1 files changed, 80 insertions, 0 deletions
diff --git a/src/mds/cephfs_features.cc b/src/mds/cephfs_features.cc
new file mode 100644
index 000000000..4a864076b
--- /dev/null
+++ b/src/mds/cephfs_features.cc
@@ -0,0 +1,80 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include <array>
+#include "cephfs_features.h"
+#include "mdstypes.h"
+
+#include <fmt/format.h>
+
+static const std::array feature_names
+{
+  "reserved",
+  "reserved",
+  "reserved",
+  "reserved",
+  "reserved",
+  "jewel",
+  "kraken",
+  "luminous",
+  "mimic",
+  "reply_encoding",
+  "reclaim_client",
+  "lazy_caps_wanted",
+  "multi_reconnect",
+  "deleg_ino",
+  "metric_collect",
+  "alternate_name",
+  "notify_session_state",
+  "op_getvxattr",
+  "32bits_retry_fwd",
+  "new_snaprealm_info",
+  "has_owner_uidgid",
+};
+static_assert(feature_names.size() == CEPHFS_FEATURE_MAX + 1);
+
+std::string_view cephfs_feature_name(size_t id)
+{
+  if (id > feature_names.size())
+    return "unknown";
+  return feature_names[id];
+}
+
+int cephfs_feature_from_name(std::string_view name)
+{
+  if (name == "reserved") {
+    return -1;
+  }
+  for (size_t i = 0; i < feature_names.size(); ++i) {
+    if (name == feature_names[i])
+      return i;
+  }
+  return -1;
+}
+
+std::string cephfs_stringify_features(const feature_bitset_t& features)
+{
+  CachedStackStringStream css;
+  bool first = true;
+  *css << "{";
+  for (size_t i = 0; i < feature_names.size(); ++i) {
+    if (!features.test(i))
+      continue;
+    if (!first)
+      *css << ",";
+    *css << i << "=" << cephfs_feature_name(i);
+    first = false;
+  }
+  *css << "}";
+  return css->str();
+}
+
+void cephfs_dump_features(ceph::Formatter *f, const feature_bitset_t& features)
+{
+  for (size_t i = 0; i < feature_names.size(); ++i) {
+    if (!features.test(i))
+      continue;
+    f->dump_string(fmt::format("feature_{}", i),
+		   cephfs_feature_name(i));
+  }
+}