ReplicatedPG: copy: do not let start_copy() return error codes

There's no failure it can actually run into, and handling error
codes in some of its callers is going to be a pain.
While we're here, document the parameters.

Signed-off-by: Greg Farnum <greg@inktank.com>

2 files changed, 13 insertions, 7 deletions

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index f466eb8ccdc..cb39889d614 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -3707,10 +3707,8 @@ int ReplicatedPG::do_osd_ops(OpContext *ctx, vector<OSDOp>& ops)
 	  hobject_t temp_target = generate_temp_object();
 	  CopyFromCallback *cb = new CopyFromCallback(ctx, temp_target);
 	  ctx->copy_cb = cb;
-	  result = start_copy(cb, ctx->obc, src, src_oloc, src_version,
+	  start_copy(cb, ctx->obc, src, src_oloc, src_version,
 	                      temp_target);
-	  if (result < 0)
-	    goto fail;
 	  result = -EINPROGRESS;
 	} else {
 	  // finish
@@ -4312,7 +4310,7 @@ struct C_Copyfrom : public Context {
   }
 };
 
-int ReplicatedPG::start_copy(CopyCallback *cb, ObjectContextRef obc,
+void ReplicatedPG::start_copy(CopyCallback *cb, ObjectContextRef obc,
 			     hobject_t src, object_locator_t oloc, version_t version,
 			     const hobject_t& temp_dest_oid)
 {
@@ -4334,8 +4332,6 @@ int ReplicatedPG::start_copy(CopyCallback *cb, ObjectContextRef obc,
   ++obc->copyfrom_readside;
 
   _copy_some(obc, cop);
-
-  return 0;
 }
 
 void ReplicatedPG::_copy_some(ObjectContextRef obc, CopyOpRef cop)
diff --git a/src/osd/ReplicatedPG.h b/src/osd/ReplicatedPG.h
index 27c9d1bb605..13c91df3d7d 100644
--- a/src/osd/ReplicatedPG.h
+++ b/src/osd/ReplicatedPG.h
@@ -808,7 +808,17 @@ protected:
   // -- copyfrom --
   map<hobject_t, CopyOpRef> copy_ops;
 
-  int start_copy(CopyCallback *cb, ObjectContextRef obc, hobject_t src,
+  /**
+   * To copy an object, call start_copy.
+   *
+   * @param cb: The CopyCallback to be activated when the copy is complete
+   * @param obc: The ObjectContext we are copying into
+   * @param src: The source object
+   * @param oloc: the source object locator
+   * @param version: the version of the source object to copy (0 for any)
+   * @param temp_dest_oid: the temporary object to use for large objects
+   */
+  void start_copy(CopyCallback *cb, ObjectContextRef obc, hobject_t src,
                  object_locator_t oloc, version_t version,
                  const hobject_t& temp_dest_oid);
   void process_copy_chunk(hobject_t oid, tid_t tid, int r);