ceph/src/librbd/Utils.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef CEPH_LIBRBD_UTILS_H
   5 #define CEPH_LIBRBD_UTILS_H
   6
   7 #include "include/rados/librados.hpp"
   8 #include "include/rbd_types.h"
   9 #include "include/Context.h"
  10 #include "common/zipkin_trace.h"
  11
  12 #include <atomic>
  13 #include <type_traits>
  14
  15 namespace librbd {
  16
  17 class ImageCtx;
  18
  19 namespace util {
  20
  21 namespace detail {
  22
  23 template <typename T>
  24 void rados_callback(rados_completion_t c, void *arg) {
  25   reinterpret_cast<T*>(arg)->complete(rados_aio_get_return_value(c));
  26 }
  27
  28 template <typename T, void(T::*MF)(int)>
  29 void rados_callback(rados_completion_t c, void *arg) {
  30   T *obj = reinterpret_cast<T*>(arg);
  31   int r = rados_aio_get_return_value(c);
  32   (obj->*MF)(r);
  33 }
  34
  35 template <typename T, Context*(T::*MF)(int*), bool destroy>
  36 void rados_state_callback(rados_completion_t c, void *arg) {
  37   T *obj = reinterpret_cast<T*>(arg);
  38   int r = rados_aio_get_return_value(c);
  39   Context *on_finish = (obj->*MF)(&r);
  40   if (on_finish != nullptr) {
  41     on_finish->complete(r);
  42     if (destroy) {
  43       delete obj;
  44     }
  45   }
  46 }
  47
  48 template <typename T, void (T::*MF)(int)>
  49 class C_CallbackAdapter : public Context {
  50   T *obj;
  51 public:
  52   C_CallbackAdapter(T *obj) : obj(obj) {
  53   }
  54
  55 protected:
  56   void finish(int r) override {
  57     (obj->*MF)(r);
  58   }
  59 };
  60
  61 template <typename T, Context*(T::*MF)(int*), bool destroy>
  62 class C_StateCallbackAdapter : public Context {
  63   T *obj;
  64 public:
  65   C_StateCallbackAdapter(T *obj) : obj(obj){
  66   }
  67
  68 protected:
  69   void complete(int r) override {
  70     Context *on_finish = (obj->*MF)(&r);
  71     if (on_finish != nullptr) {
  72       on_finish->complete(r);
  73       if (destroy) {
  74         delete obj;
  75       }
  76     }
  77     Context::complete(r);
  78   }
  79   void finish(int r) override {
  80   }
  81 };
  82
  83 template <typename WQ>
  84 struct C_AsyncCallback : public Context {
  85   WQ *op_work_queue;
  86   Context *on_finish;
  87
  88   C_AsyncCallback(WQ *op_work_queue, Context *on_finish)
  89     : op_work_queue(op_work_queue), on_finish(on_finish) {
  90   }
  91   void finish(int r) override {
  92     op_work_queue->queue(on_finish, r);
  93   }
  94 };
  95
  96 } // namespace detail
  97
  98 std::string generate_image_id(librados::IoCtx &ioctx);
  99
 100 const std::string group_header_name(const std::string &group_id);
 101 const std::string id_obj_name(const std::string &name);
 102 const std::string header_name(const std::string &image_id);
 103 const std::string old_header_name(const std::string &image_name);
 104 std::string unique_lock_name(const std::string &name, void *address);
 105
 106 librados::AioCompletion *create_rados_callback(Context *on_finish);
 107
 108 template <typename T>
 109 librados::AioCompletion *create_rados_callback(T *obj) {
 110   return librados::Rados::aio_create_completion(
 111     obj, &detail::rados_callback<T>, nullptr);
 112 }
 113
 114 template <typename T, void(T::*MF)(int)>
 115 librados::AioCompletion *create_rados_callback(T *obj) {
 116   return librados::Rados::aio_create_completion(
 117     obj, &detail::rados_callback<T, MF>, nullptr);
 118 }
 119
 120 template <typename T, Context*(T::*MF)(int*), bool destroy=true>
 121 librados::AioCompletion *create_rados_callback(T *obj) {
 122   return librados::Rados::aio_create_completion(
 123     obj, &detail::rados_state_callback<T, MF, destroy>, nullptr);
 124 }
 125
 126 template <typename T, void(T::*MF)(int) = &T::complete>
 127 Context *create_context_callback(T *obj) {
 128   return new detail::C_CallbackAdapter<T, MF>(obj);
 129 }
 130
 131 template <typename T, Context*(T::*MF)(int*), bool destroy=true>
 132 Context *create_context_callback(T *obj) {
 133   return new detail::C_StateCallbackAdapter<T, MF, destroy>(obj);
 134 }
 135
 136 template <typename I>
 137 Context *create_async_context_callback(I &image_ctx, Context *on_finish) {
 138   // use async callback to acquire a clean lock context
 139   return new detail::C_AsyncCallback<
 140     typename std::decay<decltype(*image_ctx.op_work_queue)>::type>(
 141       image_ctx.op_work_queue, on_finish);
 142 }
 143
 144 template <typename WQ>
 145 Context *create_async_context_callback(WQ *work_queue, Context *on_finish) {
 146   // use async callback to acquire a clean lock context
 147   return new detail::C_AsyncCallback<WQ>(work_queue, on_finish);
 148 }
 149
 150 // TODO: temporary until AioCompletion supports templated ImageCtx
 151 inline ImageCtx *get_image_ctx(ImageCtx *image_ctx) {
 152   return image_ctx;
 153 }
 154
 155 /// helper for tracking in-flight async ops when coordinating
 156 /// a shut down of the invoking class instance
 157 class AsyncOpTracker {
 158 public:
 159   void start_op() {
 160     m_refs++;
 161   }
 162
 163   void finish_op() {
 164     if (--m_refs == 0 && m_on_finish != nullptr) {
 165       Context *on_finish = nullptr;
 166       std::swap(on_finish, m_on_finish);
 167       on_finish->complete(0);
 168     }
 169   }
 170
 171   template <typename I>
 172   void wait(I &image_ctx, Context *on_finish) {
 173     assert(m_on_finish == nullptr);
 174
 175     on_finish = create_async_context_callback(image_ctx, on_finish);
 176     if (m_refs == 0) {
 177       on_finish->complete(0);
 178       return;
 179     }
 180     m_on_finish = on_finish;
 181   }
 182
 183 private:
 184   std::atomic<uint64_t> m_refs = { 0 };
 185   Context *m_on_finish = nullptr;
 186 };
 187
 188 uint64_t get_rbd_default_features(CephContext* cct);
 189
 190 bool calc_sparse_extent(const bufferptr &bp,
 191                         size_t sparse_size,
 192                         uint64_t length,
 193                         size_t *write_offset,
 194                         size_t *write_length,
 195                         size_t *offset);
 196
 197 template <typename I>
 198 inline ZTracer::Trace create_trace(const I &image_ctx, const char *trace_name,
 199                                    const ZTracer::Trace &parent_trace) {
 200   if (parent_trace.valid()) {
 201     return ZTracer::Trace(trace_name, &image_ctx.trace_endpoint, &parent_trace);
 202   }
 203   return ZTracer::Trace();
 204 }
 205
 206 } // namespace util
 207
 208 } // namespace librbd
 209
 210 #endif // CEPH_LIBRBD_UTILS_H