librados: add get_version64()

The C++ AioCompletion::get_version() method only returns 32-bits.  Sigh.

Add a get_version64() method that returns all 64-bits. Do not touch the
32-bit version to avoid breaking the ABI.

Backport: dumpling, cuttlefish
Signed-off-by: Sage Weil <[email protected]>

PendingReleaseNotes

@@ -17,4 +17,12 @@ v0.68
   is probably how it should have been acting from the beginning. Users are
   unlikely to notice but it could result in lower performance in some
   circumstances. Those who care should switch to using the async interfaces,
-  which let you specify safety semantics precisely.
+  which let you specify safety semantics precisely.
+
+* The C++ librados AioComplete::get_version() method was incorrectly
+  returning an int (usually 32-bits).  To avoid breaking library
+  compatibility, a get_version64() method is added that returns the
+  full-width value.  The old method is deprecated and will be removed
+  in a future release.  Users of the C++ librados API that make use of
+  the get_version() method should modify their code to avoid getting a
+  value that is truncated from 64 to to 32 bits.

src/include/rados/librados.hpp

@@ -96,7 +96,8 @@ namespace librados
     bool is_complete_and_cb();
     bool is_safe_and_cb();
     int get_return_value();
-    int get_version();
+    int get_version();  ///< DEPRECATED get_version() only returns 32-bits
+    uint64_t get_version64();
     void release();
     AioCompletionImpl *pc;
   };

src/librados/librados.cc

@@ -592,6 +592,12 @@ int librados::AioCompletion::AioCompletion::get_version()
   return c->get_version();
 }
 
+uint64_t librados::AioCompletion::AioCompletion::get_version64()
+{
+  AioCompletionImpl *c = (AioCompletionImpl *)pc;
+  return c->get_version();
+}
+
 void librados::AioCompletion::AioCompletion::release()
 {
   AioCompletionImpl *c = (AioCompletionImpl *)pc;