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, 2014 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
38extern "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 */
57typedef struct space_map_phys {
58 uint64_t smp_object; /* on-disk space map object */
59 uint64_t smp_objsize; /* size of the object */
60 uint64_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 */
77typedef struct space_map {
78 uint64_t sm_start; /* start of map */
79 uint64_t sm_size; /* size of map */
80 uint8_t sm_shift; /* unit shift */
81 uint64_t sm_length; /* synced length */
82 uint64_t sm_alloc; /* synced space allocated */
83 objset_t *sm_os; /* objset for this map */
84 uint64_t sm_object; /* object id for this map */
85 uint32_t sm_blksz; /* block size for space map */
86 dmu_buf_t *sm_dbuf; /* space_map_phys_t dbuf */
87 space_map_phys_t *sm_phys; /* on-disk space map */
88 kmutex_t *sm_lock; /* pointer to lock that protects map */
89} space_map_t;
90
91/*
92 * debug entry
93 *
94 * 1 3 10 50
95 * ,---+--------+------------+---------------------------------.
96 * | 1 | action | syncpass | txg (lower bits) |
97 * `---+--------+------------+---------------------------------'
98 * 63 62 60 59 50 49 0
99 *
100 *
101 * non-debug entry
102 *
103 * 1 47 1 15
104 * ,-----------------------------------------------------------.
105 * | 0 | offset (sm_shift units) | type | run |
106 * `-----------------------------------------------------------'
107 * 63 62 17 16 15 0
108 */
109
110/* All this stuff takes and returns bytes */
111#define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, 15) + 1)
112#define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, 15)
113#define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1)
114#define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1)
115#define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, 47)
116#define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, 47)
117#define SM_DEBUG_DECODE(x) BF64_DECODE(x, 63, 1)
118#define SM_DEBUG_ENCODE(x) BF64_ENCODE(x, 63, 1)
119
120#define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 3)
121#define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 3)
122
123#define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10)
124#define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10)
125
126#define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50)
127#define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50)
128
129#define SM_RUN_MAX SM_RUN_DECODE(~0ULL)
130
131typedef enum {
132 SM_ALLOC,
133 SM_FREE
134} maptype_t;
135
136int space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype);
137
138void space_map_histogram_clear(space_map_t *sm);
139void space_map_histogram_add(space_map_t *sm, range_tree_t *rt,
140 dmu_tx_t *tx);
141
142void space_map_update(space_map_t *sm);
143
144uint64_t space_map_object(space_map_t *sm);
145uint64_t space_map_allocated(space_map_t *sm);
146uint64_t space_map_length(space_map_t *sm);
147
148void space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
149 dmu_tx_t *tx);
150void space_map_truncate(space_map_t *sm, dmu_tx_t *tx);
151uint64_t space_map_alloc(objset_t *os, dmu_tx_t *tx);
152void space_map_free(space_map_t *sm, dmu_tx_t *tx);
153
154int space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
155 uint64_t start, uint64_t size, uint8_t shift, kmutex_t *lp);
156void space_map_close(space_map_t *sm);
157
158int64_t space_map_alloc_delta(space_map_t *sm);
159
160#ifdef __cplusplus
161}
162#endif
163
164#endif /* _SYS_SPACE_MAP_H */
165