1 | /*- |
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2 | * SPDX-License-Identifier: BSD-3-Clause |
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3 | * |
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4 | * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * 1. Redistributions of source code must retain the above copyright |
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9 | * notice, this list of conditions and the following disclaimer. |
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10 | * 2. Redistributions in binary form must reproduce the above copyright |
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11 | * notice, this list of conditions and the following disclaimer in the |
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12 | * documentation and/or other materials provided with the distribution. |
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13 | * 3. Neither the name of the University nor the names of its contributors |
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14 | * may be used to endorse or promote products derived from this software |
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15 | * without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS |
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18 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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19 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
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21 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE |
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23 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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24 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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25 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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26 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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27 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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28 | */ |
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29 | |
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30 | /* |
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31 | * Implements bitmap resource lists. |
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32 | * |
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33 | * Usage: |
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34 | * blist = blist_create(blocks, flags) |
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35 | * (void) blist_destroy(blist) |
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36 | * blkno = blist_alloc(blist, count) |
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37 | * (void) blist_free(blist, blkno, count) |
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38 | * nblks = blist_fill(blist, blkno, count) |
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39 | * (void) blist_resize(&blist, count, freeextra, flags) |
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40 | * |
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41 | * |
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42 | * Notes: |
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43 | * on creation, the entire list is marked reserved. You should |
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44 | * first blist_free() the sections you want to make available |
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45 | * for allocation before doing general blist_alloc()/free() |
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46 | * ops. |
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47 | * |
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48 | * SWAPBLK_NONE is returned on failure. This module is typically |
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49 | * capable of managing up to (2^63) blocks per blist, though |
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50 | * the memory utilization would be insane if you actually did |
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51 | * that. Managing something like 512MB worth of 4K blocks |
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52 | * eats around 32 KBytes of memory. |
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53 | * |
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54 | * $FreeBSD$ |
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55 | |
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56 | */ |
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57 | |
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58 | #ifndef _SYS_BLIST_H_ |
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59 | #define _SYS_BLIST_H_ |
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60 | |
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61 | typedef uint64_t u_daddr_t; /* unsigned disk address */ |
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62 | |
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63 | /* |
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64 | * note: currently use SWAPBLK_NONE as an absolute value rather then |
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65 | * a flag bit. |
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66 | */ |
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67 | |
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68 | #define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */ |
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69 | #define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */ |
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70 | |
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71 | /* |
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72 | * Both blmeta and bmu_bitmap MUST be a power of 2 in size. |
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73 | */ |
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74 | |
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75 | typedef struct blmeta { |
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76 | union { |
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77 | daddr_t bmu_avail; /* space available under us */ |
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78 | u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */ |
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79 | } u; |
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80 | daddr_t bm_bighint; /* biggest contiguous block hint*/ |
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81 | } blmeta_t; |
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82 | |
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83 | typedef struct blist { |
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84 | daddr_t bl_blocks; /* area of coverage */ |
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85 | u_daddr_t bl_radix; /* coverage radix */ |
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86 | daddr_t bl_cursor; /* next-fit search starts at */ |
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87 | blmeta_t bl_root[1]; /* root of radix tree */ |
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88 | } *blist_t; |
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89 | |
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90 | #define BLIST_META_RADIX 16 |
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91 | #define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8) |
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92 | |
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93 | #define BLIST_MAX_ALLOC BLIST_BMAP_RADIX |
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94 | |
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95 | struct sbuf; |
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96 | |
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97 | daddr_t blist_alloc(blist_t blist, daddr_t count); |
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98 | daddr_t blist_avail(blist_t blist); |
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99 | blist_t blist_create(daddr_t blocks, int flags); |
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100 | void blist_destroy(blist_t blist); |
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101 | daddr_t blist_fill(blist_t bl, daddr_t blkno, daddr_t count); |
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102 | void blist_free(blist_t blist, daddr_t blkno, daddr_t count); |
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103 | void blist_print(blist_t blist); |
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104 | void blist_resize(blist_t *pblist, daddr_t count, int freenew, int flags); |
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105 | void blist_stats(blist_t blist, struct sbuf *s); |
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106 | |
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107 | #endif /* _SYS_BLIST_H_ */ |
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108 | |
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