diff options
Diffstat (limited to 'src/librbd/image/SetSnapRequest.cc')
| -rw-r--r-- | src/librbd/image/SetSnapRequest.cc | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/src/librbd/image/SetSnapRequest.cc b/src/librbd/image/SetSnapRequest.cc new file mode 100644 index 00000000..f342147f --- /dev/null +++ b/src/librbd/image/SetSnapRequest.cc @@ -0,0 +1,367 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab + +#include "librbd/image/SetSnapRequest.h" +#include "common/dout.h" +#include "common/errno.h" +#include "librbd/ExclusiveLock.h" +#include "librbd/ImageCtx.h" +#include "librbd/ObjectMap.h" +#include "librbd/Utils.h" +#include "librbd/image/RefreshParentRequest.h" +#include "librbd/io/ImageRequestWQ.h" + +#define dout_subsys ceph_subsys_rbd +#undef dout_prefix +#define dout_prefix *_dout << "librbd::image::SetSnapRequest: " + +namespace librbd { +namespace image { + +using util::create_context_callback; + +template <typename I> +SetSnapRequest<I>::SetSnapRequest(I &image_ctx, uint64_t snap_id, + Context *on_finish) + : m_image_ctx(image_ctx), m_snap_id(snap_id), m_on_finish(on_finish), + m_exclusive_lock(nullptr), m_object_map(nullptr), m_refresh_parent(nullptr), + m_writes_blocked(false) { +} + +template <typename I> +SetSnapRequest<I>::~SetSnapRequest() { + ceph_assert(!m_writes_blocked); + delete m_refresh_parent; + delete m_object_map; + delete m_exclusive_lock; +} + +template <typename I> +void SetSnapRequest<I>::send() { + if (m_snap_id == CEPH_NOSNAP) { + send_init_exclusive_lock(); + } else { + send_block_writes(); + } +} + +template <typename I> +void SetSnapRequest<I>::send_init_exclusive_lock() { + { + RWLock::RLocker snap_locker(m_image_ctx.snap_lock); + if (m_image_ctx.exclusive_lock != nullptr) { + ceph_assert(m_image_ctx.snap_id == CEPH_NOSNAP); + send_complete(); + return; + } + } + + if (m_image_ctx.read_only || + !m_image_ctx.test_features(RBD_FEATURE_EXCLUSIVE_LOCK)) { + int r = 0; + if (send_refresh_parent(&r) != nullptr) { + send_complete(); + } + return; + } + + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << dendl; + + m_exclusive_lock = ExclusiveLock<I>::create(m_image_ctx); + + using klass = SetSnapRequest<I>; + Context *ctx = create_context_callback< + klass, &klass::handle_init_exclusive_lock>(this); + + RWLock::RLocker owner_locker(m_image_ctx.owner_lock); + m_exclusive_lock->init(m_image_ctx.features, ctx); +} + +template <typename I> +Context *SetSnapRequest<I>::handle_init_exclusive_lock(int *result) { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << ": r=" << *result << dendl; + + if (*result < 0) { + lderr(cct) << "failed to initialize exclusive lock: " + << cpp_strerror(*result) << dendl; + finalize(); + return m_on_finish; + } + return send_refresh_parent(result); +} + +template <typename I> +void SetSnapRequest<I>::send_block_writes() { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << dendl; + + m_writes_blocked = true; + + using klass = SetSnapRequest<I>; + Context *ctx = create_context_callback< + klass, &klass::handle_block_writes>(this); + + RWLock::RLocker owner_locker(m_image_ctx.owner_lock); + m_image_ctx.io_work_queue->block_writes(ctx); +} + +template <typename I> +Context *SetSnapRequest<I>::handle_block_writes(int *result) { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << ": r=" << *result << dendl; + + if (*result < 0) { + lderr(cct) << "failed to block writes: " << cpp_strerror(*result) + << dendl; + finalize(); + return m_on_finish; + } + + { + RWLock::RLocker snap_locker(m_image_ctx.snap_lock); + auto it = m_image_ctx.snap_info.find(m_snap_id); + if (it == m_image_ctx.snap_info.end()) { + ldout(cct, 5) << "failed to locate snapshot '" << m_snap_id << "'" + << dendl; + + *result = -ENOENT; + finalize(); + return m_on_finish; + } + } + + return send_shut_down_exclusive_lock(result); +} + +template <typename I> +Context *SetSnapRequest<I>::send_shut_down_exclusive_lock(int *result) { + { + RWLock::RLocker snap_locker(m_image_ctx.snap_lock); + m_exclusive_lock = m_image_ctx.exclusive_lock; + } + + if (m_exclusive_lock == nullptr) { + return send_refresh_parent(result); + } + + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << dendl; + + using klass = SetSnapRequest<I>; + Context *ctx = create_context_callback< + klass, &klass::handle_shut_down_exclusive_lock>(this); + m_exclusive_lock->shut_down(ctx); + return nullptr; +} + +template <typename I> +Context *SetSnapRequest<I>::handle_shut_down_exclusive_lock(int *result) { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << ": r=" << *result << dendl; + + if (*result < 0) { + lderr(cct) << "failed to shut down exclusive lock: " + << cpp_strerror(*result) << dendl; + finalize(); + return m_on_finish; + } + + return send_refresh_parent(result); +} + +template <typename I> +Context *SetSnapRequest<I>::send_refresh_parent(int *result) { + CephContext *cct = m_image_ctx.cct; + + ParentImageInfo parent_md; + bool refresh_parent; + { + RWLock::RLocker snap_locker(m_image_ctx.snap_lock); + RWLock::RLocker parent_locker(m_image_ctx.parent_lock); + + const auto parent_info = m_image_ctx.get_parent_info(m_snap_id); + if (parent_info == nullptr) { + *result = -ENOENT; + lderr(cct) << "failed to retrieve snapshot parent info" << dendl; + finalize(); + return m_on_finish; + } + + parent_md = *parent_info; + refresh_parent = RefreshParentRequest<I>::is_refresh_required( + m_image_ctx, parent_md, m_image_ctx.migration_info); + } + + if (!refresh_parent) { + if (m_snap_id == CEPH_NOSNAP) { + // object map is loaded when exclusive lock is acquired + *result = apply(); + finalize(); + return m_on_finish; + } else { + // load snapshot object map + return send_open_object_map(result); + } + } + + ldout(cct, 10) << __func__ << dendl; + + using klass = SetSnapRequest<I>; + Context *ctx = create_context_callback< + klass, &klass::handle_refresh_parent>(this); + m_refresh_parent = RefreshParentRequest<I>::create(m_image_ctx, parent_md, + m_image_ctx.migration_info, + ctx); + m_refresh_parent->send(); + return nullptr; +} + +template <typename I> +Context *SetSnapRequest<I>::handle_refresh_parent(int *result) { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << ": r=" << *result << dendl; + + if (*result < 0) { + lderr(cct) << "failed to refresh snapshot parent: " << cpp_strerror(*result) + << dendl; + finalize(); + return m_on_finish; + } + + if (m_snap_id == CEPH_NOSNAP) { + // object map is loaded when exclusive lock is acquired + *result = apply(); + if (*result < 0) { + finalize(); + return m_on_finish; + } + + return send_finalize_refresh_parent(result); + } else { + // load snapshot object map + return send_open_object_map(result); + } +} + +template <typename I> +Context *SetSnapRequest<I>::send_open_object_map(int *result) { + if (!m_image_ctx.test_features(RBD_FEATURE_OBJECT_MAP)) { + *result = apply(); + if (*result < 0) { + finalize(); + return m_on_finish; + } + + return send_finalize_refresh_parent(result); + } + + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << dendl; + + using klass = SetSnapRequest<I>; + Context *ctx = create_context_callback< + klass, &klass::handle_open_object_map>(this); + m_object_map = ObjectMap<I>::create(m_image_ctx, m_snap_id); + m_object_map->open(ctx); + return nullptr; +} + +template <typename I> +Context *SetSnapRequest<I>::handle_open_object_map(int *result) { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << ": r=" << *result << dendl; + + if (*result < 0) { + lderr(cct) << "failed to open object map: " << cpp_strerror(*result) + << dendl; + delete m_object_map; + m_object_map = nullptr; + } + + *result = apply(); + if (*result < 0) { + finalize(); + return m_on_finish; + } + + return send_finalize_refresh_parent(result); +} + +template <typename I> +Context *SetSnapRequest<I>::send_finalize_refresh_parent(int *result) { + if (m_refresh_parent == nullptr) { + finalize(); + return m_on_finish; + } + + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << this << " " << __func__ << dendl; + + using klass = SetSnapRequest<I>; + Context *ctx = create_context_callback< + klass, &klass::handle_finalize_refresh_parent>(this); + m_refresh_parent->finalize(ctx); + return nullptr; +} + +template <typename I> +Context *SetSnapRequest<I>::handle_finalize_refresh_parent(int *result) { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << this << " " << __func__ << ": r=" << *result << dendl; + + if (*result < 0) { + lderr(cct) << "failed to close parent image: " << cpp_strerror(*result) + << dendl; + } + finalize(); + return m_on_finish; +} + +template <typename I> +int SetSnapRequest<I>::apply() { + CephContext *cct = m_image_ctx.cct; + ldout(cct, 10) << __func__ << dendl; + + RWLock::WLocker owner_locker(m_image_ctx.owner_lock); + RWLock::WLocker snap_locker(m_image_ctx.snap_lock); + RWLock::WLocker parent_locker(m_image_ctx.parent_lock); + if (m_snap_id != CEPH_NOSNAP) { + ceph_assert(m_image_ctx.exclusive_lock == nullptr); + int r = m_image_ctx.snap_set(m_snap_id); + if (r < 0) { + return r; + } + } else { + std::swap(m_image_ctx.exclusive_lock, m_exclusive_lock); + m_image_ctx.snap_unset(); + } + + if (m_refresh_parent != nullptr) { + m_refresh_parent->apply(); + } + + std::swap(m_object_map, m_image_ctx.object_map); + return 0; +} + +template <typename I> +void SetSnapRequest<I>::finalize() { + if (m_writes_blocked) { + m_image_ctx.io_work_queue->unblock_writes(); + m_writes_blocked = false; + } +} + +template <typename I> +void SetSnapRequest<I>::send_complete() { + finalize(); + m_on_finish->complete(0); + delete this; +} + +} // namespace image +} // namespace librbd + +template class librbd::image::SetSnapRequest<librbd::ImageCtx>; |