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| 2435 | jelen | 1 | /* |
| 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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| 7 | * that the following conditions are met: |
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| 2363 | konopa | 8 | |
| 2435 | jelen | 9 | * - Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
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| 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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| 15 | * with the distribution. |
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| 16 | |||
| 17 | * - Neither the name of Prentice Hall nor the names of the software |
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| 18 | * authors or contributors may be used to endorse or promote |
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| 19 | * products derived from this software without specific prior |
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| 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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| 2363 | konopa | 34 | */ |
| 2435 | jelen | 35 | |
| 36 | /** @addtogroup FileSystemImpl |
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| 37 | * @{ |
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| 38 | */ |
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| 2363 | konopa | 39 | |
| 2435 | jelen | 40 | /** |
| 41 | * @file block.c |
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| 42 | * @brief Basic methods for reading blocks. |
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| 43 | */ |
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| 2363 | konopa | 44 | |
| 45 | #include <stdio.h> |
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| 46 | #include <async.h> |
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| 47 | #include <sysinfo.h> |
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| 48 | #include "fs.h" |
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| 49 | #include "block.h" |
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| 50 | #include "super.h" |
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| 51 | #include "../rd/rd.h" |
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| 52 | |||
| 2435 | jelen | 53 | block_t* work_block; /**< A temporary variable for storing the working block */ |
| 2363 | konopa | 54 | |
| 2435 | jelen | 55 | /** |
| 56 | * Allocates memory for working block |
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| 57 | */ |
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| 2363 | konopa | 58 | int init_block() |
| 59 | { |
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| 60 | |||
| 61 | /* Allocating free space for working block. */ |
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| 62 | work_block = (block_t*)malloc(sizeof(block_t)); |
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| 63 | if (work_block != NULL) |
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| 64 | return TRUE; |
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| 65 | |||
| 66 | return FALSE; |
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| 67 | } |
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| 68 | |||
| 2435 | jelen | 69 | /** |
| 70 | * Returns requested block according its number |
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| 71 | */ |
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| 2363 | konopa | 72 | block_t *get_block(register block_num_t block_nr) |
| 73 | { |
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| 74 | |||
| 75 | if (block_nr == NO_BLOCK) |
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| 76 | return (get_zero_block()); |
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| 77 | |||
| 78 | work_block->b_blocknr = block_nr; |
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| 79 | read_block(work_block); |
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| 80 | |||
| 81 | return work_block; |
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| 82 | } |
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| 83 | |||
| 2435 | jelen | 84 | /** |
| 85 | * Return a block filled with zeroes |
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| 86 | */ |
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| 2363 | konopa | 87 | block_t *get_zero_block() |
| 88 | { |
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| 89 | |||
| 90 | /* Setting all bytes inside block to 0 */ |
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| 91 | memset(work_block->b.b__data, 0, BLOCK_SIZE); |
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| 92 | |||
| 93 | return work_block; |
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| 94 | } |
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| 95 | |||
| 2435 | jelen | 96 | /** |
| 97 | * Process reading of requested block |
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| 98 | */ |
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| 2363 | konopa | 99 | void read_block(register block_t *bp) |
| 100 | { |
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| 101 | |||
| 102 | int r; |
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| 103 | offset_t pos, header_size; |
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| 104 | |||
| 105 | header_size = sysinfo_value("rd.header_size"); |
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| 106 | pos = header_size + (offset_t)bp->b_blocknr * BLOCK_SIZE; |
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| 107 | |||
| 108 | /* Reading a block with specified number from ramdisk into shared buffer. */ |
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| 109 | r = async_req_2(rd_phone, RD_READ_BLOCK, pos, BLOCK_SIZE, NULL, NULL); |
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| 110 | if (r < 0) { |
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| 111 | print_console_int("Unrecoverable disk error on RAMDISK, block: %d\n", bp->b_blocknr); |
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| 112 | print_console_int("Error number: %d\n", r); |
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| 113 | status = FS_EIO; |
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| 114 | return; |
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| 115 | } |
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| 116 | |||
| 117 | /* Copy retrieved data from buffer into work block. */ |
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| 118 | memcpy((void *)(bp->b.b__data), (void *)buffer, BLOCK_SIZE); |
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| 119 | status = BLOCK_SIZE; |
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| 120 | } |
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| 121 | |||
| 122 | |||
| 2435 | jelen | 123 | /** |
| 124 | * } |
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| 125 | */ |
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| 126 |