1 files changed, 166 insertions, 0 deletions
diff --git a/src/librbd/image/ListWatchersRequest.cc b/src/librbd/image/ListWatchersRequest.cc
new file mode 100644
index 00000000..e93fffc1
--- /dev/null
+++ b/src/librbd/image/ListWatchersRequest.cc
@@ -0,0 +1,166 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "ListWatchersRequest.h"
+#include "common/RWLock.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "cls/rbd/cls_rbd_client.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ImageWatcher.h"
+#include "librbd/Utils.h"
+
+#include <algorithm>
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::image::ListWatchersRequest: " << this \
+                           << " " << __func__ << ": "
+
+static std::ostream& operator<<(std::ostream& os, const obj_watch_t& watch) {
+  os << "{addr=" << watch.addr << ", "
+     << "watcher_id=" << watch.watcher_id << ", "
+     << "cookie=" << watch.cookie << "}";
+  return os;
+}
+
+namespace librbd {
+namespace image {
+
+using librados::IoCtx;
+using util::create_rados_callback;
+
+template<typename I>
+ListWatchersRequest<I>::ListWatchersRequest(I &image_ctx, int flags,
+                                            std::list<obj_watch_t> *watchers,
+                                            Context *on_finish)
+  : m_image_ctx(image_ctx), m_flags(flags), m_watchers(watchers),
+    m_on_finish(on_finish), m_cct(m_image_ctx.cct) {
+}
+
+template<typename I>
+void ListWatchersRequest<I>::send() {
+  ldout(m_cct, 20) << dendl;
+
+  list_image_watchers();
+}
+
+template<typename I>
+void ListWatchersRequest<I>::list_image_watchers() {
+  ldout(m_cct, 20) << dendl;
+
+  librados::ObjectReadOperation op;
+  op.list_watchers(&m_object_watchers, &m_ret_val);
+
+  using klass = ListWatchersRequest<I>;
+  librados::AioCompletion *rados_completion =
+    create_rados_callback<klass, &klass::handle_list_image_watchers>(this);
+
+  int r = m_image_ctx.md_ctx.aio_operate(m_image_ctx.header_oid,
+                                         rados_completion, &op, &m_out_bl);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+template<typename I>
+void ListWatchersRequest<I>::handle_list_image_watchers(int r) {
+  ldout(m_cct, 20) << "r=" << r << dendl;
+
+  if (r == 0 && m_ret_val < 0) {
+    r = m_ret_val;
+  }
+  if (r < 0) {
+    lderr(m_cct) << "error listing image watchers: " << cpp_strerror(r)
+                 << dendl;
+    finish(r);
+    return;
+  }
+
+  ldout(m_cct, 20) << "object_watchers=" << m_object_watchers << dendl;
+  list_mirror_watchers();
+}
+
+template<typename I>
+void ListWatchersRequest<I>::list_mirror_watchers() {
+  if ((m_object_watchers.empty()) ||
+      (m_flags & LIST_WATCHERS_FILTER_OUT_MIRROR_INSTANCES) == 0 ||
+      (m_image_ctx.features & RBD_FEATURE_JOURNALING) == 0) {
+    finish(0);
+    return;
+  }
+
+  ldout(m_cct, 20) << dendl;
+
+  librados::ObjectReadOperation op;
+  op.list_watchers(&m_mirror_watchers, &m_ret_val);
+
+  using klass = ListWatchersRequest<I>;
+  librados::AioCompletion *rados_completion =
+    create_rados_callback<klass, &klass::handle_list_mirror_watchers>(this);
+  m_out_bl.clear();
+  int r = m_image_ctx.md_ctx.aio_operate(RBD_MIRRORING, rados_completion,
+                                         &op, &m_out_bl);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+template<typename I>
+void ListWatchersRequest<I>::handle_list_mirror_watchers(int r) {
+  ldout(m_cct, 20) << "r=" << r << dendl;
+
+  if (r == 0 && m_ret_val < 0) {
+    r = m_ret_val;
+  }
+  if (r < 0 && r != -ENOENT) {
+    ldout(m_cct, 1) << "error listing mirror watchers: " << cpp_strerror(r)
+                    << dendl;
+  }
+
+  ldout(m_cct, 20) << "mirror_watchers=" << m_mirror_watchers << dendl;
+  finish(0);
+}
+
+template<typename I>
+void ListWatchersRequest<I>::finish(int r) {
+  ldout(m_cct, 20) << "r=" << r << dendl;
+
+  if (r == 0) {
+    m_watchers->clear();
+
+    if (m_object_watchers.size() > 0) {
+      RWLock::RLocker owner_locker(m_image_ctx.owner_lock);
+      uint64_t watch_handle = m_image_ctx.image_watcher != nullptr ?
+        m_image_ctx.image_watcher->get_watch_handle() : 0;
+
+      for (auto &w : m_object_watchers) {
+        if ((m_flags & LIST_WATCHERS_FILTER_OUT_MY_INSTANCE) != 0) {
+          if (w.cookie == watch_handle) {
+            ldout(m_cct, 20) << "filtering out my instance: " << w << dendl;
+            continue;
+          }
+        }
+        if ((m_flags & LIST_WATCHERS_FILTER_OUT_MIRROR_INSTANCES) != 0) {
+          auto it = std::find_if(m_mirror_watchers.begin(),
+                                 m_mirror_watchers.end(),
+                                 [w] (obj_watch_t &watcher) {
+                                   return (strncmp(w.addr, watcher.addr,
+                                                   sizeof(w.addr)) == 0);
+                                 });
+          if (it != m_mirror_watchers.end()) {
+            ldout(m_cct, 20) << "filtering out mirror instance: " << w << dendl;
+            continue;
+          }
+        }
+        m_watchers->push_back(w);
+      }
+    }
+  }
+
+  m_on_finish->complete(r);
+  delete this;
+}
+
+} // namespace image
+} // namespace librbd
+
+template class librbd::image::ListWatchersRequest<librbd::ImageCtx>;