ceph/src/librbd/ObjectMap.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/ObjectMap.h"
   5 #include "librbd/BlockGuard.h"
   6 #include "librbd/ExclusiveLock.h"
   7 #include "librbd/ImageCtx.h"
   8 #include "librbd/object_map/RefreshRequest.h"
   9 #include "librbd/object_map/ResizeRequest.h"
  10 #include "librbd/object_map/SnapshotCreateRequest.h"
  11 #include "librbd/object_map/SnapshotRemoveRequest.h"
  12 #include "librbd/object_map/SnapshotRollbackRequest.h"
  13 #include "librbd/object_map/UnlockRequest.h"
  14 #include "librbd/object_map/UpdateRequest.h"
  15 #include "librbd/Utils.h"
  16 #include "common/dout.h"
  17 #include "common/errno.h"
  18 #include "common/WorkQueue.h"
  19
  20 #include "include/rados/librados.hpp"
  21
  22 #include "cls/lock/cls_lock_client.h"
  23 #include "cls/rbd/cls_rbd_types.h"
  24 #include "include/stringify.h"
  25 #include "osdc/Striper.h"
  26 #include <sstream>
  27
  28 #define dout_subsys ceph_subsys_rbd
  29 #undef dout_prefix
  30 #define dout_prefix *_dout << "librbd::ObjectMap: " << this << " " << __func__ \
  31                            << ": "
  32
  33 namespace librbd {
  34
  35 template <typename I>
  36 ObjectMap<I>::ObjectMap(I &image_ctx, uint64_t snap_id)
  37   : m_image_ctx(image_ctx), m_snap_id(snap_id),
  38     m_update_guard(new UpdateGuard(m_image_ctx.cct)) {
  39 }
  40
  41 template <typename I>
  42 ObjectMap<I>::~ObjectMap() {
  43   delete m_update_guard;
  44 }
  45
  46 template <typename I>
  47 int ObjectMap<I>::aio_remove(librados::IoCtx &io_ctx, const std::string &image_id,
  48                              librados::AioCompletion *c) {
  49   return io_ctx.aio_remove(object_map_name(image_id, CEPH_NOSNAP), c);
  50 }
  51
  52 template <typename I>
  53 std::string ObjectMap<I>::object_map_name(const std::string &image_id,
  54                                           uint64_t snap_id) {
  55   std::string oid(RBD_OBJECT_MAP_PREFIX + image_id);
  56   if (snap_id != CEPH_NOSNAP) {
  57     std::stringstream snap_suffix;
  58     snap_suffix << "." << std::setfill('0') << std::setw(16) << std::hex
  59                 << snap_id;
  60     oid += snap_suffix.str();
  61   }
  62   return oid;
  63 }
  64
  65 template <typename I>
  66 bool ObjectMap<I>::is_compatible(const file_layout_t& layout, uint64_t size) {
  67   uint64_t object_count = Striper::get_num_objects(layout, size);
  68   return (object_count <= cls::rbd::MAX_OBJECT_MAP_OBJECT_COUNT);
  69 }
  70
  71 template <typename I>
  72 ceph::BitVector<2u>::Reference ObjectMap<I>::operator[](uint64_t object_no)
  73 {
  74   assert(m_image_ctx.object_map_lock.is_wlocked());
  75   assert(object_no < m_object_map.size());
  76   return m_object_map[object_no];
  77 }
  78
  79 template <typename I>
  80 uint8_t ObjectMap<I>::operator[](uint64_t object_no) const
  81 {
  82   assert(m_image_ctx.object_map_lock.is_locked());
  83   assert(object_no < m_object_map.size());
  84   return m_object_map[object_no];
  85 }
  86
  87 template <typename I>
  88 bool ObjectMap<I>::object_may_exist(uint64_t object_no) const
  89 {
  90   assert(m_image_ctx.snap_lock.is_locked());
  91
  92   // Fall back to default logic if object map is disabled or invalid
  93   if (!m_image_ctx.test_features(RBD_FEATURE_OBJECT_MAP,
  94                                  m_image_ctx.snap_lock)) {
  95     return true;
  96   }
  97
  98   bool flags_set;
  99   int r = m_image_ctx.test_flags(RBD_FLAG_OBJECT_MAP_INVALID,
 100                                  m_image_ctx.snap_lock, &flags_set);
 101   if (r < 0 || flags_set) {
 102     return true;
 103   }
 104
 105   RWLock::RLocker l(m_image_ctx.object_map_lock);
 106   uint8_t state = (*this)[object_no];
 107   bool exists = (state != OBJECT_NONEXISTENT);
 108   ldout(m_image_ctx.cct, 20) << "object_no=" << object_no << " r=" << exists
 109                              << dendl;
 110   return exists;
 111 }
 112
 113 template <typename I>
 114 bool ObjectMap<I>::update_required(const ceph::BitVector<2>::Iterator& it,
 115                                    uint8_t new_state) {
 116   assert(m_image_ctx.object_map_lock.is_wlocked());
 117   uint8_t state = *it;
 118   if ((state == new_state) ||
 119       (new_state == OBJECT_PENDING && state == OBJECT_NONEXISTENT) ||
 120       (new_state == OBJECT_NONEXISTENT && state != OBJECT_PENDING)) {
 121     return false;
 122   }
 123   return true;
 124 }
 125
 126 template <typename I>
 127 void ObjectMap<I>::open(Context *on_finish) {
 128   auto req = object_map::RefreshRequest<I>::create(
 129     m_image_ctx, &m_object_map, m_snap_id, on_finish);
 130   req->send();
 131 }
 132
 133 template <typename I>
 134 void ObjectMap<I>::close(Context *on_finish) {
 135   if (m_snap_id != CEPH_NOSNAP) {
 136     m_image_ctx.op_work_queue->queue(on_finish, 0);
 137     return;
 138   }
 139
 140   auto req = object_map::UnlockRequest<I>::create(m_image_ctx, on_finish);
 141   req->send();
 142 }
 143
 144 template <typename I>
 145 bool ObjectMap<I>::set_object_map(ceph::BitVector<2> &target_object_map) {
 146   assert(m_image_ctx.owner_lock.is_locked());
 147   assert(m_image_ctx.snap_lock.is_locked());
 148   assert(m_image_ctx.test_features(RBD_FEATURE_OBJECT_MAP,
 149                                    m_image_ctx.snap_lock));
 150   RWLock::RLocker object_map_locker(m_image_ctx.object_map_lock);
 151   m_object_map = target_object_map;
 152   return true;
 153 }
 154
 155 template <typename I>
 156 void ObjectMap<I>::rollback(uint64_t snap_id, Context *on_finish) {
 157   assert(m_image_ctx.snap_lock.is_locked());
 158   assert(m_image_ctx.object_map_lock.is_wlocked());
 159
 160   object_map::SnapshotRollbackRequest *req =
 161     new object_map::SnapshotRollbackRequest(m_image_ctx, snap_id, on_finish);
 162   req->send();
 163 }
 164
 165 template <typename I>
 166 void ObjectMap<I>::snapshot_add(uint64_t snap_id, Context *on_finish) {
 167   assert(m_image_ctx.snap_lock.is_locked());
 168   assert((m_image_ctx.features & RBD_FEATURE_OBJECT_MAP) != 0);
 169   assert(snap_id != CEPH_NOSNAP);
 170
 171   object_map::SnapshotCreateRequest *req =
 172     new object_map::SnapshotCreateRequest(m_image_ctx, &m_object_map, snap_id,
 173                                           on_finish);
 174   req->send();
 175 }
 176
 177 template <typename I>
 178 void ObjectMap<I>::snapshot_remove(uint64_t snap_id, Context *on_finish) {
 179   assert(m_image_ctx.snap_lock.is_wlocked());
 180   assert((m_image_ctx.features & RBD_FEATURE_OBJECT_MAP) != 0);
 181   assert(snap_id != CEPH_NOSNAP);
 182
 183   object_map::SnapshotRemoveRequest *req =
 184     new object_map::SnapshotRemoveRequest(m_image_ctx, &m_object_map, snap_id,
 185                                           on_finish);
 186   req->send();
 187 }
 188
 189 template <typename I>
 190 void ObjectMap<I>::aio_save(Context *on_finish) {
 191   assert(m_image_ctx.owner_lock.is_locked());
 192   assert(m_image_ctx.snap_lock.is_locked());
 193   assert(m_image_ctx.test_features(RBD_FEATURE_OBJECT_MAP,
 194                                    m_image_ctx.snap_lock));
 195   RWLock::RLocker object_map_locker(m_image_ctx.object_map_lock);
 196
 197   librados::ObjectWriteOperation op;
 198   if (m_snap_id == CEPH_NOSNAP) {
 199     rados::cls::lock::assert_locked(&op, RBD_LOCK_NAME, LOCK_EXCLUSIVE, "", "");
 200   }
 201   cls_client::object_map_save(&op, m_object_map);
 202
 203   std::string oid(object_map_name(m_image_ctx.id, m_snap_id));
 204   librados::AioCompletion *comp = util::create_rados_callback(on_finish);
 205
 206   int r = m_image_ctx.md_ctx.aio_operate(oid, comp, &op);
 207   assert(r == 0);
 208   comp->release();
 209 }
 210
 211 template <typename I>
 212 void ObjectMap<I>::aio_resize(uint64_t new_size, uint8_t default_object_state,
 213                               Context *on_finish) {
 214   assert(m_image_ctx.owner_lock.is_locked());
 215   assert(m_image_ctx.snap_lock.is_locked());
 216   assert(m_image_ctx.test_features(RBD_FEATURE_OBJECT_MAP,
 217                                    m_image_ctx.snap_lock));
 218   assert(m_image_ctx.image_watcher != NULL);
 219   assert(m_image_ctx.exclusive_lock == nullptr ||
 220          m_image_ctx.exclusive_lock->is_lock_owner());
 221
 222   object_map::ResizeRequest *req = new object_map::ResizeRequest(
 223     m_image_ctx, &m_object_map, m_snap_id, new_size, default_object_state,
 224     on_finish);
 225   req->send();
 226 }
 227
 228 template <typename I>
 229 void ObjectMap<I>::detained_aio_update(UpdateOperation &&op) {
 230   CephContext *cct = m_image_ctx.cct;
 231   ldout(cct, 20) << dendl;
 232
 233   assert(m_image_ctx.snap_lock.is_locked());
 234   assert(m_image_ctx.object_map_lock.is_wlocked());
 235
 236   BlockGuardCell *cell;
 237   int r = m_update_guard->detain({op.start_object_no, op.end_object_no},
 238                                  &op, &cell);
 239   if (r < 0) {
 240     lderr(cct) << "failed to detain object map update: " << cpp_strerror(r)
 241                << dendl;
 242     m_image_ctx.op_work_queue->queue(op.on_finish, r);
 243     return;
 244   } else if (r > 0) {
 245     ldout(cct, 20) << "detaining object map update due to in-flight update: "
 246                    << "start=" << op.start_object_no << ", "
 247                    << "end=" << op.end_object_no << ", "
 248                    << (op.current_state ?
 249                          stringify(static_cast<uint32_t>(*op.current_state)) :
 250                          "")
 251                    << "->" << static_cast<uint32_t>(op.new_state) << dendl;
 252     return;
 253   }
 254
 255   ldout(cct, 20) << "in-flight update cell: " << cell << dendl;
 256   Context *on_finish = op.on_finish;
 257   Context *ctx = new FunctionContext([this, cell, on_finish](int r) {
 258       handle_detained_aio_update(cell, r, on_finish);
 259     });
 260   aio_update(CEPH_NOSNAP, op.start_object_no, op.end_object_no, op.new_state,
 261              op.current_state, op.parent_trace, ctx);
 262 }
 263
 264 template <typename I>
 265 void ObjectMap<I>::handle_detained_aio_update(BlockGuardCell *cell, int r,
 266                                               Context *on_finish) {
 267   CephContext *cct = m_image_ctx.cct;
 268   ldout(cct, 20) << "cell=" << cell << ", r=" << r << dendl;
 269
 270   typename UpdateGuard::BlockOperations block_ops;
 271   m_update_guard->release(cell, &block_ops);
 272
 273   {
 274     RWLock::RLocker snap_locker(m_image_ctx.snap_lock);
 275     RWLock::WLocker object_map_locker(m_image_ctx.object_map_lock);
 276     for (auto &op : block_ops) {
 277       detained_aio_update(std::move(op));
 278     }
 279   }
 280
 281   on_finish->complete(r);
 282 }
 283
 284 template <typename I>
 285 void ObjectMap<I>::aio_update(uint64_t snap_id, uint64_t start_object_no,
 286                               uint64_t end_object_no, uint8_t new_state,
 287                               const boost::optional<uint8_t> &current_state,
 288                               const ZTracer::Trace &parent_trace,
 289                               Context *on_finish) {
 290   assert(m_image_ctx.snap_lock.is_locked());
 291   assert((m_image_ctx.features & RBD_FEATURE_OBJECT_MAP) != 0);
 292   assert(m_image_ctx.image_watcher != nullptr);
 293   assert(m_image_ctx.exclusive_lock == nullptr ||
 294          m_image_ctx.exclusive_lock->is_lock_owner());
 295   assert(snap_id != CEPH_NOSNAP || m_image_ctx.object_map_lock.is_wlocked());
 296   assert(start_object_no < end_object_no);
 297
 298   CephContext *cct = m_image_ctx.cct;
 299   ldout(cct, 20) << "start=" << start_object_no << ", "
 300                  << "end=" << end_object_no << ", "
 301                  << (current_state ?
 302                        stringify(static_cast<uint32_t>(*current_state)) : "")
 303                  << "->" << static_cast<uint32_t>(new_state) << dendl;
 304   if (snap_id == CEPH_NOSNAP) {
 305     if (end_object_no > m_object_map.size()) {
 306       ldout(cct, 20) << "skipping update of invalid object map" << dendl;
 307       m_image_ctx.op_work_queue->queue(on_finish, 0);
 308       return;
 309     }
 310
 311     auto it = m_object_map.begin() + start_object_no;
 312     auto end_it = m_object_map.begin() + end_object_no;
 313     for (; it != end_it; ++it) {
 314       if (update_required(it, new_state)) {
 315         break;
 316       }
 317     }
 318     if (it == end_it) {
 319       ldout(cct, 20) << "object map update not required" << dendl;
 320       m_image_ctx.op_work_queue->queue(on_finish, 0);
 321       return;
 322     }
 323   }
 324
 325   auto req = object_map::UpdateRequest<I>::create(
 326     m_image_ctx, &m_object_map, snap_id, start_object_no, end_object_no,
 327     new_state, current_state, parent_trace, on_finish);
 328   req->send();
 329 }
 330
 331 } // namespace librbd
 332
 333 template class librbd::ObjectMap<librbd::ImageCtx>;
 334