1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright 2023 Red Hat 4 */ 5 6 #ifndef VDO_CONSTANTS_H 7 #define VDO_CONSTANTS_H 8 9 #include <linux/blkdev.h> 10 11 #include "types.h" 12 13 enum { 14 /* 15 * The maximum number of contiguous PBNs which will go to a single bio submission queue, 16 * assuming there is more than one queue. 17 */ 18 VDO_BIO_ROTATION_INTERVAL_LIMIT = 1024, 19 20 /* The number of entries on a block map page */ 21 VDO_BLOCK_MAP_ENTRIES_PER_PAGE = 812, 22 23 /* The origin of the flat portion of the block map */ 24 VDO_BLOCK_MAP_FLAT_PAGE_ORIGIN = 1, 25 26 /* 27 * The height of a block map tree. Assuming a root count of 60 and 812 entries per page, 28 * this is big enough to represent almost 95 PB of logical space. 29 */ 30 VDO_BLOCK_MAP_TREE_HEIGHT = 5, 31 32 /* The default number of bio submission queues. */ 33 DEFAULT_VDO_BIO_SUBMIT_QUEUE_COUNT = 4, 34 35 /* The number of contiguous PBNs to be submitted to a single bio queue. */ 36 DEFAULT_VDO_BIO_SUBMIT_QUEUE_ROTATE_INTERVAL = 64, 37 38 /* The number of trees in the arboreal block map */ 39 DEFAULT_VDO_BLOCK_MAP_TREE_ROOT_COUNT = 60, 40 41 /* The default size of the recovery journal, in blocks */ 42 DEFAULT_VDO_RECOVERY_JOURNAL_SIZE = 32 * 1024, 43 44 /* The default size of each slab journal, in blocks */ 45 DEFAULT_VDO_SLAB_JOURNAL_SIZE = 224, 46 47 /* 48 * The initial size of lbn_operations and pbn_operations, which is based upon the expected 49 * maximum number of outstanding VIOs. This value was chosen to make it highly unlikely 50 * that the maps would need to be resized. 51 */ 52 VDO_LOCK_MAP_CAPACITY = 10000, 53 54 /* The maximum number of logical zones */ 55 MAX_VDO_LOGICAL_ZONES = 60, 56 57 /* The maximum number of physical zones */ 58 MAX_VDO_PHYSICAL_ZONES = 16, 59 60 /* The base-2 logarithm of the maximum blocks in one slab */ 61 MAX_VDO_SLAB_BITS = 23, 62 63 /* The maximum number of slabs the slab depot supports */ 64 MAX_VDO_SLABS = 8192, 65 66 /* 67 * The maximum number of block map pages to load simultaneously during recovery or rebuild. 68 */ 69 MAXIMUM_SIMULTANEOUS_VDO_BLOCK_MAP_RESTORATION_READS = 1024, 70 71 /* The maximum number of entries in the slab summary */ 72 MAXIMUM_VDO_SLAB_SUMMARY_ENTRIES = MAX_VDO_SLABS * MAX_VDO_PHYSICAL_ZONES, 73 74 /* The maximum number of total threads in a VDO thread configuration. */ 75 MAXIMUM_VDO_THREADS = 100, 76 77 /* The maximum number of VIOs in the system at once */ 78 MAXIMUM_VDO_USER_VIOS = 2048, 79 80 /* The only physical block size supported by VDO */ 81 VDO_BLOCK_SIZE = 4096, 82 83 /* The number of sectors per block */ 84 VDO_SECTORS_PER_BLOCK = (VDO_BLOCK_SIZE >> SECTOR_SHIFT), 85 86 /* The size of a sector that will not be torn */ 87 VDO_SECTOR_SIZE = 512, 88 89 /* The physical block number reserved for storing the zero block */ 90 VDO_ZERO_BLOCK = 0, 91 }; 92 93 #endif /* VDO_CONSTANTS_H */ 94