X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fsrc%2Flibrbd%2Fio%2FCopyupRequest.cc;fp=src%2Fceph%2Fsrc%2Flibrbd%2Fio%2FCopyupRequest.cc;h=aee2f14d7b065ffac28fff1a7df608ce8d1db724;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git

diff --git a/src/ceph/src/librbd/io/CopyupRequest.cc b/src/ceph/src/librbd/io/CopyupRequest.cc
new file mode 100644
index 0000000..aee2f14
--- /dev/null
+++ b/src/ceph/src/librbd/io/CopyupRequest.cc
@@ -0,0 +1,373 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/io/CopyupRequest.h"
+#include "common/ceph_context.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "common/Mutex.h"
+
+#include "librbd/AsyncObjectThrottle.h"
+#include "librbd/ExclusiveLock.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ObjectMap.h"
+#include "librbd/Utils.h"
+#include "librbd/io/AioCompletion.h"
+#include "librbd/io/ImageRequest.h"
+#include "librbd/io/ObjectRequest.h"
+#include "librbd/io/ReadResult.h"
+
+#include <boost/bind.hpp>
+#include <boost/lambda/bind.hpp>
+#include <boost/lambda/construct.hpp>
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::io::CopyupRequest: " << this \
+                           << " " << __func__ << ": "
+
+namespace librbd {
+namespace io {
+
+namespace {
+
+class UpdateObjectMap : public C_AsyncObjectThrottle<> {
+public:
+  UpdateObjectMap(AsyncObjectThrottle<> &throttle, ImageCtx *image_ctx,
+                  uint64_t object_no, const std::vector<uint64_t> *snap_ids,
+                  const ZTracer::Trace &trace, size_t snap_id_idx)
+    : C_AsyncObjectThrottle(throttle, *image_ctx), m_object_no(object_no),
+      m_snap_ids(*snap_ids), m_trace(trace), m_snap_id_idx(snap_id_idx)
+  {
+  }
+
+  int send() override {
+    uint64_t snap_id = m_snap_ids[m_snap_id_idx];
+    if (snap_id == CEPH_NOSNAP) {
+      RWLock::RLocker snap_locker(m_image_ctx.snap_lock);
+      RWLock::WLocker object_map_locker(m_image_ctx.object_map_lock);
+      assert(m_image_ctx.exclusive_lock->is_lock_owner());
+      assert(m_image_ctx.object_map != nullptr);
+      bool sent = m_image_ctx.object_map->aio_update<Context>(
+        CEPH_NOSNAP, m_object_no, OBJECT_EXISTS, {}, m_trace, this);
+      return (sent ? 0 : 1);
+    }
+
+    uint8_t state = OBJECT_EXISTS;
+    if (m_image_ctx.test_features(RBD_FEATURE_FAST_DIFF) &&
+        m_snap_id_idx + 1 < m_snap_ids.size()) {
+      state = OBJECT_EXISTS_CLEAN;
+    }
+
+    RWLock::RLocker snap_locker(m_image_ctx.snap_lock);
+    RWLock::RLocker object_map_locker(m_image_ctx.object_map_lock);
+    if (m_image_ctx.object_map == nullptr) {
+      return 1;
+    }
+
+    bool sent = m_image_ctx.object_map->aio_update<Context>(
+      snap_id, m_object_no, state, {}, m_trace, this);
+    assert(sent);
+    return 0;
+  }
+
+private:
+  uint64_t m_object_no;
+  const std::vector<uint64_t> &m_snap_ids;
+  const ZTracer::Trace &m_trace;
+  size_t m_snap_id_idx;
+};
+
+} // anonymous namespace
+
+
+CopyupRequest::CopyupRequest(ImageCtx *ictx, const std::string &oid,
+                             uint64_t objectno, Extents &&image_extents,
+			     const ZTracer::Trace &parent_trace)
+  : m_ictx(ictx), m_oid(oid), m_object_no(objectno),
+    m_image_extents(image_extents),
+    m_trace(util::create_trace(*m_ictx, "copy-up", parent_trace)),
+    m_state(STATE_READ_FROM_PARENT)
+{
+  m_async_op.start_op(*m_ictx);
+}
+
+CopyupRequest::~CopyupRequest() {
+  assert(m_pending_requests.empty());
+  m_async_op.finish_op();
+}
+
+void CopyupRequest::append_request(ObjectRequest<> *req) {
+  ldout(m_ictx->cct, 20) << req << dendl;
+  m_pending_requests.push_back(req);
+}
+
+void CopyupRequest::complete_requests(int r) {
+  while (!m_pending_requests.empty()) {
+    vector<ObjectRequest<> *>::iterator it = m_pending_requests.begin();
+    ObjectRequest<> *req = *it;
+    ldout(m_ictx->cct, 20) << "completing request " << req << dendl;
+    req->complete(r);
+    m_pending_requests.erase(it);
+  }
+}
+
+bool CopyupRequest::send_copyup() {
+  bool add_copyup_op = !m_copyup_data.is_zero();
+  bool copy_on_read = m_pending_requests.empty();
+  if (!add_copyup_op && copy_on_read) {
+    // copyup empty object to prevent future CoR attempts
+    m_copyup_data.clear();
+    add_copyup_op = true;
+  }
+
+  ldout(m_ictx->cct, 20) << "oid " << m_oid << dendl;
+  m_state = STATE_COPYUP;
+
+  m_ictx->snap_lock.get_read();
+  ::SnapContext snapc = m_ictx->snapc;
+  m_ictx->snap_lock.put_read();
+
+  std::vector<librados::snap_t> snaps;
+
+  if (!copy_on_read) {
+    m_pending_copyups++;
+  }
+
+  int r;
+  if (copy_on_read || (!snapc.snaps.empty() && add_copyup_op)) {
+    assert(add_copyup_op);
+    add_copyup_op = false;
+
+    librados::ObjectWriteOperation copyup_op;
+    copyup_op.exec("rbd", "copyup", m_copyup_data);
+
+    // send only the copyup request with a blank snapshot context so that
+    // all snapshots are detected from the parent for this object.  If
+    // this is a CoW request, a second request will be created for the
+    // actual modification.
+    m_pending_copyups++;
+
+    ldout(m_ictx->cct, 20) << "copyup with empty snapshot context" << dendl;
+    librados::AioCompletion *comp = util::create_rados_callback(this);
+
+    librados::Rados rados(m_ictx->data_ctx);
+    r = rados.ioctx_create2(m_ictx->data_ctx.get_id(), m_data_ctx);
+    assert(r == 0);
+
+    r = m_data_ctx.aio_operate(
+      m_oid, comp, &copyup_op, 0, snaps,
+      (m_trace.valid() ? m_trace.get_info() : nullptr));
+    assert(r == 0);
+    comp->release();
+  }
+
+  if (!copy_on_read) {
+    librados::ObjectWriteOperation write_op;
+    if (add_copyup_op) {
+      // CoW did not need to handle existing snapshots
+      write_op.exec("rbd", "copyup", m_copyup_data);
+    }
+
+    // merge all pending write ops into this single RADOS op
+    for (size_t i=0; i<m_pending_requests.size(); ++i) {
+      ObjectRequest<> *req = m_pending_requests[i];
+      ldout(m_ictx->cct, 20) << "add_copyup_ops " << req << dendl;
+      bool set_hints = (i == 0);
+      req->add_copyup_ops(&write_op, set_hints);
+    }
+    assert(write_op.size() != 0);
+
+    snaps.insert(snaps.end(), snapc.snaps.begin(), snapc.snaps.end());
+    librados::AioCompletion *comp = util::create_rados_callback(this);
+    r = m_ictx->data_ctx.aio_operate(
+      m_oid, comp, &write_op, snapc.seq, snaps,
+      (m_trace.valid() ? m_trace.get_info() : nullptr));
+    assert(r == 0);
+    comp->release();
+  }
+  return false;
+}
+
+bool CopyupRequest::is_copyup_required() {
+  bool noop = true;
+  for (const ObjectRequest<> *req : m_pending_requests) {
+    if (!req->is_op_payload_empty()) {
+      noop = false;
+      break;
+    }
+  }
+
+  return (m_copyup_data.is_zero() && noop);
+}
+
+void CopyupRequest::send()
+{
+  m_state = STATE_READ_FROM_PARENT;
+  AioCompletion *comp = AioCompletion::create_and_start(
+    this, m_ictx, AIO_TYPE_READ);
+
+  ldout(m_ictx->cct, 20) << "completion " << comp
+                         << ", oid " << m_oid
+                         << ", extents " << m_image_extents
+                         << dendl;
+  ImageRequest<>::aio_read(m_ictx->parent, comp, std::move(m_image_extents),
+                           ReadResult{&m_copyup_data}, 0, m_trace);
+}
+
+void CopyupRequest::complete(int r)
+{
+  if (should_complete(r)) {
+    complete_requests(r);
+    delete this;
+  }
+}
+
+bool CopyupRequest::should_complete(int r)
+{
+  CephContext *cct = m_ictx->cct;
+  ldout(cct, 20) << "oid " << m_oid
+                 << ", r " << r << dendl;
+
+  uint64_t pending_copyups;
+  switch (m_state) {
+  case STATE_READ_FROM_PARENT:
+    ldout(cct, 20) << "READ_FROM_PARENT" << dendl;
+    remove_from_list();
+    if (r >= 0 || r == -ENOENT) {
+      if (is_copyup_required()) {
+        ldout(cct, 20) << "nop, skipping" << dendl;
+        return true;
+      }
+
+      return send_object_map_head();
+    }
+    break;
+
+  case STATE_OBJECT_MAP_HEAD:
+    ldout(cct, 20) << "OBJECT_MAP_HEAD" << dendl;
+    assert(r == 0);
+    return send_object_map();
+
+  case STATE_OBJECT_MAP:
+    ldout(cct, 20) << "OBJECT_MAP" << dendl;
+    assert(r == 0);
+    return send_copyup();
+
+  case STATE_COPYUP:
+    // invoked via a finisher in librados, so thread safe
+    pending_copyups = --m_pending_copyups;
+    ldout(cct, 20) << "COPYUP (" << pending_copyups << " pending)"
+                   << dendl;
+    if (r == -ENOENT) {
+      // hide the -ENOENT error if this is the last op
+      if (pending_copyups == 0) {
+        complete_requests(0);
+      }
+    } else if (r < 0) {
+      complete_requests(r);
+    }
+    return (pending_copyups == 0);
+
+  default:
+    lderr(cct) << "invalid state: " << m_state << dendl;
+    assert(false);
+    break;
+  }
+  return (r < 0);
+}
+
+void CopyupRequest::remove_from_list()
+{
+  Mutex::Locker l(m_ictx->copyup_list_lock);
+
+  map<uint64_t, CopyupRequest*>::iterator it =
+    m_ictx->copyup_list.find(m_object_no);
+  assert(it != m_ictx->copyup_list.end());
+  m_ictx->copyup_list.erase(it);
+}
+
+bool CopyupRequest::send_object_map_head() {
+  CephContext *cct = m_ictx->cct;
+  ldout(cct, 20) << dendl;
+
+  m_state = STATE_OBJECT_MAP_HEAD;
+
+  {
+    RWLock::RLocker owner_locker(m_ictx->owner_lock);
+    RWLock::RLocker snap_locker(m_ictx->snap_lock);
+    if (m_ictx->object_map != nullptr) {
+      bool copy_on_read = m_pending_requests.empty();
+      assert(m_ictx->exclusive_lock->is_lock_owner());
+
+      RWLock::WLocker object_map_locker(m_ictx->object_map_lock);
+      if (!m_ictx->snaps.empty()) {
+        m_snap_ids.insert(m_snap_ids.end(), m_ictx->snaps.begin(),
+                          m_ictx->snaps.end());
+      }
+      if (copy_on_read &&
+          (*m_ictx->object_map)[m_object_no] != OBJECT_EXISTS) {
+        m_snap_ids.insert(m_snap_ids.begin(), CEPH_NOSNAP);
+        object_map_locker.unlock();
+        snap_locker.unlock();
+        owner_locker.unlock();
+        return send_object_map();
+      }
+
+      bool may_update = false;
+      uint8_t new_state, current_state;
+
+      vector<ObjectRequest<> *>::reverse_iterator r_it = m_pending_requests.rbegin();
+      for (; r_it != m_pending_requests.rend(); ++r_it) {
+        ObjectRequest<> *req = *r_it;
+        if (!req->pre_object_map_update(&new_state)) {
+          continue;
+        }
+
+        current_state = (*m_ictx->object_map)[m_object_no];
+        ldout(cct, 20) << req->get_op_type() << " object no "
+                       << m_object_no << " current state "
+                       << stringify(static_cast<uint32_t>(current_state))
+                       << " new state " << stringify(static_cast<uint32_t>(new_state))
+                       << dendl;
+        may_update = true;
+        break;
+      }
+
+      if (may_update && (new_state != current_state) &&
+          m_ictx->object_map->aio_update<CopyupRequest>(
+            CEPH_NOSNAP, m_object_no, new_state, current_state, m_trace,
+            this)) {
+        return false;
+      }
+    }
+  }
+
+  return send_object_map();
+}
+
+bool CopyupRequest::send_object_map() {
+  // avoid possible recursive lock attempts
+  if (m_snap_ids.empty()) {
+    // no object map update required
+    return send_copyup();
+  } else {
+    // update object maps for HEAD and all existing snapshots
+    ldout(m_ictx->cct, 20) << "oid " << m_oid << dendl;
+    m_state = STATE_OBJECT_MAP;
+
+    RWLock::RLocker owner_locker(m_ictx->owner_lock);
+    AsyncObjectThrottle<>::ContextFactory context_factory(
+      boost::lambda::bind(boost::lambda::new_ptr<UpdateObjectMap>(),
+      boost::lambda::_1, m_ictx, m_object_no, &m_snap_ids, m_trace,
+      boost::lambda::_2));
+    AsyncObjectThrottle<> *throttle = new AsyncObjectThrottle<>(
+      NULL, *m_ictx, context_factory, util::create_context_callback(this),
+      NULL, 0, m_snap_ids.size());
+    throttle->start_ops(m_ictx->concurrent_management_ops);
+  }
+  return false;
+}
+
+} // namespace io
+} // namespace librbd