From dcb101eab351cb842441b9ff23f58954881a9174 Mon Sep 17 00:00:00 2001
From: Mykola Golub <mgolub@suse.com>
Date: Fri, 15 Mar 2019 15:01:26 +0000
Subject: [PATCH] common: add "requeue_back" WorkQueue method

and rename "requeue" method to "requeue_front" for clarity.

Signed-off-by: Mykola Golub <mgolub@suse.com>
(cherry picked from commit 060ef69eb4ce8473ea5ecc796027729dff883269)
---
 src/common/WorkQueue.h                         |  7 ++++++-
 src/librbd/io/ImageRequestWQ.cc                |  6 +++---
 src/test/librbd/io/test_mock_ImageRequestWQ.cc | 10 +++++-----
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/common/WorkQueue.h b/src/common/WorkQueue.h
index d3d76412d36d1..a978a6d698433 100644
--- a/src/common/WorkQueue.h
+++ b/src/common/WorkQueue.h
@@ -428,11 +428,16 @@ public:
       }
       return m_items.front();
     }
-    void requeue(T *item) {
+    void requeue_front(T *item) {
       std::lock_guard pool_locker(m_pool->_lock);
       _void_process_finish(nullptr);
       m_items.push_front(item);
     }
+    void requeue_back(T *item) {
+      std::lock_guard pool_locker(m_pool->_lock);
+      _void_process_finish(nullptr);
+      m_items.push_back(item);
+    }
     void signal() {
       std::lock_guard pool_locker(m_pool->_lock);
       m_pool->_cond.notify_one();
diff --git a/src/librbd/io/ImageRequestWQ.cc b/src/librbd/io/ImageRequestWQ.cc
index 752ef82c72fbc..a5101aa048438 100644
--- a/src/librbd/io/ImageRequestWQ.cc
+++ b/src/librbd/io/ImageRequestWQ.cc
@@ -661,7 +661,7 @@ void ImageRequestWQ<I>::handle_throttle_ready(int r, ImageDispatchSpec<I> *item,
   ceph_assert(m_io_throttled.load() > 0);
   item->set_throttled(flag);
   if (item->were_all_throttled()) {
-    this->requeue(item);
+    this->requeue_front(item);
     --m_io_throttled;
     this->signal();
   }
@@ -910,7 +910,7 @@ void ImageRequestWQ<I>::handle_acquire_lock(
   } else {
     // since IO was stalled for acquire -- original IO order is preserved
     // if we requeue this op for work queue processing
-    this->requeue(req);
+    this->requeue_front(req);
   }
 
   ceph_assert(m_io_blockers.load() > 0);
@@ -929,7 +929,7 @@ void ImageRequestWQ<I>::handle_refreshed(
   } else {
     // since IO was stalled for refresh -- original IO order is preserved
     // if we requeue this op for work queue processing
-    this->requeue(req);
+    this->requeue_front(req);
   }
 
   ceph_assert(m_io_blockers.load() > 0);
diff --git a/src/test/librbd/io/test_mock_ImageRequestWQ.cc b/src/test/librbd/io/test_mock_ImageRequestWQ.cc
index 2dd72bff76cc2..352b888d3996b 100644
--- a/src/test/librbd/io/test_mock_ImageRequestWQ.cc
+++ b/src/test/librbd/io/test_mock_ImageRequestWQ.cc
@@ -104,7 +104,7 @@ struct ThreadPool::PointerWQ<librbd::io::ImageDispatchSpec<librbd::MockTestImage
   MOCK_METHOD0(process_finish, void());
 
   MOCK_METHOD0(front, ImageDispatchSpec*());
-  MOCK_METHOD1(requeue, void(ImageDispatchSpec*));
+  MOCK_METHOD1(requeue_front, void(ImageDispatchSpec*));
 
   MOCK_METHOD0(dequeue, void*());
   MOCK_METHOD1(queue, void(ImageDispatchSpec*));
@@ -170,8 +170,8 @@ struct TestMockIoImageRequestWQ : public TestMockFixture {
     EXPECT_CALL(image_request_wq, queue(_));
   }
 
-  void expect_requeue(MockImageRequestWQ &image_request_wq) {
-    EXPECT_CALL(image_request_wq, requeue(_));
+  void expect_requeue_front(MockImageRequestWQ &image_request_wq) {
+    EXPECT_CALL(image_request_wq, requeue_front(_));
   }
 
   void expect_front(MockImageRequestWQ &image_request_wq,
@@ -425,7 +425,7 @@ TEST_F(TestMockIoImageRequestWQ, BPSQosNoBurst) {
   expect_tokens_requested(mock_queued_image_request, 2, true);
   expect_dequeue(mock_image_request_wq, &mock_queued_image_request);
   expect_all_throttled(mock_queued_image_request, true);
-  expect_requeue(mock_image_request_wq);
+  expect_requeue_front(mock_image_request_wq);
   expect_signal(mock_image_request_wq);
   ASSERT_TRUE(mock_image_request_wq.invoke_dequeue() == nullptr);
 }
@@ -449,7 +449,7 @@ TEST_F(TestMockIoImageRequestWQ, BPSQosWithBurst) {
   expect_tokens_requested(mock_queued_image_request, 2, true);
   expect_dequeue(mock_image_request_wq, &mock_queued_image_request);
   expect_all_throttled(mock_queued_image_request, true);
-  expect_requeue(mock_image_request_wq);
+  expect_requeue_front(mock_image_request_wq);
   expect_signal(mock_image_request_wq);
   ASSERT_TRUE(mock_image_request_wq.invoke_dequeue() == nullptr);
 }
-- 
2.39.5