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 "librbd/ImageCtx.h"
   6 #include "common/dout.h"
   7 #include "common/WorkQueue.h"
   8 #include "include/assert.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, std::list<Context *> &&flush_contexts)
  24     : image_ctx(image_ctx), flush_contexts(std::move(flush_contexts)) {
  25   }
  26   void finish(int r) override {
  27     RWLock::RLocker owner_locker(image_ctx->owner_lock);
  28     while (!flush_contexts.empty()) {
  29       Context *flush_ctx = flush_contexts.front();
  30       flush_contexts.pop_front();
  31
  32       ldout(image_ctx->cct, 20) << "completed flush: " << flush_ctx << dendl;
  33       flush_ctx->complete(0);
  34     }
  35   }
  36 };
  37
  38 } // anonymous namespace
  39
  40 void AsyncOperation::start_op(ImageCtx &image_ctx) {
  41   assert(m_image_ctx == NULL);
  42   m_image_ctx = &image_ctx;
  43
  44   ldout(m_image_ctx->cct, 20) << this << " " << __func__ << dendl;
  45   Mutex::Locker l(m_image_ctx->async_ops_lock);
  46   m_image_ctx->async_ops.push_front(&m_xlist_item);
  47 }
  48
  49 void AsyncOperation::finish_op() {
  50   ldout(m_image_ctx->cct, 20) << this << " " << __func__ << dendl;
  51
  52   {
  53     Mutex::Locker l(m_image_ctx->async_ops_lock);
  54     xlist<AsyncOperation *>::iterator iter(&m_xlist_item);
  55     ++iter;
  56     assert(m_xlist_item.remove_myself());
  57
  58     // linked list stored newest -> oldest ops
  59     if (!iter.end() && !m_flush_contexts.empty()) {
  60       ldout(m_image_ctx->cct, 20) << "moving flush contexts to previous op: "
  61                                   << *iter << dendl;
  62       (*iter)->m_flush_contexts.insert((*iter)->m_flush_contexts.end(),
  63                                        m_flush_contexts.begin(),
  64                                        m_flush_contexts.end());
  65       return;
  66     }
  67   }
  68
  69   if (!m_flush_contexts.empty()) {
  70     C_CompleteFlushes *ctx = new C_CompleteFlushes(m_image_ctx,
  71                                                    std::move(m_flush_contexts));
  72     m_image_ctx->op_work_queue->queue(ctx);
  73   }
  74 }
  75
  76 void AsyncOperation::add_flush_context(Context *on_finish) {
  77   assert(m_image_ctx->async_ops_lock.is_locked());
  78   ldout(m_image_ctx->cct, 20) << this << " " << __func__ << ": "
  79                               << "flush=" << on_finish << dendl;
  80   m_flush_contexts.push_back(on_finish);
  81 }
  82
  83 } // namespace io
  84 } // namespace librbd