/*
* Copyright (c) 2020 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* $Id: //eng/vdo-releases/aluminum/src/c++/vdo/base/hashLockInternals.h#2 $
*/
#ifndef HASH_LOCK_INTERNALS_H
#define HASH_LOCK_INTERNALS_H
#include "completion.h"
#include "ringNode.h"
#include "types.h"
#include "uds.h"
#include "waitQueue.h"
typedef enum {
/** State for locks that are not in use or are being initialized. */
HASH_LOCK_INITIALIZING = 0,
// This is the sequence of states typically used on the non-dedupe path.
HASH_LOCK_QUERYING,
HASH_LOCK_WRITING,
HASH_LOCK_UPDATING,
// The remaining states are typically used on the dedupe path in this order.
HASH_LOCK_LOCKING,
HASH_LOCK_VERIFYING,
HASH_LOCK_DEDUPING,
HASH_LOCK_UNLOCKING,
// XXX This is a temporary state denoting a lock which is sending VIOs back
// to the old dedupe and vioWrite pathways. It won't be in the final version
// of VDOSTORY-190.
HASH_LOCK_BYPASSING,
/**
* Terminal state for locks returning to the pool. Must be last both because
* it's the final state, and also because it's used to count the states.
**/
HASH_LOCK_DESTROYING,
} HashLockState;
struct hashLock {
/** When the lock is unused, this RingNode allows the lock to be pooled */
RingNode poolNode;
/** The block hash covered by this lock */
UdsChunkName hash;
/**
* A ring containing the DataVIOs sharing this lock, all having the same
* chunk name and data block contents, linked by their hashLockNode fields.
**/
RingNode duplicateRing;
/** The number of DataVIOs sharing this lock instance */
VIOCount referenceCount;
/** The maximum value of referenceCount in the lifetime of this lock */
VIOCount maxReferences;
/** The current state of this lock */
HashLockState state;
/** True if the UDS index should be updated with new advice */
bool updateAdvice;
/** True if the advice has been verified to be a true duplicate */
bool verified;
/** True if the lock has already accounted for an initial verification */
bool verifyCounted;
/** True if this lock is registered in the lock map (cleared on rollover) */
bool registered;
/**
* If verified is false, this is the location of a possible duplicate.
* If verified is true, is is the verified location of a true duplicate.
**/
ZonedPBN duplicate;
/** The PBN lock on the block containing the duplicate data */
PBNLock *duplicateLock;
/** The DataVIO designated to act on behalf of the lock */
DataVIO *agent;
/**
* Other DataVIOs with data identical to the agent who are currently waiting
* for the agent to get the information they all need to deduplicate--either
* against each other, or against an existing duplicate on disk.
**/
WaitQueue waiters;
};
/**
* Initialize a HashLock instance which has been newly allocated.
*
* @param lock The lock to initialize
**/
static inline void initializeHashLock(HashLock *lock)
{
initializeRing(&lock->poolNode);
initializeRing(&lock->duplicateRing);
initializeWaitQueue(&lock->waiters);
}
/**
* Get the string representation of a hash lock state.
*
* @param state The hash lock state
*
* @return The short string representing the state
**/
const char *getHashLockStateName(HashLockState state)
__attribute__((warn_unused_result));
#endif // HASH_LOCK_INTERNALS_H