1 files changed, 111 insertions, 0 deletions
diff --git a/src/librbd/Features.cc b/src/librbd/Features.cc
new file mode 100644
index 000000000..9da5b1dc4
--- /dev/null
+++ b/src/librbd/Features.cc
@@ -0,0 +1,111 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include <boost/lexical_cast.hpp>
+#include <boost/algorithm/string.hpp>
+
+#include "librbd/Features.h"
+#include "include/rbd/features.h"
+
+#include <map>
+#include <vector>
+
+static const std::map<std::string, uint64_t> RBD_FEATURE_MAP = {
+  {RBD_FEATURE_NAME_LAYERING, RBD_FEATURE_LAYERING},
+  {RBD_FEATURE_NAME_STRIPINGV2, RBD_FEATURE_STRIPINGV2},
+  {RBD_FEATURE_NAME_EXCLUSIVE_LOCK, RBD_FEATURE_EXCLUSIVE_LOCK},
+  {RBD_FEATURE_NAME_OBJECT_MAP, RBD_FEATURE_OBJECT_MAP},
+  {RBD_FEATURE_NAME_FAST_DIFF, RBD_FEATURE_FAST_DIFF},
+  {RBD_FEATURE_NAME_DEEP_FLATTEN, RBD_FEATURE_DEEP_FLATTEN},
+  {RBD_FEATURE_NAME_JOURNALING, RBD_FEATURE_JOURNALING},
+  {RBD_FEATURE_NAME_DATA_POOL, RBD_FEATURE_DATA_POOL},
+  {RBD_FEATURE_NAME_OPERATIONS, RBD_FEATURE_OPERATIONS},
+  {RBD_FEATURE_NAME_MIGRATING, RBD_FEATURE_MIGRATING},
+  {RBD_FEATURE_NAME_NON_PRIMARY, RBD_FEATURE_NON_PRIMARY},
+  {RBD_FEATURE_NAME_DIRTY_CACHE, RBD_FEATURE_DIRTY_CACHE},
+};
+static_assert((RBD_FEATURE_DIRTY_CACHE << 1) > RBD_FEATURES_ALL,
+	      "new RBD feature added");
+
+
+namespace librbd {
+
+std::string rbd_features_to_string(uint64_t features,
+				   std::ostream *err)
+{
+  std::string r;
+  for (auto& i : RBD_FEATURE_MAP) {
+    if (features & i.second) {
+      if (!r.empty()) {
+      r += ",";
+      }
+      r += i.first;
+      features &= ~i.second;
+    }
+  }
+  if (err && features) {
+    *err << "ignoring unknown feature mask 0x"
+	 << std::hex << features << std::dec;
+  }
+  return r;
+}
+
+uint64_t rbd_features_from_string(const std::string& orig_value,
+				  std::ostream *err)
+{
+  uint64_t features = 0;
+  std::string value = orig_value;
+  boost::trim(value);
+
+  // empty string means default features
+  if (!value.size()) {
+    return RBD_FEATURES_DEFAULT;
+  }
+
+  try {
+    // numeric?
+    features = boost::lexical_cast<uint64_t>(value);
+
+    // drop unrecognized bits
+    uint64_t unsupported_features = (features & ~RBD_FEATURES_ALL);
+    if (unsupported_features != 0ull) {
+      features &= RBD_FEATURES_ALL;
+      if (err) {
+	*err << "ignoring unknown feature mask 0x"
+             << std::hex << unsupported_features << std::dec;
+      }
+    }
+
+    uint64_t ignore_features_mask = (
+      RBD_FEATURES_INTERNAL | RBD_FEATURES_MUTABLE_INTERNAL);
+    uint64_t ignored_features = (features & ignore_features_mask);
+    if (ignored_features != 0ULL) {
+      features &= ~ignore_features_mask;
+      if (err) {
+	*err << "ignoring feature mask 0x" << std::hex << ignored_features;
+      }
+    }
+  } catch (boost::bad_lexical_cast&) {
+    // feature name list?
+    bool errors = false;
+    std::vector<std::string> feature_names;
+    boost::split(feature_names, value, boost::is_any_of(","));
+    for (auto feature_name: feature_names) {
+      boost::trim(feature_name);
+      auto feature_it = RBD_FEATURE_MAP.find(feature_name);
+      if (feature_it != RBD_FEATURE_MAP.end()) {
+	features += feature_it->second;
+      } else if (err) {
+	if (errors) {
+	  *err << ", ";
+	} else {
+	  errors = true;
+	}
+	*err << "ignoring unknown feature " << feature_name;
+      }
+    }
+  }
+  return features;
+}
+
+} // namespace librbd