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SnapshotRemoveRequest.h
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/
SnapshotRemoveRequest.h
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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#ifndef CEPH_LIBRBD_OBJECT_MAP_SNAPSHOT_REMOVE_REQUEST_H
#define CEPH_LIBRBD_OBJECT_MAP_SNAPSHOT_REMOVE_REQUEST_H
#include "include/int_types.h"
#include "include/buffer.h"
#include "common/bit_vector.hpp"
#include "librbd/AsyncRequest.h"
namespace librbd {
namespace object_map {
class SnapshotRemoveRequest : public AsyncRequest<> {
public:
/**
* Snapshot rollback goes through the following state machine:
*
* @verbatim
*
* <start> -----------> STATE_LOAD_MAP ----\
* . * |
* . * (error) |
* . (invalid object map) v |
* . . . > STATE_INVALIDATE_NEXT_MAP |
* . | |
* . | |
* . (fast diff disabled) v v
* . . . . . . . . . . > STATE_REMOVE_MAP
* |
* v
* <finish>
*
* @endverbatim
*
* The _LOAD_MAP state is skipped if the fast diff feature is disabled.
* If the fast diff feature is enabled and the snapshot is flagged as
* invalid, the next snapshot / HEAD object mapis flagged as invalid;
* otherwise, the state machine proceeds to remove the object map.
*/
enum State {
STATE_LOAD_MAP,
STATE_REMOVE_SNAPSHOT,
STATE_INVALIDATE_NEXT_MAP,
STATE_REMOVE_MAP
};
SnapshotRemoveRequest(ImageCtx &image_ctx, ceph::BitVector<2> *object_map,
uint64_t snap_id, Context *on_finish)
: AsyncRequest(image_ctx, on_finish), m_object_map(*object_map),
m_snap_id(snap_id), m_next_snap_id(CEPH_NOSNAP) {
}
virtual void send();
protected:
virtual bool should_complete(int r);
virtual int filter_return_code(int r) const {
if ((m_state == STATE_LOAD_MAP || m_state == STATE_REMOVE_MAP) &&
r == -ENOENT) {
return 0;
}
return r;
}
private:
State m_state;
ceph::BitVector<2> &m_object_map;
uint64_t m_snap_id;
uint64_t m_next_snap_id;
ceph::BitVector<2> m_snap_object_map;
bufferlist m_out_bl;
void send_load_map();
void send_remove_snapshot();
void send_invalidate_next_map();
void send_remove_map();
void compute_next_snap_id();
void update_object_map();
};
} // namespace object_map
} // namespace librbd
#endif // CEPH_LIBRBD_OBJECT_MAP_SNAPSHOT_REMOVE_REQUEST_H