/*

 * 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/vdo.h#3 $

 */

#ifndef VDO_H

#define VDO_H

#include "types.h"

/**

 * Allocate a VDO and associate it with its physical layer.

 *

 * @param [in]  layer       The physical layer the VDO sits on

 * @param [out] vdoPtr      A pointer to hold the allocated VDO

 *

 * @return VDO_SUCCESS or an error

 **/

int allocateVDO(PhysicalLayer *layer, VDO **vdoPtr)

  __attribute__((warn_unused_result));

/**

 * Construct a VDO for use in user space with a synchronous layer.

 *

 * @param [in]  layer   The physical layer the VDO sits on

 * @param [out] vdoPtr  A pointer to hold the allocated VDO

 *

 * @return VDO_SUCCESS or an error

 **/

int makeVDO(PhysicalLayer *layer, VDO **vdoPtr)

  __attribute__((warn_unused_result));

/**

 * Destroy a VDO instance.

 *

 * @param vdo  The VDO to destroy

 **/

void destroyVDO(VDO *vdo);

/**

 * Destroy a VDO instance, free it, and null out the reference to it.

 *

 * @param vdoPtr  A reference to the VDO to free

 **/

void freeVDO(VDO **vdoPtr);

/**

 * Put a VDO into read-only mode and save the read-only state in the super

 * block.

 *

 * @param vdo             The VDO to put into read-only mode

 * @param errorCode       The error which caused the VDO to enter read-only

 *                        mode

 **/

void makeVDOReadOnly(VDO *vdo, int errorCode);

/**

 * Set whether compression is enabled in VDO.

 *

 * @param vdo                The VDO

 * @param enableCompression  Whether to enable compression in VDO

 *

 * @return State of compression before new value is set

 **/

bool setVDOCompressing(VDO *vdo, bool enableCompression);

/**

 * Get whether compression is enabled in VDO.

 *

 * @param vdo  The VDO

 *

 * @return State of compression

 **/

bool getVDOCompressing(VDO *vdo);

/**

 * Get the VDO statistics.

 *

 * @param [in]  vdo    The VDO

 * @param [out] stats  The VDO statistics are returned here

 **/

void getVDOStatistics(const VDO *vdo, VDOStatistics *stats);

/**

 * Get the number of physical blocks in use by user data.

 *

 * @param vdo  The VDO

 *

 * @return The number of blocks allocated for user data

 **/

BlockCount getPhysicalBlocksAllocated(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the number of unallocated physical blocks.

 *

 * @param vdo  The VDO

 *

 * @return The number of free blocks

 **/

BlockCount getPhysicalBlocksFree(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the number of physical blocks used by VDO metadata.

 *

 * @param vdo  The VDO

 *

 * @return The number of overhead blocks

 **/

BlockCount getPhysicalBlocksOverhead(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the total number of blocks used for the block map.

 *

 * @param vdo  The VDO

 *

 * @return The number of block map blocks

 **/

BlockCount getTotalBlockMapBlocks(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the VDO write policy.

 *

 * @param vdo  The VDO

 *

 * @return The write policy

 **/

WritePolicy getWritePolicy(const VDO *vdo);

/**

 * Set the VDO write policy.

 *

 * @param vdo  The VDO

 * @param new  The new write policy

 **/

void setWritePolicy(VDO *vdo, WritePolicy new);

/**

 * Get a copy of the load-time configuration of the VDO.

 *

 * @param vdo  The VDO

 *

 * @return The load-time configuration of the VDO

 **/

const VDOLoadConfig *getVDOLoadConfig(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the thread config of the VDO.

 *

 * @param vdo  The VDO

 *

 * @return The thread config

 **/

const ThreadConfig *getThreadConfig(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the configured maximum age of a dirty block map page.

 *

 * @param vdo  The VDO

 *

 * @return The block map era length

 **/

BlockCount getConfiguredBlockMapMaximumAge(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the configured page cache size of the VDO.

 *

 * @param vdo  The VDO

 *

 * @return The number of pages for the page cache

 **/

PageCount getConfiguredCacheSize(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Get the location of the first block of the VDO.

 *

 * @param vdo  The VDO

 *

 * @return The location of the first block managed by the VDO

 **/

PhysicalBlockNumber getFirstBlockOffset(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Check whether the VDO was new when it was loaded.

 *

 * @param vdo  The VDO to query

 *

 * @return true if the VDO was new

 **/

bool wasNew(const VDO *vdo)

  __attribute__((warn_unused_result));

/**

 * Check whether a DataLocation containing potential dedupe advice is

 * well-formed and addresses a data block in one of the configured physical

 * zones of the VDO. If it is, return the location and zone as a ZonedPBN;

 * otherwise increment statistics tracking invalid advice and return an

 * unmapped ZonedPBN.

 *

 * @param vdo     The VDO

 * @param advice  The advice to validate (NULL indicates no advice)

 * @param lbn     The logical block number of the write that requested advice,

 *                which is only used for debug-level logging of invalid advice

 *

 * @return The ZonedPBN representing the advice, if valid, otherwise an

 *         unmapped ZonedPBN if the advice was invalid or NULL

 **/

ZonedPBN validateDedupeAdvice(VDO                *vdo,

                              const DataLocation *advice,

                              LogicalBlockNumber  lbn)

  __attribute__((warn_unused_result));

// TEST SUPPORT ONLY BEYOND THIS POINT

/**

 * Dump status information about VDO to the log for debugging.

 *

 * @param vdo  The vdo to dump

 **/

void dumpVDOStatus(const VDO *vdo);

/**

 * Set the VIO tracing flag.

 *

 * @param vdo         The VDO

 * @param vioTracing  Whether VIO tracing is enabled for this device

 **/

void setVDOTracingFlags(VDO *vdo, bool vioTracing);

/**

 * Indicate whether VIO tracing is enabled.

 *

 * @param vdo  The VDO

 *

 * @return Whether VIO tracing is enabled

 **/

bool vdoVIOTracingEnabled(const VDO *vdo);

/**

 * Indicate whether extent tracing is enabled.

 *

 * @param vdo  The VDO

 *

 * @return Whether extent tracing is enabled

 **/

bool vdoExtentTracingEnabled(const VDO *vdo);

#endif /* VDO_H */