ceph/src/librbd/AsyncOperation.cc

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