ceph/src/librbd/io/AsyncOperation.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include "librbd/io/AsyncOperation.h"
   5 #include "include/ceph_assert.h"
   6 #include "common/dout.h"
   7 #include "librbd/AsioEngine.h"
   8 #include "librbd/ImageCtx.h"
   9
  10 #define dout_subsys ceph_subsys_rbd
  11 #undef dout_prefix
  12 #define dout_prefix *_dout << "librbd::io::AsyncOperation: "
  13
  14 namespace librbd {
  15 namespace io {
  16
  17 namespace {
  18
  19 struct C_CompleteFlushes : public Context {
  20   ImageCtx *image_ctx;
  21   std::list<Context *> flush_contexts;
  22
  23   explicit C_CompleteFlushes(ImageCtx *image_ctx,
  24                              std::list<Context *> &&flush_contexts)
  25     : image_ctx(image_ctx), flush_contexts(std::move(flush_contexts)) {
  26   }
  27   void finish(int r) override {
  28     std::shared_lock owner_locker{image_ctx->owner_lock};
  29     while (!flush_contexts.empty()) {
  30       Context *flush_ctx = flush_contexts.front();
  31       flush_contexts.pop_front();
  32
  33       ldout(image_ctx->cct, 20) << "completed flush: " << flush_ctx << dendl;
  34       flush_ctx->complete(0);
  35     }
  36   }
  37 };
  38
  39 } // anonymous namespace
  40
  41 void AsyncOperation::start_op(ImageCtx &image_ctx) {
  42   ceph_assert(m_image_ctx == NULL);
  43   m_image_ctx = &image_ctx;
  44
  45   ldout(m_image_ctx->cct, 20) << this << " " << __func__ << dendl;
  46   std::lock_guard l{m_image_ctx->async_ops_lock};
  47   m_image_ctx->async_ops.push_front(&m_xlist_item);
  48 }
  49
  50 void AsyncOperation::finish_op() {
  51   ldout(m_image_ctx->cct, 20) << this << " " << __func__ << dendl;
  52
  53   {
  54     std::lock_guard l{m_image_ctx->async_ops_lock};
  55     xlist<AsyncOperation *>::iterator iter(&m_xlist_item);
  56     ++iter;
  57     ceph_assert(m_xlist_item.remove_myself());
  58
  59     // linked list stored newest -> oldest ops
  60     if (!iter.end() && !m_flush_contexts.empty()) {
  61       ldout(m_image_ctx->cct, 20) << "moving flush contexts to previous op: "
  62                                   << *iter << dendl;
  63       (*iter)->m_flush_contexts.insert((*iter)->m_flush_contexts.end(),
  64                                        m_flush_contexts.begin(),
  65                                        m_flush_contexts.end());
  66       return;
  67     }
  68   }
  69
  70   if (!m_flush_contexts.empty()) {
  71     C_CompleteFlushes *ctx = new C_CompleteFlushes(m_image_ctx,
  72                                                    std::move(m_flush_contexts));
  73     m_image_ctx->asio_engine->post(ctx, 0);
  74   }
  75 }
  76
  77 void AsyncOperation::flush(Context* on_finish) {
  78   {
  79     std::lock_guard locker{m_image_ctx->async_ops_lock};
  80     xlist<AsyncOperation *>::iterator iter(&m_xlist_item);
  81     ++iter;
  82
  83     // linked list stored newest -> oldest ops
  84     if (!iter.end()) {
  85       (*iter)->m_flush_contexts.push_back(on_finish);
  86       return;
  87     }
  88   }
  89
  90   m_image_ctx->asio_engine->post(on_finish, 0);
  91 }
  92
  93 } // namespace io
  94 } // namespace librbd