1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* 27 * Copyright (c) 2013 by Delphix. All rights reserved. 28 */ 29 30 #ifndef _SYS_SPACE_MAP_H 31 #define _SYS_SPACE_MAP_H 32 33 #include <sys/avl.h> 34 #include <sys/range_tree.h> 35 #include <sys/dmu.h> 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 /* 42 * The size of the space map object has increased to include a histogram. 43 * The SPACE_MAP_SIZE_V0 designates the original size and is used to 44 * maintain backward compatibility. 45 */ 46 #define SPACE_MAP_SIZE_V0 (3 * sizeof (uint64_t)) 47 #define SPACE_MAP_HISTOGRAM_SIZE(sm) \ 48 (sizeof ((sm)->sm_phys->smp_histogram) / \ 49 sizeof ((sm)->sm_phys->smp_histogram[0])) 50 51 /* 52 * The space_map_phys is the on-disk representation of the space map. 53 * Consumers of space maps should never reference any of the members of this 54 * structure directly. These members may only be updated in syncing context. 55 * 56 * Note the smp_object is no longer used but remains in the structure 57 * for backward compatibility. 58 */ 59 typedef struct space_map_phys { 60 uint64_t smp_object; /* on-disk space map object */ 61 uint64_t smp_objsize; /* size of the object */ 62 uint64_t smp_alloc; /* space allocated from the map */ 63 uint64_t smp_pad[5]; /* reserved */ 64 65 /* 66 * The smp_histogram maintains a histogram of free regions. Each 67 * bucket, smp_histogram[i], contains the number of free regions 68 * whose size is: 69 * 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1) 70 */ 71 uint64_t smp_histogram[32]; /* histogram of free space */ 72 } space_map_phys_t; 73 74 /* 75 * The space map object defines a region of space, its size, how much is 76 * allocated, and the on-disk object that stores this information. 77 * Consumers of space maps may only access the members of this structure. 78 */ 79 typedef struct space_map { 80 uint64_t sm_start; /* start of map */ 81 uint64_t sm_size; /* size of map */ 82 uint8_t sm_shift; /* unit shift */ 83 uint64_t sm_length; /* synced length */ 84 uint64_t sm_alloc; /* synced space allocated */ 85 objset_t *sm_os; /* objset for this map */ 86 uint64_t sm_object; /* object id for this map */ 87 uint32_t sm_blksz; /* block size for space map */ 88 dmu_buf_t *sm_dbuf; /* space_map_phys_t dbuf */ 89 space_map_phys_t *sm_phys; /* on-disk space map */ 90 kmutex_t *sm_lock; /* pointer to lock that protects map */ 91 } space_map_t; 92 93 /* 94 * debug entry 95 * 96 * 1 3 10 50 97 * ,---+--------+------------+---------------------------------. 98 * | 1 | action | syncpass | txg (lower bits) | 99 * `---+--------+------------+---------------------------------' 100 * 63 62 60 59 50 49 0 101 * 102 * 103 * non-debug entry 104 * 105 * 1 47 1 15 106 * ,-----------------------------------------------------------. 107 * | 0 | offset (sm_shift units) | type | run | 108 * `-----------------------------------------------------------' 109 * 63 62 17 16 15 0 110 */ 111 112 /* All this stuff takes and returns bytes */ 113 #define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, 15) + 1) 114 #define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, 15) 115 #define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1) 116 #define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1) 117 #define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, 47) 118 #define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, 47) 119 #define SM_DEBUG_DECODE(x) BF64_DECODE(x, 63, 1) 120 #define SM_DEBUG_ENCODE(x) BF64_ENCODE(x, 63, 1) 121 122 #define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 3) 123 #define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 3) 124 125 #define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10) 126 #define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10) 127 128 #define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50) 129 #define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50) 130 131 #define SM_RUN_MAX SM_RUN_DECODE(~0ULL) 132 133 typedef enum { 134 SM_ALLOC, 135 SM_FREE 136 } maptype_t; 137 138 /* 139 * The data for a given space map can be kept on blocks of any size. 140 * Larger blocks entail fewer i/o operations, but they also cause the 141 * DMU to keep more data in-core, and also to waste more i/o bandwidth 142 * when only a few blocks have changed since the last transaction group. 143 * Rather than having a fixed block size for all space maps the block size 144 * can adjust as needed (see space_map_max_blksz). Set the initial block 145 * size for the space map to 4k. 146 */ 147 #define SPACE_MAP_INITIAL_BLOCKSIZE (1ULL << 12) 148 149 int space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype); 150 151 void space_map_histogram_clear(space_map_t *sm); 152 void space_map_histogram_add(space_map_t *sm, range_tree_t *rt, 153 dmu_tx_t *tx); 154 155 void space_map_update(space_map_t *sm); 156 157 uint64_t space_map_object(space_map_t *sm); 158 uint64_t space_map_allocated(space_map_t *sm); 159 uint64_t space_map_length(space_map_t *sm); 160 161 void space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype, 162 dmu_tx_t *tx); 163 void space_map_truncate(space_map_t *sm, dmu_tx_t *tx); 164 uint64_t space_map_alloc(objset_t *os, dmu_tx_t *tx); 165 void space_map_free(space_map_t *sm, dmu_tx_t *tx); 166 167 int space_map_open(space_map_t **smp, objset_t *os, uint64_t object, 168 uint64_t start, uint64_t size, uint8_t shift, kmutex_t *lp); 169 void space_map_close(space_map_t *sm); 170 171 int64_t space_map_alloc_delta(space_map_t *sm); 172 173 #ifdef __cplusplus 174 } 175 #endif 176 177 #endif /* _SYS_SPACE_MAP_H */ 178