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-rw-r--r--src/librbd/io/CopyupRequest.cc774
1 files changed, 774 insertions, 0 deletions
diff --git a/src/librbd/io/CopyupRequest.cc b/src/librbd/io/CopyupRequest.cc
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+++ b/src/librbd/io/CopyupRequest.cc
@@ -0,0 +1,774 @@
+// -*- 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 "include/neorados/RADOS.hpp"
+#include "common/ceph_context.h"
+#include "common/ceph_mutex.h"
+#include "common/dout.h"
+#include "common/errno.h"
+#include "librbd/AsioEngine.h"
+#include "librbd/AsyncObjectThrottle.h"
+#include "librbd/ExclusiveLock.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/ObjectMap.h"
+#include "librbd/Utils.h"
+#include "librbd/asio/ContextWQ.h"
+#include "librbd/asio/Utils.h"
+#include "librbd/deep_copy/ObjectCopyRequest.h"
+#include "librbd/io/AioCompletion.h"
+#include "librbd/io/ImageDispatchSpec.h"
+#include "librbd/io/ObjectDispatcherInterface.h"
+#include "librbd/io/ObjectRequest.h"
+#include "librbd/io/ReadResult.h"
+#include "librbd/io/Utils.h"
+
+#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__ << ": " \
+ << data_object_name(m_image_ctx, m_object_no) << " "
+
+namespace librbd {
+namespace io {
+
+using librbd::util::data_object_name;
+
+namespace {
+
+template <typename I>
+class C_UpdateObjectMap : public C_AsyncObjectThrottle<I> {
+public:
+ C_UpdateObjectMap(AsyncObjectThrottle<I> &throttle, I *image_ctx,
+ uint64_t object_no, uint8_t head_object_map_state,
+ const std::vector<uint64_t> *snap_ids,
+ bool first_snap_is_clean, const ZTracer::Trace &trace,
+ size_t snap_id_idx)
+ : C_AsyncObjectThrottle<I>(throttle, *image_ctx), m_object_no(object_no),
+ m_head_object_map_state(head_object_map_state), m_snap_ids(*snap_ids),
+ m_first_snap_is_clean(first_snap_is_clean), m_trace(trace),
+ m_snap_id_idx(snap_id_idx)
+ {
+ }
+
+ int send() override {
+ auto& image_ctx = this->m_image_ctx;
+ ceph_assert(ceph_mutex_is_locked(image_ctx.owner_lock));
+ if (image_ctx.exclusive_lock == nullptr) {
+ return 1;
+ }
+ ceph_assert(image_ctx.exclusive_lock->is_lock_owner());
+
+ std::shared_lock image_locker{image_ctx.image_lock};
+ if (image_ctx.object_map == nullptr) {
+ return 1;
+ }
+
+ uint64_t snap_id = m_snap_ids[m_snap_id_idx];
+ if (snap_id == CEPH_NOSNAP) {
+ return update_head();
+ } else {
+ return update_snapshot(snap_id);
+ }
+ }
+
+ int update_head() {
+ auto& image_ctx = this->m_image_ctx;
+ ceph_assert(ceph_mutex_is_locked(image_ctx.image_lock));
+
+ bool sent = image_ctx.object_map->template aio_update<Context>(
+ CEPH_NOSNAP, m_object_no, m_head_object_map_state, {}, m_trace, false,
+ this);
+ return (sent ? 0 : 1);
+ }
+
+ int update_snapshot(uint64_t snap_id) {
+ auto& image_ctx = this->m_image_ctx;
+ ceph_assert(ceph_mutex_is_locked(image_ctx.image_lock));
+
+ uint8_t state = OBJECT_EXISTS;
+ if (image_ctx.test_features(RBD_FEATURE_FAST_DIFF, image_ctx.image_lock) &&
+ (m_snap_id_idx > 0 || m_first_snap_is_clean)) {
+ // first snapshot should be exists+dirty since it contains
+ // the copyup data -- later snapshots inherit the data.
+ state = OBJECT_EXISTS_CLEAN;
+ }
+
+ bool sent = image_ctx.object_map->template aio_update<Context>(
+ snap_id, m_object_no, state, {}, m_trace, true, this);
+ ceph_assert(sent);
+ return 0;
+ }
+
+private:
+ uint64_t m_object_no;
+ uint8_t m_head_object_map_state;
+ const std::vector<uint64_t> &m_snap_ids;
+ bool m_first_snap_is_clean;
+ const ZTracer::Trace &m_trace;
+ size_t m_snap_id_idx;
+};
+
+} // anonymous namespace
+
+template <typename I>
+CopyupRequest<I>::CopyupRequest(I *ictx, uint64_t objectno,
+ Extents &&image_extents,
+ const ZTracer::Trace &parent_trace)
+ : m_image_ctx(ictx), m_object_no(objectno), m_image_extents(image_extents),
+ m_trace(librbd::util::create_trace(*m_image_ctx, "copy-up", parent_trace))
+{
+ ceph_assert(m_image_ctx->data_ctx.is_valid());
+ m_async_op.start_op(*librbd::util::get_image_ctx(m_image_ctx));
+}
+
+template <typename I>
+CopyupRequest<I>::~CopyupRequest() {
+ ceph_assert(m_pending_requests.empty());
+ m_async_op.finish_op();
+}
+
+template <typename I>
+void CopyupRequest<I>::append_request(AbstractObjectWriteRequest<I> *req,
+ const Extents& object_extents) {
+ std::lock_guard locker{m_lock};
+
+ auto cct = m_image_ctx->cct;
+ ldout(cct, 20) << "object_request=" << req << ", "
+ << "append=" << m_append_request_permitted << dendl;
+ if (m_append_request_permitted) {
+ m_pending_requests.push_back(req);
+
+ for (auto [offset, length] : object_extents) {
+ if (length > 0) {
+ m_write_object_extents.union_insert(offset, length);
+ }
+ }
+ } else {
+ m_restart_requests.push_back(req);
+ }
+}
+
+template <typename I>
+void CopyupRequest<I>::send() {
+ read_from_parent();
+}
+
+template <typename I>
+void CopyupRequest<I>::read_from_parent() {
+ auto cct = m_image_ctx->cct;
+ std::shared_lock image_locker{m_image_ctx->image_lock};
+
+ if (m_image_ctx->parent == nullptr) {
+ ldout(cct, 5) << "parent detached" << dendl;
+
+ m_image_ctx->asio_engine->post(
+ [this]() { handle_read_from_parent(-ENOENT); });
+ return;
+ } else if (is_deep_copy()) {
+ deep_copy();
+ return;
+ }
+
+ auto comp = AioCompletion::create_and_start<
+ CopyupRequest<I>,
+ &CopyupRequest<I>::handle_read_from_parent>(
+ this, librbd::util::get_image_ctx(m_image_ctx->parent), AIO_TYPE_READ);
+
+ ldout(cct, 20) << "completion=" << comp << ", "
+ << "extents=" << m_image_extents
+ << dendl;
+ auto req = io::ImageDispatchSpec::create_read(
+ *m_image_ctx->parent, io::IMAGE_DISPATCH_LAYER_INTERNAL_START, comp,
+ std::move(m_image_extents),
+ ReadResult{&m_copyup_extent_map, &m_copyup_data},
+ m_image_ctx->parent->get_data_io_context(), 0, 0, m_trace);
+ req->send();
+}
+
+template <typename I>
+void CopyupRequest<I>::handle_read_from_parent(int r) {
+ auto cct = m_image_ctx->cct;
+ ldout(cct, 20) << "r=" << r << dendl;
+
+ if (r < 0 && r != -ENOENT) {
+ m_lock.lock();
+ disable_append_requests();
+ m_lock.unlock();
+
+ lderr(cct) << "error reading from parent: " << cpp_strerror(r) << dendl;
+ finish(r);
+ return;
+ }
+
+ convert_copyup_extent_map();
+
+ m_image_ctx->image_lock.lock_shared();
+ m_lock.lock();
+ disable_append_requests();
+
+ r = prepare_copyup_data();
+ if (r < 0) {
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ lderr(m_image_ctx->cct) << "failed to prepare copyup data: "
+ << cpp_strerror(r) << dendl;
+ finish(r);
+ return;
+ }
+
+ m_copyup_is_zero = m_copyup_data.is_zero();
+ m_copyup_required = is_copyup_required();
+ if (!m_copyup_required) {
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ ldout(cct, 20) << "no-op, skipping" << dendl;
+ finish(0);
+ return;
+ }
+
+ // copyup() will affect snapshots only if parent data is not all
+ // zeros.
+ if (!m_copyup_is_zero) {
+ m_snap_ids.insert(m_snap_ids.end(), m_image_ctx->snaps.rbegin(),
+ m_image_ctx->snaps.rend());
+ }
+
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ update_object_maps();
+}
+
+template <typename I>
+void CopyupRequest<I>::deep_copy() {
+ auto cct = m_image_ctx->cct;
+ ceph_assert(ceph_mutex_is_locked(m_image_ctx->image_lock));
+ ceph_assert(m_image_ctx->parent != nullptr);
+
+ m_lock.lock();
+ m_deep_copied = true;
+ m_flatten = is_copyup_required() ? true : m_image_ctx->migration_info.flatten;
+ m_lock.unlock();
+
+ ldout(cct, 20) << "flatten=" << m_flatten << dendl;
+
+ uint32_t flags = deep_copy::OBJECT_COPY_REQUEST_FLAG_MIGRATION;
+ if (m_flatten) {
+ flags |= deep_copy::OBJECT_COPY_REQUEST_FLAG_FLATTEN;
+ }
+
+ auto ctx = librbd::util::create_context_callback<
+ CopyupRequest<I>, &CopyupRequest<I>::handle_deep_copy>(this);
+ auto req = deep_copy::ObjectCopyRequest<I>::create(
+ m_image_ctx->parent, m_image_ctx, 0, 0,
+ m_image_ctx->migration_info.snap_map, m_object_no, flags, nullptr, ctx);
+
+ req->send();
+}
+
+template <typename I>
+void CopyupRequest<I>::handle_deep_copy(int r) {
+ auto cct = m_image_ctx->cct;
+ ldout(cct, 20) << "r=" << r << dendl;
+
+ m_image_ctx->image_lock.lock_shared();
+ m_lock.lock();
+ m_copyup_required = is_copyup_required();
+ if (r == -ENOENT && !m_flatten && m_copyup_required) {
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ ldout(cct, 10) << "restart deep-copy with flatten" << dendl;
+ send();
+ return;
+ }
+
+ disable_append_requests();
+
+ if (r < 0 && r != -ENOENT) {
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ lderr(cct) << "error encountered during deep-copy: " << cpp_strerror(r)
+ << dendl;
+ finish(r);
+ return;
+ }
+
+ if (!m_copyup_required && !is_update_object_map_required(r)) {
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ if (r == -ENOENT) {
+ r = 0;
+ }
+
+ ldout(cct, 20) << "skipping" << dendl;
+ finish(r);
+ return;
+ }
+
+ // For deep-copy, copyup() will never affect snapshots. However,
+ // this state machine is responsible for updating object maps for
+ // snapshots that have been created on destination image after
+ // migration started.
+ if (r != -ENOENT) {
+ compute_deep_copy_snap_ids();
+ }
+
+ m_lock.unlock();
+ m_image_ctx->image_lock.unlock_shared();
+
+ update_object_maps();
+}
+
+template <typename I>
+void CopyupRequest<I>::update_object_maps() {
+ std::shared_lock owner_locker{m_image_ctx->owner_lock};
+ std::shared_lock image_locker{m_image_ctx->image_lock};
+ if (m_image_ctx->object_map == nullptr) {
+ image_locker.unlock();
+ owner_locker.unlock();
+
+ copyup();
+ return;
+ }
+
+ auto cct = m_image_ctx->cct;
+ ldout(cct, 20) << dendl;
+
+ bool copy_on_read = m_pending_requests.empty();
+ uint8_t head_object_map_state = OBJECT_EXISTS;
+ if (copy_on_read && !m_snap_ids.empty() &&
+ m_image_ctx->test_features(RBD_FEATURE_FAST_DIFF,
+ m_image_ctx->image_lock)) {
+ // HEAD is non-dirty since data is tied to first snapshot
+ head_object_map_state = OBJECT_EXISTS_CLEAN;
+ }
+
+ auto r_it = m_pending_requests.rbegin();
+ if (r_it != m_pending_requests.rend()) {
+ // last write-op determines the final object map state
+ head_object_map_state = (*r_it)->get_pre_write_object_map_state();
+ }
+
+ if ((*m_image_ctx->object_map)[m_object_no] != head_object_map_state) {
+ // (maybe) need to update the HEAD object map state
+ m_snap_ids.push_back(CEPH_NOSNAP);
+ }
+ image_locker.unlock();
+
+ ceph_assert(m_image_ctx->exclusive_lock->is_lock_owner());
+ typename AsyncObjectThrottle<I>::ContextFactory context_factory(
+ boost::lambda::bind(boost::lambda::new_ptr<C_UpdateObjectMap<I>>(),
+ boost::lambda::_1, m_image_ctx, m_object_no, head_object_map_state,
+ &m_snap_ids, m_first_snap_is_clean, m_trace, boost::lambda::_2));
+ auto ctx = librbd::util::create_context_callback<
+ CopyupRequest<I>, &CopyupRequest<I>::handle_update_object_maps>(this);
+ auto throttle = new AsyncObjectThrottle<I>(
+ nullptr, *m_image_ctx, context_factory, ctx, nullptr, 0, m_snap_ids.size());
+ throttle->start_ops(
+ m_image_ctx->config.template get_val<uint64_t>("rbd_concurrent_management_ops"));
+}
+
+template <typename I>
+void CopyupRequest<I>::handle_update_object_maps(int r) {
+ auto cct = m_image_ctx->cct;
+ ldout(cct, 20) << "r=" << r << dendl;
+
+ if (r < 0) {
+ lderr(m_image_ctx->cct) << "failed to update object map: "
+ << cpp_strerror(r) << dendl;
+
+ finish(r);
+ return;
+ }
+
+ copyup();
+}
+
+template <typename I>
+void CopyupRequest<I>::copyup() {
+ auto cct = m_image_ctx->cct;
+ m_image_ctx->image_lock.lock_shared();
+ auto snapc = m_image_ctx->snapc;
+ auto io_context = m_image_ctx->get_data_io_context();
+ m_image_ctx->image_lock.unlock_shared();
+
+ m_lock.lock();
+ if (!m_copyup_required) {
+ m_lock.unlock();
+
+ ldout(cct, 20) << "skipping copyup" << dendl;
+ finish(0);
+ return;
+ }
+
+ ldout(cct, 20) << dendl;
+
+ bool copy_on_read = m_pending_requests.empty() && !m_deep_copied;
+ bool deep_copyup = !snapc.snaps.empty() && !m_copyup_is_zero;
+ if (m_copyup_is_zero) {
+ m_copyup_data.clear();
+ m_copyup_extent_map.clear();
+ }
+
+ neorados::WriteOp copyup_op;
+ neorados::WriteOp write_op;
+ neorados::WriteOp* op;
+ if (copy_on_read || deep_copyup) {
+ // copyup-op will use its own request issued to the initial object revision
+ op = &copyup_op;
+ ++m_pending_copyups;
+ } else {
+ // copyup-op can be combined with the write-ops (if any)
+ op = &write_op;
+ }
+
+ if (m_image_ctx->enable_sparse_copyup) {
+ cls_client::sparse_copyup(op, m_copyup_extent_map, m_copyup_data);
+ } else {
+ // convert the sparse read back into a standard (thick) read
+ Striper::StripedReadResult destriper;
+ destriper.add_partial_sparse_result(
+ cct, std::move(m_copyup_data), m_copyup_extent_map, 0,
+ {{0, m_image_ctx->layout.object_size}});
+
+ bufferlist thick_bl;
+ destriper.assemble_result(cct, thick_bl, false);
+ cls_client::copyup(op, thick_bl);
+ }
+ ObjectRequest<I>::add_write_hint(*m_image_ctx, op);
+
+ if (!copy_on_read) {
+ // merge all pending write ops into this single RADOS op
+ for (auto req : m_pending_requests) {
+ ldout(cct, 20) << "add_copyup_ops " << req << dendl;
+ req->add_copyup_ops(&write_op);
+ }
+
+ if (write_op.size() > 0) {
+ ++m_pending_copyups;
+ }
+ }
+ m_lock.unlock();
+
+ // issue librados ops at the end to simplify test cases
+ auto object = neorados::Object{data_object_name(m_image_ctx, m_object_no)};
+ if (copyup_op.size() > 0) {
+ // 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.
+ ldout(cct, 20) << "copyup with empty snapshot context" << dendl;
+
+ auto copyup_io_context = *io_context;
+ copyup_io_context.write_snap_context({});
+
+ m_image_ctx->rados_api.execute(
+ object, copyup_io_context, std::move(copyup_op),
+ librbd::asio::util::get_callback_adapter(
+ [this](int r) { handle_copyup(r); }), nullptr,
+ (this->m_trace.valid() ? this->m_trace.get_info() : nullptr));
+ }
+
+ if (write_op.size() > 0) {
+ // compare-and-write doesn't add any write ops (copyup+cmpext+write
+ // can't be executed in the same RADOS op because, unless the object
+ // was already present in the clone, cmpext wouldn't see it)
+ ldout(cct, 20) << (!deep_copyup && write_op.size() > 2 ?
+ "copyup + ops" : !deep_copyup ? "copyup" : "ops")
+ << " with current snapshot context" << dendl;
+
+ m_image_ctx->rados_api.execute(
+ object, *io_context, std::move(write_op),
+ librbd::asio::util::get_callback_adapter(
+ [this](int r) { handle_copyup(r); }), nullptr,
+ (this->m_trace.valid() ? this->m_trace.get_info() : nullptr));
+ }
+}
+
+template <typename I>
+void CopyupRequest<I>::handle_copyup(int r) {
+ auto cct = m_image_ctx->cct;
+ unsigned pending_copyups;
+ int copyup_ret_val = r;
+ {
+ std::lock_guard locker{m_lock};
+ ceph_assert(m_pending_copyups > 0);
+ pending_copyups = --m_pending_copyups;
+ if (m_copyup_ret_val < 0) {
+ copyup_ret_val = m_copyup_ret_val;
+ } else if (r < 0) {
+ m_copyup_ret_val = r;
+ }
+ }
+
+ ldout(cct, 20) << "r=" << r << ", "
+ << "pending=" << pending_copyups << dendl;
+
+ if (pending_copyups == 0) {
+ if (copyup_ret_val < 0 && copyup_ret_val != -ENOENT) {
+ lderr(cct) << "failed to copyup object: " << cpp_strerror(copyup_ret_val)
+ << dendl;
+ complete_requests(false, copyup_ret_val);
+ }
+
+ finish(0);
+ }
+}
+
+template <typename I>
+void CopyupRequest<I>::finish(int r) {
+ auto cct = m_image_ctx->cct;
+ ldout(cct, 20) << "r=" << r << dendl;
+
+ complete_requests(true, r);
+ delete this;
+}
+
+template <typename I>
+void CopyupRequest<I>::complete_requests(bool override_restart_retval, int r) {
+ auto cct = m_image_ctx->cct;
+ remove_from_list();
+
+ while (!m_pending_requests.empty()) {
+ auto it = m_pending_requests.begin();
+ auto req = *it;
+ ldout(cct, 20) << "completing request " << req << dendl;
+ req->handle_copyup(r);
+ m_pending_requests.erase(it);
+ }
+
+ if (override_restart_retval) {
+ r = -ERESTART;
+ }
+
+ while (!m_restart_requests.empty()) {
+ auto it = m_restart_requests.begin();
+ auto req = *it;
+ ldout(cct, 20) << "restarting request " << req << dendl;
+ req->handle_copyup(r);
+ m_restart_requests.erase(it);
+ }
+}
+
+template <typename I>
+void CopyupRequest<I>::disable_append_requests() {
+ ceph_assert(ceph_mutex_is_locked(m_lock));
+ m_append_request_permitted = false;
+}
+
+template <typename I>
+void CopyupRequest<I>::remove_from_list() {
+ std::lock_guard copyup_list_locker{m_image_ctx->copyup_list_lock};
+
+ auto it = m_image_ctx->copyup_list.find(m_object_no);
+ if (it != m_image_ctx->copyup_list.end()) {
+ m_image_ctx->copyup_list.erase(it);
+ }
+}
+
+template <typename I>
+bool CopyupRequest<I>::is_copyup_required() {
+ ceph_assert(ceph_mutex_is_locked(m_lock));
+
+ bool copy_on_read = m_pending_requests.empty();
+ if (copy_on_read) {
+ // always force a copyup if CoR enabled
+ return true;
+ }
+
+ if (!m_copyup_is_zero) {
+ return true;
+ }
+
+ for (auto req : m_pending_requests) {
+ if (!req->is_empty_write_op()) {
+ return true;
+ }
+ }
+ return false;
+}
+
+template <typename I>
+bool CopyupRequest<I>::is_deep_copy() const {
+ ceph_assert(ceph_mutex_is_locked(m_image_ctx->image_lock));
+ return !m_image_ctx->migration_info.empty();
+}
+
+template <typename I>
+bool CopyupRequest<I>::is_update_object_map_required(int r) {
+ ceph_assert(ceph_mutex_is_locked(m_image_ctx->image_lock));
+
+ if (r < 0) {
+ return false;
+ }
+
+ if (m_image_ctx->object_map == nullptr) {
+ return false;
+ }
+
+ if (m_image_ctx->migration_info.empty()) {
+ // migration might have completed while IO was in-flight,
+ // assume worst-case and perform an object map update
+ return true;
+ }
+
+ auto it = m_image_ctx->migration_info.snap_map.find(CEPH_NOSNAP);
+ ceph_assert(it != m_image_ctx->migration_info.snap_map.end());
+ return it->second[0] != CEPH_NOSNAP;
+}
+
+template <typename I>
+void CopyupRequest<I>::compute_deep_copy_snap_ids() {
+ ceph_assert(ceph_mutex_is_locked(m_image_ctx->image_lock));
+
+ // don't copy ids for the snaps updated by object deep copy or
+ // that don't overlap
+ std::set<uint64_t> deep_copied;
+ for (auto &it : m_image_ctx->migration_info.snap_map) {
+ if (it.first != CEPH_NOSNAP) {
+ deep_copied.insert(it.second.front());
+ }
+ }
+ ldout(m_image_ctx->cct, 15) << "deep_copied=" << deep_copied << dendl;
+
+ std::copy_if(m_image_ctx->snaps.rbegin(), m_image_ctx->snaps.rend(),
+ std::back_inserter(m_snap_ids),
+ [this, cct=m_image_ctx->cct, &deep_copied](uint64_t snap_id) {
+ if (deep_copied.count(snap_id)) {
+ m_first_snap_is_clean = true;
+ return false;
+ }
+
+ uint64_t parent_overlap = 0;
+ int r = m_image_ctx->get_parent_overlap(snap_id, &parent_overlap);
+ if (r < 0) {
+ ldout(cct, 5) << "failed getting parent overlap for snap_id: "
+ << snap_id << ": " << cpp_strerror(r) << dendl;
+ }
+ if (parent_overlap == 0) {
+ return false;
+ }
+ std::vector<std::pair<uint64_t, uint64_t>> extents;
+ util::extent_to_file(m_image_ctx, m_object_no, 0,
+ m_image_ctx->layout.object_size, extents);
+ auto overlap = m_image_ctx->prune_parent_extents(
+ extents, parent_overlap);
+ return overlap > 0;
+ });
+}
+
+template <typename I>
+void CopyupRequest<I>::convert_copyup_extent_map() {
+ auto cct = m_image_ctx->cct;
+
+ Extents image_extent_map;
+ image_extent_map.swap(m_copyup_extent_map);
+ m_copyup_extent_map.reserve(image_extent_map.size());
+
+ // convert the image-extent extent map to object-extents
+ for (auto [image_offset, image_length] : image_extent_map) {
+ striper::LightweightObjectExtents object_extents;
+ util::file_to_extents(
+ m_image_ctx, image_offset, image_length, 0, &object_extents);
+ for (auto& object_extent : object_extents) {
+ m_copyup_extent_map.emplace_back(
+ object_extent.offset, object_extent.length);
+ }
+ }
+
+ ldout(cct, 20) << "image_extents=" << image_extent_map << ", "
+ << "object_extents=" << m_copyup_extent_map << dendl;
+}
+
+template <typename I>
+int CopyupRequest<I>::prepare_copyup_data() {
+ ceph_assert(ceph_mutex_is_locked(m_image_ctx->image_lock));
+ auto cct = m_image_ctx->cct;
+
+ SnapshotSparseBufferlist snapshot_sparse_bufferlist;
+ auto& sparse_bufferlist = snapshot_sparse_bufferlist[0];
+
+ bool copy_on_read = m_pending_requests.empty();
+ bool maybe_deep_copyup = !m_image_ctx->snapc.snaps.empty();
+ if (copy_on_read || maybe_deep_copyup) {
+ // stand-alone copyup that will not be overwritten until HEAD revision
+ ldout(cct, 20) << "processing full copy-up" << dendl;
+
+ uint64_t buffer_offset = 0;
+ for (auto [object_offset, object_length] : m_copyup_extent_map) {
+ bufferlist sub_bl;
+ sub_bl.substr_of(m_copyup_data, buffer_offset, object_length);
+ buffer_offset += object_length;
+
+ sparse_bufferlist.insert(
+ object_offset, object_length,
+ {SPARSE_EXTENT_STATE_DATA, object_length, std::move(sub_bl)});
+ }
+ } else {
+ // copyup that will concurrently written to the HEAD revision with the
+ // associated write-ops so only process partial extents
+ uint64_t buffer_offset = 0;
+ for (auto [object_offset, object_length] : m_copyup_extent_map) {
+ interval_set<uint64_t> copyup_object_extents;
+ copyup_object_extents.insert(object_offset, object_length);
+
+ interval_set<uint64_t> intersection;
+ intersection.intersection_of(copyup_object_extents,
+ m_write_object_extents);
+
+ // extract only portions of the parent copyup data that have not
+ // been overwritten by write-ops
+ copyup_object_extents.subtract(intersection);
+ for (auto [copyup_offset, copyup_length] : copyup_object_extents) {
+ bufferlist sub_bl;
+ sub_bl.substr_of(
+ m_copyup_data, buffer_offset + (copyup_offset - object_offset),
+ copyup_length);
+ ceph_assert(sub_bl.length() == copyup_length);
+
+ sparse_bufferlist.insert(
+ copyup_offset, copyup_length,
+ {SPARSE_EXTENT_STATE_DATA, copyup_length, std::move(sub_bl)});
+ }
+ buffer_offset += object_length;
+ }
+
+ ldout(cct, 20) << "processing partial copy-up: " << sparse_bufferlist
+ << dendl;
+ }
+
+ // Let dispatch layers have a chance to process the data
+ auto r = m_image_ctx->io_object_dispatcher->prepare_copyup(
+ m_object_no, &snapshot_sparse_bufferlist);
+ if (r < 0) {
+ return r;
+ }
+
+ // Convert sparse extents back to extent map
+ m_copyup_data.clear();
+ m_copyup_extent_map.clear();
+ m_copyup_extent_map.reserve(sparse_bufferlist.ext_count());
+ for (auto& extent : sparse_bufferlist) {
+ auto& sbe = extent.get_val();
+ if (sbe.state == SPARSE_EXTENT_STATE_DATA) {
+ m_copyup_extent_map.emplace_back(extent.get_off(), extent.get_len());
+ m_copyup_data.append(sbe.bl);
+ }
+ }
+
+ return 0;
+}
+
+} // namespace io
+} // namespace librbd
+
+template class librbd::io::CopyupRequest<librbd::ImageCtx>;