1 files changed, 58 insertions, 0 deletions
diff --git a/src/common/ceph_releases.cc b/src/common/ceph_releases.cc
new file mode 100644
index 000000000..92e58256f
--- /dev/null
+++ b/src/common/ceph_releases.cc
@@ -0,0 +1,58 @@
+#include "ceph_releases.h"
+
+#include <ostream>
+
+#include "ceph_ver.h"
+
+std::ostream& operator<<(std::ostream& os, const ceph_release_t r)
+{
+  return os << ceph_release_name(static_cast<int>(r));
+}
+
+ceph_release_t ceph_release()
+{
+  return ceph_release_t{CEPH_RELEASE};
+}
+
+ceph_release_t ceph_release_from_name(std::string_view s)
+{
+  ceph_release_t r = ceph_release_t::max;
+  while (--r != ceph_release_t::unknown) {
+    if (s == to_string(r)) {
+      return r;
+    }
+  }
+  return ceph_release_t::unknown;
+}
+
+bool can_upgrade_from(ceph_release_t from_release,
+                      std::string_view from_release_name,
+                      std::ostream& err)
+{
+  if (from_release == ceph_release_t::unknown) {
+    // cannot tell, but i am optimistic
+    return true;
+  }
+  const ceph_release_t cutoff{static_cast<uint8_t>(static_cast<uint8_t>(from_release) + 2)};
+  const auto to_release = ceph_release();
+  if (cutoff < to_release) {
+    err << "recorded " << from_release_name << " "
+        << to_integer<int>(from_release) << " (" << from_release << ") "
+        << "is more than two releases older than installed "
+        << to_integer<int>(to_release) << " (" << to_release << "); "
+        << "you can only upgrade 2 releases at a time\n"
+        << "you should first upgrade to ";
+    auto release = from_release;
+    while (++release <= cutoff) {
+      err << to_integer<int>(release) << " (" << release << ")";
+      if (release < cutoff) {
+        err << " or ";
+      } else {
+        err << "\n";
+      }
+    }
+    return false;
+  } else {
+    return true;
+  }
+}