1 files changed, 131 insertions, 0 deletions
diff --git a/src/librbd/object_map/SnapshotRollbackRequest.cc b/src/librbd/object_map/SnapshotRollbackRequest.cc
new file mode 100644
index 000000000..7c2f441cc
--- /dev/null
+++ b/src/librbd/object_map/SnapshotRollbackRequest.cc
@@ -0,0 +1,131 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/object_map/SnapshotRollbackRequest.h"
+#include "common/dout.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ObjectMap.h"
+#include "librbd/object_map/InvalidateRequest.h"
+#include "cls/lock/cls_lock_client.h"
+#include <iostream>
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::object_map::SnapshotRollbackRequest: "
+
+namespace librbd {
+namespace object_map {
+
+namespace {
+
+std::ostream& operator<<(std::ostream& os,
+                         const SnapshotRollbackRequest::State& state) {
+  switch(state) {
+  case SnapshotRollbackRequest::STATE_READ_MAP:
+    os << "READ_MAP";
+    break;
+  case SnapshotRollbackRequest::STATE_INVALIDATE_MAP:
+    os << "INVALIDATE_MAP";
+    break;
+  case SnapshotRollbackRequest::STATE_WRITE_MAP:
+    os << "WRITE_MAP";
+    break;
+  default:
+    os << "UNKNOWN (" << static_cast<uint32_t>(state) << ")";
+    break;
+  }
+  return os;
+}
+
+} // anonymous namespace
+
+void SnapshotRollbackRequest::send() {
+  send_read_map();
+}
+
+bool SnapshotRollbackRequest::should_complete(int r) {
+  CephContext *cct = m_image_ctx.cct;
+  ldout(cct, 5) << this << " " << __func__ << ": state=" << m_state << ", "
+                << "r=" << r << dendl;
+  if (r < 0 && m_ret_val == 0) {
+    m_ret_val = r;
+  }
+
+  bool finished = false;
+  switch (m_state) {
+  case STATE_READ_MAP:
+    if (r < 0) {
+      // invalidate the snapshot object map
+      send_invalidate_map();
+    } else {
+      send_write_map();
+    }
+    break;
+  case STATE_INVALIDATE_MAP:
+    // invalidate the HEAD object map as well
+    finished = Request::should_complete(m_ret_val);
+    break;
+  case STATE_WRITE_MAP:
+    finished = Request::should_complete(r);
+    break;
+  default:
+    ceph_abort();
+    break;
+  }
+  return finished;
+}
+
+void SnapshotRollbackRequest::send_read_map() {
+  std::string snap_oid(ObjectMap<>::object_map_name(m_image_ctx.id, m_snap_id));
+
+  CephContext *cct = m_image_ctx.cct;
+  ldout(cct, 5) << this << " " << __func__ << ": snap_oid=" << snap_oid
+                << dendl;
+  m_state = STATE_READ_MAP;
+
+  librados::ObjectReadOperation op;
+  op.read(0, 0, NULL, NULL);
+
+  librados::AioCompletion *rados_completion = create_callback_completion();
+  int r = m_image_ctx.md_ctx.aio_operate(snap_oid, rados_completion, &op,
+                                         &m_read_bl);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+void SnapshotRollbackRequest::send_write_map() {
+  std::shared_lock owner_locker{m_image_ctx.owner_lock};
+
+  CephContext *cct = m_image_ctx.cct;
+  std::string snap_oid(ObjectMap<>::object_map_name(m_image_ctx.id,
+                                                    CEPH_NOSNAP));
+  ldout(cct, 5) << this << " " << __func__ << ": snap_oid=" << snap_oid
+                << dendl;
+  m_state = STATE_WRITE_MAP;
+
+  librados::ObjectWriteOperation op;
+  rados::cls::lock::assert_locked(&op, RBD_LOCK_NAME, ClsLockType::EXCLUSIVE, "", "");
+  op.write_full(m_read_bl);
+
+  librados::AioCompletion *rados_completion = create_callback_completion();
+  int r = m_image_ctx.md_ctx.aio_operate(snap_oid, rados_completion, &op);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+void SnapshotRollbackRequest::send_invalidate_map() {
+  std::shared_lock owner_locker{m_image_ctx.owner_lock};
+  std::unique_lock image_locker{m_image_ctx.image_lock};
+
+  CephContext *cct = m_image_ctx.cct;
+  ldout(cct, 5) << this << " " << __func__ << dendl;
+  m_state = STATE_INVALIDATE_MAP;
+
+  InvalidateRequest<> *req = new InvalidateRequest<>(m_image_ctx, m_snap_id,
+                                                     false,
+                                                     create_callback_context());
+  req->send();
+}
+
+} // namespace object_map
+} // namespace librbd