xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/space_map.h (revision 7ae111d47a973fff4c6e231cc31f271dd9cef473)
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 2006 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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/avl.h>
32 #include <sys/dmu.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 typedef struct space_map_ops space_map_ops_t;
39 
40 typedef struct space_map {
41 	avl_tree_t	sm_root;	/* AVL tree of map segments */
42 	uint64_t	sm_space;	/* sum of all segments in the map */
43 	uint64_t	sm_start;	/* start of map */
44 	uint64_t	sm_size;	/* size of map */
45 	uint8_t		sm_shift;	/* unit shift */
46 	uint8_t		sm_pad[3];	/* unused */
47 	uint8_t		sm_loaded;	/* map loaded? */
48 	uint8_t		sm_loading;	/* map loading? */
49 	kcondvar_t	sm_load_cv;	/* map load completion */
50 	space_map_ops_t	*sm_ops;	/* space map block picker ops vector */
51 	void		*sm_ppd;	/* picker-private data */
52 	kmutex_t	*sm_lock;	/* pointer to lock that protects map */
53 } space_map_t;
54 
55 typedef struct space_seg {
56 	avl_node_t	ss_node;	/* AVL 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_map_obj {
62 	uint64_t	smo_object;	/* on-disk space map object */
63 	uint64_t	smo_objsize;	/* size of the object */
64 	uint64_t	smo_alloc;	/* space allocated from the map */
65 } space_map_obj_t;
66 
67 struct space_map_ops {
68 	void	(*smop_load)(space_map_t *sm);
69 	void	(*smop_unload)(space_map_t *sm);
70 	uint64_t (*smop_alloc)(space_map_t *sm, uint64_t size);
71 	void	(*smop_claim)(space_map_t *sm, uint64_t start, uint64_t size);
72 	void	(*smop_free)(space_map_t *sm, uint64_t start, uint64_t size);
73 };
74 
75 /*
76  * debug entry
77  *
78  *    1      3         10                     50
79  *  ,---+--------+------------+---------------------------------.
80  *  | 1 | action |  syncpass  |        txg (lower bits)         |
81  *  `---+--------+------------+---------------------------------'
82  *   63  62    60 59        50 49                               0
83  *
84  *
85  *
86  * non-debug entry
87  *
88  *    1               47                   1           15
89  *  ,-----------------------------------------------------------.
90  *  | 0 |   offset (sm_shift units)    | type |       run       |
91  *  `-----------------------------------------------------------'
92  *   63  62                          17   16   15               0
93  */
94 
95 /* All this stuff takes and returns bytes */
96 #define	SM_RUN_DECODE(x)	(BF64_DECODE(x, 0, 15) + 1)
97 #define	SM_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, 0, 15)
98 #define	SM_TYPE_DECODE(x)	BF64_DECODE(x, 15, 1)
99 #define	SM_TYPE_ENCODE(x)	BF64_ENCODE(x, 15, 1)
100 #define	SM_OFFSET_DECODE(x)	BF64_DECODE(x, 16, 47)
101 #define	SM_OFFSET_ENCODE(x)	BF64_ENCODE(x, 16, 47)
102 #define	SM_DEBUG_DECODE(x)	BF64_DECODE(x, 63, 1)
103 #define	SM_DEBUG_ENCODE(x)	BF64_ENCODE(x, 63, 1)
104 
105 #define	SM_DEBUG_ACTION_DECODE(x)	BF64_DECODE(x, 60, 3)
106 #define	SM_DEBUG_ACTION_ENCODE(x)	BF64_ENCODE(x, 60, 3)
107 
108 #define	SM_DEBUG_SYNCPASS_DECODE(x)	BF64_DECODE(x, 50, 10)
109 #define	SM_DEBUG_SYNCPASS_ENCODE(x)	BF64_ENCODE(x, 50, 10)
110 
111 #define	SM_DEBUG_TXG_DECODE(x)		BF64_DECODE(x, 0, 50)
112 #define	SM_DEBUG_TXG_ENCODE(x)		BF64_ENCODE(x, 0, 50)
113 
114 #define	SM_RUN_MAX			SM_RUN_DECODE(~0ULL)
115 
116 #define	SM_ALLOC	0x0
117 #define	SM_FREE		0x1
118 
119 /*
120  * The data for a given space map can be kept on blocks of any size.
121  * Larger blocks entail fewer i/o operations, but they also cause the
122  * DMU to keep more data in-core, and also to waste more i/o bandwidth
123  * when only a few blocks have changed since the last transaction group.
124  * This could use a lot more research, but for now, set the freelist
125  * block size to 4k (2^12).
126  */
127 #define	SPACE_MAP_BLOCKSHIFT	12
128 
129 typedef void space_map_func_t(space_map_t *sm, uint64_t start, uint64_t size);
130 
131 extern void space_map_create(space_map_t *sm, uint64_t start, uint64_t size,
132     uint8_t shift, kmutex_t *lp);
133 extern void space_map_destroy(space_map_t *sm);
134 extern void space_map_add(space_map_t *sm, uint64_t start, uint64_t size);
135 extern void space_map_remove(space_map_t *sm, uint64_t start, uint64_t size);
136 extern int space_map_contains(space_map_t *sm, uint64_t start, uint64_t size);
137 extern void space_map_vacate(space_map_t *sm,
138     space_map_func_t *func, space_map_t *mdest);
139 extern void space_map_walk(space_map_t *sm,
140     space_map_func_t *func, space_map_t *mdest);
141 extern void space_map_excise(space_map_t *sm, uint64_t start, uint64_t size);
142 extern void space_map_union(space_map_t *smd, space_map_t *sms);
143 
144 extern void space_map_load_wait(space_map_t *sm);
145 extern int space_map_load(space_map_t *sm, space_map_ops_t *ops,
146     uint8_t maptype, space_map_obj_t *smo, objset_t *os);
147 extern void space_map_unload(space_map_t *sm);
148 
149 extern uint64_t space_map_alloc(space_map_t *sm, uint64_t size);
150 extern void space_map_claim(space_map_t *sm, uint64_t start, uint64_t size);
151 extern void space_map_free(space_map_t *sm, uint64_t start, uint64_t size);
152 
153 extern void space_map_sync(space_map_t *sm, uint8_t maptype,
154     space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx);
155 extern void space_map_truncate(space_map_obj_t *smo,
156     objset_t *os, dmu_tx_t *tx);
157 
158 #ifdef	__cplusplus
159 }
160 #endif
161 
162 #endif	/* _SYS_SPACE_MAP_H */
163