1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief General operations on "fat-file" |
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5 | * @ingroup libfs_ff Fat File |
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6 | */ |
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7 | |
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8 | /* |
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9 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
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10 | * Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru> |
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11 | * |
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12 | */ |
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13 | |
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14 | #define MSDOS_TRACE 1 |
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15 | |
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16 | #if HAVE_CONFIG_H |
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17 | #include "config.h" |
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18 | #endif |
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19 | |
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20 | #include <sys/types.h> |
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21 | #include <sys/stat.h> |
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22 | #include <fcntl.h> |
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23 | #include <unistd.h> |
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24 | #include <stdarg.h> |
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25 | #include <errno.h> |
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26 | #include <stdlib.h> |
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27 | #include <assert.h> |
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28 | #include <time.h> |
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29 | |
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30 | #include <rtems/libio_.h> |
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31 | |
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32 | #include "fat.h" |
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33 | #include "fat_fat_operations.h" |
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34 | #include "fat_file.h" |
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35 | |
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36 | static inline void |
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37 | _hash_insert(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
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38 | fat_file_fd_t *el); |
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39 | |
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40 | static inline void |
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41 | _hash_delete(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
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42 | fat_file_fd_t *el); |
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43 | |
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44 | static inline int |
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45 | _hash_search( |
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46 | const fat_fs_info_t *fs_info, |
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47 | rtems_chain_control *hash, |
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48 | uint32_t key1, |
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49 | uint32_t key2, |
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50 | fat_file_fd_t **ret |
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51 | ); |
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52 | |
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53 | static off_t |
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54 | fat_file_lseek( |
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55 | fat_fs_info_t *fs_info, |
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56 | fat_file_fd_t *fat_fd, |
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57 | uint32_t file_cln, |
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58 | uint32_t *disk_cln |
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59 | ); |
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60 | |
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61 | /* fat_file_open -- |
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62 | * Open fat-file. Two hash tables are accessed by key |
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63 | * constructed from cluster num and offset of the node (i.e. |
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64 | * files/directories are distinguished by location on the disk). |
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65 | * First, hash table("vhash") consists of fat-file descriptors corresponded |
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66 | * to "valid" files is accessed. Search is made by 2 fields equal to key |
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67 | * constructed. If descriptor is found in the "vhash" - return it. |
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68 | * Otherwise search is made in hash table("rhash") consits of fat-file |
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69 | * descriptors corresponded to "removed-but-still-open" files with the |
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70 | * same keys. |
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71 | * If search failed, new fat-file descriptor is added to "vhash" |
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72 | * with both key fields equal to constructed key. Otherwise new fat-file |
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73 | * descriptor is added to "vhash" with first key field equal to key |
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74 | * constructed and the second equal to an unique (unique among all values |
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75 | * of second key fields) value. |
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76 | * |
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77 | * PARAMETERS: |
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78 | * fs_info - FS info |
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79 | * pos - cluster and offset of the node |
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80 | * fat_fd - placeholder for returned fat-file descriptor |
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81 | * |
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82 | * RETURNS: |
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83 | * RC_OK and pointer to opened descriptor on success, or -1 if error |
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84 | * occured (errno set appropriately) |
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85 | */ |
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86 | int |
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87 | fat_file_open( |
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88 | fat_fs_info_t *fs_info, |
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89 | fat_dir_pos_t *dir_pos, |
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90 | fat_file_fd_t **fat_fd |
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91 | ) |
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92 | { |
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93 | int rc = RC_OK; |
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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(fs_info, &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(fs_info, 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(fs_info, 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(fs_info); |
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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 | int |
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169 | fat_file_update(fat_fs_info_t *fs_info, fat_file_fd_t *fat_fd) |
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170 | { |
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171 | int ret_rc = RC_OK; |
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172 | |
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173 | /* |
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174 | * if fat-file descriptor is not marked as "removed", synchronize |
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175 | * size, first cluster number, write time and date fields of the file |
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176 | */ |
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177 | if (!FAT_FILE_IS_REMOVED(fat_fd) && FAT_FILE_HAS_META_DATA_CHANGED(fat_fd)) |
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178 | { |
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179 | int rc; |
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180 | |
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181 | rc = fat_file_write_first_cluster_num(fs_info, fat_fd); |
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182 | if (rc != RC_OK) |
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183 | ret_rc = rc; |
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184 | |
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185 | rc = fat_file_write_file_size(fs_info, fat_fd); |
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186 | if (rc != RC_OK) |
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187 | ret_rc = rc; |
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188 | |
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189 | rc = fat_file_write_time_and_date(fs_info, fat_fd); |
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190 | if (rc != RC_OK) |
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191 | ret_rc = rc; |
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192 | } |
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193 | |
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194 | return ret_rc; |
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195 | } |
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196 | |
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197 | /* fat_file_close -- |
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198 | * Close fat-file. If count of links to fat-file |
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199 | * descriptor is greater than 1 (i.e. somebody esle holds pointer |
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200 | * to this descriptor) just decrement it. Otherwise |
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201 | * do the following. If this descriptor corresponded to removed fat-file |
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202 | * then free clusters contained fat-file data, delete descriptor from |
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203 | * "rhash" table and free memory allocated by descriptor. If descriptor |
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204 | * correspondes to non-removed fat-file and 'ino' field has value from |
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205 | * unique inode numbers pool then set count of links to descriptor to zero |
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206 | * and leave it in hash, otherwise delete descriptor from "vhash" and free |
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207 | * memory allocated by the descriptor |
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208 | * |
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209 | * PARAMETERS: |
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210 | * fs_info - FS info |
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211 | * fat_fd - fat-file descriptor |
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212 | * |
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213 | * RETURNS: |
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214 | * RC_OK, or -1 if error occured (errno set appropriately) |
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215 | */ |
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216 | int |
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217 | fat_file_close( |
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218 | fat_fs_info_t *fs_info, |
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219 | fat_file_fd_t *fat_fd |
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220 | ) |
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221 | { |
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222 | int rc = RC_OK; |
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223 | |
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224 | /* |
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225 | * if links_num field of fat-file descriptor is greater than 1 |
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226 | * decrement only the count of links |
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227 | */ |
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228 | if (fat_fd->links_num > 1) |
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229 | { |
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230 | fat_fd->links_num--; |
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231 | } |
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232 | else |
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233 | { |
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234 | uint32_t key = fat_construct_key(fs_info, &fat_fd->dir_pos.sname); |
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235 | |
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236 | fat_file_update(fs_info, fat_fd); |
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237 | |
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238 | if (fat_fd->flags & FAT_FILE_REMOVED) |
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239 | { |
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240 | rc = fat_file_truncate(fs_info, fat_fd, 0); |
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241 | if (rc == RC_OK) |
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242 | { |
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243 | _hash_delete(fs_info->rhash, key, fat_fd->ino, fat_fd); |
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244 | |
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245 | if (fat_ino_is_unique(fs_info, fat_fd->ino)) |
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246 | fat_free_unique_ino(fs_info, fat_fd->ino); |
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247 | |
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248 | free(fat_fd); |
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249 | } |
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250 | } |
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251 | else |
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252 | { |
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253 | if (fat_ino_is_unique(fs_info, fat_fd->ino)) |
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254 | { |
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255 | fat_fd->links_num = 0; |
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256 | } |
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257 | else |
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258 | { |
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259 | _hash_delete(fs_info->vhash, key, fat_fd->ino, fat_fd); |
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260 | free(fat_fd); |
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261 | } |
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262 | } |
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263 | } |
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264 | |
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265 | /* |
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266 | * flush any modified "cached" buffer back to disk |
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267 | */ |
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268 | rc = fat_buf_release(fs_info); |
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269 | |
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270 | return rc; |
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271 | } |
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272 | |
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273 | /* fat_file_read -- |
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274 | * Read 'count' bytes from 'start' position from fat-file. This |
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275 | * interface hides the architecture of fat-file, represents it as |
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276 | * linear file |
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277 | * |
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278 | * PARAMETERS: |
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279 | * fs_info - FS info |
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280 | * fat_fd - fat-file descriptor |
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281 | * start - offset in fat-file (in bytes) to read from |
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282 | * count - count of bytes to read |
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283 | * buf - buffer provided by user |
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284 | * |
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285 | * RETURNS: |
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286 | * the number of bytes read on success, or -1 if error occured (errno |
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287 | * set appropriately) |
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288 | */ |
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289 | ssize_t |
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290 | fat_file_read( |
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291 | fat_fs_info_t *fs_info, |
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292 | fat_file_fd_t *fat_fd, |
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293 | uint32_t start, |
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294 | uint32_t count, |
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295 | uint8_t *buf |
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296 | ) |
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297 | { |
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298 | int rc = RC_OK; |
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299 | ssize_t ret = 0; |
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300 | uint32_t cmpltd = 0; |
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301 | uint32_t cur_cln = 0; |
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302 | uint32_t cl_start = 0; |
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303 | uint32_t save_cln = 0; |
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304 | uint32_t ofs = 0; |
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305 | uint32_t save_ofs; |
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306 | uint32_t sec = 0; |
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307 | uint32_t byte = 0; |
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308 | uint32_t c = 0; |
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309 | |
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310 | /* it couldn't be removed - otherwise cache update will be broken */ |
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311 | if (count == 0) |
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312 | return cmpltd; |
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313 | |
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314 | /* |
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315 | * >= because start is offset and computed from 0 and file_size |
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316 | * computed from 1 |
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317 | */ |
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318 | if ( start >= fat_fd->fat_file_size ) |
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319 | return FAT_EOF; |
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320 | |
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321 | if ((count > fat_fd->fat_file_size) || |
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322 | (start > fat_fd->fat_file_size - count)) |
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323 | count = fat_fd->fat_file_size - start; |
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324 | |
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325 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
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326 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
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327 | { |
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328 | sec = fat_cluster_num_to_sector_num(fs_info, fat_fd->cln); |
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329 | sec += (start >> fs_info->vol.sec_log2); |
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330 | byte = start & (fs_info->vol.bps - 1); |
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331 | |
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332 | ret = _fat_block_read(fs_info, sec, byte, count, buf); |
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333 | if ( ret < 0 ) |
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334 | return -1; |
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335 | |
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336 | return ret; |
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337 | } |
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338 | |
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339 | cl_start = start >> fs_info->vol.bpc_log2; |
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340 | save_ofs = ofs = start & (fs_info->vol.bpc - 1); |
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341 | |
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342 | rc = fat_file_lseek(fs_info, fat_fd, cl_start, &cur_cln); |
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343 | if (rc != RC_OK) |
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344 | return rc; |
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345 | |
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346 | while (count > 0) |
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347 | { |
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348 | c = MIN(count, (fs_info->vol.bpc - ofs)); |
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349 | |
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350 | sec = fat_cluster_num_to_sector_num(fs_info, cur_cln); |
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351 | sec += (ofs >> fs_info->vol.sec_log2); |
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352 | byte = ofs & (fs_info->vol.bps - 1); |
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353 | |
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354 | ret = _fat_block_read(fs_info, sec, byte, c, buf + cmpltd); |
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355 | if ( ret < 0 ) |
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356 | return -1; |
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357 | |
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358 | count -= c; |
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359 | cmpltd += c; |
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360 | save_cln = cur_cln; |
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361 | rc = fat_get_fat_cluster(fs_info, cur_cln, &cur_cln); |
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362 | if ( rc != RC_OK ) |
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363 | return rc; |
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364 | |
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365 | ofs = 0; |
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366 | } |
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367 | |
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368 | /* update cache */ |
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369 | /* XXX: check this - I'm not sure :( */ |
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370 | fat_fd->map.file_cln = cl_start + |
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371 | ((save_ofs + cmpltd - 1) >> fs_info->vol.bpc_log2); |
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372 | fat_fd->map.disk_cln = save_cln; |
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373 | |
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374 | return cmpltd; |
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375 | } |
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376 | |
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377 | /* fat_is_fat12_or_fat16_root_dir -- |
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378 | * Returns true for FAT12 root directories respectively FAT16 |
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379 | * root directories. Returns false for everything else. |
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380 | * |
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381 | * PARAMETERS: |
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382 | * fat_fd - fat-file descriptor |
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383 | * volume_type - type of fat volume: FAT_FAT12 or FAT_FAT16 or FAT_FAT32 |
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384 | * |
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385 | * RETURNS: |
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386 | * true if conditions for FAT12 root directory or FAT16 root directory |
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387 | * match, false if not |
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388 | */ |
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389 | static bool |
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390 | fat_is_fat12_or_fat16_root_dir (const fat_file_fd_t *fat_fd, |
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391 | const uint8_t volume_type) |
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392 | { |
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393 | return (FAT_FD_OF_ROOT_DIR(fat_fd)) && (volume_type & (FAT_FAT12 | FAT_FAT16)); |
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394 | } |
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395 | |
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396 | /* fat_file_write_fat32_or_non_root_dir -- |
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397 | * Execute fat file write for FAT32 respectively for non-root |
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398 | * directories of FAT12 or FAT16 |
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399 | * |
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400 | * PARAMETERS: |
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401 | * fs_info - FS info |
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402 | * fat_fd - fat-file descriptor |
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403 | * start - offset(in bytes) to write from |
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404 | * count - count |
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405 | * buf - buffer provided by user |
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406 | * file_cln_initial - initial current cluster number of the file |
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407 | * |
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408 | * RETURNS: |
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409 | * number of bytes actually written to the file on success, or -1 if |
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410 | * error occured (errno set appropriately) |
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411 | */ |
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412 | static ssize_t |
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413 | fat_file_write_fat32_or_non_root_dir( |
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414 | fat_fs_info_t *fs_info, |
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415 | fat_file_fd_t *fat_fd, |
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416 | const uint32_t start, |
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417 | const uint32_t count, |
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418 | const uint8_t *buf, |
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419 | const uint32_t file_cln_initial) |
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420 | { |
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421 | int rc = RC_OK; |
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422 | uint32_t cmpltd = 0; |
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423 | uint32_t cur_cln = 0; |
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424 | uint32_t save_cln = 0; /* FIXME: This might be incorrect, cf. below */ |
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425 | uint32_t start_cln = start >> fs_info->vol.bpc_log2; |
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426 | uint32_t ofs_cln = start - (start_cln << fs_info->vol.bpc_log2); |
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427 | uint32_t ofs_cln_save = ofs_cln; |
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428 | uint32_t bytes_to_write = count; |
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429 | uint32_t file_cln_cnt; |
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430 | ssize_t ret; |
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431 | uint32_t c; |
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432 | bool overwrite_cluster = false; |
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433 | |
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434 | rc = fat_file_lseek(fs_info, fat_fd, start_cln, &cur_cln); |
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435 | if (RC_OK == rc) |
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436 | { |
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437 | file_cln_cnt = cur_cln - fat_fd->cln; |
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438 | while ( (RC_OK == rc) |
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439 | && (bytes_to_write > 0)) |
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440 | { |
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441 | c = MIN(bytes_to_write, (fs_info->vol.bpc - ofs_cln)); |
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442 | |
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443 | if (file_cln_initial < file_cln_cnt) |
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444 | overwrite_cluster = true; |
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445 | |
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446 | ret = fat_cluster_write(fs_info, |
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447 | cur_cln, |
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448 | ofs_cln, |
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449 | c, |
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450 | &buf[cmpltd], |
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451 | overwrite_cluster); |
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452 | if (0 > ret) |
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453 | rc = -1; |
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454 | |
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455 | if (RC_OK == rc) |
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456 | { |
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457 | ++file_cln_cnt; |
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458 | bytes_to_write -= ret; |
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459 | cmpltd += ret; |
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460 | save_cln = cur_cln; |
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461 | if (0 < bytes_to_write) |
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462 | rc = fat_get_fat_cluster(fs_info, cur_cln, &cur_cln); |
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463 | |
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464 | ofs_cln = 0; |
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465 | } |
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466 | } |
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467 | |
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468 | /* update cache */ |
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469 | /* XXX: check this - I'm not sure :( */ |
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470 | fat_fd->map.file_cln = start_cln + |
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471 | ((ofs_cln_save + cmpltd - 1) >> fs_info->vol.bpc_log2); |
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472 | fat_fd->map.disk_cln = save_cln; |
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473 | } |
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474 | |
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475 | if (RC_OK != rc) |
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476 | return rc; |
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477 | else |
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478 | return cmpltd; |
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479 | } |
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480 | |
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481 | /* fat_file_write -- |
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482 | * Write 'count' bytes of data from user supplied buffer to fat-file |
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483 | * starting at offset 'start'. This interface hides the architecture |
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484 | * of fat-file, represents it as linear file |
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485 | * |
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486 | * PARAMETERS: |
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487 | * fs_info - FS info |
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488 | * fat_fd - fat-file descriptor |
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489 | * start - offset(in bytes) to write from |
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490 | * count - count |
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491 | * buf - buffer provided by user |
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492 | * |
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493 | * RETURNS: |
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494 | * number of bytes actually written to the file on success, or -1 if |
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495 | * error occured (errno set appropriately) |
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496 | */ |
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497 | ssize_t |
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498 | fat_file_write( |
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499 | fat_fs_info_t *fs_info, |
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500 | fat_file_fd_t *fat_fd, |
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501 | uint32_t start, |
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502 | uint32_t count, |
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503 | const uint8_t *buf |
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504 | ) |
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505 | { |
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506 | int rc = RC_OK; |
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507 | ssize_t ret; |
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508 | uint32_t cmpltd = 0; |
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509 | uint32_t byte; |
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510 | uint32_t c = 0; |
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511 | bool zero_fill = start > fat_fd->fat_file_size; |
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512 | uint32_t file_cln_initial = fat_fd->map.file_cln; |
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513 | uint32_t cln; |
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514 | |
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515 | |
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516 | if ( count == 0 ) |
---|
517 | return cmpltd; |
---|
518 | |
---|
519 | if (start >= fat_fd->size_limit) |
---|
520 | rtems_set_errno_and_return_minus_one(EFBIG); |
---|
521 | |
---|
522 | if (count > fat_fd->size_limit - start) |
---|
523 | count = fat_fd->size_limit - start; |
---|
524 | |
---|
525 | rc = fat_file_extend(fs_info, fat_fd, zero_fill, start + count, &c); |
---|
526 | if (RC_OK == rc) |
---|
527 | { |
---|
528 | /* |
---|
529 | * check whether there was enough room on device to locate |
---|
530 | * file of 'start + count' bytes |
---|
531 | */ |
---|
532 | if (c != (start + count)) |
---|
533 | count = c - start; |
---|
534 | |
---|
535 | /* for the root directory of FAT12 and FAT16 we need this special handling */ |
---|
536 | if (fat_is_fat12_or_fat16_root_dir(fat_fd, fs_info->vol.type)) |
---|
537 | { |
---|
538 | cln = fat_fd->cln; |
---|
539 | cln += (start >> fs_info->vol.bpc_log2); |
---|
540 | byte = start & (fs_info->vol.bpc -1); |
---|
541 | |
---|
542 | ret = fat_cluster_write(fs_info, |
---|
543 | cln, |
---|
544 | byte, |
---|
545 | count, |
---|
546 | buf, |
---|
547 | false); |
---|
548 | if (0 > ret) |
---|
549 | rc = -1; |
---|
550 | else |
---|
551 | cmpltd = ret; |
---|
552 | } |
---|
553 | else |
---|
554 | { |
---|
555 | ret = fat_file_write_fat32_or_non_root_dir(fs_info, |
---|
556 | fat_fd, |
---|
557 | start, |
---|
558 | count, |
---|
559 | buf, |
---|
560 | file_cln_initial); |
---|
561 | if (0 > ret) |
---|
562 | rc = -1; |
---|
563 | else |
---|
564 | cmpltd = ret; |
---|
565 | } |
---|
566 | } |
---|
567 | if (RC_OK != rc) |
---|
568 | return rc; |
---|
569 | else |
---|
570 | return cmpltd; |
---|
571 | } |
---|
572 | |
---|
573 | /* fat_file_extend -- |
---|
574 | * Extend fat-file. If new length less than current fat-file size - |
---|
575 | * do nothing. Otherwise calculate necessary count of clusters to add, |
---|
576 | * allocate it and add new clusters chain to the end of |
---|
577 | * existing clusters chain. |
---|
578 | * |
---|
579 | * PARAMETERS: |
---|
580 | * fs_info - FS info |
---|
581 | * fat_fd - fat-file descriptor |
---|
582 | * new_length - new length |
---|
583 | * a_length - placeholder for result - actual new length of file |
---|
584 | * |
---|
585 | * RETURNS: |
---|
586 | * RC_OK and new length of file on success, or -1 if error occured (errno |
---|
587 | * set appropriately) |
---|
588 | */ |
---|
589 | int |
---|
590 | fat_file_extend( |
---|
591 | fat_fs_info_t *fs_info, |
---|
592 | fat_file_fd_t *fat_fd, |
---|
593 | bool zero_fill, |
---|
594 | uint32_t new_length, |
---|
595 | uint32_t *a_length |
---|
596 | ) |
---|
597 | { |
---|
598 | int rc = RC_OK; |
---|
599 | uint32_t chain = 0; |
---|
600 | uint32_t bytes2add = 0; |
---|
601 | uint32_t cls2add = 0; |
---|
602 | uint32_t old_last_cl; |
---|
603 | uint32_t last_cl = 0; |
---|
604 | uint32_t bytes_remain = 0; |
---|
605 | uint32_t cls_added; |
---|
606 | ssize_t bytes_written; |
---|
607 | |
---|
608 | *a_length = new_length; |
---|
609 | |
---|
610 | if (new_length <= fat_fd->fat_file_size) |
---|
611 | return RC_OK; |
---|
612 | |
---|
613 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
---|
614 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
---|
615 | rtems_set_errno_and_return_minus_one( ENOSPC ); |
---|
616 | |
---|
617 | bytes_remain = (fs_info->vol.bpc - |
---|
618 | (fat_fd->fat_file_size & (fs_info->vol.bpc - 1))) & |
---|
619 | (fs_info->vol.bpc - 1); |
---|
620 | |
---|
621 | bytes2add = new_length - fat_fd->fat_file_size; |
---|
622 | |
---|
623 | if (bytes2add > bytes_remain) |
---|
624 | bytes2add -= bytes_remain; |
---|
625 | else |
---|
626 | bytes2add = 0; |
---|
627 | |
---|
628 | if (zero_fill && bytes_remain > 0) { |
---|
629 | uint32_t start = fat_fd->fat_file_size; |
---|
630 | uint32_t cl_start = start >> fs_info->vol.bpc_log2; |
---|
631 | uint32_t ofs = start & (fs_info->vol.bpc - 1); |
---|
632 | uint32_t cur_cln; |
---|
633 | |
---|
634 | rc = fat_file_lseek(fs_info, fat_fd, cl_start, &cur_cln); |
---|
635 | if (rc != RC_OK) |
---|
636 | return rc; |
---|
637 | |
---|
638 | bytes_written = fat_cluster_set (fs_info, cur_cln, ofs, bytes_remain, 0); |
---|
639 | if (bytes_remain != bytes_written) |
---|
640 | return -1; |
---|
641 | } |
---|
642 | |
---|
643 | /* |
---|
644 | * if in last cluster allocated for the file there is enough room to |
---|
645 | * handle extention (hence we don't need to add even one cluster to the |
---|
646 | * file ) - return |
---|
647 | */ |
---|
648 | if (bytes2add == 0) |
---|
649 | return RC_OK; |
---|
650 | |
---|
651 | cls2add = ((bytes2add - 1) >> fs_info->vol.bpc_log2) + 1; |
---|
652 | |
---|
653 | rc = fat_scan_fat_for_free_clusters(fs_info, &chain, cls2add, |
---|
654 | &cls_added, &last_cl, zero_fill); |
---|
655 | |
---|
656 | /* this means that low level I/O error occured */ |
---|
657 | if (rc != RC_OK) |
---|
658 | return rc; |
---|
659 | |
---|
660 | /* this means that no space left on device */ |
---|
661 | if ((cls_added == 0) && (bytes_remain == 0)) |
---|
662 | rtems_set_errno_and_return_minus_one(ENOSPC); |
---|
663 | |
---|
664 | /* check wether we satisfied request for 'cls2add' clusters */ |
---|
665 | if (cls2add != cls_added) |
---|
666 | { |
---|
667 | uint32_t missing = (cls2add - cls_added) << fs_info->vol.bpc_log2; |
---|
668 | |
---|
669 | new_length -= bytes2add < missing ? bytes2add : missing; |
---|
670 | } |
---|
671 | |
---|
672 | if (cls_added > 0) |
---|
673 | { |
---|
674 | /* add new chain to the end of existing */ |
---|
675 | if ( fat_fd->fat_file_size == 0 ) |
---|
676 | { |
---|
677 | fat_fd->map.disk_cln = chain; |
---|
678 | fat_fd->map.file_cln = 0; |
---|
679 | fat_file_set_first_cluster_num(fat_fd, chain); |
---|
680 | } |
---|
681 | else |
---|
682 | { |
---|
683 | if (fat_fd->map.last_cln != FAT_UNDEFINED_VALUE) |
---|
684 | { |
---|
685 | old_last_cl = fat_fd->map.last_cln; |
---|
686 | } |
---|
687 | else |
---|
688 | { |
---|
689 | rc = fat_file_ioctl(fs_info, fat_fd, F_CLU_NUM, |
---|
690 | (fat_fd->fat_file_size - 1), &old_last_cl); |
---|
691 | if ( rc != RC_OK ) |
---|
692 | { |
---|
693 | fat_free_fat_clusters_chain(fs_info, chain); |
---|
694 | return rc; |
---|
695 | } |
---|
696 | } |
---|
697 | |
---|
698 | rc = fat_set_fat_cluster(fs_info, old_last_cl, chain); |
---|
699 | if ( rc != RC_OK ) |
---|
700 | { |
---|
701 | fat_free_fat_clusters_chain(fs_info, chain); |
---|
702 | return rc; |
---|
703 | } |
---|
704 | fat_buf_release(fs_info); |
---|
705 | } |
---|
706 | |
---|
707 | /* update number of the last cluster of the file */ |
---|
708 | fat_fd->map.last_cln = last_cl; |
---|
709 | |
---|
710 | if (fat_fd->fat_file_type == FAT_DIRECTORY) |
---|
711 | { |
---|
712 | rc = fat_init_clusters_chain(fs_info, chain); |
---|
713 | if ( rc != RC_OK ) |
---|
714 | { |
---|
715 | fat_free_fat_clusters_chain(fs_info, chain); |
---|
716 | return rc; |
---|
717 | } |
---|
718 | } |
---|
719 | } |
---|
720 | |
---|
721 | *a_length = new_length; |
---|
722 | fat_file_set_file_size(fat_fd, new_length); |
---|
723 | |
---|
724 | return RC_OK; |
---|
725 | } |
---|
726 | |
---|
727 | /* fat_file_truncate -- |
---|
728 | * Truncate fat-file. If new length greater than current fat-file size - |
---|
729 | * do nothing. Otherwise find first cluster to free and free all clusters |
---|
730 | * in the chain starting from this cluster. |
---|
731 | * |
---|
732 | * PARAMETERS: |
---|
733 | * fs_info - FS info |
---|
734 | * fat_fd - fat-file descriptor |
---|
735 | * new_length - new length |
---|
736 | * |
---|
737 | * RETURNS: |
---|
738 | * RC_OK on success, or -1 if error occured (errno set appropriately) |
---|
739 | */ |
---|
740 | int |
---|
741 | fat_file_truncate( |
---|
742 | fat_fs_info_t *fs_info, |
---|
743 | fat_file_fd_t *fat_fd, |
---|
744 | uint32_t new_length |
---|
745 | ) |
---|
746 | { |
---|
747 | int rc = RC_OK; |
---|
748 | uint32_t cur_cln = 0; |
---|
749 | uint32_t cl_start = 0; |
---|
750 | uint32_t new_last_cln = FAT_UNDEFINED_VALUE; |
---|
751 | |
---|
752 | |
---|
753 | if ( new_length >= fat_fd->fat_file_size ) |
---|
754 | return rc; |
---|
755 | |
---|
756 | assert(fat_fd->fat_file_size); |
---|
757 | |
---|
758 | cl_start = (new_length + fs_info->vol.bpc - 1) >> fs_info->vol.bpc_log2; |
---|
759 | |
---|
760 | if ((cl_start << fs_info->vol.bpc_log2) >= fat_fd->fat_file_size) |
---|
761 | return RC_OK; |
---|
762 | |
---|
763 | if (cl_start != 0) |
---|
764 | { |
---|
765 | rc = fat_file_lseek(fs_info, fat_fd, cl_start - 1, &new_last_cln); |
---|
766 | if (rc != RC_OK) |
---|
767 | return rc; |
---|
768 | |
---|
769 | } |
---|
770 | |
---|
771 | rc = fat_file_lseek(fs_info, fat_fd, cl_start, &cur_cln); |
---|
772 | if (rc != RC_OK) |
---|
773 | return rc; |
---|
774 | |
---|
775 | rc = fat_free_fat_clusters_chain(fs_info, cur_cln); |
---|
776 | if (rc != RC_OK) |
---|
777 | return rc; |
---|
778 | |
---|
779 | if (cl_start != 0) |
---|
780 | { |
---|
781 | rc = fat_set_fat_cluster(fs_info, new_last_cln, FAT_GENFAT_EOC); |
---|
782 | if ( rc != RC_OK ) |
---|
783 | return rc; |
---|
784 | fat_fd->map.file_cln = cl_start - 1; |
---|
785 | fat_fd->map.disk_cln = new_last_cln; |
---|
786 | fat_fd->map.last_cln = new_last_cln; |
---|
787 | } |
---|
788 | return RC_OK; |
---|
789 | } |
---|
790 | |
---|
791 | /* fat_file_ioctl -- |
---|
792 | * F_CLU_NUM: |
---|
793 | * make mapping between serial number of the cluster in fat-file and |
---|
794 | * its real number on the volume |
---|
795 | * |
---|
796 | * PARAMETERS: |
---|
797 | * fat_fd - fat-file descriptor |
---|
798 | * fs_info - FS info |
---|
799 | * cmd - command |
---|
800 | * ... |
---|
801 | * |
---|
802 | * RETURNS: |
---|
803 | * RC_OK on success, or -1 if error occured and errno set appropriately |
---|
804 | */ |
---|
805 | int |
---|
806 | fat_file_ioctl( |
---|
807 | fat_fs_info_t *fs_info, |
---|
808 | fat_file_fd_t *fat_fd, |
---|
809 | int cmd, |
---|
810 | ...) |
---|
811 | { |
---|
812 | int rc = RC_OK; |
---|
813 | uint32_t cur_cln = 0; |
---|
814 | uint32_t cl_start = 0; |
---|
815 | uint32_t pos = 0; |
---|
816 | uint32_t *ret; |
---|
817 | va_list ap; |
---|
818 | |
---|
819 | va_start(ap, cmd); |
---|
820 | |
---|
821 | switch (cmd) |
---|
822 | { |
---|
823 | case F_CLU_NUM: |
---|
824 | pos = va_arg(ap, uint32_t); |
---|
825 | ret = va_arg(ap, uint32_t *); |
---|
826 | |
---|
827 | /* sanity check */ |
---|
828 | if ( pos >= fat_fd->fat_file_size ) { |
---|
829 | va_end(ap); |
---|
830 | rtems_set_errno_and_return_minus_one( EIO ); |
---|
831 | } |
---|
832 | |
---|
833 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
---|
834 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
---|
835 | { |
---|
836 | /* cluster 0 (zero) reserved for root dir */ |
---|
837 | *ret = 0; |
---|
838 | rc = RC_OK; |
---|
839 | break; |
---|
840 | } |
---|
841 | |
---|
842 | cl_start = pos >> fs_info->vol.bpc_log2; |
---|
843 | |
---|
844 | rc = fat_file_lseek(fs_info, fat_fd, cl_start, &cur_cln); |
---|
845 | if ( rc != RC_OK ) |
---|
846 | break; |
---|
847 | |
---|
848 | *ret = cur_cln; |
---|
849 | break; |
---|
850 | |
---|
851 | default: |
---|
852 | errno = EINVAL; |
---|
853 | rc = -1; |
---|
854 | break; |
---|
855 | } |
---|
856 | va_end(ap); |
---|
857 | return rc; |
---|
858 | } |
---|
859 | |
---|
860 | /* fat_file_mark_removed -- |
---|
861 | * Remove the fat-file descriptor from "valid" hash table, insert it |
---|
862 | * into "removed-but-still-open" hash table and set up "removed" bit. |
---|
863 | * |
---|
864 | * PARAMETERS: |
---|
865 | * fat_fd - fat-file descriptor |
---|
866 | * fs_info - FS info |
---|
867 | * |
---|
868 | * RETURNS: |
---|
869 | * None |
---|
870 | */ |
---|
871 | void |
---|
872 | fat_file_mark_removed( |
---|
873 | fat_fs_info_t *fs_info, |
---|
874 | fat_file_fd_t *fat_fd |
---|
875 | ) |
---|
876 | { |
---|
877 | uint32_t key = 0; |
---|
878 | |
---|
879 | key = fat_construct_key(fs_info, &fat_fd->dir_pos.sname); |
---|
880 | |
---|
881 | _hash_delete(fs_info->vhash, key, fat_fd->ino, fat_fd); |
---|
882 | |
---|
883 | _hash_insert(fs_info->rhash, key, fat_fd->ino, fat_fd); |
---|
884 | |
---|
885 | fat_fd->flags |= FAT_FILE_REMOVED; |
---|
886 | } |
---|
887 | |
---|
888 | /* fat_file_size -- |
---|
889 | * Calculate fat-file size - fat-file is nothing that clusters chain, so |
---|
890 | * go through all clusters in the chain and count it. Only |
---|
891 | * special case is root directory for FAT12/16 volumes. |
---|
892 | * This function is used only for directories which are fat-files with |
---|
893 | * non-zero length, hence 'fat_fd->cln' always contains valid data. |
---|
894 | * Calculated size is stored in 'fat_file_size' field of fat-file |
---|
895 | * descriptor. |
---|
896 | * |
---|
897 | * PARAMETERS: |
---|
898 | * fs_info - FS info |
---|
899 | * fat_fd - fat-file descriptor |
---|
900 | * |
---|
901 | * RETURNS: |
---|
902 | * RC_OK on success, or -1 if error occured (errno set appropriately) |
---|
903 | */ |
---|
904 | int |
---|
905 | fat_file_size( |
---|
906 | fat_fs_info_t *fs_info, |
---|
907 | fat_file_fd_t *fat_fd |
---|
908 | ) |
---|
909 | { |
---|
910 | int rc = RC_OK; |
---|
911 | uint32_t cur_cln = fat_fd->cln; |
---|
912 | uint32_t save_cln = 0; |
---|
913 | |
---|
914 | /* Have we requested root dir size for FAT12/16? */ |
---|
915 | if ((FAT_FD_OF_ROOT_DIR(fat_fd)) && |
---|
916 | (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16))) |
---|
917 | { |
---|
918 | fat_fd->fat_file_size = fs_info->vol.rdir_size; |
---|
919 | return rc; |
---|
920 | } |
---|
921 | |
---|
922 | fat_fd->fat_file_size = 0; |
---|
923 | |
---|
924 | while ((cur_cln & fs_info->vol.mask) < fs_info->vol.eoc_val) |
---|
925 | { |
---|
926 | save_cln = cur_cln; |
---|
927 | rc = fat_get_fat_cluster(fs_info, cur_cln, &cur_cln); |
---|
928 | if ( rc != RC_OK ) |
---|
929 | return rc; |
---|
930 | |
---|
931 | fat_fd->fat_file_size += fs_info->vol.bpc; |
---|
932 | } |
---|
933 | fat_fd->map.last_cln = save_cln; |
---|
934 | return rc; |
---|
935 | } |
---|
936 | |
---|
937 | /* hash support routines */ |
---|
938 | |
---|
939 | /* _hash_insert -- |
---|
940 | * Insert elemnt into hash based on key 'key1' |
---|
941 | * |
---|
942 | * PARAMETERS: |
---|
943 | * hash - hash element will be inserted into |
---|
944 | * key1 - key on which insertion is based on |
---|
945 | * key2 - not used during insertion |
---|
946 | * el - element to insert |
---|
947 | * |
---|
948 | * RETURNS: |
---|
949 | * None |
---|
950 | */ |
---|
951 | static inline void |
---|
952 | _hash_insert(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
---|
953 | fat_file_fd_t *el) |
---|
954 | { |
---|
955 | rtems_chain_append_unprotected((hash) + ((key1) % FAT_HASH_MODULE), &(el)->link); |
---|
956 | } |
---|
957 | |
---|
958 | |
---|
959 | /* _hash_delete -- |
---|
960 | * Remove element from hash |
---|
961 | * |
---|
962 | * PARAMETERS: |
---|
963 | * hash - hash element will be removed from |
---|
964 | * key1 - not used |
---|
965 | * key2 - not used |
---|
966 | * el - element to delete |
---|
967 | * |
---|
968 | * RETURNS: |
---|
969 | * None |
---|
970 | */ |
---|
971 | static inline void |
---|
972 | _hash_delete(rtems_chain_control *hash, uint32_t key1, uint32_t key2, |
---|
973 | fat_file_fd_t *el) |
---|
974 | { |
---|
975 | rtems_chain_extract_unprotected(&(el)->link); |
---|
976 | } |
---|
977 | |
---|
978 | /* _hash_search -- |
---|
979 | * Search element in hash. If both keys match pointer to found element |
---|
980 | * is returned |
---|
981 | * |
---|
982 | * PARAMETERS: |
---|
983 | * fs_info - FS info |
---|
984 | * hash - hash element will be removed from |
---|
985 | * key1 - search key |
---|
986 | * key2 - search key |
---|
987 | * ret - placeholder for result |
---|
988 | * |
---|
989 | * RETURNS: |
---|
990 | * 0 and pointer to found element on success, -1 otherwise |
---|
991 | */ |
---|
992 | static inline int |
---|
993 | _hash_search( |
---|
994 | const fat_fs_info_t *fs_info, |
---|
995 | rtems_chain_control *hash, |
---|
996 | uint32_t key1, |
---|
997 | uint32_t key2, |
---|
998 | fat_file_fd_t **ret |
---|
999 | ) |
---|
1000 | { |
---|
1001 | uint32_t mod = (key1) % FAT_HASH_MODULE; |
---|
1002 | rtems_chain_node *the_node = rtems_chain_first(hash + mod); |
---|
1003 | |
---|
1004 | for ( ; !rtems_chain_is_tail((hash) + mod, the_node) ; ) |
---|
1005 | { |
---|
1006 | fat_file_fd_t *ffd = (fat_file_fd_t *)the_node; |
---|
1007 | uint32_t ck = fat_construct_key(fs_info, &ffd->dir_pos.sname); |
---|
1008 | |
---|
1009 | if ( (key1) == ck) |
---|
1010 | { |
---|
1011 | if ( ((key2) == 0) || ((key2) == ffd->ino) ) |
---|
1012 | { |
---|
1013 | *ret = (void *)the_node; |
---|
1014 | return 0; |
---|
1015 | } |
---|
1016 | } |
---|
1017 | the_node = the_node->next; |
---|
1018 | } |
---|
1019 | return -1; |
---|
1020 | } |
---|
1021 | |
---|
1022 | static off_t |
---|
1023 | fat_file_lseek( |
---|
1024 | fat_fs_info_t *fs_info, |
---|
1025 | fat_file_fd_t *fat_fd, |
---|
1026 | uint32_t file_cln, |
---|
1027 | uint32_t *disk_cln |
---|
1028 | ) |
---|
1029 | { |
---|
1030 | int rc = RC_OK; |
---|
1031 | |
---|
1032 | if (file_cln == fat_fd->map.file_cln) |
---|
1033 | *disk_cln = fat_fd->map.disk_cln; |
---|
1034 | else |
---|
1035 | { |
---|
1036 | uint32_t cur_cln; |
---|
1037 | uint32_t count; |
---|
1038 | uint32_t i; |
---|
1039 | |
---|
1040 | if (file_cln > fat_fd->map.file_cln) |
---|
1041 | { |
---|
1042 | cur_cln = fat_fd->map.disk_cln; |
---|
1043 | count = file_cln - fat_fd->map.file_cln; |
---|
1044 | } |
---|
1045 | else |
---|
1046 | { |
---|
1047 | cur_cln = fat_fd->cln; |
---|
1048 | count = file_cln; |
---|
1049 | } |
---|
1050 | |
---|
1051 | /* skip over the clusters */ |
---|
1052 | for (i = 0; i < count; i++) |
---|
1053 | { |
---|
1054 | rc = fat_get_fat_cluster(fs_info, cur_cln, &cur_cln); |
---|
1055 | if ( rc != RC_OK ) |
---|
1056 | return rc; |
---|
1057 | } |
---|
1058 | |
---|
1059 | /* update cache */ |
---|
1060 | fat_fd->map.file_cln = file_cln; |
---|
1061 | fat_fd->map.disk_cln = cur_cln; |
---|
1062 | |
---|
1063 | *disk_cln = cur_cln; |
---|
1064 | } |
---|
1065 | return RC_OK; |
---|
1066 | } |
---|