/*

 * 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/recoveryJournalBlock.h#8 $

 */

#ifndef RECOVERY_JOURNAL_BLOCK_H

#define RECOVERY_JOURNAL_BLOCK_H

#include "permassert.h"

#include "packedRecoveryJournalBlock.h"

#include "recoveryJournalInternals.h"

#include "ringNode.h"

#include "types.h"

#include "waitQueue.h"

struct recoveryJournalBlock {

  /** The doubly linked pointers for the free or active lists */

  RingNode             ringNode;

  /** The waiter for the pending full block list */

  Waiter               writeWaiter;

  /** The journal to which this block belongs */

  RecoveryJournal     *journal;

  /** A pointer to a block-sized buffer holding the packed block data */

  char                *block;

  /** A pointer to the current sector in the packed block buffer */

  PackedJournalSector *sector;

  /** The VIO for writing this block */

  VIO                 *vio;

  /** The sequence number for this block */

  SequenceNumber       sequenceNumber;

  /** The location of this block in the on-disk journal */

  PhysicalBlockNumber  blockNumber;

  /** Whether this block is being committed */

  bool                 committing;

  /** Whether this block has an uncommitted increment for a partial write */

  bool                 hasPartialWriteEntry;

  /** Whether this block has an uncommitted increment for a write with FUA */

  bool                 hasFUAEntry;

  /** The total number of entries in this block */

  JournalEntryCount    entryCount;

  /** The total number of uncommitted entries (queued or committing) */

  JournalEntryCount    uncommittedEntryCount;

  /** The number of new entries in the current commit */

  JournalEntryCount    entriesInCommit;

  /** The queue of VIOs which will make entries for the next commit */

  WaitQueue            entryWaiters;

  /** The queue of VIOs waiting for the current commit */

  WaitQueue            commitWaiters;

};

/**

 * Return the block associated with a ring node.

 *

 * @param node The ring node to recast as a block

 *

 * @return The block

 **/

static inline RecoveryJournalBlock *blockFromRingNode(RingNode *node)

{

  STATIC_ASSERT(offsetof(RecoveryJournalBlock, ringNode) == 0);

  return (RecoveryJournalBlock *) node;

}

/**

 * Return the block associated with a waiter

 *

 * @param waiter  The waiter to recast as a block

 *

 * @return The block

 **/

static inline RecoveryJournalBlock *blockFromWaiter(Waiter *waiter)

{

  return (RecoveryJournalBlock *)

    ((uintptr_t) waiter - offsetof(RecoveryJournalBlock, writeWaiter));

}

/**

 * Check whether a recovery block is dirty, indicating it has any uncommitted

 * entries, which includes both entries not written and entries written but

 * not yet acknowledged.

 *

 * @param block  The block to check

 *

 * @return true if the block has any uncommitted entries

 **/

__attribute__((warn_unused_result))

static inline bool isRecoveryBlockDirty(const RecoveryJournalBlock *block)

{

  return (block->uncommittedEntryCount > 0);

}

/**

 * Check whether a journal block is empty.

 *

 * @param block  The block to check

 *

 * @return true if the block has no entries

 **/

__attribute__((warn_unused_result))

static inline bool isRecoveryBlockEmpty(const RecoveryJournalBlock *block)

{

  return (block->entryCount == 0);

}

/**

 * Check whether a journal block is full.

 *

 * @param block  The block to check

 *

 * @return true if the the block is full

 **/

__attribute__((warn_unused_result))

static inline bool isRecoveryBlockFull(const RecoveryJournalBlock *block)

{

  return ((block == NULL)

          || (block->journal->entriesPerBlock == block->entryCount));

}

/**

 * Construct a journal block.

 *

 * @param [in]  layer     The layer from which to construct VIOs

 * @param [in]  journal   The journal to which the block will belong

 * @param [out] blockPtr  A pointer to receive the new block

 *

 * @return VDO_SUCCESS or an error

 **/

int makeRecoveryBlock(PhysicalLayer         *layer,

                      RecoveryJournal       *journal,

                      RecoveryJournalBlock **blockPtr)

  __attribute__((warn_unused_result));

/**

 * Free a tail block and null out the reference to it.

 *

 * @param blockPtr  The reference to the tail block to free

 **/

void freeRecoveryBlock(RecoveryJournalBlock **blockPtr);

/**

 * Initialize the next active recovery journal block.

 *

 * @param block  The journal block to initialize

 **/

void initializeRecoveryBlock(RecoveryJournalBlock *block);

/**

 * Enqueue a DataVIO to asynchronously encode and commit its next recovery

 * journal entry in this block. The DataVIO will not be continued until the

 * entry is committed to the on-disk journal. The caller is responsible for

 * ensuring the block is not already full.

 *

 * @param block    The journal block in which to make an entry

 * @param dataVIO  The DataVIO to enqueue

 *

 * @return VDO_SUCCESS or an error code if the DataVIO could not be enqueued

 **/

int enqueueRecoveryBlockEntry(RecoveryJournalBlock *block, DataVIO *dataVIO)

  __attribute__((warn_unused_result));

/**

 * Attempt to commit a block. If the block is not the oldest block with

 * uncommitted entries or if it is already being committed, nothing will be

 * done.

 *

 * @param block         The block to write

 * @param callback      The function to call when the write completes

 * @param errorHandler  The handler for flush or write errors

 *

 * @return VDO_SUCCESS, or an error if the write could not be launched

 **/

int commitRecoveryBlock(RecoveryJournalBlock *block,

                        VDOAction            *callback,

                        VDOAction            *errorHandler)

  __attribute__((warn_unused_result));

/**

 * Dump the contents of the recovery block to the log.

 *

 * @param block  The block to dump

 **/

void dumpRecoveryBlock(const RecoveryJournalBlock *block);

/**

 * Check whether a journal block can be committed.

 *

 * @param block  The journal block in question

 *

 * @return true if the block can be committed now

 **/

bool canCommitRecoveryBlock(RecoveryJournalBlock *block)

  __attribute__((warn_unused_result));

#endif // RECOVERY_JOURNAL_BLOCK_H