xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/space_map.h (revision b1d7ec75953cd517f5b7c3d9cb427ff8ec5d7d07)
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 #ifndef _SYS_SPACE_MAP_H
27 #define	_SYS_SPACE_MAP_H
28 
29 #include <sys/avl.h>
30 #include <sys/dmu.h>
31 
32 #ifdef	__cplusplus
33 extern "C" {
34 #endif
35 
36 typedef struct space_map_ops space_map_ops_t;
37 
38 typedef struct space_map {
39 	avl_tree_t	sm_root;	/* AVL tree of map segments */
40 	uint64_t	sm_space;	/* sum of all segments in the map */
41 	uint64_t	sm_start;	/* start of map */
42 	uint64_t	sm_size;	/* size of map */
43 	uint8_t		sm_shift;	/* unit shift */
44 	uint8_t		sm_pad[3];	/* unused */
45 	uint8_t		sm_loaded;	/* map loaded? */
46 	uint8_t		sm_loading;	/* map loading? */
47 	kcondvar_t	sm_load_cv;	/* map load completion */
48 	space_map_ops_t	*sm_ops;	/* space map block picker ops vector */
49 	avl_tree_t	*sm_pp_root;	/* picker-private AVL tree */
50 	void		*sm_ppd;	/* picker-private data */
51 	kmutex_t	*sm_lock;	/* pointer to lock that protects map */
52 } space_map_t;
53 
54 typedef struct space_seg {
55 	avl_node_t	ss_node;	/* AVL node */
56 	avl_node_t	ss_pp_node;	/* AVL picker-private node */
57 	uint64_t	ss_start;	/* starting offset of this segment */
58 	uint64_t	ss_end;		/* ending offset (non-inclusive) */
59 } space_seg_t;
60 
61 typedef struct space_ref {
62 	avl_node_t	sr_node;	/* AVL node */
63 	uint64_t	sr_offset;	/* offset (start or end) */
64 	int64_t		sr_refcnt;	/* associated reference count */
65 } space_ref_t;
66 
67 typedef struct space_map_obj {
68 	uint64_t	smo_object;	/* on-disk space map object */
69 	uint64_t	smo_objsize;	/* size of the object */
70 	uint64_t	smo_alloc;	/* space allocated from the map */
71 } space_map_obj_t;
72 
73 struct space_map_ops {
74 	void	(*smop_load)(space_map_t *sm);
75 	void	(*smop_unload)(space_map_t *sm);
76 	uint64_t (*smop_alloc)(space_map_t *sm, uint64_t size);
77 	void	(*smop_claim)(space_map_t *sm, uint64_t start, uint64_t size);
78 	void	(*smop_free)(space_map_t *sm, uint64_t start, uint64_t size);
79 	uint64_t (*smop_max)(space_map_t *sm);
80 	boolean_t (*smop_fragmented)(space_map_t *sm);
81 };
82 
83 /*
84  * debug entry
85  *
86  *    1      3         10                     50
87  *  ,---+--------+------------+---------------------------------.
88  *  | 1 | action |  syncpass  |        txg (lower bits)         |
89  *  `---+--------+------------+---------------------------------'
90  *   63  62    60 59        50 49                               0
91  *
92  *
93  *
94  * non-debug entry
95  *
96  *    1               47                   1           15
97  *  ,-----------------------------------------------------------.
98  *  | 0 |   offset (sm_shift units)    | type |       run       |
99  *  `-----------------------------------------------------------'
100  *   63  62                          17   16   15               0
101  */
102 
103 /* All this stuff takes and returns bytes */
104 #define	SM_RUN_DECODE(x)	(BF64_DECODE(x, 0, 15) + 1)
105 #define	SM_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, 0, 15)
106 #define	SM_TYPE_DECODE(x)	BF64_DECODE(x, 15, 1)
107 #define	SM_TYPE_ENCODE(x)	BF64_ENCODE(x, 15, 1)
108 #define	SM_OFFSET_DECODE(x)	BF64_DECODE(x, 16, 47)
109 #define	SM_OFFSET_ENCODE(x)	BF64_ENCODE(x, 16, 47)
110 #define	SM_DEBUG_DECODE(x)	BF64_DECODE(x, 63, 1)
111 #define	SM_DEBUG_ENCODE(x)	BF64_ENCODE(x, 63, 1)
112 
113 #define	SM_DEBUG_ACTION_DECODE(x)	BF64_DECODE(x, 60, 3)
114 #define	SM_DEBUG_ACTION_ENCODE(x)	BF64_ENCODE(x, 60, 3)
115 
116 #define	SM_DEBUG_SYNCPASS_DECODE(x)	BF64_DECODE(x, 50, 10)
117 #define	SM_DEBUG_SYNCPASS_ENCODE(x)	BF64_ENCODE(x, 50, 10)
118 
119 #define	SM_DEBUG_TXG_DECODE(x)		BF64_DECODE(x, 0, 50)
120 #define	SM_DEBUG_TXG_ENCODE(x)		BF64_ENCODE(x, 0, 50)
121 
122 #define	SM_RUN_MAX			SM_RUN_DECODE(~0ULL)
123 
124 #define	SM_ALLOC	0x0
125 #define	SM_FREE		0x1
126 
127 /*
128  * The data for a given space map can be kept on blocks of any size.
129  * Larger blocks entail fewer i/o operations, but they also cause the
130  * DMU to keep more data in-core, and also to waste more i/o bandwidth
131  * when only a few blocks have changed since the last transaction group.
132  * This could use a lot more research, but for now, set the freelist
133  * block size to 4k (2^12).
134  */
135 #define	SPACE_MAP_BLOCKSHIFT	12
136 
137 typedef void space_map_func_t(space_map_t *sm, uint64_t start, uint64_t size);
138 
139 extern void space_map_create(space_map_t *sm, uint64_t start, uint64_t size,
140     uint8_t shift, kmutex_t *lp);
141 extern void space_map_destroy(space_map_t *sm);
142 extern void space_map_add(space_map_t *sm, uint64_t start, uint64_t size);
143 extern void space_map_remove(space_map_t *sm, uint64_t start, uint64_t size);
144 extern boolean_t space_map_contains(space_map_t *sm,
145     uint64_t start, uint64_t size);
146 extern void space_map_vacate(space_map_t *sm,
147     space_map_func_t *func, space_map_t *mdest);
148 extern void space_map_walk(space_map_t *sm,
149     space_map_func_t *func, space_map_t *mdest);
150 
151 extern void space_map_load_wait(space_map_t *sm);
152 extern int space_map_load(space_map_t *sm, space_map_ops_t *ops,
153     uint8_t maptype, space_map_obj_t *smo, objset_t *os);
154 extern void space_map_unload(space_map_t *sm);
155 
156 extern uint64_t space_map_alloc(space_map_t *sm, uint64_t size);
157 extern void space_map_claim(space_map_t *sm, uint64_t start, uint64_t size);
158 extern void space_map_free(space_map_t *sm, uint64_t start, uint64_t size);
159 extern uint64_t space_map_maxsize(space_map_t *sm);
160 
161 extern void space_map_sync(space_map_t *sm, uint8_t maptype,
162     space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx);
163 extern void space_map_truncate(space_map_obj_t *smo,
164     objset_t *os, dmu_tx_t *tx);
165 
166 extern void space_map_ref_create(avl_tree_t *t);
167 extern void space_map_ref_destroy(avl_tree_t *t);
168 extern void space_map_ref_add_seg(avl_tree_t *t,
169     uint64_t start, uint64_t end, int64_t refcnt);
170 extern void space_map_ref_add_map(avl_tree_t *t,
171     space_map_t *sm, int64_t refcnt);
172 extern void space_map_ref_generate_map(avl_tree_t *t,
173     space_map_t *sm, int64_t minref);
174 
175 #ifdef	__cplusplus
176 }
177 #endif
178 
179 #endif	/* _SYS_SPACE_MAP_H */
180