From 66f4ebbb905f097c20636858a1127b938c5e9833 Mon Sep 17 00:00:00 2001
From: Jason Dillaman <dillaman@redhat.com>
Date: Mon, 8 Oct 2018 10:45:59 -0400
Subject: [PATCH] librbd: helper method to apply pool-level config overrides

Signed-off-by: Jason Dillaman <dillaman@redhat.com>
---
 src/librbd/api/Config.cc | 24 ++++++++++++++++++++++++
 src/librbd/api/Config.h  |  5 +++++
 2 files changed, 29 insertions(+)

diff --git a/src/librbd/api/Config.cc b/src/librbd/api/Config.cc
index 6b7061043e690..eec026f319110 100644
--- a/src/librbd/api/Config.cc
+++ b/src/librbd/api/Config.cc
@@ -207,6 +207,30 @@ int Config<I>::list(I *image_ctx, std::vector<config_option_t> *options) {
   return 0;
 }
 
+template <typename I>
+void Config<I>::apply_pool_overrides(librados::IoCtx& io_ctx,
+                                     ConfigProxy* config) {
+  CephContext *cct = reinterpret_cast<CephContext *>(io_ctx.cct());
+
+  Options opts(io_ctx, false);
+  int r = opts.init();
+  if (r < 0) {
+    lderr(cct) << "failed to read pool config overrides: " << cpp_strerror(r)
+               << dendl;
+    return;
+  }
+
+  for (auto& pair : opts) {
+    if (pair.second.second == RBD_CONFIG_SOURCE_POOL) {
+      r = config->set_val(pair.first, pair.second.first);
+      if (r < 0) {
+        lderr(cct) << "failed to override pool config " << pair.first << "="
+                   << pair.second.first << ": " << cpp_strerror(r) << dendl;
+      }
+    }
+  }
+}
+
 } // namespace api
 } // namespace librbd
 
diff --git a/src/librbd/api/Config.h b/src/librbd/api/Config.h
index 9f27000966dfd..13213728bd479 100644
--- a/src/librbd/api/Config.h
+++ b/src/librbd/api/Config.h
@@ -6,6 +6,8 @@
 
 #include "include/rbd/librbd.hpp"
 
+struct ConfigProxy;
+
 namespace librados {
 
 class IoCtx;
@@ -27,6 +29,9 @@ public:
 
   static bool is_option_name(ImageCtxT *image_ctx, const std::string &name);
   static int list(ImageCtxT *image_ctx, std::vector<config_option_t> *options);
+
+  static void apply_pool_overrides(librados::IoCtx& io_ctx,
+                                   ConfigProxy* config);
 };
 
 } // namespace api
-- 
2.39.5