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, 2017 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 uint64_t smp_object; /* on-disk space map object */
59 uint64_t smp_objsize; /* size of the object */
60 int64_t smp_alloc; /* space allocated from the map */
61 uint64_t smp_pad[5]; /* reserved */
62
63 /*
64 * The smp_histogram maintains a histogram of free regions. Each
65 * bucket, smp_histogram[i], contains the number of free regions
66 * whose size is:
67 * 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1)
68 */
69 uint64_t smp_histogram[SPACE_MAP_HISTOGRAM_SIZE];
70 } space_map_phys_t;
71
72 /*
73 * The space map object defines a region of space, its size, how much is
74 * allocated, and the on-disk object that stores this information.
75 * Consumers of space maps may only access the members of this structure.
76 *
77 * Note: the space_map may not be accessed concurrently; consumers
78 * must provide external locking if required.
79 */
80 typedef struct space_map {
81 uint64_t sm_start; /* start of map */
82 uint64_t sm_size; /* size of map */
83 uint8_t sm_shift; /* unit shift */
84 uint64_t sm_length; /* synced length */
85 int64_t sm_alloc; /* synced space allocated */
86 objset_t *sm_os; /* objset for this map */
87 uint64_t sm_object; /* object id for this map */
88 uint32_t sm_blksz; /* block size for space map */
89 dmu_buf_t *sm_dbuf; /* space_map_phys_t dbuf */
90 space_map_phys_t *sm_phys; /* on-disk space map */
91 } space_map_t;
92
93 /*
94 * debug entry
95 *
96 * 2 2 10 50
97 * +-----+-----+------------+----------------------------------+
98 * | 1 0 | act | syncpass | txg (lower bits) |
99 * +-----+-----+------------+----------------------------------+
100 * 63 62 61 60 59 50 49 0
101 *
102 *
103 * one-word entry
104 *
105 * 1 47 1 15
106 * +-----------------------------------------------------------+
107 * | 0 | offset (sm_shift units) | type | run |
108 * +-----------------------------------------------------------+
109 * 63 62 16 15 14 0
110 *
111 *
112 * two-word entry
113 *
114 * 2 2 36 24
115 * +-----+-----+---------------------------+-------------------+
116 * | 1 1 | pad | run | vdev |
117 * +-----+-----+---------------------------+-------------------+
118 * 63 62 61 60 59 24 23 0
119 *
120 * 1 63
121 * +------+----------------------------------------------------+
122 * | type | offset |
123 * +------+----------------------------------------------------+
124 * 63 62 0
125 *
126 * Note that a two-word entry will not strandle a block boundary.
127 * If necessary, the last word of a block will be padded with a
128 * debug entry (with act = syncpass = txg = 0).
129 */
130
131 typedef enum {
132 SM_ALLOC,
133 SM_FREE
134 } maptype_t;
135
136 typedef struct space_map_entry {
137 maptype_t sme_type;
138 uint32_t sme_vdev; /* max is 2^24-1; SM_NO_VDEVID if not present */
139 uint64_t sme_offset; /* max is 2^63-1; units of sm_shift */
140 uint64_t sme_run; /* max is 2^36; units of sm_shift */
141 } space_map_entry_t;
142
143 #define SM_NO_VDEVID (1 << SPA_VDEVBITS)
144
145 /* one-word entry constants */
146 #define SM_DEBUG_PREFIX 2
147 #define SM_OFFSET_BITS 47
148 #define SM_RUN_BITS 15
149
150 /* two-word entry constants */
151 #define SM2_PREFIX 3
152 #define SM2_OFFSET_BITS 63
153 #define SM2_RUN_BITS 36
154
155 #define SM_PREFIX_DECODE(x) BF64_DECODE(x, 62, 2)
156 #define SM_PREFIX_ENCODE(x) BF64_ENCODE(x, 62, 2)
157
158 #define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 2)
159 #define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 2)
160 #define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10)
161 #define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10)
162 #define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50)
163 #define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50)
164
165 #define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, SM_OFFSET_BITS)
166 #define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, SM_OFFSET_BITS)
167 #define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1)
168 #define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1)
169 #define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, SM_RUN_BITS) + 1)
170 #define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, SM_RUN_BITS)
171 #define SM_RUN_MAX SM_RUN_DECODE(~0ULL)
172 #define SM_OFFSET_MAX SM_OFFSET_DECODE(~0ULL)
173
174 #define SM2_RUN_DECODE(x) (BF64_DECODE(x, SPA_VDEVBITS, SM2_RUN_BITS) + 1)
175 #define SM2_RUN_ENCODE(x) BF64_ENCODE((x) - 1, SPA_VDEVBITS, SM2_RUN_BITS)
176 #define SM2_VDEV_DECODE(x) BF64_DECODE(x, 0, SPA_VDEVBITS)
177 #define SM2_VDEV_ENCODE(x) BF64_ENCODE(x, 0, SPA_VDEVBITS)
178 #define SM2_TYPE_DECODE(x) BF64_DECODE(x, SM2_OFFSET_BITS, 1)
179 #define SM2_TYPE_ENCODE(x) BF64_ENCODE(x, SM2_OFFSET_BITS, 1)
180 #define SM2_OFFSET_DECODE(x) BF64_DECODE(x, 0, SM2_OFFSET_BITS)
181 #define SM2_OFFSET_ENCODE(x) BF64_ENCODE(x, 0, SM2_OFFSET_BITS)
182 #define SM2_RUN_MAX SM2_RUN_DECODE(~0ULL)
183 #define SM2_OFFSET_MAX SM2_OFFSET_DECODE(~0ULL)
184
185 boolean_t sm_entry_is_debug(uint64_t e);
186 boolean_t sm_entry_is_single_word(uint64_t e);
187 boolean_t sm_entry_is_double_word(uint64_t e);
188
189 typedef int (*sm_cb_t)(space_map_entry_t *sme, void *arg);
190
191 int space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype);
192 int space_map_iterate(space_map_t *sm, sm_cb_t callback, void *arg);
193 int space_map_incremental_destroy(space_map_t *sm, sm_cb_t callback, void *arg,
194 dmu_tx_t *tx);
195
196 void space_map_histogram_clear(space_map_t *sm);
197 void space_map_histogram_add(space_map_t *sm, range_tree_t *rt,
198 dmu_tx_t *tx);
199
200 void space_map_update(space_map_t *sm);
201
202 uint64_t space_map_object(space_map_t *sm);
203 uint64_t space_map_allocated(space_map_t *sm);
204 uint64_t space_map_length(space_map_t *sm);
205
206 void space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
207 uint64_t vdev_id, dmu_tx_t *tx);
208 uint64_t space_map_estimate_optimal_size(space_map_t *sm, range_tree_t *rt,
209 uint64_t vdev_id);
210 void space_map_truncate(space_map_t *sm, int blocksize, dmu_tx_t *tx);
211 uint64_t space_map_alloc(objset_t *os, int blocksize, dmu_tx_t *tx);
212 void space_map_free(space_map_t *sm, dmu_tx_t *tx);
213 void space_map_free_obj(objset_t *os, uint64_t smobj, dmu_tx_t *tx);
214
215 int space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
216 uint64_t start, uint64_t size, uint8_t shift);
217 void space_map_close(space_map_t *sm);
218
219 int64_t space_map_alloc_delta(space_map_t *sm);
220
221 #ifdef __cplusplus
222 }
223 #endif
224
225 #endif /* _SYS_SPACE_MAP_H */