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) 2012, 2018 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 32
48
49 /*
50 * The space_map_phys is the on-disk representation of the space map.
51 * Consumers of space maps should never reference any of the members of this
52 * structure directly. These members may only be updated in syncing context.
53 *
54 * Note the smp_object is no longer used but remains in the structure
55 * for backward compatibility.
56 */
57 typedef struct space_map_phys {
58 /* object number: not needed but kept for backwards compatibility */
59 uint64_t smp_object;
60
61 /* length of the object in bytes */
62 uint64_t smp_length;
63
64 /* space allocated from the map */
65 int64_t smp_alloc;
66
67 /* reserved */
68 uint64_t smp_pad[5];
69
70 /*
71 * The smp_histogram maintains a histogram of free regions. Each
72 * bucket, smp_histogram[i], contains the number of free regions
73 * whose size is:
74 * 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1)
75 */
76 uint64_t smp_histogram[SPACE_MAP_HISTOGRAM_SIZE];
77 } space_map_phys_t;
78
79 /*
80 * The space map object defines a region of space, its size, how much is
81 * allocated, and the on-disk object that stores this information.
82 * Consumers of space maps may only access the members of this structure.
83 *
84 * Note: the space_map may not be accessed concurrently; consumers
85 * must provide external locking if required.
86 */
87 typedef struct space_map {
88 uint64_t sm_start; /* start of map */
89 uint64_t sm_size; /* size of map */
90 uint8_t sm_shift; /* unit shift */
91 objset_t *sm_os; /* objset for this map */
92 uint64_t sm_object; /* object id for this map */
93 uint32_t sm_blksz; /* block size for space map */
94 dmu_buf_t *sm_dbuf; /* space_map_phys_t dbuf */
95 space_map_phys_t *sm_phys; /* on-disk space map */
96 } space_map_t;
97
98 /*
99 * debug entry
100 *
101 * 2 2 10 50
102 * +-----+-----+------------+----------------------------------+
103 * | 1 0 | act | syncpass | txg (lower bits) |
104 * +-----+-----+------------+----------------------------------+
105 * 63 62 61 60 59 50 49 0
106 *
107 *
108 * one-word entry
109 *
110 * 1 47 1 15
111 * +-----------------------------------------------------------+
112 * | 0 | offset (sm_shift units) | type | run |
113 * +-----------------------------------------------------------+
114 * 63 62 16 15 14 0
115 *
116 *
117 * two-word entry
118 *
119 * 2 2 36 24
120 * +-----+-----+---------------------------+-------------------+
121 * | 1 1 | pad | run | vdev |
122 * +-----+-----+---------------------------+-------------------+
123 * 63 62 61 60 59 24 23 0
124 *
125 * 1 63
126 * +------+----------------------------------------------------+
127 * | type | offset |
128 * +------+----------------------------------------------------+
129 * 63 62 0
130 *
131 * Note that a two-word entry will not strandle a block boundary.
132 * If necessary, the last word of a block will be padded with a
133 * debug entry (with act = syncpass = txg = 0).
134 */
135
136 typedef enum {
137 SM_ALLOC,
138 SM_FREE
139 } maptype_t;
140
141 typedef struct space_map_entry {
142 maptype_t sme_type;
143 uint32_t sme_vdev; /* max is 2^24-1; SM_NO_VDEVID if not present */
144 uint64_t sme_offset; /* max is 2^63-1; units of sm_shift */
145 uint64_t sme_run; /* max is 2^36; units of sm_shift */
146 } space_map_entry_t;
147
148 #define SM_NO_VDEVID (1 << SPA_VDEVBITS)
149
150 /* one-word entry constants */
151 #define SM_DEBUG_PREFIX 2
152 #define SM_OFFSET_BITS 47
153 #define SM_RUN_BITS 15
154
155 /* two-word entry constants */
156 #define SM2_PREFIX 3
157 #define SM2_OFFSET_BITS 63
158 #define SM2_RUN_BITS 36
159
160 #define SM_PREFIX_DECODE(x) BF64_DECODE(x, 62, 2)
161 #define SM_PREFIX_ENCODE(x) BF64_ENCODE(x, 62, 2)
162
163 #define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 2)
164 #define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 2)
165 #define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10)
166 #define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10)
167 #define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50)
168 #define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50)
169
170 #define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, SM_OFFSET_BITS)
171 #define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, SM_OFFSET_BITS)
172 #define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1)
173 #define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1)
174 #define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, SM_RUN_BITS) + 1)
175 #define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, SM_RUN_BITS)
176 #define SM_RUN_MAX SM_RUN_DECODE(~0ULL)
177 #define SM_OFFSET_MAX SM_OFFSET_DECODE(~0ULL)
178
179 #define SM2_RUN_DECODE(x) (BF64_DECODE(x, SPA_VDEVBITS, SM2_RUN_BITS) + 1)
180 #define SM2_RUN_ENCODE(x) BF64_ENCODE((x) - 1, SPA_VDEVBITS, SM2_RUN_BITS)
181 #define SM2_VDEV_DECODE(x) BF64_DECODE(x, 0, SPA_VDEVBITS)
182 #define SM2_VDEV_ENCODE(x) BF64_ENCODE(x, 0, SPA_VDEVBITS)
183 #define SM2_TYPE_DECODE(x) BF64_DECODE(x, SM2_OFFSET_BITS, 1)
184 #define SM2_TYPE_ENCODE(x) BF64_ENCODE(x, SM2_OFFSET_BITS, 1)
185 #define SM2_OFFSET_DECODE(x) BF64_DECODE(x, 0, SM2_OFFSET_BITS)
186 #define SM2_OFFSET_ENCODE(x) BF64_ENCODE(x, 0, SM2_OFFSET_BITS)
187 #define SM2_RUN_MAX SM2_RUN_DECODE(~0ULL)
188 #define SM2_OFFSET_MAX SM2_OFFSET_DECODE(~0ULL)
189
190 boolean_t sm_entry_is_debug(uint64_t e);
191 boolean_t sm_entry_is_single_word(uint64_t e);
192 boolean_t sm_entry_is_double_word(uint64_t e);
193
194 typedef int (*sm_cb_t)(space_map_entry_t *sme, void *arg);
195
196 int space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype);
197 int space_map_load_length(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
198 uint64_t length);
199 int space_map_iterate(space_map_t *sm, uint64_t length,
200 sm_cb_t callback, void *arg);
201 int space_map_incremental_destroy(space_map_t *sm, sm_cb_t callback, void *arg,
202 dmu_tx_t *tx);
203
204 boolean_t space_map_histogram_verify(space_map_t *sm, range_tree_t *rt);
205 void space_map_histogram_clear(space_map_t *sm);
206 void space_map_histogram_add(space_map_t *sm, range_tree_t *rt,
207 dmu_tx_t *tx);
208
209 uint64_t space_map_object(space_map_t *sm);
210 int64_t space_map_allocated(space_map_t *sm);
211 uint64_t space_map_length(space_map_t *sm);
212
213 void space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
214 uint64_t vdev_id, dmu_tx_t *tx);
215 uint64_t space_map_estimate_optimal_size(space_map_t *sm, range_tree_t *rt,
216 uint64_t vdev_id);
217 void space_map_truncate(space_map_t *sm, int blocksize, dmu_tx_t *tx);
218 uint64_t space_map_alloc(objset_t *os, int blocksize, dmu_tx_t *tx);
219 void space_map_free(space_map_t *sm, dmu_tx_t *tx);
220 void space_map_free_obj(objset_t *os, uint64_t smobj, dmu_tx_t *tx);
221
222 int space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
223 uint64_t start, uint64_t size, uint8_t shift);
224 void space_map_close(space_map_t *sm);
225
226 #ifdef __cplusplus
227 }
228 #endif
229
230 #endif /* _SYS_SPACE_MAP_H */