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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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| 2365 | 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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| 2365 | konopa | 34 | */ |
| 2435 | jelen | 35 | |
| 36 | /** @addtogroup FileSystemImpl |
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| 37 | * @{ |
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| 38 | */ |
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| 2365 | konopa | 39 | |
| 2435 | jelen | 40 | /** |
| 41 | * @file dir.c |
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| 42 | * @brief This file contains the procedures for support directory operations. |
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| 43 | */ |
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| 2365 | konopa | 44 | |
| 45 | #include <stdio.h> |
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| 46 | #include "fs.h" |
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| 47 | #include "dir.h" |
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| 48 | #include "block.h" |
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| 49 | #include "inode.h" |
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| 50 | #include "param.h" |
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| 51 | |||
| 2435 | jelen | 52 | /** |
| 53 | * Return total number of directory entries |
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| 54 | */ |
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| 2365 | konopa | 55 | int do_sum() |
| 56 | { |
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| 57 | |||
| 58 | /* Perform dsum system call. */ |
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| 59 | |||
| 60 | inode_t *rip; |
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| 61 | int dir_count; |
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| 62 | offset_t dir_size; |
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| 63 | |||
| 64 | rip = fp->fp_workdir; |
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| 65 | dir_size = rip->i_size; |
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| 66 | |||
| 67 | /* We must calculate with both versions of directory entry sizes. */ |
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| 68 | if (rip->i_sp->s_extend) { |
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| 69 | dir_count = dir_size/DIR_ENTRY_SIZE; |
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| 70 | } |
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| 71 | else { |
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| 72 | dir_count = dir_size/DIR_ENTRY_SIZE_EX; |
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| 73 | } |
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| 74 | if (dir_size % DIR_ENTRY_SIZE_EX != 0) { |
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| 75 | print_console("dir_size % DIR_ENTRY_SIZE_EX != 0\n"); |
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| 76 | } |
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| 77 | |||
| 78 | return dir_count; |
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| 79 | } |
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| 80 | |||
| 2435 | jelen | 81 | /** |
| 82 | * Fill in the user buffer with directory entry specified by number |
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| 83 | */ |
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| 2365 | konopa | 84 | int do_readentry() |
| 85 | { |
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| 86 | |||
| 87 | /* Perform readentry(numb, buffer) system call. */ |
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| 88 | |||
| 89 | int actual_sum, extend; |
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| 90 | offset_t pos; |
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| 91 | inode_t *rip; |
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| 92 | block_num_t b; |
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| 93 | block_t *bp; |
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| 94 | register int r; |
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| 95 | direct_t *dir; |
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| 96 | directex_t *direx; |
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| 97 | |||
| 98 | /* Get actual number of directory entries within the block. */ |
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| 99 | actual_sum = do_sum(); |
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| 100 | if (entry_number < 0 || actual_sum <= entry_number) |
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| 101 | return FS_EINVAL; |
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| 102 | |||
| 103 | rip = fp->fp_workdir; |
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| 104 | extend = rip->i_sp->s_extend; |
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| 105 | |||
| 106 | if (extend) { |
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| 107 | pos = entry_number * DIR_ENTRY_SIZE_EX; |
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| 108 | } |
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| 109 | else { |
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| 110 | pos = entry_number * DIR_ENTRY_SIZE; |
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| 111 | } |
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| 112 | |||
| 113 | /* Get number of block within the entry is. */ |
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| 114 | b = read_map(rip, pos); |
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| 115 | if (b == NO_BLOCK) |
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| 116 | return 0; |
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| 117 | |||
| 118 | bp = get_block(b); |
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| 119 | |||
| 120 | /* Copy the entry data into address space of actual consument. */ |
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| 121 | if (extend) { |
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| 122 | direx = &bp->b.b__direx[entry_number]; |
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| 123 | memcpy(fp->buffer, (void*)direx, DIR_ENTRY_SIZE_EX); |
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| 124 | } |
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| 125 | else { |
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| 126 | dir = &bp->b.b__dir[entry_number]; |
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| 127 | memcpy(fp->buffer, (void*)dir, DIR_ENTRY_SIZE); |
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| 128 | } |
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| 129 | |||
| 130 | r = (extend ? DIR_ENTRY_SIZE_EX : DIR_ENTRY_SIZE); |
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| 131 | |||
| 132 | return r; |
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| 133 | } |
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| 134 | |||
| 135 | |||
| 2435 | jelen | 136 | /** |
| 137 | * } |
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| 138 | */ |
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| 139 |