include/sys/space_map.h

   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 */