1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * This file and its contents are supplied under the terms of the 4 * Common Development and Distribution License ("CDDL"), version 1.0. 5 * You may only use this file in accordance with the terms of version 6 * 1.0 of the CDDL. 7 * 8 * A full copy of the text of the CDDL should have accompanied this 9 * source. A copy of the CDDL is also available via the Internet at 10 * https://opensource.org/license/CDDL-1.0. 11 */ 12 /* 13 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 14 * Use is subject to license terms. 15 */ 16 17 /* 18 * Copyright (c) 2012, 2019 by Delphix. All rights reserved. 19 */ 20 21 #ifndef _SYS_SPACE_MAP_H 22 #define _SYS_SPACE_MAP_H 23 24 #include <sys/avl.h> 25 #include <sys/range_tree.h> 26 #include <sys/dmu.h> 27 28 #ifdef __cplusplus 29 extern "C" { 30 #endif 31 32 /* 33 * The size of the space map object has increased to include a histogram. 34 * The SPACE_MAP_SIZE_V0 designates the original size and is used to 35 * maintain backward compatibility. 36 */ 37 #define SPACE_MAP_SIZE_V0 (3 * sizeof (uint64_t)) 38 #define SPACE_MAP_HISTOGRAM_SIZE 32 39 40 /* 41 * The space_map_phys is the on-disk representation of the space map. 42 * Consumers of space maps should never reference any of the members of this 43 * structure directly. These members may only be updated in syncing context. 44 * 45 * Note the smp_object is no longer used but remains in the structure 46 * for backward compatibility. 47 */ 48 typedef struct space_map_phys { 49 /* object number: not needed but kept for backwards compatibility */ 50 uint64_t smp_object; 51 52 /* length of the object in bytes */ 53 uint64_t smp_length; 54 55 /* space allocated from the map */ 56 int64_t smp_alloc; 57 58 /* reserved */ 59 uint64_t smp_pad[5]; 60 61 /* 62 * The smp_histogram maintains a histogram of free regions. Each 63 * bucket, smp_histogram[i], contains the number of free regions 64 * whose size is: 65 * 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1) 66 * 67 * Note that, if log space map feature is enabled, histograms of 68 * space maps that belong to metaslabs will take into account any 69 * unflushed changes for their metaslabs, even though the actual 70 * space map doesn't have entries for these changes. 71 */ 72 uint64_t smp_histogram[SPACE_MAP_HISTOGRAM_SIZE]; 73 } space_map_phys_t; 74 75 /* 76 * The space map object defines a region of space, its size, how much is 77 * allocated, and the on-disk object that stores this information. 78 * Consumers of space maps may only access the members of this structure. 79 * 80 * Note: the space_map may not be accessed concurrently; consumers 81 * must provide external locking if required. 82 */ 83 typedef struct space_map { 84 uint64_t sm_start; /* start of map */ 85 uint64_t sm_size; /* size of map */ 86 uint8_t sm_shift; /* unit shift */ 87 objset_t *sm_os; /* objset for this map */ 88 uint64_t sm_object; /* object id for this map */ 89 uint32_t sm_blksz; /* block size for space map */ 90 dmu_buf_t *sm_dbuf; /* space_map_phys_t dbuf */ 91 space_map_phys_t *sm_phys; /* on-disk space map */ 92 } space_map_t; 93 94 /* 95 * debug entry 96 * 97 * 2 2 10 50 98 * +-----+-----+------------+----------------------------------+ 99 * | 1 0 | act | syncpass | txg (lower bits) | 100 * +-----+-----+------------+----------------------------------+ 101 * 63 62 61 60 59 50 49 0 102 * 103 * 104 * one-word entry 105 * 106 * 1 47 1 15 107 * +-----------------------------------------------------------+ 108 * | 0 | offset (sm_shift units) | type | run | 109 * +-----------------------------------------------------------+ 110 * 63 62 16 15 14 0 111 * 112 * 113 * two-word entry 114 * 115 * 2 2 36 24 116 * +-----+-----+---------------------------+-------------------+ 117 * | 1 1 | pad | run | vdev | 118 * +-----+-----+---------------------------+-------------------+ 119 * 63 62 61 60 59 24 23 0 120 * 121 * 1 63 122 * +------+----------------------------------------------------+ 123 * | type | offset | 124 * +------+----------------------------------------------------+ 125 * 63 62 0 126 * 127 * Note that a two-word entry will not straddle a block boundary. 128 * If necessary, the last word of a block will be padded with a 129 * debug entry (with act = syncpass = txg = 0). 130 */ 131 132 typedef enum { 133 SM_ALLOC, 134 SM_FREE 135 } maptype_t; 136 137 typedef struct space_map_entry { 138 maptype_t sme_type; 139 uint32_t sme_vdev; /* max is 2^24-1; SM_NO_VDEVID if not present */ 140 uint64_t sme_offset; /* max is 2^63-1; units of sm_shift */ 141 uint64_t sme_run; /* max is 2^36; units of sm_shift */ 142 143 /* 144 * The following fields are not part of the actual space map entry 145 * on-disk and they are populated with the values from the debug 146 * entry most recently visited starting from the beginning to the 147 * end of the space map. 148 */ 149 uint64_t sme_txg; 150 uint64_t sme_sync_pass; 151 } space_map_entry_t; 152 153 #define SM_NO_VDEVID (1 << SPA_VDEVBITS) 154 155 /* one-word entry constants */ 156 #define SM_DEBUG_PREFIX 2 157 #define SM_OFFSET_BITS 47 158 #define SM_RUN_BITS 15 159 160 /* two-word entry constants */ 161 #define SM2_PREFIX 3 162 #define SM2_OFFSET_BITS 63 163 #define SM2_RUN_BITS 36 164 165 #define SM_PREFIX_DECODE(x) BF64_DECODE(x, 62, 2) 166 #define SM_PREFIX_ENCODE(x) BF64_ENCODE(x, 62, 2) 167 168 #define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 2) 169 #define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 2) 170 #define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10) 171 #define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10) 172 #define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50) 173 #define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50) 174 175 #define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, SM_OFFSET_BITS) 176 #define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, SM_OFFSET_BITS) 177 #define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1) 178 #define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1) 179 #define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, SM_RUN_BITS) + 1) 180 #define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, SM_RUN_BITS) 181 #define SM_RUN_MAX SM_RUN_DECODE(~0ULL) 182 #define SM_OFFSET_MAX SM_OFFSET_DECODE(~0ULL) 183 184 #define SM2_RUN_DECODE(x) (BF64_DECODE(x, SPA_VDEVBITS, SM2_RUN_BITS) + 1) 185 #define SM2_RUN_ENCODE(x) BF64_ENCODE((x) - 1, SPA_VDEVBITS, SM2_RUN_BITS) 186 #define SM2_VDEV_DECODE(x) BF64_DECODE(x, 0, SPA_VDEVBITS) 187 #define SM2_VDEV_ENCODE(x) BF64_ENCODE(x, 0, SPA_VDEVBITS) 188 #define SM2_TYPE_DECODE(x) BF64_DECODE(x, SM2_OFFSET_BITS, 1) 189 #define SM2_TYPE_ENCODE(x) BF64_ENCODE(x, SM2_OFFSET_BITS, 1) 190 #define SM2_OFFSET_DECODE(x) BF64_DECODE(x, 0, SM2_OFFSET_BITS) 191 #define SM2_OFFSET_ENCODE(x) BF64_ENCODE(x, 0, SM2_OFFSET_BITS) 192 #define SM2_RUN_MAX SM2_RUN_DECODE(~0ULL) 193 #define SM2_OFFSET_MAX SM2_OFFSET_DECODE(~0ULL) 194 195 boolean_t sm_entry_is_debug(uint64_t e); 196 boolean_t sm_entry_is_single_word(uint64_t e); 197 boolean_t sm_entry_is_double_word(uint64_t e); 198 199 typedef int (*sm_cb_t)(space_map_entry_t *sme, void *arg); 200 201 int space_map_load(space_map_t *sm, zfs_range_tree_t *rt, maptype_t maptype); 202 int space_map_load_length(space_map_t *sm, zfs_range_tree_t *rt, 203 maptype_t maptype, uint64_t length); 204 int space_map_iterate(space_map_t *sm, uint64_t length, 205 sm_cb_t callback, void *arg); 206 int space_map_incremental_destroy(space_map_t *sm, sm_cb_t callback, void *arg, 207 dmu_tx_t *tx); 208 209 boolean_t space_map_histogram_verify(space_map_t *sm, zfs_range_tree_t *rt); 210 void space_map_histogram_clear(space_map_t *sm); 211 void space_map_histogram_add(space_map_t *sm, zfs_range_tree_t *rt, 212 dmu_tx_t *tx); 213 214 uint64_t space_map_object(space_map_t *sm); 215 int64_t space_map_allocated(space_map_t *sm); 216 uint64_t space_map_length(space_map_t *sm); 217 uint64_t space_map_entries(space_map_t *sm, zfs_range_tree_t *rt); 218 uint64_t space_map_nblocks(space_map_t *sm); 219 220 void space_map_write(space_map_t *sm, zfs_range_tree_t *rt, maptype_t maptype, 221 uint64_t vdev_id, dmu_tx_t *tx); 222 uint64_t space_map_estimate_optimal_size(space_map_t *sm, zfs_range_tree_t *rt, 223 uint64_t vdev_id); 224 void space_map_truncate(space_map_t *sm, int blocksize, dmu_tx_t *tx); 225 uint64_t space_map_alloc(objset_t *os, int blocksize, dmu_tx_t *tx); 226 void space_map_free(space_map_t *sm, dmu_tx_t *tx); 227 void space_map_free_obj(objset_t *os, uint64_t smobj, dmu_tx_t *tx); 228 229 int space_map_open(space_map_t **smp, objset_t *os, uint64_t object, 230 uint64_t start, uint64_t size, uint8_t shift); 231 void space_map_close(space_map_t *sm); 232 233 #ifdef __cplusplus 234 } 235 #endif 236 237 #endif /* _SYS_SPACE_MAP_H */ 238