1 files changed, 122 insertions, 0 deletions
diff --git a/src/mds/JournalPointer.cc b/src/mds/JournalPointer.cc
new file mode 100644
index 000000000..8a446a20f
--- /dev/null
+++ b/src/mds/JournalPointer.cc
@@ -0,0 +1,122 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+
+#include "common/debug.h"
+#include "common/errno.h"
+#include "common/Cond.h"
+#include "osdc/Objecter.h"
+#include "mds/mdstypes.h"
+#include "msg/Messenger.h"
+
+#include "mds/JournalPointer.h"
+
+
+#define dout_context g_ceph_context
+#define dout_subsys ceph_subsys_journaler
+#undef dout_prefix
+#define dout_prefix *_dout << objecter->messenger->get_myname() << ".journalpointer "
+
+
+std::string JournalPointer::get_object_id() const
+{
+  inodeno_t const pointer_ino = MDS_INO_LOG_POINTER_OFFSET + node_id;
+  char buf[32];
+  snprintf(buf, sizeof(buf), "%llx.%08llx", (long long unsigned)pointer_ino, (long long unsigned)0);
+
+  return std::string(buf);
+}
+
+
+/**
+ * Blocking read of JournalPointer for this MDS
+ */
+int JournalPointer::load(Objecter *objecter)
+{
+  ceph_assert(objecter != NULL);
+
+  // Blocking read of data
+  std::string const object_id = get_object_id();
+  dout(4) << "Reading journal pointer '" << object_id << "'" << dendl;
+  bufferlist data;
+  C_SaferCond waiter;
+  objecter->read_full(object_t(object_id), object_locator_t(pool_id),
+      CEPH_NOSNAP, &data, 0, &waiter);
+  int r = waiter.wait();
+
+  // Construct JournalPointer result, null or decoded data
+  if (r == 0) {
+    auto q = data.cbegin();
+    try {
+      decode(q);
+    } catch (const buffer::error &e) {
+      return -CEPHFS_EINVAL;
+    }
+  } else {
+    dout(1) << "Journal pointer '" << object_id << "' read failed: " << cpp_strerror(r) << dendl;
+  }
+  return r;
+}
+
+
+/**
+ * Blocking write of JournalPointer for this MDS
+ *
+ * @return objecter write op status code
+ */
+int JournalPointer::save(Objecter *objecter) const
+{
+  ceph_assert(objecter != NULL);
+  // It is not valid to persist a null pointer
+  ceph_assert(!is_null());
+
+  // Serialize JournalPointer object
+  bufferlist data;
+  encode(data);
+
+  // Write to RADOS and wait for durability
+  std::string const object_id = get_object_id();
+  dout(4) << "Writing pointer object '" << object_id << "': 0x"
+    << std::hex << front << ":0x" << back << std::dec << dendl;
+
+  C_SaferCond waiter;
+  objecter->write_full(object_t(object_id), object_locator_t(pool_id),
+		       SnapContext(), data,
+		       ceph::real_clock::now(), 0,
+		       &waiter);
+  int write_result = waiter.wait();
+  if (write_result < 0) {
+    derr << "Error writing pointer object '" << object_id << "': " << cpp_strerror(write_result) << dendl;
+  }
+  return write_result;
+}
+
+
+/**
+ * Non-blocking variant of save() that assumes objecter lock already held by
+ * caller
+ */
+void JournalPointer::save(Objecter *objecter, Context *completion) const
+{
+  ceph_assert(objecter != NULL);
+
+  bufferlist data;
+  encode(data);
+
+  objecter->write_full(object_t(get_object_id()), object_locator_t(pool_id),
+		       SnapContext(), data,
+		       ceph::real_clock::now(), 0,
+		       completion);
+}
+