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| - | 1 | /* |
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| - | 2 | * Copyright (c) 1987,1997, Prentice Hall |
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| - | 3 | * All rights reserved. |
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| - | 4 | * |
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| - | 5 | * Redistribution and use of the MINIX operating system in source and |
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| - | 6 | * binary forms, with or without modification, are permitted provided |
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| 1 | /* Basic methods for reading blocks. */ |
7 | * that the following conditions are met: |
| - | 8 | ||
| - | 9 | * - Redistributions of source code must retain the above copyright |
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| - | 10 | * notice, this list of conditions and the following disclaimer. |
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| 2 | 11 | ||
| - | 12 | * - Redistributions in binary form must reproduce the above |
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| - | 13 | * copyright notice, this list of conditions and the following |
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| - | 14 | * disclaimer in the documentation and/or other materials provided |
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| 3 | /* Methods: |
15 | * with the distribution. |
| - | 16 | ||
| - | 17 | * - Neither the name of Prentice Hall nor the names of the software |
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| 4 | * init_block: Allocates memory for working block |
18 | * authors or contributors may be used to endorse or promote |
| 5 | * get_block: Returns requested block according its number |
19 | * products derived from this software without specific prior |
| - | 20 | * written permission. |
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| - | 21 | ||
| - | 22 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS, AUTHORS, AND |
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| - | 23 | * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, |
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| - | 24 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
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| - | 25 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| - | 26 | * IN NO EVENT SHALL PRENTICE HALL OR ANY AUTHORS OR CONTRIBUTORS BE |
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| - | 27 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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| - | 28 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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| - | 29 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
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| - | 30 | * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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| - | 31 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE |
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| - | 32 | * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, |
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| - | 33 | * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| - | 34 | */ |
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| - | 35 | ||
| - | 36 | /** @addtogroup FileSystemImpl |
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| - | 37 | * @{ |
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| - | 38 | */ |
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| - | 39 | ||
| - | 40 | /** |
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| - | 41 | * @file block.c |
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| 6 | * read_block: Process reading of requested block |
42 | * @brief Basic methods for reading blocks. |
| 7 | */ |
43 | */ |
| 8 | - | ||
| 9 | 44 | ||
| 10 | #include <stdio.h> |
45 | #include <stdio.h> |
| 11 | #include <async.h> |
46 | #include <async.h> |
| 12 | #include <sysinfo.h> |
47 | #include <sysinfo.h> |
| 13 | #include "fs.h" |
48 | #include "fs.h" |
| 14 | #include "block.h" |
49 | #include "block.h" |
| 15 | #include "super.h" |
50 | #include "super.h" |
| 16 | #include "../rd/rd.h" |
51 | #include "../rd/rd.h" |
| 17 | 52 | ||
| - | 53 | block_t* work_block; /**< A temporary variable for storing the working block */ |
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| 18 | 54 | ||
| - | 55 | /** |
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| 19 | block_t* work_block; |
56 | * Allocates memory for working block |
| 20 | 57 | */ |
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| 21 | int init_block() |
58 | int init_block() |
| 22 | { |
59 | { |
| 23 | 60 | ||
| 24 | /* Allocating free space for working block. */ |
61 | /* Allocating free space for working block. */ |
| 25 | work_block = (block_t*)malloc(sizeof(block_t)); |
62 | work_block = (block_t*)malloc(sizeof(block_t)); |
| Line 27... | Line 64... | ||
| 27 | return TRUE; |
64 | return TRUE; |
| 28 | 65 | ||
| 29 | return FALSE; |
66 | return FALSE; |
| 30 | } |
67 | } |
| 31 | 68 | ||
| - | 69 | /** |
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| - | 70 | * Returns requested block according its number |
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| - | 71 | */ |
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| 32 | block_t *get_block(register block_num_t block_nr) |
72 | block_t *get_block(register block_num_t block_nr) |
| 33 | { |
73 | { |
| 34 | 74 | ||
| 35 | if (block_nr == NO_BLOCK) |
75 | if (block_nr == NO_BLOCK) |
| 36 | return (get_zero_block()); |
76 | return (get_zero_block()); |
| Line 39... | Line 79... | ||
| 39 | read_block(work_block); |
79 | read_block(work_block); |
| 40 | 80 | ||
| 41 | return work_block; |
81 | return work_block; |
| 42 | } |
82 | } |
| 43 | 83 | ||
| - | 84 | /** |
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| - | 85 | * Return a block filled with zeroes |
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| - | 86 | */ |
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| 44 | block_t *get_zero_block() |
87 | block_t *get_zero_block() |
| 45 | { |
88 | { |
| 46 | 89 | ||
| 47 | /* Setting all bytes inside block to 0 */ |
90 | /* Setting all bytes inside block to 0 */ |
| 48 | memset(work_block->b.b__data, 0, BLOCK_SIZE); |
91 | memset(work_block->b.b__data, 0, BLOCK_SIZE); |
| 49 | 92 | ||
| 50 | return work_block; |
93 | return work_block; |
| 51 | } |
94 | } |
| 52 | 95 | ||
| - | 96 | /** |
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| - | 97 | * Process reading of requested block |
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| - | 98 | */ |
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| 53 | void read_block(register block_t *bp) |
99 | void read_block(register block_t *bp) |
| 54 | { |
100 | { |
| 55 | 101 | ||
| 56 | int r; |
102 | int r; |
| 57 | offset_t pos, header_size; |
103 | offset_t pos, header_size; |
| Line 72... | Line 118... | ||
| 72 | memcpy((void *)(bp->b.b__data), (void *)buffer, BLOCK_SIZE); |
118 | memcpy((void *)(bp->b.b__data), (void *)buffer, BLOCK_SIZE); |
| 73 | status = BLOCK_SIZE; |
119 | status = BLOCK_SIZE; |
| 74 | } |
120 | } |
| 75 | 121 | ||
| 76 | 122 | ||
| - | 123 | /** |
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| - | 124 | * } |
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| - | 125 | */ |
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| - | 126 | ||