/*
* 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/constants.h#2 $
*/
#ifndef CONSTANTS_H
#define CONSTANTS_H
#include "types.h"
enum {
/** The number of entries on a block map page */
BLOCK_MAP_ENTRIES_PER_PAGE = 812,
/** The origin of the flat portion of the block map */
BLOCK_MAP_FLAT_PAGE_ORIGIN = 1,
/**
* The height of a block map tree. Assuming a root count of 60 and 812
* entries per page, this is big enough to represent almost 95 PB of logical
* space.
**/
BLOCK_MAP_TREE_HEIGHT = 5,
/** The number of trees in the arboreal block map */
DEFAULT_BLOCK_MAP_TREE_ROOT_COUNT = 60,
/** The default size of the recovery journal, in blocks */
DEFAULT_RECOVERY_JOURNAL_SIZE = 32 * 1024,
/** The default size of each slab journal, in blocks */
DEFAULT_SLAB_JOURNAL_SIZE = 224,
/**
* The initial size of lbnOperations and pbnOperations, which is based
* upon the expected maximum number of outstanding VIOs. This value was
* chosen to make it highly unlikely that the maps would need to be resized.
**/
LOCK_MAP_CAPACITY = 10000,
/** The maximum number of logical zones */
MAX_LOGICAL_ZONES = 60,
/** The maximum number of physical zones */
MAX_PHYSICAL_ZONES = 16,
/** The base-2 logarithm of the maximum blocks in one slab */
MAX_SLAB_BITS = 23,
/** The maximum number of slabs the slab depot supports */
MAX_SLABS = 8192,
/**
* The maximum number of block map pages to load simultaneously during
* recovery or rebuild.
**/
MAXIMUM_SIMULTANEOUS_BLOCK_MAP_RESTORATION_READS = 1024,
/** The maximum number of VIOs in the system at once */
MAXIMUM_USER_VIOS = 2048,
/**
* The number of in-memory recovery journal blocks is determined by:
* -- 311 journal entries in a 4k block
* -- maximum of 2048 VIOs making entries at once
* so we need at least 2048 / 312 = 7 journal blocks.
**/
RECOVERY_JOURNAL_TAIL_BUFFER_SIZE = 64,
/** The number of sectors per block */
SECTORS_PER_BLOCK = 8,
/** The only physical block size supported by VDO */
VDO_BLOCK_SIZE = 4096,
/** The size of a sector that will not be torn */
VDO_SECTOR_SIZE = 512,
/** The physical block number reserved for storing the zero block */
ZERO_BLOCK = 0,
};
/** The maximum logical space is 4 petabytes, which is 1 terablock. */
extern const BlockCount MAXIMUM_LOGICAL_BLOCKS;
/** The maximum physical space is 256 terabytes, which is 64 gigablocks. */
extern const BlockCount MAXIMUM_PHYSICAL_BLOCKS;
// unit test minimum
extern const BlockCount MINIMUM_SLAB_JOURNAL_BLOCKS;
#endif // CONSTANTS_H