1 files changed, 147 insertions, 0 deletions
diff --git a/src/librbd/object_map/SnapshotCreateRequest.cc b/src/librbd/object_map/SnapshotCreateRequest.cc
new file mode 100644
index 000000000..3b2e7ee82
--- /dev/null
+++ b/src/librbd/object_map/SnapshotCreateRequest.cc
@@ -0,0 +1,147 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/object_map/SnapshotCreateRequest.h"
+#include "common/dout.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ObjectMap.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::SnapshotCreateRequest: "
+
+namespace librbd {
+namespace object_map {
+
+namespace {
+
+std::ostream& operator<<(std::ostream& os,
+                         const SnapshotCreateRequest::State& state) {
+  switch(state) {
+  case SnapshotCreateRequest::STATE_READ_MAP:
+    os << "READ_MAP";
+    break;
+  case SnapshotCreateRequest::STATE_WRITE_MAP:
+    os << "WRITE_MAP";
+    break;
+  case SnapshotCreateRequest::STATE_ADD_SNAPSHOT:
+    os << "ADD_SNAPSHOT";
+    break;
+  default:
+    os << "UNKNOWN (" << static_cast<uint32_t>(state) << ")";
+    break;
+  }
+  return os;
+}
+
+} // anonymous namespace
+
+void SnapshotCreateRequest::send() {
+  send_read_map();
+}
+
+bool SnapshotCreateRequest::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;
+  }
+  if (m_ret_val < 0) {
+    // pass errors down to base class to invalidate the object map
+    return Request::should_complete(r);
+  }
+
+  std::shared_lock owner_locker{m_image_ctx.owner_lock};
+  bool finished = false;
+  switch (m_state) {
+  case STATE_READ_MAP:
+    send_write_map();
+    break;
+  case STATE_WRITE_MAP:
+    finished = send_add_snapshot();
+    break;
+  case STATE_ADD_SNAPSHOT:
+    update_object_map();
+    finished = true;
+    break;
+  default:
+    ceph_abort();
+    break;
+  }
+  return finished;
+}
+
+void SnapshotCreateRequest::send_read_map() {
+  ceph_assert(ceph_mutex_is_locked(m_image_ctx.image_lock));
+
+  CephContext *cct = m_image_ctx.cct;
+  std::string oid(ObjectMap<>::object_map_name(m_image_ctx.id, CEPH_NOSNAP));
+  ldout(cct, 5) << this << " " << __func__ << ": oid=" << oid << dendl;
+  m_state = STATE_READ_MAP;
+
+  // IO is blocked due to the snapshot creation -- consistent to read from disk
+  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(oid, rados_completion, &op,
+                                         &m_read_bl);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+void SnapshotCreateRequest::send_write_map() {
+  CephContext *cct = m_image_ctx.cct;
+  std::string snap_oid(ObjectMap<>::object_map_name(m_image_ctx.id, m_snap_id));
+  ldout(cct, 5) << this << " " << __func__ << ": snap_oid=" << snap_oid
+                << dendl;
+  m_state = STATE_WRITE_MAP;
+
+  librados::ObjectWriteOperation op;
+  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();
+}
+
+bool SnapshotCreateRequest::send_add_snapshot() {
+  std::shared_lock image_locker{m_image_ctx.image_lock};
+  if ((m_image_ctx.features & RBD_FEATURE_FAST_DIFF) == 0) {
+    return true;
+  }
+
+  CephContext *cct = m_image_ctx.cct;
+  std::string oid(ObjectMap<>::object_map_name(m_image_ctx.id, CEPH_NOSNAP));
+  ldout(cct, 5) << this << " " << __func__ << ": oid=" << oid << dendl;
+  m_state = STATE_ADD_SNAPSHOT;
+
+  librados::ObjectWriteOperation op;
+  rados::cls::lock::assert_locked(&op, RBD_LOCK_NAME, ClsLockType::EXCLUSIVE, "", "");
+  cls_client::object_map_snap_add(&op);
+
+  librados::AioCompletion *rados_completion = create_callback_completion();
+  int r = m_image_ctx.md_ctx.aio_operate(oid, rados_completion, &op);
+  ceph_assert(r == 0);
+  rados_completion->release();
+  return false;
+}
+
+void SnapshotCreateRequest::update_object_map() {
+  std::unique_lock object_map_locker{*m_object_map_lock};
+
+  auto it = m_object_map.begin();
+  auto end_it = m_object_map.end();
+  for (; it != end_it; ++it) {
+    if (*it == OBJECT_EXISTS) {
+      *it = OBJECT_EXISTS_CLEAN;
+    }
+  }
+}
+
+} // namespace object_map
+} // namespace librbd