1 | /* |
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2 | * fat_file.c |
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3 | * |
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4 | * General operations on "fat-file" |
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5 | * |
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6 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
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7 | * Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru> |
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8 | * |
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9 | * @(#) $Id$ |
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10 | * |
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11 | */ |
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12 | |
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13 | #define MSDOS_TRACE 1 |
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14 | |
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15 | #if HAVE_CONFIG_H |
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16 | #include "config.h" |
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17 | #endif |
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18 | |
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19 | #include <sys/types.h> |
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20 | #include <sys/stat.h> |
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21 | #include <fcntl.h> |
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22 | #include <unistd.h> |
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23 | #include <stdarg.h> |
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24 | #include <errno.h> |
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25 | #include <stdlib.h> |
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26 | #include <assert.h> |
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27 | #include <time.h> |
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28 | |
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29 | #include <rtems/libio_.h> |
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30 | |
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31 | #include "fat.h" |
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32 | #include "fat_fat_operations.h" |
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33 | #include "fat_file.h" |
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34 | |
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35 | static inline void |
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36 | _hash_insert(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
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37 | fat_file_fd_t *el); |
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38 | |
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39 | static inline void |
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40 | _hash_delete(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
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41 | fat_file_fd_t *el); |
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42 | |
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43 | static inline int |
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44 | _hash_search( |
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45 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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46 | rtems_chain_control *hash, |
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47 | uint32_t key1, |
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48 | uint32_t key2, |
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49 | fat_file_fd_t **ret |
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50 | ); |
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51 | |
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52 | static off_t |
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53 | fat_file_lseek( |
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54 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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55 | fat_file_fd_t *fat_fd, |
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56 | uint32_t file_cln, |
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57 | uint32_t *disk_cln |
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58 | ); |
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59 | |
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60 | /* fat_file_open -- |
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61 | * Open fat-file. Two hash tables are accessed by key |
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62 | * constructed from cluster num and offset of the node (i.e. |
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63 | * files/directories are distinguished by location on the disk). |
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64 | * First, hash table("vhash") consists of fat-file descriptors corresponded |
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65 | * to "valid" files is accessed. Search is made by 2 fields equal to key |
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66 | * constructed. If descriptor is found in the "vhash" - return it. |
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67 | * Otherwise search is made in hash table("rhash") consits of fat-file |
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68 | * descriptors corresponded to "removed-but-still-open" files with the |
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69 | * same keys. |
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70 | * If search failed, new fat-file descriptor is added to "vhash" |
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71 | * with both key fields equal to constructed key. Otherwise new fat-file |
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72 | * descriptor is added to "vhash" with first key field equal to key |
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73 | * constructed and the second equal to an unique (unique among all values |
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74 | * of second key fields) value. |
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75 | * |
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76 | * PARAMETERS: |
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77 | * mt_entry - mount table entry |
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78 | * pos - cluster and offset of the node |
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79 | * fat_fd - placeholder for returned fat-file descriptor |
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80 | * |
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81 | * RETURNS: |
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82 | * RC_OK and pointer to opened descriptor on success, or -1 if error |
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83 | * occured (errno set appropriately) |
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84 | */ |
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85 | int |
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86 | fat_file_open( |
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87 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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88 | fat_dir_pos_t *dir_pos, |
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89 | fat_file_fd_t **fat_fd |
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90 | ) |
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91 | { |
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92 | int rc = RC_OK; |
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93 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
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94 | fat_file_fd_t *lfat_fd = NULL; |
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95 | uint32_t key = 0; |
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96 | |
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97 | /* construct key */ |
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98 | key = fat_construct_key(mt_entry, &dir_pos->sname); |
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99 | |
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100 | /* access "valid" hash table */ |
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101 | rc = _hash_search(mt_entry, fs_info->vhash, key, 0, &lfat_fd); |
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102 | if ( rc == RC_OK ) |
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103 | { |
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104 | /* return pointer to fat_file_descriptor allocated before */ |
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105 | (*fat_fd) = lfat_fd; |
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106 | lfat_fd->links_num++; |
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107 | return rc; |
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108 | } |
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109 | |
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110 | /* access "removed-but-still-open" hash table */ |
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111 | rc = _hash_search(mt_entry, fs_info->rhash, key, key, &lfat_fd); |
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112 | |
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113 | lfat_fd = (*fat_fd) = (fat_file_fd_t*)malloc(sizeof(fat_file_fd_t)); |
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114 | if ( lfat_fd == NULL ) |
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115 | rtems_set_errno_and_return_minus_one( ENOMEM ); |
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116 | |
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117 | memset(lfat_fd, 0, sizeof(fat_file_fd_t)); |
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118 | |
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119 | lfat_fd->links_num = 1; |
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120 | lfat_fd->flags &= ~FAT_FILE_REMOVED; |
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121 | lfat_fd->map.last_cln = FAT_UNDEFINED_VALUE; |
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122 | |
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123 | lfat_fd->dir_pos = *dir_pos; |
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124 | |
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125 | if ( rc != RC_OK ) |
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126 | lfat_fd->ino = key; |
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127 | else |
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128 | { |
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129 | lfat_fd->ino = fat_get_unique_ino(mt_entry); |
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130 | |
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131 | if ( lfat_fd->ino == 0 ) |
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132 | { |
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133 | free((*fat_fd)); |
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134 | /* |
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135 | * XXX: kernel resource is unsufficient, but not the memory, |
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136 | * but there is no suitable errno :( |
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137 | */ |
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138 | rtems_set_errno_and_return_minus_one( ENOMEM ); |
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139 | } |
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140 | } |
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141 | _hash_insert(fs_info->vhash, key, lfat_fd->ino, lfat_fd); |
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142 | |
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143 | /* |
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144 | * other fields of fat-file descriptor will be initialized on upper |
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145 | * level |
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146 | */ |
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147 | |
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148 | return RC_OK; |
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149 | } |
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150 | |
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151 | |
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152 | /* fat_file_reopen -- |
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153 | * Increment by 1 number of links |
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154 | * |
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155 | * PARAMETERS: |
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156 | * fat_fd - fat-file descriptor |
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157 | * |
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158 | * RETURNS: |
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159 | * RC_OK |
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160 | */ |
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161 | int |
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162 | fat_file_reopen(fat_file_fd_t *fat_fd) |
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163 | { |
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164 | fat_fd->links_num++; |
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165 | return RC_OK; |
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166 | } |
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167 | |
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168 | /* fat_file_close -- |
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169 | * Close fat-file. If count of links to fat-file |
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170 | * descriptor is greater than 1 (i.e. somebody esle holds pointer |
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171 | * to this descriptor) just decrement it. Otherwise |
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172 | * do the following. If this descriptor corresponded to removed fat-file |
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173 | * then free clusters contained fat-file data, delete descriptor from |
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174 | * "rhash" table and free memory allocated by descriptor. If descriptor |
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175 | * correspondes to non-removed fat-file and 'ino' field has value from |
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176 | * unique inode numbers pool then set count of links to descriptor to zero |
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177 | * and leave it in hash, otherwise delete descriptor from "vhash" and free |
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178 | * memory allocated by the descriptor |
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179 | * |
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180 | * PARAMETERS: |
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181 | * mt_entry - mount table entry |
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182 | * fat_fd - fat-file descriptor |
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183 | * |
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184 | * RETURNS: |
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185 | * RC_OK, or -1 if error occured (errno set appropriately) |
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186 | */ |
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187 | int |
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188 | fat_file_close( |
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189 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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190 | fat_file_fd_t *fat_fd |
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191 | ) |
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192 | { |
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193 | int rc = RC_OK; |
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194 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
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195 | uint32_t key = 0; |
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196 | |
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197 | /* |
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198 | * if links_num field of fat-file descriptor is greater than 1 |
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199 | * decrement the count of links and return |
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200 | */ |
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201 | if (fat_fd->links_num > 1) |
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202 | { |
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203 | fat_fd->links_num--; |
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204 | return rc; |
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205 | } |
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206 | |
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207 | key = fat_construct_key(mt_entry, &fat_fd->dir_pos.sname); |
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208 | |
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209 | if (fat_fd->flags & FAT_FILE_REMOVED) |
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210 | { |
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211 | rc = fat_file_truncate(mt_entry, fat_fd, 0); |
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212 | if ( rc != RC_OK ) |
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213 | return rc; |
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214 | |
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215 | _hash_delete(fs_info->rhash, key, fat_fd->ino, fat_fd); |
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216 | |
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217 | if ( fat_ino_is_unique(mt_entry, fat_fd->ino) ) |
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218 | fat_free_unique_ino(mt_entry, fat_fd->ino); |
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219 | |
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220 | free(fat_fd); |
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221 | } |
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222 | else |
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223 | { |
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224 | if (fat_ino_is_unique(mt_entry, fat_fd->ino)) |
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225 | { |
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226 | fat_fd->links_num = 0; |
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227 | } |
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228 | else |
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229 | { |
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230 | _hash_delete(fs_info->vhash, key, fat_fd->ino, fat_fd); |
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231 | free(fat_fd); |
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232 | } |
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233 | } |
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234 | /* |
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235 | * flush any modified "cached" buffer back to disk |
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236 | */ |
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237 | rc = fat_buf_release(fs_info); |
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238 | |
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239 | return rc; |
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240 | } |
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241 | |
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242 | /* fat_file_read -- |
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243 | * Read 'count' bytes from 'start' position from fat-file. This |
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244 | * interface hides the architecture of fat-file, represents it as |
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245 | * linear file |
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246 | * |
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247 | * PARAMETERS: |
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248 | * mt_entry - mount table entry |
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249 | * fat_fd - fat-file descriptor |
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250 | * start - offset in fat-file (in bytes) to read from |
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251 | * count - count of bytes to read |
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252 | * buf - buffer provided by user |
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253 | * |
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254 | * RETURNS: |
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255 | * the number of bytes read on success, or -1 if error occured (errno |
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256 | * set appropriately) |
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257 | */ |
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258 | ssize_t |
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259 | fat_file_read( |
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260 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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261 | fat_file_fd_t *fat_fd, |
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262 | uint32_t start, |
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263 | uint32_t count, |
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264 | uint8_t *buf |
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265 | ) |
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266 | { |
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267 | int rc = RC_OK; |
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268 | ssize_t ret = 0; |
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269 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
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270 | uint32_t cmpltd = 0; |
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271 | uint32_t cur_cln = 0; |
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272 | uint32_t cl_start = 0; |
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273 | uint32_t save_cln = 0; |
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274 | uint32_t ofs = 0; |
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275 | uint32_t save_ofs; |
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276 | uint32_t sec = 0; |
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277 | uint32_t byte = 0; |
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278 | uint32_t c = 0; |
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279 | |
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280 | /* it couldn't be removed - otherwise cache update will be broken */ |
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281 | if (count == 0) |
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282 | return cmpltd; |
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283 | |
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284 | /* |
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285 | * >= because start is offset and computed from 0 and file_size |
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286 | * computed from 1 |
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287 | */ |
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288 | if ( start >= fat_fd->fat_file_size ) |
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289 | return FAT_EOF; |
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290 | |
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291 | if ((count > fat_fd->fat_file_size) || |
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292 | (start > fat_fd->fat_file_size - count)) |
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293 | count = fat_fd->fat_file_size - start; |
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294 | |
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295 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
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296 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
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297 | { |
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298 | sec = fat_cluster_num_to_sector_num(mt_entry, fat_fd->cln); |
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299 | sec += (start >> fs_info->vol.sec_log2); |
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300 | byte = start & (fs_info->vol.bps - 1); |
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301 | |
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302 | ret = _fat_block_read(mt_entry, sec, byte, count, buf); |
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303 | if ( ret < 0 ) |
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304 | return -1; |
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305 | |
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306 | return ret; |
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307 | } |
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308 | |
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309 | cl_start = start >> fs_info->vol.bpc_log2; |
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310 | save_ofs = ofs = start & (fs_info->vol.bpc - 1); |
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311 | |
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312 | rc = fat_file_lseek(mt_entry, fat_fd, cl_start, &cur_cln); |
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313 | if (rc != RC_OK) |
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314 | return rc; |
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315 | |
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316 | while (count > 0) |
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317 | { |
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318 | c = MIN(count, (fs_info->vol.bpc - ofs)); |
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319 | |
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320 | sec = fat_cluster_num_to_sector_num(mt_entry, cur_cln); |
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321 | sec += (ofs >> fs_info->vol.sec_log2); |
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322 | byte = ofs & (fs_info->vol.bps - 1); |
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323 | |
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324 | ret = _fat_block_read(mt_entry, sec, byte, c, buf + cmpltd); |
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325 | if ( ret < 0 ) |
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326 | return -1; |
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327 | |
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328 | count -= c; |
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329 | cmpltd += c; |
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330 | save_cln = cur_cln; |
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331 | rc = fat_get_fat_cluster(mt_entry, cur_cln, &cur_cln); |
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332 | if ( rc != RC_OK ) |
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333 | return rc; |
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334 | |
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335 | ofs = 0; |
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336 | } |
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337 | |
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338 | /* update cache */ |
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339 | /* XXX: check this - I'm not sure :( */ |
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340 | fat_fd->map.file_cln = cl_start + |
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341 | ((save_ofs + cmpltd - 1) >> fs_info->vol.bpc_log2); |
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342 | fat_fd->map.disk_cln = save_cln; |
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343 | |
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344 | return cmpltd; |
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345 | } |
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346 | |
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347 | /* fat_file_write -- |
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348 | * Write 'count' bytes of data from user supplied buffer to fat-file |
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349 | * starting at offset 'start'. This interface hides the architecture |
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350 | * of fat-file, represents it as linear file |
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351 | * |
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352 | * PARAMETERS: |
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353 | * mt_entry - mount table entry |
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354 | * fat_fd - fat-file descriptor |
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355 | * start - offset(in bytes) to write from |
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356 | * count - count |
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357 | * buf - buffer provided by user |
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358 | * |
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359 | * RETURNS: |
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360 | * number of bytes actually written to the file on success, or -1 if |
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361 | * error occured (errno set appropriately) |
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362 | */ |
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363 | ssize_t |
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364 | fat_file_write( |
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365 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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366 | fat_file_fd_t *fat_fd, |
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367 | uint32_t start, |
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368 | uint32_t count, |
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369 | const uint8_t *buf |
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370 | ) |
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371 | { |
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372 | int rc = 0; |
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373 | ssize_t ret = 0; |
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374 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
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375 | uint32_t cmpltd = 0; |
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376 | uint32_t cur_cln = 0; |
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377 | uint32_t save_cln = 0; /* FIXME: This might be incorrect, cf. below */ |
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378 | uint32_t cl_start = 0; |
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379 | uint32_t ofs = 0; |
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380 | uint32_t save_ofs; |
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381 | uint32_t sec = 0; |
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382 | uint32_t byte = 0; |
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383 | uint32_t c = 0; |
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384 | |
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385 | if ( count == 0 ) |
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386 | return cmpltd; |
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387 | |
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388 | if ( start > fat_fd->fat_file_size ) |
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389 | rtems_set_errno_and_return_minus_one( EIO ); |
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390 | |
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391 | if ((count > fat_fd->size_limit) || |
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392 | (start > fat_fd->size_limit - count)) |
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393 | rtems_set_errno_and_return_minus_one( EIO ); |
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394 | |
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395 | rc = fat_file_extend(mt_entry, fat_fd, start + count, &c); |
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396 | if (rc != RC_OK) |
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397 | return rc; |
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398 | |
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399 | /* |
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400 | * check whether there was enough room on device to locate |
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401 | * file of 'start + count' bytes |
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402 | */ |
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403 | if (c != (start + count)) |
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404 | count = c - start; |
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405 | |
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406 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
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407 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
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408 | { |
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409 | sec = fat_cluster_num_to_sector_num(mt_entry, fat_fd->cln); |
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410 | sec += (start >> fs_info->vol.sec_log2); |
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411 | byte = start & (fs_info->vol.bps - 1); |
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412 | |
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413 | ret = _fat_block_write(mt_entry, sec, byte, count, buf); |
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414 | if ( ret < 0 ) |
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415 | return -1; |
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416 | |
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417 | return ret; |
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418 | } |
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419 | |
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420 | cl_start = start >> fs_info->vol.bpc_log2; |
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421 | save_ofs = ofs = start & (fs_info->vol.bpc - 1); |
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422 | |
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423 | rc = fat_file_lseek(mt_entry, fat_fd, cl_start, &cur_cln); |
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424 | if (rc != RC_OK) |
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425 | return rc; |
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426 | |
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427 | while (count > 0) |
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428 | { |
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429 | c = MIN(count, (fs_info->vol.bpc - ofs)); |
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430 | |
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431 | sec = fat_cluster_num_to_sector_num(mt_entry, cur_cln); |
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432 | sec += (ofs >> fs_info->vol.sec_log2); |
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433 | byte = ofs & (fs_info->vol.bps - 1); |
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434 | |
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435 | ret = _fat_block_write(mt_entry, sec, byte, c, buf + cmpltd); |
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436 | if ( ret < 0 ) |
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437 | return -1; |
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438 | |
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439 | count -= c; |
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440 | cmpltd += c; |
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441 | save_cln = cur_cln; |
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442 | rc = fat_get_fat_cluster(mt_entry, cur_cln, &cur_cln); |
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443 | if ( rc != RC_OK ) |
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444 | return rc; |
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445 | |
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446 | ofs = 0; |
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447 | } |
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448 | |
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449 | /* update cache */ |
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450 | /* XXX: check this - I'm not sure :( */ |
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451 | fat_fd->map.file_cln = cl_start + |
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452 | ((save_ofs + cmpltd - 1) >> fs_info->vol.bpc_log2); |
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453 | fat_fd->map.disk_cln = save_cln; |
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454 | |
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455 | return cmpltd; |
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456 | } |
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457 | |
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458 | /* fat_file_extend -- |
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459 | * Extend fat-file. If new length less than current fat-file size - |
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460 | * do nothing. Otherwise calculate necessary count of clusters to add, |
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461 | * allocate it and add new clusters chain to the end of |
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462 | * existing clusters chain. |
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463 | * |
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464 | * PARAMETERS: |
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465 | * mt_entry - mount table entry |
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466 | * fat_fd - fat-file descriptor |
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467 | * new_length - new length |
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468 | * a_length - placeholder for result - actual new length of file |
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469 | * |
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470 | * RETURNS: |
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471 | * RC_OK and new length of file on success, or -1 if error occured (errno |
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472 | * set appropriately) |
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473 | */ |
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474 | int |
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475 | fat_file_extend( |
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476 | rtems_filesystem_mount_table_entry_t *mt_entry, |
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477 | fat_file_fd_t *fat_fd, |
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478 | uint32_t new_length, |
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479 | uint32_t *a_length |
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480 | ) |
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481 | { |
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482 | int rc = RC_OK; |
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483 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
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484 | uint32_t chain = 0; |
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485 | uint32_t bytes2add = 0; |
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486 | uint32_t cls2add = 0; |
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487 | uint32_t old_last_cl; |
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488 | uint32_t last_cl = 0; |
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489 | uint32_t bytes_remain = 0; |
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490 | uint32_t cls_added; |
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491 | |
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492 | *a_length = new_length; |
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493 | |
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494 | if (new_length <= fat_fd->fat_file_size) |
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495 | return RC_OK; |
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496 | |
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497 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
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498 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
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499 | rtems_set_errno_and_return_minus_one( ENOSPC ); |
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500 | |
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501 | bytes_remain = (fs_info->vol.bpc - |
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502 | (fat_fd->fat_file_size & (fs_info->vol.bpc - 1))) & |
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503 | (fs_info->vol.bpc - 1); |
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504 | |
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505 | bytes2add = new_length - fat_fd->fat_file_size; |
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506 | |
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507 | if (bytes2add > bytes_remain) |
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508 | bytes2add -= bytes_remain; |
---|
509 | else |
---|
510 | bytes2add = 0; |
---|
511 | |
---|
512 | /* |
---|
513 | * if in last cluster allocated for the file there is enough room to |
---|
514 | * handle extention (hence we don't need to add even one cluster to the |
---|
515 | * file ) - return |
---|
516 | */ |
---|
517 | if (bytes2add == 0) |
---|
518 | return RC_OK; |
---|
519 | |
---|
520 | cls2add = ((bytes2add - 1) >> fs_info->vol.bpc_log2) + 1; |
---|
521 | |
---|
522 | rc = fat_scan_fat_for_free_clusters(mt_entry, &chain, cls2add, |
---|
523 | &cls_added, &last_cl); |
---|
524 | |
---|
525 | /* this means that low level I/O error occured */ |
---|
526 | if (rc != RC_OK) |
---|
527 | return rc; |
---|
528 | |
---|
529 | /* this means that no space left on device */ |
---|
530 | if ((cls_added == 0) && (bytes_remain == 0)) |
---|
531 | rtems_set_errno_and_return_minus_one(ENOSPC); |
---|
532 | |
---|
533 | /* check wether we satisfied request for 'cls2add' clusters */ |
---|
534 | if (cls2add != cls_added) |
---|
535 | *a_length = new_length - |
---|
536 | ((cls2add - cls_added - 1) << fs_info->vol.bpc_log2) - |
---|
537 | (bytes2add & (fs_info->vol.bpc - 1)); |
---|
538 | |
---|
539 | /* add new chain to the end of existed */ |
---|
540 | if ( fat_fd->fat_file_size == 0 ) |
---|
541 | { |
---|
542 | fat_fd->map.disk_cln = fat_fd->cln = chain; |
---|
543 | fat_fd->map.file_cln = 0; |
---|
544 | } |
---|
545 | else |
---|
546 | { |
---|
547 | if (fat_fd->map.last_cln != FAT_UNDEFINED_VALUE) |
---|
548 | { |
---|
549 | old_last_cl = fat_fd->map.last_cln; |
---|
550 | } |
---|
551 | else |
---|
552 | { |
---|
553 | rc = fat_file_ioctl(mt_entry, fat_fd, F_CLU_NUM, |
---|
554 | (fat_fd->fat_file_size - 1), &old_last_cl); |
---|
555 | if ( rc != RC_OK ) |
---|
556 | { |
---|
557 | fat_free_fat_clusters_chain(mt_entry, chain); |
---|
558 | return rc; |
---|
559 | } |
---|
560 | } |
---|
561 | |
---|
562 | rc = fat_set_fat_cluster(mt_entry, old_last_cl, chain); |
---|
563 | if ( rc != RC_OK ) |
---|
564 | { |
---|
565 | fat_free_fat_clusters_chain(mt_entry, chain); |
---|
566 | return rc; |
---|
567 | } |
---|
568 | fat_buf_release(fs_info); |
---|
569 | } |
---|
570 | |
---|
571 | /* update number of the last cluster of the file if it changed */ |
---|
572 | if (cls_added != 0) |
---|
573 | { |
---|
574 | fat_fd->map.last_cln = last_cl; |
---|
575 | if (fat_fd->fat_file_type == FAT_DIRECTORY) |
---|
576 | { |
---|
577 | rc = fat_init_clusters_chain(mt_entry, chain); |
---|
578 | if ( rc != RC_OK ) |
---|
579 | { |
---|
580 | fat_free_fat_clusters_chain(mt_entry, chain); |
---|
581 | return rc; |
---|
582 | } |
---|
583 | } |
---|
584 | } |
---|
585 | |
---|
586 | fat_fd->fat_file_size = new_length; |
---|
587 | |
---|
588 | return RC_OK; |
---|
589 | } |
---|
590 | |
---|
591 | /* fat_file_truncate -- |
---|
592 | * Truncate fat-file. If new length greater than current fat-file size - |
---|
593 | * do nothing. Otherwise find first cluster to free and free all clusters |
---|
594 | * in the chain starting from this cluster. |
---|
595 | * |
---|
596 | * PARAMETERS: |
---|
597 | * mt_entry - mount table entry |
---|
598 | * fat_fd - fat-file descriptor |
---|
599 | * new_length - new length |
---|
600 | * |
---|
601 | * RETURNS: |
---|
602 | * RC_OK on success, or -1 if error occured (errno set appropriately) |
---|
603 | */ |
---|
604 | int |
---|
605 | fat_file_truncate( |
---|
606 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
607 | fat_file_fd_t *fat_fd, |
---|
608 | uint32_t new_length |
---|
609 | ) |
---|
610 | { |
---|
611 | int rc = RC_OK; |
---|
612 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
---|
613 | uint32_t cur_cln = 0; |
---|
614 | uint32_t cl_start = 0; |
---|
615 | uint32_t new_last_cln = FAT_UNDEFINED_VALUE; |
---|
616 | |
---|
617 | |
---|
618 | if ( new_length >= fat_fd->fat_file_size ) |
---|
619 | return rc; |
---|
620 | |
---|
621 | assert(fat_fd->fat_file_size); |
---|
622 | |
---|
623 | cl_start = (new_length + fs_info->vol.bpc - 1) >> fs_info->vol.bpc_log2; |
---|
624 | |
---|
625 | if ((cl_start << fs_info->vol.bpc_log2) >= fat_fd->fat_file_size) |
---|
626 | return RC_OK; |
---|
627 | |
---|
628 | if (cl_start != 0) |
---|
629 | { |
---|
630 | rc = fat_file_lseek(mt_entry, fat_fd, cl_start - 1, &new_last_cln); |
---|
631 | if (rc != RC_OK) |
---|
632 | return rc; |
---|
633 | |
---|
634 | } |
---|
635 | |
---|
636 | rc = fat_file_lseek(mt_entry, fat_fd, cl_start, &cur_cln); |
---|
637 | if (rc != RC_OK) |
---|
638 | return rc; |
---|
639 | |
---|
640 | rc = fat_free_fat_clusters_chain(mt_entry, cur_cln); |
---|
641 | if (rc != RC_OK) |
---|
642 | return rc; |
---|
643 | |
---|
644 | if (cl_start != 0) |
---|
645 | { |
---|
646 | rc = fat_set_fat_cluster(mt_entry, new_last_cln, FAT_GENFAT_EOC); |
---|
647 | if ( rc != RC_OK ) |
---|
648 | return rc; |
---|
649 | fat_fd->map.file_cln = cl_start - 1; |
---|
650 | fat_fd->map.disk_cln = new_last_cln; |
---|
651 | fat_fd->map.last_cln = new_last_cln; |
---|
652 | } |
---|
653 | return RC_OK; |
---|
654 | } |
---|
655 | |
---|
656 | /* fat_file_ioctl -- |
---|
657 | * F_CLU_NUM: |
---|
658 | * make mapping between serial number of the cluster in fat-file and |
---|
659 | * its real number on the volume |
---|
660 | * |
---|
661 | * PARAMETERS: |
---|
662 | * fat_fd - fat-file descriptor |
---|
663 | * mt_entry - mount table entry |
---|
664 | * cmd - command |
---|
665 | * ... |
---|
666 | * |
---|
667 | * RETURNS: |
---|
668 | * RC_OK on success, or -1 if error occured and errno set appropriately |
---|
669 | */ |
---|
670 | int |
---|
671 | fat_file_ioctl( |
---|
672 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
673 | fat_file_fd_t *fat_fd, |
---|
674 | int cmd, |
---|
675 | ...) |
---|
676 | { |
---|
677 | int rc = RC_OK; |
---|
678 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
---|
679 | uint32_t cur_cln = 0; |
---|
680 | uint32_t cl_start = 0; |
---|
681 | uint32_t pos = 0; |
---|
682 | uint32_t *ret; |
---|
683 | va_list ap; |
---|
684 | |
---|
685 | va_start(ap, cmd); |
---|
686 | |
---|
687 | switch (cmd) |
---|
688 | { |
---|
689 | case F_CLU_NUM: |
---|
690 | pos = va_arg(ap, uint32_t ); |
---|
691 | ret = va_arg(ap, uint32_t *); |
---|
692 | |
---|
693 | /* sanity check */ |
---|
694 | if ( pos >= fat_fd->fat_file_size ) |
---|
695 | rtems_set_errno_and_return_minus_one( EIO ); |
---|
696 | |
---|
697 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
---|
698 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
---|
699 | { |
---|
700 | /* cluster 0 (zero) reserved for root dir */ |
---|
701 | *ret = 0; |
---|
702 | return RC_OK; |
---|
703 | } |
---|
704 | |
---|
705 | cl_start = pos >> fs_info->vol.bpc_log2; |
---|
706 | |
---|
707 | rc = fat_file_lseek(mt_entry, fat_fd, cl_start, &cur_cln); |
---|
708 | if ( rc != RC_OK ) |
---|
709 | return rc; |
---|
710 | |
---|
711 | *ret = cur_cln; |
---|
712 | break; |
---|
713 | |
---|
714 | default: |
---|
715 | errno = EINVAL; |
---|
716 | rc = -1; |
---|
717 | break; |
---|
718 | } |
---|
719 | return rc; |
---|
720 | } |
---|
721 | |
---|
722 | /* fat_file_mark_removed -- |
---|
723 | * Remove the fat-file descriptor from "valid" hash table, insert it |
---|
724 | * into "removed-but-still-open" hash table and set up "removed" bit. |
---|
725 | * |
---|
726 | * PARAMETERS: |
---|
727 | * fat_fd - fat-file descriptor |
---|
728 | * mt_entry - mount table entry |
---|
729 | * |
---|
730 | * RETURNS: |
---|
731 | * None |
---|
732 | */ |
---|
733 | void |
---|
734 | fat_file_mark_removed( |
---|
735 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
736 | fat_file_fd_t *fat_fd |
---|
737 | ) |
---|
738 | { |
---|
739 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
---|
740 | uint32_t key = 0; |
---|
741 | |
---|
742 | key = fat_construct_key(mt_entry, &fat_fd->dir_pos.sname); |
---|
743 | |
---|
744 | _hash_delete(fs_info->vhash, key, fat_fd->ino, fat_fd); |
---|
745 | |
---|
746 | _hash_insert(fs_info->rhash, key, fat_fd->ino, fat_fd); |
---|
747 | |
---|
748 | fat_fd->flags |= FAT_FILE_REMOVED; |
---|
749 | } |
---|
750 | |
---|
751 | /* fat_file_datasync -- |
---|
752 | * Synchronize fat-file - flush all buffered data to the media. |
---|
753 | * |
---|
754 | * PARAMETERS: |
---|
755 | * mt_entry - mount table entry |
---|
756 | * fat_fd - fat-file descriptor |
---|
757 | * |
---|
758 | * RETURNS: |
---|
759 | * RC_OK on success, or -1 if error occured and errno set appropriately |
---|
760 | */ |
---|
761 | int |
---|
762 | fat_file_datasync( |
---|
763 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
764 | fat_file_fd_t *fat_fd |
---|
765 | ) |
---|
766 | { |
---|
767 | int rc = RC_OK; |
---|
768 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
769 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
---|
770 | uint32_t cur_cln = fat_fd->cln; |
---|
771 | rtems_bdbuf_buffer *block = NULL; |
---|
772 | uint32_t sec = 0; |
---|
773 | uint32_t i = 0; |
---|
774 | |
---|
775 | if (fat_fd->fat_file_size == 0) |
---|
776 | return RC_OK; |
---|
777 | |
---|
778 | /* |
---|
779 | * we can use only one bdbuf :( and we also know that cache is useless |
---|
780 | * for sync operation, so don't use it |
---|
781 | */ |
---|
782 | rc = fat_buf_release(fs_info); |
---|
783 | if (rc != RC_OK) |
---|
784 | return rc; |
---|
785 | |
---|
786 | /* for each cluster of the file ... */ |
---|
787 | while ((cur_cln & fs_info->vol.mask) < fs_info->vol.eoc_val) |
---|
788 | { |
---|
789 | sec = fat_cluster_num_to_sector_num(mt_entry, cur_cln); |
---|
790 | /* for each sector in cluster ... */ |
---|
791 | for ( i = 0; i < fs_info->vol.spc; i++ ) |
---|
792 | { |
---|
793 | /* ... sync it */ |
---|
794 | sc = rtems_bdbuf_read(fs_info->vol.dev, (sec + i), &block); |
---|
795 | if (sc != RTEMS_SUCCESSFUL) |
---|
796 | rtems_set_errno_and_return_minus_one( EIO ); |
---|
797 | |
---|
798 | sc = rtems_bdbuf_sync(block); |
---|
799 | if ( sc != RTEMS_SUCCESSFUL ) |
---|
800 | rtems_set_errno_and_return_minus_one( EIO ); |
---|
801 | } |
---|
802 | |
---|
803 | rc = fat_get_fat_cluster(mt_entry, cur_cln, &cur_cln); |
---|
804 | if ( rc != RC_OK ) |
---|
805 | return rc; |
---|
806 | } |
---|
807 | return rc; |
---|
808 | } |
---|
809 | |
---|
810 | /* fat_file_size -- |
---|
811 | * Calculate fat-file size - fat-file is nothing that clusters chain, so |
---|
812 | * go through all clusters in the chain and count it. Only |
---|
813 | * special case is root directory for FAT12/16 volumes. |
---|
814 | * This function is used only for directories which are fat-files with |
---|
815 | * non-zero length, hence 'fat_fd->cln' always contains valid data. |
---|
816 | * Calculated size is stored in 'fat_file_size' field of fat-file |
---|
817 | * descriptor. |
---|
818 | * |
---|
819 | * PARAMETERS: |
---|
820 | * mt_entry - mount table entry |
---|
821 | * fat_fd - fat-file descriptor |
---|
822 | * |
---|
823 | * RETURNS: |
---|
824 | * RC_OK on success, or -1 if error occured (errno set appropriately) |
---|
825 | */ |
---|
826 | int |
---|
827 | fat_file_size( |
---|
828 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
829 | fat_file_fd_t *fat_fd |
---|
830 | ) |
---|
831 | { |
---|
832 | int rc = RC_OK; |
---|
833 | fat_fs_info_t *fs_info = mt_entry->fs_info; |
---|
834 | uint32_t cur_cln = fat_fd->cln; |
---|
835 | uint32_t save_cln = 0; |
---|
836 | |
---|
837 | /* Have we requested root dir size for FAT12/16? */ |
---|
838 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
---|
839 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
---|
840 | { |
---|
841 | fat_fd->fat_file_size = fs_info->vol.rdir_size; |
---|
842 | return rc; |
---|
843 | } |
---|
844 | |
---|
845 | fat_fd->fat_file_size = 0; |
---|
846 | |
---|
847 | while ((cur_cln & fs_info->vol.mask) < fs_info->vol.eoc_val) |
---|
848 | { |
---|
849 | save_cln = cur_cln; |
---|
850 | rc = fat_get_fat_cluster(mt_entry, cur_cln, &cur_cln); |
---|
851 | if ( rc != RC_OK ) |
---|
852 | return rc; |
---|
853 | |
---|
854 | fat_fd->fat_file_size += fs_info->vol.bpc; |
---|
855 | } |
---|
856 | fat_fd->map.last_cln = save_cln; |
---|
857 | return rc; |
---|
858 | } |
---|
859 | |
---|
860 | /* hash support routines */ |
---|
861 | |
---|
862 | /* _hash_insert -- |
---|
863 | * Insert elemnt into hash based on key 'key1' |
---|
864 | * |
---|
865 | * PARAMETERS: |
---|
866 | * hash - hash element will be inserted into |
---|
867 | * key1 - key on which insertion is based on |
---|
868 | * key2 - not used during insertion |
---|
869 | * el - element to insert |
---|
870 | * |
---|
871 | * RETURNS: |
---|
872 | * None |
---|
873 | */ |
---|
874 | static inline void |
---|
875 | _hash_insert(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
---|
876 | fat_file_fd_t *el) |
---|
877 | { |
---|
878 | rtems_chain_append((hash) + ((key1) % FAT_HASH_MODULE), &(el)->link); |
---|
879 | } |
---|
880 | |
---|
881 | |
---|
882 | /* _hash_delete -- |
---|
883 | * Remove element from hash |
---|
884 | * |
---|
885 | * PARAMETERS: |
---|
886 | * hash - hash element will be removed from |
---|
887 | * key1 - not used |
---|
888 | * key2 - not used |
---|
889 | * el - element to delete |
---|
890 | * |
---|
891 | * RETURNS: |
---|
892 | * None |
---|
893 | */ |
---|
894 | static inline void |
---|
895 | _hash_delete(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
---|
896 | fat_file_fd_t *el) |
---|
897 | { |
---|
898 | rtems_chain_extract(&(el)->link); |
---|
899 | } |
---|
900 | |
---|
901 | /* _hash_search -- |
---|
902 | * Search element in hash. If both keys match pointer to found element |
---|
903 | * is returned |
---|
904 | * |
---|
905 | * PARAMETERS: |
---|
906 | * mt_entry - mount table entry |
---|
907 | * hash - hash element will be removed from |
---|
908 | * key1 - search key |
---|
909 | * key2 - search key |
---|
910 | * ret - placeholder for result |
---|
911 | * |
---|
912 | * RETURNS: |
---|
913 | * 0 and pointer to found element on success, -1 otherwise |
---|
914 | */ |
---|
915 | static inline int |
---|
916 | _hash_search( |
---|
917 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
918 | rtems_chain_control *hash, |
---|
919 | uint32_t key1, |
---|
920 | uint32_t key2, |
---|
921 | fat_file_fd_t **ret |
---|
922 | ) |
---|
923 | { |
---|
924 | uint32_t mod = (key1) % FAT_HASH_MODULE; |
---|
925 | rtems_chain_node *the_node = ((rtems_chain_control *)((hash) + mod))->first; |
---|
926 | |
---|
927 | for ( ; !rtems_chain_is_tail((hash) + mod, the_node) ; ) |
---|
928 | { |
---|
929 | fat_file_fd_t *ffd = (fat_file_fd_t *)the_node; |
---|
930 | uint32_t ck = fat_construct_key(mt_entry, &ffd->dir_pos.sname); |
---|
931 | |
---|
932 | if ( (key1) == ck) |
---|
933 | { |
---|
934 | if ( ((key2) == 0) || ((key2) == ffd->ino) ) |
---|
935 | { |
---|
936 | *ret = (void *)the_node; |
---|
937 | return 0; |
---|
938 | } |
---|
939 | } |
---|
940 | the_node = the_node->next; |
---|
941 | } |
---|
942 | return -1; |
---|
943 | } |
---|
944 | |
---|
945 | static off_t |
---|
946 | fat_file_lseek( |
---|
947 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
948 | fat_file_fd_t *fat_fd, |
---|
949 | uint32_t file_cln, |
---|
950 | uint32_t *disk_cln |
---|
951 | ) |
---|
952 | { |
---|
953 | int rc = RC_OK; |
---|
954 | |
---|
955 | if (file_cln == fat_fd->map.file_cln) |
---|
956 | *disk_cln = fat_fd->map.disk_cln; |
---|
957 | else |
---|
958 | { |
---|
959 | uint32_t cur_cln; |
---|
960 | uint32_t count; |
---|
961 | uint32_t i; |
---|
962 | |
---|
963 | if (file_cln > fat_fd->map.file_cln) |
---|
964 | { |
---|
965 | cur_cln = fat_fd->map.disk_cln; |
---|
966 | count = file_cln - fat_fd->map.file_cln; |
---|
967 | } |
---|
968 | else |
---|
969 | { |
---|
970 | cur_cln = fat_fd->cln; |
---|
971 | count = file_cln; |
---|
972 | } |
---|
973 | |
---|
974 | /* skip over the clusters */ |
---|
975 | for (i = 0; i < count; i++) |
---|
976 | { |
---|
977 | rc = fat_get_fat_cluster(mt_entry, cur_cln, &cur_cln); |
---|
978 | if ( rc != RC_OK ) |
---|
979 | return rc; |
---|
980 | } |
---|
981 | |
---|
982 | /* update cache */ |
---|
983 | fat_fd->map.file_cln = file_cln; |
---|
984 | fat_fd->map.disk_cln = cur_cln; |
---|
985 | |
---|
986 | *disk_cln = cur_cln; |
---|
987 | } |
---|
988 | return RC_OK; |
---|
989 | } |
---|