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      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