1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief RTEMS File System Directory Support |
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5 | * |
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6 | * @ingroup rtems_rfs |
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7 | * |
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8 | * RTEMS File System Directory Support |
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9 | * |
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10 | * This file provides the directory support functions. |
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11 | */ |
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12 | |
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13 | /* |
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14 | * COPYRIGHT (c) 2010 Chris Johns <chrisj@rtems.org> |
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15 | * |
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16 | * The license and distribution terms for this file may be |
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17 | * found in the file LICENSE in this distribution or at |
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18 | * http://www.rtems.com/license/LICENSE. |
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19 | */ |
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20 | |
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21 | #if !defined (_RTEMS_RFS_DIR_H_) |
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22 | #define _RTEMS_RFS_DIR_H_ |
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23 | |
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24 | #include <dirent.h> |
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25 | |
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26 | #include <rtems/libio_.h> |
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27 | |
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28 | #include <rtems/rfs/rtems-rfs-data.h> |
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29 | #include <rtems/rfs/rtems-rfs-file-system.h> |
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30 | #include <rtems/rfs/rtems-rfs-inode.h> |
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31 | |
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32 | /** |
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33 | * Define the offsets of the fields of a directory entry. |
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34 | */ |
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35 | #define RTEMS_RFS_DIR_ENTRY_INO (0) /**< The ino offset in a directory |
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36 | * entry. */ |
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37 | #define RTEMS_RFS_DIR_ENTRY_HASH (4) /**< The hash offset in a directory |
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38 | * entry. The hash is 32bits. We need at |
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39 | * least 16bits and given the length and |
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40 | * ino field are 4 the extra 2 bytes is |
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41 | * not a big overhead.*/ |
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42 | #define RTEMS_RFS_DIR_ENTRY_LEN (8) /**< The length offset in a directory |
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43 | * entry. */ |
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44 | |
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45 | /** |
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46 | * The length of the directory entry header. |
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47 | */ |
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48 | #define RTEMS_RFS_DIR_ENTRY_SIZE (4 + 4 + 2) |
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49 | |
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50 | /** |
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51 | * The length when the remainder of the directory block is empty. |
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52 | */ |
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53 | #define RTEMS_RFS_DIR_ENTRY_EMPTY (0xffff) |
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54 | |
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55 | /** |
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56 | * Return the hash of the entry. |
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57 | * |
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58 | * @param[in] _e is a pointer to the directory entry. |
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59 | * |
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60 | * @retval hash The uint32_t hash of the entry. |
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61 | */ |
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62 | #define rtems_rfs_dir_entry_hash(_e) \ |
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63 | rtems_rfs_read_u32 (_e + RTEMS_RFS_DIR_ENTRY_HASH) |
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64 | |
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65 | /** |
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66 | * Set the hash of the entry. |
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67 | * |
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68 | * @param[in] _e is a pointer to the directory entry. |
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69 | * |
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70 | * @param[in] _h is the hash of the entry. |
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71 | */ |
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72 | #define rtems_rfs_dir_set_entry_hash(_e, _h) \ |
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73 | rtems_rfs_write_u32 (_e + RTEMS_RFS_DIR_ENTRY_HASH, _h) |
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74 | |
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75 | /** |
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76 | * Return the ino of the entry. |
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77 | * |
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78 | * @param[in] _e is a pointer to the directory entry. |
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79 | * |
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80 | * @retval ino The ino of the entry. |
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81 | */ |
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82 | #define rtems_rfs_dir_entry_ino(_e) \ |
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83 | rtems_rfs_read_u32 (_e + RTEMS_RFS_DIR_ENTRY_INO) |
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84 | |
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85 | /** |
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86 | * Set the ino of the entry. |
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87 | * |
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88 | * @param[in] _e is a pointer to the directory entry. |
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89 | * |
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90 | * @param[in] _i is the ino of the entry. |
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91 | */ |
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92 | #define rtems_rfs_dir_set_entry_ino(_e, _i) \ |
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93 | rtems_rfs_write_u32 (_e + RTEMS_RFS_DIR_ENTRY_INO, _i) |
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94 | |
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95 | /** |
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96 | * Return the length of the entry. |
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97 | * |
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98 | * @param[in] _e Pointer to the directory entry. |
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99 | * |
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100 | * @retval length The length of the entry. |
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101 | */ |
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102 | #define rtems_rfs_dir_entry_length(_e) \ |
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103 | rtems_rfs_read_u16 (_e + RTEMS_RFS_DIR_ENTRY_LEN) |
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104 | |
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105 | /** |
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106 | * Set the length of the entry. |
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107 | * |
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108 | * @param[in] _e is a pointer to the directory entry. |
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109 | * @param[in] _l is the length. |
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110 | */ |
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111 | #define rtems_rfs_dir_set_entry_length(_e, _l) \ |
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112 | rtems_rfs_write_u16 (_e + RTEMS_RFS_DIR_ENTRY_LEN, _l) |
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113 | |
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114 | /** |
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115 | * Look up a directory entry in the directory pointed to by the inode. The look |
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116 | * up is local to this directory. No need to decend. |
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117 | * |
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118 | * @param[in] fs is the file system. |
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119 | * @param[in] inode is a pointer to the inode of the directory to search. |
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120 | * @param[in] name is a pointer to the name to look up. The name may not be |
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121 | * nul terminated. |
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122 | * @param[in] length is the length of the name. |
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123 | * @param[out] ino will be filled in with the inode number |
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124 | * if there is no error. |
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125 | * @param[in] offset is the offset in the directory for the entry. |
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126 | * |
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127 | * @retval 0 Successful operation. |
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128 | * @retval error_code An error occurred. |
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129 | */ |
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130 | int rtems_rfs_dir_lookup_ino (rtems_rfs_file_system* fs, |
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131 | rtems_rfs_inode_handle* inode, |
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132 | const char* name, |
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133 | int length, |
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134 | rtems_rfs_ino* ino, |
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135 | uint32_t* offset); |
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136 | |
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137 | /** |
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138 | * Add an entry to the directory returing the inode number allocated to the |
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139 | * entry. |
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140 | * |
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141 | * @param[in] fs is the file system data. |
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142 | * @param[in] dir is a pointer to the directory inode the |
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143 | * entry is to be added too. |
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144 | * @param[in] name is a pointer to the name of the entry to be added. |
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145 | * @param[in] length is the length of the name excluding a terminating 0. |
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146 | * @param[in] ino is the ino of the entry. |
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147 | * |
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148 | * @retval 0 Successful operation. |
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149 | * @retval error_code An error occurred. |
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150 | */ |
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151 | int rtems_rfs_dir_add_entry (rtems_rfs_file_system* fs, |
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152 | rtems_rfs_inode_handle* dir, |
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153 | const char* name, |
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154 | size_t length, |
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155 | rtems_rfs_ino ino); |
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156 | |
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157 | /** |
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158 | * Del an entry from the directory using an inode number as a key. |
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159 | * |
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160 | * @param[in] fs is the file system data. |
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161 | * @param[in] dir is a pointer to the directory inode the |
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162 | * entry is to be deleted from. |
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163 | * @param[in] ino is the ino of the entry. |
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164 | * @param[in] offset is the offset in the directory of the entry |
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165 | * to delete. If 0 search from the start for the ino. |
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166 | * |
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167 | * @retval 0 Successful operation. |
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168 | * @retval error_code An error occurred. |
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169 | */ |
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170 | int rtems_rfs_dir_del_entry (rtems_rfs_file_system* fs, |
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171 | rtems_rfs_inode_handle* dir, |
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172 | rtems_rfs_ino ino, |
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173 | uint32_t offset); |
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174 | |
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175 | /** |
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176 | * Read the directory entry from offset into the directory entry buffer and |
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177 | * return the length of space this entry uses in the directory table. |
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178 | * |
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179 | * @param[in] fs is the file system data. |
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180 | * @param[in] dir is a pointer to the direct inode handler. |
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181 | * @param[in] offset is the offset in the directory to read from. |
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182 | * @param[in] dirent is a ointer to the dirent structure the entry |
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183 | * is written into. |
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184 | * @param[out] length will contain the length this entry |
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185 | * takes in the directory. |
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186 | * |
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187 | * @retval 0 Successful operation. |
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188 | * @retval error_code An error occurred. |
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189 | */ |
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190 | int rtems_rfs_dir_read (rtems_rfs_file_system* fs, |
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191 | rtems_rfs_inode_handle* dir, |
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192 | rtems_rfs_pos_rel offset, |
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193 | struct dirent* dirent, |
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194 | size_t* length); |
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195 | |
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196 | /** |
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197 | * Check if the directory is empty. The current and parent directory entries |
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198 | * are ignored. |
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199 | * |
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200 | * @param[in] fs is the file system data |
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201 | * @param[in] dir is a pointer to the directory inode to check. |
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202 | * |
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203 | * @retval 0 Successful operation. |
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204 | * @retval error_code An error occurred. |
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205 | */ |
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206 | int rtems_rfs_dir_empty (rtems_rfs_file_system* fs, |
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207 | rtems_rfs_inode_handle* dir); |
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208 | |
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209 | #endif |
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