librbd: add AsyncRequest task enqueue helper method

In order to support the invariant that all state machine
callbacks occur without holding locks, transitions that
don't always involve a librados call should queue their
callback.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>
(cherry picked from commit 218bc2d0f8d90c9c64408cb22e26680e88138844)

diff --git a/src/librbd/AsyncRequest.cc b/src/librbd/AsyncRequest.cc
index 825c8c4e50a5fda4147ab4e5c4262b2faa405845..543e723bca7415b9943df2db78b5187267c9b7a2 100644 (file)
--- a/src/librbd/AsyncRequest.cc
+++ b/src/librbd/AsyncRequest.cc
@@ -1,6 +1,7 @@
 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
 // vim: ts=8 sw=2 smarttab
 #include "librbd/AsyncRequest.h"
+#include "common/WorkQueue.h"
 #include "librbd/ImageCtx.h"
 #include "librbd/internal.h"
 #include <boost/bind.hpp>
@@ -21,6 +22,10 @@ AsyncRequest::~AsyncRequest() {
   m_image_ctx.async_requests_cond.Signal();
 }
 
+void AsyncRequest::async_complete(int r) {
+  m_image_ctx.op_work_queue->queue(create_callback_context(), r);
+}
+
 librados::AioCompletion *AsyncRequest::create_callback_completion() {
   return librados::Rados::aio_create_completion(create_callback_context(),
                                                NULL, rados_ctx_cb);

diff --git a/src/librbd/AsyncRequest.h b/src/librbd/AsyncRequest.h
index fd260a912c9be5592fa7de557521c63f4cf5f1f1..9f7ba244a0645b02c43c64e5a85ce3a2552e2212 100644 (file)
--- a/src/librbd/AsyncRequest.h
+++ b/src/librbd/AsyncRequest.h
@@ -44,6 +44,8 @@ protected:
   librados::AioCompletion *create_callback_completion();
   Context *create_callback_context();
 
+  void async_complete(int r);
+
   virtual bool safely_cancel(int r) {
     return true;
   }