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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#include "librbd/object_map/DiffRequest.h"
#include "common/debug.h"
#include "common/errno.h"
#include "librbd/ImageCtx.h"
#include "librbd/ObjectMap.h"
#include "librbd/Utils.h"
#include "osdc/Striper.h"
#include <string>
#define dout_subsys ceph_subsys_rbd
#undef dout_prefix
#define dout_prefix *_dout << "librbd::object_map::DiffRequest: " \
<< this << " " << __func__ << ": "
namespace librbd {
namespace object_map {
using util::create_rados_callback;
template <typename I>
void DiffRequest<I>::send() {
std::shared_lock image_locker{m_image_ctx->image_lock};
m_diff_from_start = (m_snap_id_start == 0);
if (m_snap_id_start == 0) {
if (!m_image_ctx->snap_info.empty()) {
m_snap_id_start = m_image_ctx->snap_info.begin()->first;
} else {
m_snap_id_start = CEPH_NOSNAP;
}
}
m_object_diff_state->clear();
m_current_snap_id = m_snap_id_start;
m_next_snap_id = m_snap_id_end;
load_object_map(&image_locker);
}
template <typename I>
void DiffRequest<I>::load_object_map(
std::shared_lock<ceph::shared_mutex>* image_locker) {
ceph_assert(ceph_mutex_is_locked(m_image_ctx->image_lock));
auto cct = m_image_ctx->cct;
ldout(cct, 10) << dendl;
m_current_size = m_image_ctx->size;
if (m_current_snap_id != CEPH_NOSNAP) {
auto snap_it = m_image_ctx->snap_info.find(m_current_snap_id);
ceph_assert(snap_it != m_image_ctx->snap_info.end());
m_current_size = snap_it->second.size;
++snap_it;
if (snap_it != m_image_ctx->snap_info.end()) {
m_next_snap_id = snap_it->first;
} else {
m_next_snap_id = CEPH_NOSNAP;
}
}
if ((m_image_ctx->features & RBD_FEATURE_FAST_DIFF) == 0) {
image_locker->unlock();
ldout(cct, 10) << "fast-diff feature not enabled" << dendl;
finish(-EINVAL);
return;
}
uint64_t flags = 0;
int r = m_image_ctx->get_flags(m_current_snap_id, &flags);
if (r < 0) {
image_locker->unlock();
lderr(cct) << "failed to retrieve image flags: " << cpp_strerror(r)
<< dendl;
finish(r);
return;
}
if ((flags & RBD_FLAG_FAST_DIFF_INVALID) != 0) {
image_locker->unlock();
ldout(cct, 1) << "cannot perform fast diff on invalid object map"
<< dendl;
finish(-EINVAL);
return;
}
std::string oid(ObjectMap<>::object_map_name(m_image_ctx->id,
m_current_snap_id));
librados::ObjectReadOperation op;
cls_client::object_map_load_start(&op);
m_out_bl.clear();
auto aio_comp = create_rados_callback<
DiffRequest<I>, &DiffRequest<I>::handle_load_object_map>(this);
r = m_image_ctx->md_ctx.aio_operate(oid, aio_comp, &op, &m_out_bl);
ceph_assert(r == 0);
aio_comp->release();
}
template <typename I>
void DiffRequest<I>::handle_load_object_map(int r) {
auto cct = m_image_ctx->cct;
ldout(cct, 10) << "r=" << r << dendl;
if (r == 0) {
auto bl_it = m_out_bl.cbegin();
r = cls_client::object_map_load_finish(&bl_it, &m_object_map);
}
std::string oid(ObjectMap<>::object_map_name(m_image_ctx->id,
m_current_snap_id));
if (r < 0) {
lderr(cct) << "failed to load object map: " << oid << dendl;
finish(r);
return;
}
ldout(cct, 20) << "loaded object map " << oid << dendl;
uint64_t num_objs = Striper::get_num_objects(m_image_ctx->layout,
m_current_size);
if (m_object_map.size() < num_objs) {
ldout(cct, 1) << "object map too small: "
<< m_object_map.size() << " < " << num_objs << dendl;
finish(-EINVAL);
return;
} else {
m_object_map.resize(num_objs);
}
if (m_object_diff_state->size() < num_objs) {
// the diff state should be the largest of all snapshots in the set
m_object_diff_state->resize(num_objs);
}
if (m_object_map.size() < m_object_diff_state->size()) {
// the image was shrunk so expanding the object map will flag end objects
// as non-existent and they will be compared against the previous object
// map
m_object_map.resize(m_object_diff_state->size());
}
uint64_t overlap = std::min(m_object_map.size(), m_prev_object_map.size());
auto it = m_object_map.begin();
auto overlap_end_it = it + overlap;
auto pre_it = m_prev_object_map.begin();
auto diff_it = m_object_diff_state->begin();
uint64_t i = 0;
for (; it != overlap_end_it; ++it, ++pre_it, ++diff_it, ++i) {
ldout(cct, 20) << "object state: " << i << " "
<< static_cast<uint32_t>(*pre_it)
<< "->" << static_cast<uint32_t>(*it) << dendl;
if (*it == OBJECT_NONEXISTENT) {
if (*pre_it != OBJECT_NONEXISTENT) {
*diff_it = DIFF_STATE_HOLE;
}
} else if (*it == OBJECT_EXISTS ||
(*pre_it != *it &&
!(*pre_it == OBJECT_EXISTS &&
*it == OBJECT_EXISTS_CLEAN))) {
*diff_it = DIFF_STATE_UPDATED;
}
}
ldout(cct, 20) << "computed overlap diffs" << dendl;
auto end_it = m_object_map.end();
if (m_object_map.size() > m_prev_object_map.size() &&
(m_diff_from_start || m_prev_object_map_valid)) {
for (; it != end_it; ++it,++diff_it, ++i) {
ldout(cct, 20) << "object state: " << i << " "
<< "->" << static_cast<uint32_t>(*it) << dendl;
if (*it == OBJECT_NONEXISTENT) {
*diff_it = DIFF_STATE_NONE;
} else {
*diff_it = DIFF_STATE_UPDATED;
}
}
}
ldout(cct, 20) << "computed resize diffs" << dendl;
if (m_current_snap_id == m_next_snap_id || m_next_snap_id > m_snap_id_end) {
finish(0);
return;
}
m_current_snap_id = m_next_snap_id;
m_prev_object_map = m_object_map;
m_prev_object_map_valid = true;
std::shared_lock image_locker{m_image_ctx->image_lock};
load_object_map(&image_locker);
}
template <typename I>
void DiffRequest<I>::finish(int r) {
auto cct = m_image_ctx->cct;
ldout(cct, 10) << "r=" << r << dendl;
m_on_finish->complete(r);
delete this;
}
} // namespace object_map
} // namespace librbd
template class librbd::object_map::DiffRequest<librbd::ImageCtx>;
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