xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/space_map.h (revision 69c7619071dc71a079b65cd199d237df0f487d15)
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 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/dmu.h>
35 
36 #ifdef	__cplusplus
37 extern "C" {
38 #endif
39 
40 typedef struct space_map_ops space_map_ops_t;
41 
42 typedef struct space_map {
43 	avl_tree_t	sm_root;	/* offset-ordered segment AVL tree */
44 	uint64_t	sm_space;	/* sum of all segments in the map */
45 	uint64_t	sm_start;	/* start of map */
46 	uint64_t	sm_size;	/* size of map */
47 	uint8_t		sm_shift;	/* unit shift */
48 	uint8_t		sm_loaded;	/* map loaded? */
49 	uint8_t		sm_loading;	/* map loading? */
50 	uint8_t		sm_condensing;	/* map condensing? */
51 	kcondvar_t	sm_load_cv;	/* map load completion */
52 	space_map_ops_t	*sm_ops;	/* space map block picker ops vector */
53 	avl_tree_t	*sm_pp_root;	/* size-ordered, picker-private tree */
54 	void		*sm_ppd;	/* picker-private data */
55 	kmutex_t	*sm_lock;	/* pointer to lock that protects map */
56 } space_map_t;
57 
58 typedef struct space_seg {
59 	avl_node_t	ss_node;	/* AVL node */
60 	avl_node_t	ss_pp_node;	/* AVL picker-private node */
61 	uint64_t	ss_start;	/* starting offset of this segment */
62 	uint64_t	ss_end;		/* ending offset (non-inclusive) */
63 } space_seg_t;
64 
65 typedef struct space_ref {
66 	avl_node_t	sr_node;	/* AVL node */
67 	uint64_t	sr_offset;	/* offset (start or end) */
68 	int64_t		sr_refcnt;	/* associated reference count */
69 } space_ref_t;
70 
71 typedef struct space_map_obj {
72 	uint64_t	smo_object;	/* on-disk space map object */
73 	uint64_t	smo_objsize;	/* size of the object */
74 	uint64_t	smo_alloc;	/* space allocated from the map */
75 } space_map_obj_t;
76 
77 struct space_map_ops {
78 	void	(*smop_load)(space_map_t *sm);
79 	void	(*smop_unload)(space_map_t *sm);
80 	uint64_t (*smop_alloc)(space_map_t *sm, uint64_t size);
81 	void	(*smop_claim)(space_map_t *sm, uint64_t start, uint64_t size);
82 	void	(*smop_free)(space_map_t *sm, uint64_t start, uint64_t size);
83 	uint64_t (*smop_max)(space_map_t *sm);
84 	boolean_t (*smop_fragmented)(space_map_t *sm);
85 };
86 
87 /*
88  * debug entry
89  *
90  *    1      3         10                     50
91  *  ,---+--------+------------+---------------------------------.
92  *  | 1 | action |  syncpass  |        txg (lower bits)         |
93  *  `---+--------+------------+---------------------------------'
94  *   63  62    60 59        50 49                               0
95  *
96  *
97  * non-debug entry
98  *
99  *    1               47                   1           15
100  *  ,-----------------------------------------------------------.
101  *  | 0 |   offset (sm_shift units)    | type |       run       |
102  *  `-----------------------------------------------------------'
103  *   63  62                          17   16   15               0
104  */
105 
106 /* All this stuff takes and returns bytes */
107 #define	SM_RUN_DECODE(x)	(BF64_DECODE(x, 0, 15) + 1)
108 #define	SM_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, 0, 15)
109 #define	SM_TYPE_DECODE(x)	BF64_DECODE(x, 15, 1)
110 #define	SM_TYPE_ENCODE(x)	BF64_ENCODE(x, 15, 1)
111 #define	SM_OFFSET_DECODE(x)	BF64_DECODE(x, 16, 47)
112 #define	SM_OFFSET_ENCODE(x)	BF64_ENCODE(x, 16, 47)
113 #define	SM_DEBUG_DECODE(x)	BF64_DECODE(x, 63, 1)
114 #define	SM_DEBUG_ENCODE(x)	BF64_ENCODE(x, 63, 1)
115 
116 #define	SM_DEBUG_ACTION_DECODE(x)	BF64_DECODE(x, 60, 3)
117 #define	SM_DEBUG_ACTION_ENCODE(x)	BF64_ENCODE(x, 60, 3)
118 
119 #define	SM_DEBUG_SYNCPASS_DECODE(x)	BF64_DECODE(x, 50, 10)
120 #define	SM_DEBUG_SYNCPASS_ENCODE(x)	BF64_ENCODE(x, 50, 10)
121 
122 #define	SM_DEBUG_TXG_DECODE(x)		BF64_DECODE(x, 0, 50)
123 #define	SM_DEBUG_TXG_ENCODE(x)		BF64_ENCODE(x, 0, 50)
124 
125 #define	SM_RUN_MAX			SM_RUN_DECODE(~0ULL)
126 
127 #define	SM_ALLOC	0x0
128 #define	SM_FREE		0x1
129 
130 /*
131  * The data for a given space map can be kept on blocks of any size.
132  * Larger blocks entail fewer i/o operations, but they also cause the
133  * DMU to keep more data in-core, and also to waste more i/o bandwidth
134  * when only a few blocks have changed since the last transaction group.
135  * This could use a lot more research, but for now, set the freelist
136  * block size to 4k (2^12).
137  */
138 #define	SPACE_MAP_BLOCKSHIFT	12
139 
140 typedef void space_map_func_t(space_map_t *sm, uint64_t start, uint64_t size);
141 
142 extern void space_map_init(void);
143 extern void space_map_fini(void);
144 extern void space_map_create(space_map_t *sm, uint64_t start, uint64_t size,
145     uint8_t shift, kmutex_t *lp);
146 extern void space_map_destroy(space_map_t *sm);
147 extern void space_map_add(space_map_t *sm, uint64_t start, uint64_t size);
148 extern void space_map_remove(space_map_t *sm, uint64_t start, uint64_t size);
149 extern boolean_t space_map_contains(space_map_t *sm,
150     uint64_t start, uint64_t size);
151 extern space_seg_t *space_map_find(space_map_t *sm, uint64_t start,
152     uint64_t size, avl_index_t *wherep);
153 extern void space_map_swap(space_map_t **msrc, space_map_t **mdest);
154 extern void space_map_vacate(space_map_t *sm,
155     space_map_func_t *func, space_map_t *mdest);
156 extern void space_map_walk(space_map_t *sm,
157     space_map_func_t *func, space_map_t *mdest);
158 
159 extern void space_map_load_wait(space_map_t *sm);
160 extern int space_map_load(space_map_t *sm, space_map_ops_t *ops,
161     uint8_t maptype, space_map_obj_t *smo, objset_t *os);
162 extern void space_map_unload(space_map_t *sm);
163 
164 extern uint64_t space_map_alloc(space_map_t *sm, uint64_t size);
165 extern void space_map_claim(space_map_t *sm, uint64_t start, uint64_t size);
166 extern void space_map_free(space_map_t *sm, uint64_t start, uint64_t size);
167 extern uint64_t space_map_maxsize(space_map_t *sm);
168 
169 extern void space_map_sync(space_map_t *sm, uint8_t maptype,
170     space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx);
171 extern void space_map_truncate(space_map_obj_t *smo,
172     objset_t *os, dmu_tx_t *tx);
173 
174 extern void space_map_ref_create(avl_tree_t *t);
175 extern void space_map_ref_destroy(avl_tree_t *t);
176 extern void space_map_ref_add_seg(avl_tree_t *t,
177     uint64_t start, uint64_t end, int64_t refcnt);
178 extern void space_map_ref_add_map(avl_tree_t *t,
179     space_map_t *sm, int64_t refcnt);
180 extern void space_map_ref_generate_map(avl_tree_t *t,
181     space_map_t *sm, int64_t minref);
182 
183 #ifdef	__cplusplus
184 }
185 #endif
186 
187 #endif	/* _SYS_SPACE_MAP_H */
188