+                  << dendl;
+    clone_v2_close_parent();
+    return;
+  }
+
+  bool in_trash = false;
+
+  if (r == 0) {
+    cls::rbd::TrashImageSpec trash_spec;
+    auto it = m_out_bl.cbegin();
+    r = cls_client::trash_get_finish(&it, &trash_spec);
+
+    if (r == 0 &&
+        trash_spec.source == cls::rbd::TRASH_IMAGE_SOURCE_USER_PARENT &&
+        trash_spec.state == cls::rbd::TRASH_IMAGE_STATE_NORMAL &&
+        trash_spec.deferment_end_time <= ceph_clock_now()) {
+      in_trash = true;
+    }
+  }
+
+  if (in_trash) {
+    clone_v2_remove_parent_from_trash();
+  } else {
+    clone_v2_close_parent();
+  }
+}
+
+template<typename I>
+void DetachChildRequest<I>::clone_v2_remove_parent_from_trash() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  auto ctx = create_context_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_remove_parent_from_trash>(this);
+  auto req = librbd::trash::RemoveRequest<I>::create(
+      m_parent_io_ctx, m_parent_image_ctx, m_image_ctx.op_work_queue, false,
+      m_no_op, ctx);
+  req->send();
+}
+
+template<typename I>
+void DetachChildRequest<I>::handle_clone_v2_remove_parent_from_trash(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r < 0) {
+    ldout(cct, 5) << "failed to remove parent image:" << cpp_strerror(r)
+                  << dendl;
+  }
+
+  m_parent_image_ctx = nullptr;
+  finish(0);
+}
+
+template<typename I>
+void DetachChildRequest<I>::clone_v2_close_parent() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  auto ctx = create_context_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v2_close_parent>(this);
+  m_parent_image_ctx->state->close(ctx);
+}
+
+template<typename I>
+void DetachChildRequest<I>::handle_clone_v2_close_parent(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r < 0) {
+    ldout(cct, 5) << "failed to close parent image:" << cpp_strerror(r)
+                  << dendl;
+  }
+
+  m_parent_image_ctx = nullptr;
+  finish(0);
+}
+
+template<typename I>
+void DetachChildRequest<I>::clone_v1_remove_child() {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  m_parent_spec.pool_namespace = "";
+
+  librados::ObjectWriteOperation op;
+  librbd::cls_client::remove_child(&op, m_parent_spec, m_image_ctx.id);
+
+  auto aio_comp = create_rados_callback<
+    DetachChildRequest<I>,
+    &DetachChildRequest<I>::handle_clone_v1_remove_child>(this);
+  int r = m_image_ctx.md_ctx.aio_operate(RBD_CHILDREN, aio_comp, &op);
+  ceph_assert(r == 0);
+  aio_comp->release();
+}
+
+template<typename I>
+void DetachChildRequest<I>::handle_clone_v1_remove_child(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  if (r == -ENOENT) {
+    r = 0;
+  } else if (r < 0) {
+    lderr(cct) << "failed to remove child from children list: "
+               << cpp_strerror(r) << dendl;
+    finish(r);
+    return;
+  }
+
+  finish(0);
+}
+
+template <typename I>
+void DetachChildRequest<I>::finish(int r) {
+  auto cct = m_image_ctx.cct;
+  ldout(cct, 5) << "r=" << r << dendl;
+
+  m_on_finish->complete(r);
+  delete this;
+}
+
+} // namespace image
+} // namespace librbd
+
+template class librbd::image::DetachChildRequest<librbd::ImageCtx>;