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Diffstat (limited to '')
| -rw-r--r-- | src/librbd/io/ObjectRequest.cc | 1073 |
1 files changed, 1073 insertions, 0 deletions
diff --git a/src/librbd/io/ObjectRequest.cc b/src/librbd/io/ObjectRequest.cc new file mode 100644 index 000000000..6d246cdf3 --- /dev/null +++ b/src/librbd/io/ObjectRequest.cc @@ -0,0 +1,1073 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab + +#include "librbd/io/ObjectRequest.h" +#include "common/ceph_context.h" +#include "common/dout.h" +#include "common/errno.h" +#include "common/ceph_mutex.h" +#include "include/Context.h" +#include "include/err.h" +#include "include/neorados/RADOS.hpp" +#include "osd/osd_types.h" +#include "librados/snap_set_diff.h" +#include "librbd/AsioEngine.h" +#include "librbd/ExclusiveLock.h" +#include "librbd/ImageCtx.h" +#include "librbd/ObjectMap.h" +#include "librbd/Utils.h" +#include "librbd/asio/Utils.h" +#include "librbd/io/AioCompletion.h" +#include "librbd/io/CopyupRequest.h" +#include "librbd/io/ImageRequest.h" +#include "librbd/io/Utils.h" + +#include <boost/optional.hpp> + +#define dout_subsys ceph_subsys_rbd +#undef dout_prefix +#define dout_prefix *_dout << "librbd::io::ObjectRequest: " << this \ + << " " << __func__ << ": " \ + << data_object_name(this->m_ictx, \ + this->m_object_no) << " " + +namespace librbd { +namespace io { + +using librbd::util::data_object_name; +using librbd::util::create_context_callback; +using librbd::util::create_trace; + +namespace { + +template <typename I> +inline bool is_copy_on_read(I *ictx, const IOContext& io_context) { + std::shared_lock image_locker{ictx->image_lock}; + return (ictx->clone_copy_on_read && !ictx->read_only && + io_context->read_snap().value_or(CEPH_NOSNAP) == CEPH_NOSNAP && + (ictx->exclusive_lock == nullptr || + ictx->exclusive_lock->is_lock_owner())); +} + +template <typename S, typename D> +void convert_snap_set(const S& src_snap_set, + D* dst_snap_set) { + dst_snap_set->seq = src_snap_set.seq; + dst_snap_set->clones.reserve(src_snap_set.clones.size()); + for (auto& src_clone : src_snap_set.clones) { + dst_snap_set->clones.emplace_back(); + auto& dst_clone = dst_snap_set->clones.back(); + dst_clone.cloneid = src_clone.cloneid; + dst_clone.snaps = src_clone.snaps; + dst_clone.overlap = src_clone.overlap; + dst_clone.size = src_clone.size; + } +} + +} // anonymous namespace + +template <typename I> +ObjectRequest<I>* +ObjectRequest<I>::create_write( + I *ictx, uint64_t object_no, uint64_t object_off, ceph::bufferlist&& data, + IOContext io_context, int op_flags, int write_flags, + std::optional<uint64_t> assert_version, + const ZTracer::Trace &parent_trace, Context *completion) { + return new ObjectWriteRequest<I>(ictx, object_no, object_off, + std::move(data), io_context, op_flags, + write_flags, assert_version, + parent_trace, completion); +} + +template <typename I> +ObjectRequest<I>* +ObjectRequest<I>::create_discard( + I *ictx, uint64_t object_no, uint64_t object_off, uint64_t object_len, + IOContext io_context, int discard_flags, + const ZTracer::Trace &parent_trace, Context *completion) { + return new ObjectDiscardRequest<I>(ictx, object_no, object_off, + object_len, io_context, discard_flags, + parent_trace, completion); +} + +template <typename I> +ObjectRequest<I>* +ObjectRequest<I>::create_write_same( + I *ictx, uint64_t object_no, uint64_t object_off, uint64_t object_len, + ceph::bufferlist&& data, IOContext io_context, int op_flags, + const ZTracer::Trace &parent_trace, Context *completion) { + return new ObjectWriteSameRequest<I>(ictx, object_no, object_off, + object_len, std::move(data), io_context, + op_flags, parent_trace, completion); +} + +template <typename I> +ObjectRequest<I>* +ObjectRequest<I>::create_compare_and_write( + I *ictx, uint64_t object_no, uint64_t object_off, + ceph::bufferlist&& cmp_data, ceph::bufferlist&& write_data, + IOContext io_context, uint64_t *mismatch_offset, int op_flags, + const ZTracer::Trace &parent_trace, Context *completion) { + return new ObjectCompareAndWriteRequest<I>(ictx, object_no, object_off, + std::move(cmp_data), + std::move(write_data), io_context, + mismatch_offset, op_flags, + parent_trace, completion); +} + +template <typename I> +ObjectRequest<I>::ObjectRequest( + I *ictx, uint64_t objectno, IOContext io_context, + const char *trace_name, const ZTracer::Trace &trace, Context *completion) + : m_ictx(ictx), m_object_no(objectno), m_io_context(io_context), + m_completion(completion), + m_trace(create_trace(*ictx, "", trace)) { + ceph_assert(m_ictx->data_ctx.is_valid()); + if (m_trace.valid()) { + m_trace.copy_name(trace_name + std::string(" ") + + data_object_name(ictx, objectno)); + m_trace.event("start"); + } +} + +template <typename I> +void ObjectRequest<I>::add_write_hint(I& image_ctx, neorados::WriteOp* wr) { + auto alloc_hint_flags = static_cast<neorados::alloc_hint::alloc_hint_t>( + image_ctx.alloc_hint_flags); + if (image_ctx.enable_alloc_hint) { + wr->set_alloc_hint(image_ctx.get_object_size(), + image_ctx.get_object_size(), + alloc_hint_flags); + } else if (image_ctx.alloc_hint_flags != 0U) { + wr->set_alloc_hint(0, 0, alloc_hint_flags); + } +} + +template <typename I> +bool ObjectRequest<I>::compute_parent_extents(Extents *parent_extents, + ImageArea *area, + bool read_request) { + ceph_assert(ceph_mutex_is_locked(m_ictx->image_lock)); + + m_has_parent = false; + parent_extents->clear(); + *area = ImageArea::DATA; + + uint64_t raw_overlap; + int r = m_ictx->get_parent_overlap( + m_io_context->read_snap().value_or(CEPH_NOSNAP), &raw_overlap); + if (r < 0) { + // NOTE: it's possible for a snapshot to be deleted while we are + // still reading from it + lderr(m_ictx->cct) << "failed to retrieve parent overlap: " + << cpp_strerror(r) << dendl; + return false; + } + bool migration_write = !read_request && !m_ictx->migration_info.empty(); + if (migration_write) { + raw_overlap = m_ictx->migration_info.overlap; + } + if (raw_overlap == 0) { + return false; + } + + std::tie(*parent_extents, *area) = io::util::object_to_area_extents( + m_ictx, m_object_no, {{0, m_ictx->layout.object_size}}); + uint64_t object_overlap = m_ictx->prune_parent_extents( + *parent_extents, *area, raw_overlap, migration_write); + if (object_overlap > 0) { + m_has_parent = true; + return true; + } + return false; +} + +template <typename I> +void ObjectRequest<I>::async_finish(int r) { + ldout(m_ictx->cct, 20) << "r=" << r << dendl; + m_ictx->asio_engine->post([this, r]() { finish(r); }); +} + +template <typename I> +void ObjectRequest<I>::finish(int r) { + ldout(m_ictx->cct, 20) << "r=" << r << dendl; + m_completion->complete(r); + delete this; +} + +/** read **/ + +template <typename I> +ObjectReadRequest<I>::ObjectReadRequest( + I *ictx, uint64_t objectno, ReadExtents* extents, + IOContext io_context, int op_flags, int read_flags, + const ZTracer::Trace &parent_trace, uint64_t* version, + Context *completion) + : ObjectRequest<I>(ictx, objectno, io_context, "read", parent_trace, + completion), + m_extents(extents), m_op_flags(op_flags),m_read_flags(read_flags), + m_version(version) { +} + +template <typename I> +void ObjectReadRequest<I>::send() { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << dendl; + + read_object(); +} + +template <typename I> +void ObjectReadRequest<I>::read_object() { + I *image_ctx = this->m_ictx; + + std::shared_lock image_locker{image_ctx->image_lock}; + auto read_snap_id = this->m_io_context->read_snap().value_or(CEPH_NOSNAP); + if (read_snap_id == image_ctx->snap_id && + image_ctx->object_map != nullptr && + !image_ctx->object_map->object_may_exist(this->m_object_no)) { + image_ctx->asio_engine->post([this]() { read_parent(); }); + return; + } + image_locker.unlock(); + + ldout(image_ctx->cct, 20) << "snap_id=" << read_snap_id << dendl; + + neorados::ReadOp read_op; + for (auto& extent: *this->m_extents) { + if (extent.length >= image_ctx->sparse_read_threshold_bytes) { + read_op.sparse_read(extent.offset, extent.length, &extent.bl, + &extent.extent_map); + } else { + read_op.read(extent.offset, extent.length, &extent.bl); + } + } + util::apply_op_flags( + m_op_flags, image_ctx->get_read_flags(read_snap_id), &read_op); + + image_ctx->rados_api.execute( + {data_object_name(this->m_ictx, this->m_object_no)}, + *this->m_io_context, std::move(read_op), nullptr, + librbd::asio::util::get_callback_adapter( + [this](int r) { handle_read_object(r); }), m_version, + (this->m_trace.valid() ? this->m_trace.get_info() : nullptr)); +} + +template <typename I> +void ObjectReadRequest<I>::handle_read_object(int r) { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << "r=" << r << dendl; + if (m_version != nullptr) { + ldout(image_ctx->cct, 20) << "version=" << *m_version << dendl; + } + + if (r == -ENOENT) { + read_parent(); + return; + } else if (r < 0) { + lderr(image_ctx->cct) << "failed to read from object: " + << cpp_strerror(r) << dendl; + this->finish(r); + return; + } + + this->finish(0); +} + +template <typename I> +void ObjectReadRequest<I>::read_parent() { + if ((m_read_flags & READ_FLAG_DISABLE_READ_FROM_PARENT) != 0) { + this->finish(-ENOENT); + return; + } + + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << dendl; + + auto ctx = create_context_callback< + ObjectReadRequest<I>, &ObjectReadRequest<I>::handle_read_parent>(this); + + io::util::read_parent<I>( + image_ctx, this->m_object_no, this->m_extents, + this->m_io_context->read_snap().value_or(CEPH_NOSNAP), this->m_trace, + ctx); +} + +template <typename I> +void ObjectReadRequest<I>::handle_read_parent(int r) { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << "r=" << r << dendl; + + if (r == -ENOENT) { + this->finish(r); + return; + } else if (r < 0) { + lderr(image_ctx->cct) << "failed to read parent extents: " + << cpp_strerror(r) << dendl; + this->finish(r); + return; + } + + copyup(); +} + +template <typename I> +void ObjectReadRequest<I>::copyup() { + I *image_ctx = this->m_ictx; + if (!is_copy_on_read(image_ctx, this->m_io_context)) { + this->finish(0); + return; + } + + image_ctx->owner_lock.lock_shared(); + image_ctx->image_lock.lock_shared(); + Extents parent_extents; + ImageArea area; + if (!this->compute_parent_extents(&parent_extents, &area, true) || + (image_ctx->exclusive_lock != nullptr && + !image_ctx->exclusive_lock->is_lock_owner())) { + image_ctx->image_lock.unlock_shared(); + image_ctx->owner_lock.unlock_shared(); + this->finish(0); + return; + } + + ldout(image_ctx->cct, 20) << dendl; + + image_ctx->copyup_list_lock.lock(); + auto it = image_ctx->copyup_list.find(this->m_object_no); + if (it == image_ctx->copyup_list.end()) { + // create and kick off a CopyupRequest + auto new_req = CopyupRequest<I>::create( + image_ctx, this->m_object_no, std::move(parent_extents), area, + this->m_trace); + + image_ctx->copyup_list[this->m_object_no] = new_req; + image_ctx->copyup_list_lock.unlock(); + image_ctx->image_lock.unlock_shared(); + new_req->send(); + } else { + image_ctx->copyup_list_lock.unlock(); + image_ctx->image_lock.unlock_shared(); + } + + image_ctx->owner_lock.unlock_shared(); + this->finish(0); +} + +/** write **/ + +template <typename I> +AbstractObjectWriteRequest<I>::AbstractObjectWriteRequest( + I *ictx, uint64_t object_no, uint64_t object_off, uint64_t len, + IOContext io_context, const char *trace_name, + const ZTracer::Trace &parent_trace, Context *completion) + : ObjectRequest<I>(ictx, object_no, io_context, trace_name, parent_trace, + completion), + m_object_off(object_off), m_object_len(len) +{ + if (this->m_object_off == 0 && + this->m_object_len == ictx->get_object_size()) { + m_full_object = true; + } + + compute_parent_info(); + + ictx->image_lock.lock_shared(); + if (!ictx->migration_info.empty()) { + m_guarding_migration_write = true; + } + ictx->image_lock.unlock_shared(); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::compute_parent_info() { + I *image_ctx = this->m_ictx; + std::shared_lock image_locker{image_ctx->image_lock}; + + this->compute_parent_extents(&m_parent_extents, &m_image_area, false); + + if (!this->has_parent() || + (m_full_object && + !this->m_io_context->write_snap_context() && + !is_post_copyup_write_required())) { + m_copyup_enabled = false; + } +} + +template <typename I> +void AbstractObjectWriteRequest<I>::add_write_hint( + neorados::WriteOp *wr) { + I *image_ctx = this->m_ictx; + std::shared_lock image_locker{image_ctx->image_lock}; + if (image_ctx->object_map == nullptr || !this->m_object_may_exist || + image_ctx->alloc_hint_flags != 0U) { + ObjectRequest<I>::add_write_hint(*image_ctx, wr); + } +} + +template <typename I> +void AbstractObjectWriteRequest<I>::send() { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << this->get_op_type() << " " + << this->m_object_off << "~" << this->m_object_len + << dendl; + { + std::shared_lock image_lock{image_ctx->image_lock}; + if (image_ctx->object_map == nullptr) { + m_object_may_exist = true; + } else { + // should have been flushed prior to releasing lock + ceph_assert(image_ctx->exclusive_lock->is_lock_owner()); + m_object_may_exist = image_ctx->object_map->object_may_exist( + this->m_object_no); + } + } + + if (!m_object_may_exist && is_no_op_for_nonexistent_object()) { + ldout(image_ctx->cct, 20) << "skipping no-op on nonexistent object" + << dendl; + this->async_finish(0); + return; + } + + pre_write_object_map_update(); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::pre_write_object_map_update() { + I *image_ctx = this->m_ictx; + + image_ctx->image_lock.lock_shared(); + if (image_ctx->object_map == nullptr || !is_object_map_update_enabled()) { + image_ctx->image_lock.unlock_shared(); + write_object(); + return; + } + + if (!m_object_may_exist && m_copyup_enabled) { + // optimization: copyup required + image_ctx->image_lock.unlock_shared(); + copyup(); + return; + } + + uint8_t new_state = this->get_pre_write_object_map_state(); + ldout(image_ctx->cct, 20) << this->m_object_off << "~" << this->m_object_len + << dendl; + + if (image_ctx->object_map->template aio_update< + AbstractObjectWriteRequest<I>, + &AbstractObjectWriteRequest<I>::handle_pre_write_object_map_update>( + CEPH_NOSNAP, this->m_object_no, new_state, {}, this->m_trace, false, + this)) { + image_ctx->image_lock.unlock_shared(); + return; + } + + image_ctx->image_lock.unlock_shared(); + write_object(); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::handle_pre_write_object_map_update(int r) { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << "r=" << r << dendl; + if (r < 0) { + lderr(image_ctx->cct) << "failed to update object map: " + << cpp_strerror(r) << dendl; + this->finish(r); + return; + } + + write_object(); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::write_object() { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << dendl; + + neorados::WriteOp write_op; + if (m_copyup_enabled) { + if (m_guarding_migration_write) { + auto snap_seq = (this->m_io_context->write_snap_context() ? + this->m_io_context->write_snap_context()->first : 0); + ldout(image_ctx->cct, 20) << "guarding write: snap_seq=" << snap_seq + << dendl; + + cls_client::assert_snapc_seq( + &write_op, snap_seq, cls::rbd::ASSERT_SNAPC_SEQ_LE_SNAPSET_SEQ); + } else { + ldout(image_ctx->cct, 20) << "guarding write" << dendl; + write_op.assert_exists(); + } + } + + add_write_hint(&write_op); + add_write_ops(&write_op); + ceph_assert(write_op.size() != 0); + + image_ctx->rados_api.execute( + {data_object_name(this->m_ictx, this->m_object_no)}, + *this->m_io_context, std::move(write_op), + librbd::asio::util::get_callback_adapter( + [this](int r) { handle_write_object(r); }), nullptr, + (this->m_trace.valid() ? this->m_trace.get_info() : nullptr)); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::handle_write_object(int r) { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << "r=" << r << dendl; + + r = filter_write_result(r); + if (r == -ENOENT) { + if (m_copyup_enabled) { + copyup(); + return; + } + } else if (r == -ERANGE && m_guarding_migration_write) { + image_ctx->image_lock.lock_shared(); + m_guarding_migration_write = !image_ctx->migration_info.empty(); + image_ctx->image_lock.unlock_shared(); + + if (m_guarding_migration_write) { + copyup(); + } else { + ldout(image_ctx->cct, 10) << "migration parent gone, restart io" << dendl; + compute_parent_info(); + write_object(); + } + return; + } else if (r == -EILSEQ) { + ldout(image_ctx->cct, 10) << "failed to write object" << dendl; + this->finish(r); + return; + } else if (r < 0) { + lderr(image_ctx->cct) << "failed to write object: " << cpp_strerror(r) + << dendl; + this->finish(r); + return; + } + + post_write_object_map_update(); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::copyup() { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << dendl; + + ceph_assert(!m_copyup_in_progress); + m_copyup_in_progress = true; + + image_ctx->copyup_list_lock.lock(); + auto it = image_ctx->copyup_list.find(this->m_object_no); + if (it == image_ctx->copyup_list.end()) { + auto new_req = CopyupRequest<I>::create( + image_ctx, this->m_object_no, std::move(this->m_parent_extents), + m_image_area, this->m_trace); + this->m_parent_extents.clear(); + + // make sure to wait on this CopyupRequest + new_req->append_request(this, std::move(get_copyup_overwrite_extents())); + image_ctx->copyup_list[this->m_object_no] = new_req; + + image_ctx->copyup_list_lock.unlock(); + new_req->send(); + } else { + it->second->append_request(this, std::move(get_copyup_overwrite_extents())); + image_ctx->copyup_list_lock.unlock(); + } +} + +template <typename I> +void AbstractObjectWriteRequest<I>::handle_copyup(int r) { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << "r=" << r << dendl; + + ceph_assert(m_copyup_in_progress); + m_copyup_in_progress = false; + + if (r < 0 && r != -ERESTART) { + lderr(image_ctx->cct) << "failed to copyup object: " << cpp_strerror(r) + << dendl; + this->finish(r); + return; + } + + if (r == -ERESTART || is_post_copyup_write_required()) { + write_object(); + return; + } + + post_write_object_map_update(); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::post_write_object_map_update() { + I *image_ctx = this->m_ictx; + + image_ctx->image_lock.lock_shared(); + if (image_ctx->object_map == nullptr || !is_object_map_update_enabled() || + !is_non_existent_post_write_object_map_state()) { + image_ctx->image_lock.unlock_shared(); + this->finish(0); + return; + } + + ldout(image_ctx->cct, 20) << dendl; + + // should have been flushed prior to releasing lock + ceph_assert(image_ctx->exclusive_lock->is_lock_owner()); + if (image_ctx->object_map->template aio_update< + AbstractObjectWriteRequest<I>, + &AbstractObjectWriteRequest<I>::handle_post_write_object_map_update>( + CEPH_NOSNAP, this->m_object_no, OBJECT_NONEXISTENT, OBJECT_PENDING, + this->m_trace, false, this)) { + image_ctx->image_lock.unlock_shared(); + return; + } + + image_ctx->image_lock.unlock_shared(); + this->finish(0); +} + +template <typename I> +void AbstractObjectWriteRequest<I>::handle_post_write_object_map_update(int r) { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << "r=" << r << dendl; + if (r < 0) { + lderr(image_ctx->cct) << "failed to update object map: " + << cpp_strerror(r) << dendl; + this->finish(r); + return; + } + + this->finish(0); +} + +template <typename I> +void ObjectWriteRequest<I>::add_write_hint(neorados::WriteOp* wr) { + if ((m_write_flags & OBJECT_WRITE_FLAG_CREATE_EXCLUSIVE) != 0) { + wr->create(true); + } else if (m_assert_version.has_value()) { + wr->assert_version(m_assert_version.value()); + } + AbstractObjectWriteRequest<I>::add_write_hint(wr); +} + +template <typename I> +void ObjectWriteRequest<I>::add_write_ops(neorados::WriteOp* wr) { + if (this->m_full_object) { + wr->write_full(bufferlist{m_write_data}); + } else { + wr->write(this->m_object_off, bufferlist{m_write_data}); + } + util::apply_op_flags(m_op_flags, 0U, wr); +} + +template <typename I> +void ObjectDiscardRequest<I>::add_write_ops(neorados::WriteOp* wr) { + switch (m_discard_action) { + case DISCARD_ACTION_REMOVE: + wr->remove(); + break; + case DISCARD_ACTION_REMOVE_TRUNCATE: + wr->create(false); + // fall through + case DISCARD_ACTION_TRUNCATE: + wr->truncate(this->m_object_off); + break; + case DISCARD_ACTION_ZERO: + wr->zero(this->m_object_off, this->m_object_len); + break; + default: + ceph_abort(); + break; + } +} + +template <typename I> +void ObjectWriteSameRequest<I>::add_write_ops(neorados::WriteOp* wr) { + wr->writesame(this->m_object_off, this->m_object_len, + bufferlist{m_write_data}); + util::apply_op_flags(m_op_flags, 0U, wr); +} + +template <typename I> +void ObjectCompareAndWriteRequest<I>::add_write_ops(neorados::WriteOp* wr) { + wr->cmpext(this->m_object_off, bufferlist{m_cmp_bl}, nullptr); + + if (this->m_full_object) { + wr->write_full(bufferlist{m_write_bl}); + } else { + wr->write(this->m_object_off, bufferlist{m_write_bl}); + } + util::apply_op_flags(m_op_flags, 0U, wr); +} + +template <typename I> +int ObjectCompareAndWriteRequest<I>::filter_write_result(int r) const { + if (r <= -MAX_ERRNO) { + I *image_ctx = this->m_ictx; + + // object extent compare mismatch + uint64_t offset = -MAX_ERRNO - r; + auto [image_extents, _] = io::util::object_to_area_extents( + image_ctx, this->m_object_no, {{offset, this->m_object_len}}); + ceph_assert(image_extents.size() == 1); + + if (m_mismatch_offset) { + *m_mismatch_offset = image_extents[0].first; + } + r = -EILSEQ; + } + return r; +} + +template <typename I> +ObjectListSnapsRequest<I>::ObjectListSnapsRequest( + I *ictx, uint64_t objectno, Extents&& object_extents, SnapIds&& snap_ids, + int list_snaps_flags, const ZTracer::Trace &parent_trace, + SnapshotDelta* snapshot_delta, Context *completion) + : ObjectRequest<I>( + ictx, objectno, ictx->duplicate_data_io_context(), "snap_list", + parent_trace, completion), + m_object_extents(std::move(object_extents)), + m_snap_ids(std::move(snap_ids)), m_list_snaps_flags(list_snaps_flags), + m_snapshot_delta(snapshot_delta) { + this->m_io_context->read_snap(CEPH_SNAPDIR); +} + +template <typename I> +void ObjectListSnapsRequest<I>::send() { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << dendl; + + if (m_snap_ids.size() < 2) { + lderr(image_ctx->cct) << "invalid snap ids: " << m_snap_ids << dendl; + this->async_finish(-EINVAL); + return; + } + + list_snaps(); +} + +template <typename I> +void ObjectListSnapsRequest<I>::list_snaps() { + I *image_ctx = this->m_ictx; + ldout(image_ctx->cct, 20) << dendl; + + neorados::ReadOp read_op; + read_op.list_snaps(&m_snap_set, &m_ec); + + image_ctx->rados_api.execute( + {data_object_name(this->m_ictx, this->m_object_no)}, + *this->m_io_context, std::move(read_op), nullptr, + librbd::asio::util::get_callback_adapter( + [this](int r) { handle_list_snaps(r); }), nullptr, + (this->m_trace.valid() ? this->m_trace.get_info() : nullptr)); +} + +template <typename I> +void ObjectListSnapsRequest<I>::handle_list_snaps(int r) { + I *image_ctx = this->m_ictx; + auto cct = image_ctx->cct; + + if (r >= 0) { + r = -m_ec.value(); + } + + ldout(cct, 20) << "r=" << r << dendl; + + m_snapshot_delta->clear(); + auto& snapshot_delta = *m_snapshot_delta; + + ceph_assert(!m_snap_ids.empty()); + librados::snap_t start_snap_id = 0; + librados::snap_t first_snap_id = *m_snap_ids.begin(); + librados::snap_t last_snap_id = *m_snap_ids.rbegin(); + + if (r == -ENOENT) { + // the object does not exist -- mark the missing extents + zero_extent(first_snap_id, true); + list_from_parent(); + return; + } else if (r < 0) { + lderr(cct) << "failed to retrieve object snapshot list: " << cpp_strerror(r) + << dendl; + this->finish(r); + return; + } + + // helper function requires the librados legacy data structure + librados::snap_set_t snap_set; + convert_snap_set(m_snap_set, &snap_set); + + bool initial_extents_written = false; + + interval_set<uint64_t> object_interval; + for (auto& object_extent : m_object_extents) { + object_interval.insert(object_extent.first, object_extent.second); + } + ldout(cct, 20) << "object_interval=" << object_interval << dendl; + + // loop through all expected snapshots and build interval sets for + // data and zeroed ranges for each snapshot + uint64_t prev_end_size = 0; + interval_set<uint64_t> initial_written_extents; + for (auto end_snap_id : m_snap_ids) { + if (start_snap_id == end_snap_id) { + continue; + } else if (end_snap_id > last_snap_id) { + break; + } + + interval_set<uint64_t> diff; + uint64_t end_size; + bool exists; + librados::snap_t clone_end_snap_id; + bool read_whole_object; + calc_snap_set_diff(cct, snap_set, start_snap_id, + end_snap_id, &diff, &end_size, &exists, + &clone_end_snap_id, &read_whole_object); + + if (read_whole_object || + (!diff.empty() && + ((m_list_snaps_flags & LIST_SNAPS_FLAG_WHOLE_OBJECT) != 0))) { + ldout(cct, 1) << "need to read full object" << dendl; + diff.clear(); + diff.insert(0, image_ctx->layout.object_size); + end_size = image_ctx->layout.object_size; + clone_end_snap_id = end_snap_id; + } else if (!exists) { + end_size = 0; + } + + if (exists) { + // reads should be issued against the newest (existing) snapshot within + // the associated snapshot object clone. writes should be issued + // against the oldest snapshot in the snap_map. + ceph_assert(clone_end_snap_id >= end_snap_id); + if (clone_end_snap_id > last_snap_id) { + // do not read past the copy point snapshot + clone_end_snap_id = last_snap_id; + } + } + + // clip diff to current object extent + interval_set<uint64_t> diff_interval; + diff_interval.intersection_of(object_interval, diff); + + // clip diff to size of object (in case it was truncated) + interval_set<uint64_t> zero_interval; + if (end_size < prev_end_size) { + zero_interval.insert(end_size, prev_end_size - end_size); + zero_interval.intersection_of(object_interval); + + interval_set<uint64_t> trunc_interval; + trunc_interval.intersection_of(zero_interval, diff_interval); + if (!trunc_interval.empty()) { + diff_interval.subtract(trunc_interval); + ldout(cct, 20) << "clearing truncate diff: " << trunc_interval << dendl; + } + } + + ldout(cct, 20) << "start_snap_id=" << start_snap_id << ", " + << "end_snap_id=" << end_snap_id << ", " + << "clone_end_snap_id=" << clone_end_snap_id << ", " + << "diff=" << diff << ", " + << "diff_interval=" << diff_interval<< ", " + << "zero_interval=" << zero_interval<< ", " + << "end_size=" << end_size << ", " + << "prev_end_size=" << prev_end_size << ", " + << "exists=" << exists << ", " + << "whole_object=" << read_whole_object << dendl; + + // check if object exists prior to start of incremental snap delta so that + // we don't DNE the object if no additional deltas exist + if (exists && start_snap_id == 0 && + (!diff_interval.empty() || !zero_interval.empty())) { + ldout(cct, 20) << "object exists at snap id " << end_snap_id << dendl; + initial_extents_written = true; + } + + prev_end_size = end_size; + start_snap_id = end_snap_id; + + if (end_snap_id <= first_snap_id) { + // don't include deltas from the starting snapshots, but we iterate over + // it to track its existence and size + ldout(cct, 20) << "skipping prior snapshot " << dendl; + continue; + } + + if (exists) { + for (auto& interval : diff_interval) { + snapshot_delta[{end_snap_id, clone_end_snap_id}].insert( + interval.first, interval.second, + SparseExtent(SPARSE_EXTENT_STATE_DATA, interval.second)); + } + } else { + zero_interval.union_of(diff_interval); + } + + if ((m_list_snaps_flags & LIST_SNAPS_FLAG_IGNORE_ZEROED_EXTENTS) == 0) { + for (auto& interval : zero_interval) { + snapshot_delta[{end_snap_id, end_snap_id}].insert( + interval.first, interval.second, + SparseExtent(SPARSE_EXTENT_STATE_ZEROED, interval.second)); + } + } + } + + bool snapshot_delta_empty = snapshot_delta.empty(); + if (!initial_extents_written) { + zero_extent(first_snap_id, first_snap_id > 0); + } + ldout(cct, 20) << "snapshot_delta=" << snapshot_delta << dendl; + + if (snapshot_delta_empty) { + list_from_parent(); + return; + } + + this->finish(0); +} + +template <typename I> +void ObjectListSnapsRequest<I>::list_from_parent() { + I *image_ctx = this->m_ictx; + auto cct = image_ctx->cct; + + ceph_assert(!m_snap_ids.empty()); + librados::snap_t snap_id_start = *m_snap_ids.begin(); + librados::snap_t snap_id_end = *m_snap_ids.rbegin(); + + std::unique_lock image_locker{image_ctx->image_lock}; + if ((snap_id_start > 0) || (image_ctx->parent == nullptr) || + ((m_list_snaps_flags & LIST_SNAPS_FLAG_DISABLE_LIST_FROM_PARENT) != 0)) { + image_locker.unlock(); + + this->finish(0); + return; + } + + Extents parent_extents; + uint64_t raw_overlap = 0; + uint64_t object_overlap = 0; + image_ctx->get_parent_overlap(snap_id_end, &raw_overlap); + if (raw_overlap > 0) { + // calculate reverse mapping onto the parent image + std::tie(parent_extents, m_image_area) = io::util::object_to_area_extents( + image_ctx, this->m_object_no, m_object_extents); + object_overlap = image_ctx->prune_parent_extents( + parent_extents, m_image_area, raw_overlap, false); + } + if (object_overlap == 0) { + image_locker.unlock(); + + this->finish(0); + return; + } + + auto ctx = create_context_callback< + ObjectListSnapsRequest<I>, + &ObjectListSnapsRequest<I>::handle_list_from_parent>(this); + auto aio_comp = AioCompletion::create_and_start( + ctx, librbd::util::get_image_ctx(image_ctx->parent), AIO_TYPE_GENERIC); + ldout(cct, 20) << "completion=" << aio_comp + << " parent_extents=" << parent_extents + << " area=" << m_image_area << dendl; + + auto list_snaps_flags = ( + m_list_snaps_flags | LIST_SNAPS_FLAG_IGNORE_ZEROED_EXTENTS); + + ImageListSnapsRequest<I> req( + *image_ctx->parent, aio_comp, std::move(parent_extents), m_image_area, + {0, image_ctx->parent->snap_id}, list_snaps_flags, &m_parent_snapshot_delta, + this->m_trace); + req.send(); +} + +template <typename I> +void ObjectListSnapsRequest<I>::handle_list_from_parent(int r) { + I *image_ctx = this->m_ictx; + auto cct = image_ctx->cct; + + ldout(cct, 20) << "r=" << r << ", " + << "parent_snapshot_delta=" << m_parent_snapshot_delta + << dendl; + + // ignore special-case of fully empty dataset (we ignore zeroes) + if (m_parent_snapshot_delta.empty()) { + this->finish(0); + return; + } + + // the write/read snapshot id key is not useful for parent images so + // map the the special-case INITIAL_WRITE_READ_SNAP_IDS key + *m_snapshot_delta = {}; + auto& intervals = (*m_snapshot_delta)[INITIAL_WRITE_READ_SNAP_IDS]; + for (auto& [key, image_extents] : m_parent_snapshot_delta) { + for (auto image_extent : image_extents) { + auto state = image_extent.get_val().state; + + // map image-extents back to this object + striper::LightweightObjectExtents object_extents; + io::util::area_to_object_extents(image_ctx, image_extent.get_off(), + image_extent.get_len(), m_image_area, 0, + &object_extents); + for (auto& object_extent : object_extents) { + ceph_assert(object_extent.object_no == this->m_object_no); + intervals.insert( + object_extent.offset, object_extent.length, + {state, object_extent.length}); + } + } + } + + ldout(cct, 20) << "snapshot_delta=" << *m_snapshot_delta << dendl; + this->finish(0); +} + +template <typename I> +void ObjectListSnapsRequest<I>::zero_extent(uint64_t snap_id, bool dne) { + I *image_ctx = this->m_ictx; + auto cct = image_ctx->cct; + + // the object does not exist or is (partially) under whiteout -- mark the + // missing extents which would be any portion of the object that does not + // have data in the initial snapshot set + if ((m_list_snaps_flags & LIST_SNAPS_FLAG_IGNORE_ZEROED_EXTENTS) == 0) { + interval_set<uint64_t> interval; + for (auto [object_offset, object_length] : m_object_extents) { + interval.insert(object_offset, object_length); + } + + for (auto [offset, length] : interval) { + ldout(cct, 20) << "snapshot " << snap_id << ": " + << (dne ? "DNE" : "zeroed") << " extent " + << offset << "~" << length << dendl; + (*m_snapshot_delta)[{snap_id, snap_id}].insert( + offset, length, + SparseExtent( + (dne ? SPARSE_EXTENT_STATE_DNE : SPARSE_EXTENT_STATE_ZEROED), + length)); + } + } +} + +} // namespace io +} // namespace librbd + +template class librbd::io::ObjectRequest<librbd::ImageCtx>; +template class librbd::io::ObjectReadRequest<librbd::ImageCtx>; +template class librbd::io::AbstractObjectWriteRequest<librbd::ImageCtx>; +template class librbd::io::ObjectWriteRequest<librbd::ImageCtx>; +template class librbd::io::ObjectDiscardRequest<librbd::ImageCtx>; +template class librbd::io::ObjectWriteSameRequest<librbd::ImageCtx>; +template class librbd::io::ObjectCompareAndWriteRequest<librbd::ImageCtx>; +template class librbd::io::ObjectListSnapsRequest<librbd::ImageCtx>; |