1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief RTEMS File Systems Link Routines |
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5 | * @ingroup rtems_rfs |
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6 | * |
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7 | * These functions manage links. A link is the addition of a directory entry |
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8 | * in a parent directory and incrementing the links count in the inode. |
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9 | */ |
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10 | |
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11 | /* |
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12 | * COPYRIGHT (c) 2010 Chris Johns <chrisj@rtems.org> |
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13 | * |
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14 | * The license and distribution terms for this file may be |
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15 | * found in the file LICENSE in this distribution or at |
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16 | * http://www.rtems.org/license/LICENSE. |
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17 | */ |
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18 | |
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19 | #if HAVE_CONFIG_H |
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20 | #include "config.h" |
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21 | #endif |
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22 | |
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23 | #include <inttypes.h> |
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24 | #include <string.h> |
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25 | |
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26 | #include <rtems/rfs/rtems-rfs-block.h> |
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27 | #include <rtems/rfs/rtems-rfs-buffer.h> |
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28 | #include <rtems/rfs/rtems-rfs-file-system.h> |
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29 | #include <rtems/rfs/rtems-rfs-trace.h> |
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30 | #include <rtems/rfs/rtems-rfs-dir.h> |
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31 | #include <rtems/rfs/rtems-rfs-dir-hash.h> |
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32 | #include <rtems/rfs/rtems-rfs-link.h> |
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33 | |
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34 | int |
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35 | rtems_rfs_link (rtems_rfs_file_system* fs, |
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36 | const char* name, |
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37 | int length, |
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38 | rtems_rfs_ino parent, |
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39 | rtems_rfs_ino target, |
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40 | bool link_dir) |
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41 | { |
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42 | rtems_rfs_inode_handle parent_inode; |
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43 | rtems_rfs_inode_handle target_inode; |
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44 | uint16_t links; |
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45 | int rc; |
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46 | |
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47 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_LINK)) |
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48 | { |
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49 | int c; |
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50 | printf ("rtems-rfs: link: parent(%" PRIu32 ") -> ", parent); |
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51 | for (c = 0; c < length; c++) |
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52 | printf ("%c", name[c]); |
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53 | printf ("(%" PRIu32 ")\n", target); |
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54 | } |
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55 | |
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56 | rc = rtems_rfs_inode_open (fs, target, &target_inode, true); |
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57 | if (rc) |
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58 | return rc; |
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59 | |
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60 | /* |
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61 | * If the target inode is a directory and we cannot link directories |
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62 | * return a not supported error code. |
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63 | */ |
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64 | if (!link_dir && S_ISDIR (rtems_rfs_inode_get_mode (&target_inode))) |
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65 | { |
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66 | rtems_rfs_inode_close (fs, &target_inode); |
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67 | return ENOTSUP; |
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68 | } |
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69 | |
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70 | rc = rtems_rfs_inode_open (fs, parent, &parent_inode, true); |
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71 | if (rc) |
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72 | { |
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73 | rtems_rfs_inode_close (fs, &target_inode); |
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74 | return rc; |
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75 | } |
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76 | |
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77 | rc = rtems_rfs_dir_add_entry (fs, &parent_inode, name, length, target); |
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78 | if (rc > 0) |
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79 | { |
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80 | rtems_rfs_inode_close (fs, &parent_inode); |
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81 | rtems_rfs_inode_close (fs, &target_inode); |
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82 | return rc; |
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83 | } |
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84 | |
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85 | links = rtems_rfs_inode_get_links (&target_inode) + 1; |
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86 | rtems_rfs_inode_set_links (&target_inode, links); |
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87 | |
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88 | rc = rtems_rfs_inode_time_stamp_now (&parent_inode, true, true); |
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89 | if (rc > 0) |
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90 | { |
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91 | rtems_rfs_inode_close (fs, &parent_inode); |
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92 | rtems_rfs_inode_close (fs, &target_inode); |
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93 | return rc; |
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94 | } |
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95 | |
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96 | rc = rtems_rfs_inode_close (fs, &parent_inode); |
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97 | if (rc > 0) |
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98 | { |
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99 | rtems_rfs_inode_close (fs, &target_inode); |
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100 | return rc; |
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101 | } |
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102 | |
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103 | rc = rtems_rfs_inode_close (fs, &target_inode); |
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104 | |
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105 | return rc; |
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106 | } |
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107 | |
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108 | int |
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109 | rtems_rfs_unlink (rtems_rfs_file_system* fs, |
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110 | rtems_rfs_ino parent, |
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111 | rtems_rfs_ino target, |
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112 | uint32_t doff, |
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113 | rtems_rfs_unlink_dir dir_mode) |
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114 | { |
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115 | rtems_rfs_inode_handle parent_inode; |
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116 | rtems_rfs_inode_handle target_inode; |
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117 | uint16_t links; |
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118 | bool dir; |
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119 | int rc; |
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120 | |
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121 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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122 | printf ("rtems-rfs: unlink: parent(%" PRIu32 ") -X-> (%" PRIu32 ")\n", parent, target); |
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123 | |
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124 | rc = rtems_rfs_inode_open (fs, target, &target_inode, true); |
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125 | if (rc) |
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126 | return rc; |
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127 | |
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128 | /* |
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129 | * If a directory process the unlink mode. |
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130 | */ |
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131 | |
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132 | dir = RTEMS_RFS_S_ISDIR (rtems_rfs_inode_get_mode (&target_inode)); |
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133 | if (dir) |
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134 | { |
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135 | switch (dir_mode) |
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136 | { |
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137 | case rtems_rfs_unlink_dir_denied: |
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138 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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139 | printf ("rtems-rfs: link is a directory\n"); |
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140 | rtems_rfs_inode_close (fs, &target_inode); |
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141 | return EISDIR; |
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142 | |
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143 | case rtems_rfs_unlink_dir_if_empty: |
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144 | rc = rtems_rfs_dir_empty (fs, &target_inode); |
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145 | if (rc > 0) |
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146 | { |
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147 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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148 | printf ("rtems-rfs: dir-empty: %d: %s\n", rc, strerror (rc)); |
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149 | rtems_rfs_inode_close (fs, &target_inode); |
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150 | return rc; |
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151 | } |
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152 | break; |
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153 | |
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154 | default: |
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155 | break; |
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156 | } |
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157 | } |
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158 | |
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159 | rc = rtems_rfs_inode_open (fs, parent, &parent_inode, true); |
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160 | if (rc) |
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161 | { |
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162 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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163 | printf ("rtems-rfs: link: inode-open failed: %d: %s\n", |
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164 | rc, strerror (rc)); |
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165 | rtems_rfs_inode_close (fs, &target_inode); |
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166 | return rc; |
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167 | } |
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168 | |
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169 | rc = rtems_rfs_dir_del_entry (fs, &parent_inode, target, doff); |
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170 | if (rc > 0) |
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171 | { |
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172 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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173 | printf ("rtems-rfs: unlink: dir-del failed: %d: %s\n", |
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174 | rc, strerror (rc)); |
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175 | rtems_rfs_inode_close (fs, &parent_inode); |
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176 | rtems_rfs_inode_close (fs, &target_inode); |
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177 | return rc; |
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178 | } |
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179 | |
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180 | links = rtems_rfs_inode_get_links (&target_inode); |
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181 | |
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182 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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183 | printf ("rtems-rfs: unlink: target:%" PRIu32 " links:%u\n", target, links); |
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184 | |
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185 | if (links > 1) |
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186 | { |
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187 | links--; |
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188 | rtems_rfs_inode_set_links (&target_inode, links); |
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189 | } |
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190 | else |
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191 | { |
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192 | /* |
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193 | * Erasing the inode releases all blocks attached to it. |
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194 | */ |
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195 | rc = rtems_rfs_inode_delete (fs, &target_inode); |
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196 | if (rc > 0) |
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197 | { |
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198 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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199 | printf ("rtems-rfs: unlink: inode-del failed: %d: %s\n", |
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200 | rc, strerror (rc)); |
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201 | rtems_rfs_inode_close (fs, &parent_inode); |
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202 | rtems_rfs_inode_close (fs, &target_inode); |
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203 | return rc; |
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204 | } |
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205 | |
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206 | if (dir) |
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207 | { |
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208 | links = rtems_rfs_inode_get_links (&parent_inode); |
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209 | if (links > 1) |
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210 | links--; |
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211 | rtems_rfs_inode_set_links (&parent_inode, links); |
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212 | } |
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213 | } |
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214 | |
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215 | rc = rtems_rfs_inode_time_stamp_now (&parent_inode, true, true); |
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216 | if (rc > 0) |
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217 | { |
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218 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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219 | printf ("rtems-rfs: link: inode-time-stamp failed: %d: %s\n", |
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220 | rc, strerror (rc)); |
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221 | rtems_rfs_inode_close (fs, &parent_inode); |
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222 | rtems_rfs_inode_close (fs, &target_inode); |
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223 | return rc; |
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224 | } |
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225 | |
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226 | rc = rtems_rfs_inode_close (fs, &parent_inode); |
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227 | if (rc > 0) |
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228 | { |
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229 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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230 | printf ("rtems-rfs: link: parent inode-close failed: %d: %s\n", |
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231 | rc, strerror (rc)); |
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232 | rtems_rfs_inode_close (fs, &target_inode); |
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233 | return rc; |
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234 | } |
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235 | |
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236 | rc = rtems_rfs_inode_close (fs, &target_inode); |
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237 | |
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238 | if ((rc > 0) && rtems_rfs_trace (RTEMS_RFS_TRACE_UNLINK)) |
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239 | printf ("rtems-rfs: link: target inode-close failed: %d: %s\n", |
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240 | rc, strerror (rc)); |
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241 | |
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242 | return rc; |
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243 | } |
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244 | |
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245 | int |
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246 | rtems_rfs_symlink (rtems_rfs_file_system* fs, |
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247 | const char* name, |
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248 | int length, |
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249 | const char* link, |
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250 | int link_length, |
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251 | uid_t uid, |
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252 | gid_t gid, |
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253 | rtems_rfs_ino parent) |
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254 | { |
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255 | rtems_rfs_inode_handle inode; |
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256 | rtems_rfs_ino ino; |
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257 | int rc; |
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258 | |
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259 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_SYMLINK)) |
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260 | { |
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261 | int c; |
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262 | printf ("rtems-rfs: symlink: parent:%" PRIu32 " name:", parent); |
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263 | for (c = 0; c < length; c++) |
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264 | printf ("%c", name[c]); |
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265 | printf (" link:"); |
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266 | for (c = 0; c < link_length; c++) |
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267 | printf ("%c", link[c]); |
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268 | } |
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269 | |
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270 | if (link_length >= rtems_rfs_fs_block_size (fs)) |
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271 | return ENAMETOOLONG; |
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272 | |
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273 | rc = rtems_rfs_inode_create (fs, parent, name, strlen (name), |
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274 | RTEMS_RFS_S_SYMLINK, |
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275 | 1, uid, gid, &ino); |
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276 | if (rc > 0) |
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277 | return rc; |
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278 | |
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279 | rc = rtems_rfs_inode_open (fs, ino, &inode, true); |
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280 | if (rc > 0) |
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281 | return rc; |
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282 | |
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283 | /* |
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284 | * If the link length is less than the length of data union in the inode |
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285 | * place the link into the data area else allocate a block and write the link |
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286 | * to that. |
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287 | */ |
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288 | if (link_length < RTEMS_RFS_INODE_DATA_NAME_SIZE) |
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289 | { |
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290 | memset (inode.node->data.name, 0, RTEMS_RFS_INODE_DATA_NAME_SIZE); |
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291 | memcpy (inode.node->data.name, link, link_length); |
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292 | rtems_rfs_inode_set_block_count (&inode, 0); |
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293 | } |
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294 | else |
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295 | { |
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296 | rtems_rfs_block_map map; |
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297 | rtems_rfs_block_no block; |
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298 | rtems_rfs_buffer_handle buffer; |
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299 | uint8_t* data; |
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300 | |
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301 | rc = rtems_rfs_block_map_open (fs, &inode, &map); |
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302 | if (rc > 0) |
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303 | { |
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304 | rtems_rfs_inode_close (fs, &inode); |
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305 | return rc; |
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306 | } |
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307 | |
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308 | rc = rtems_rfs_block_map_grow (fs, &map, 1, &block); |
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309 | if (rc > 0) |
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310 | { |
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311 | rtems_rfs_block_map_close (fs, &map); |
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312 | rtems_rfs_inode_close (fs, &inode); |
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313 | return rc; |
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314 | } |
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315 | |
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316 | rc = rtems_rfs_buffer_handle_open (fs, &buffer); |
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317 | if (rc > 0) |
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318 | { |
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319 | rtems_rfs_block_map_close (fs, &map); |
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320 | rtems_rfs_inode_close (fs, &inode); |
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321 | return rc; |
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322 | } |
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323 | |
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324 | rc = rtems_rfs_buffer_handle_request (fs, &buffer, block, false); |
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325 | if (rc > 0) |
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326 | { |
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327 | rtems_rfs_block_map_close (fs, &map); |
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328 | rtems_rfs_inode_close (fs, &inode); |
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329 | return rc; |
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330 | } |
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331 | |
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332 | data = rtems_rfs_buffer_data (&buffer); |
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333 | |
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334 | memset (data, 0xff, rtems_rfs_fs_block_size (fs)); |
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335 | memcpy (data, link, link_length); |
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336 | |
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337 | rc = rtems_rfs_buffer_handle_close (fs, &buffer); |
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338 | if (rc > 0) |
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339 | { |
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340 | rtems_rfs_block_map_close (fs, &map); |
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341 | rtems_rfs_inode_close (fs, &inode); |
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342 | return rc; |
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343 | } |
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344 | |
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345 | rc = rtems_rfs_block_map_close (fs, &map); |
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346 | if (rc > 0) |
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347 | { |
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348 | rtems_rfs_inode_close (fs, &inode); |
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349 | return rc; |
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350 | } |
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351 | } |
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352 | |
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353 | rtems_rfs_inode_set_block_offset (&inode, link_length); |
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354 | |
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355 | rc = rtems_rfs_inode_close (fs, &inode); |
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356 | |
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357 | return rc; |
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358 | } |
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359 | |
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360 | int |
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361 | rtems_rfs_symlink_read (rtems_rfs_file_system* fs, |
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362 | rtems_rfs_ino link, |
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363 | char* path, |
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364 | size_t size, |
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365 | size_t* length) |
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366 | { |
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367 | rtems_rfs_inode_handle inode; |
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368 | int rc; |
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369 | |
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370 | if (rtems_rfs_trace (RTEMS_RFS_TRACE_SYMLINK_READ)) |
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371 | printf ("rtems-rfs: symlink-read: link:%" PRIu32 "\n", link); |
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372 | |
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373 | rc = rtems_rfs_inode_open (fs, link, &inode, true); |
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374 | if (rc) |
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375 | return rc; |
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376 | |
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377 | if (!RTEMS_RFS_S_ISLNK (rtems_rfs_inode_get_mode (&inode))) |
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378 | { |
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379 | rtems_rfs_inode_close (fs, &inode); |
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380 | return EINVAL; |
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381 | } |
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382 | |
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383 | *length = rtems_rfs_inode_get_block_offset (&inode); |
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384 | |
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385 | if (size < *length) |
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386 | { |
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387 | *length = size; |
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388 | } |
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389 | |
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390 | if (rtems_rfs_inode_get_block_count (&inode) == 0) |
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391 | { |
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392 | memcpy (path, inode.node->data.name, *length); |
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393 | } |
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394 | else |
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395 | { |
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396 | rtems_rfs_block_map map; |
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397 | rtems_rfs_block_no block; |
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398 | rtems_rfs_buffer_handle buffer; |
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399 | char* data; |
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400 | |
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401 | rc = rtems_rfs_block_map_open (fs, &inode, &map); |
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402 | if (rc > 0) |
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403 | { |
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404 | rtems_rfs_inode_close (fs, &inode); |
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405 | return rc; |
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406 | } |
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407 | |
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408 | rc = rtems_rfs_block_map_seek (fs, &map, 0, &block); |
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409 | if (rc > 0) |
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410 | { |
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411 | rtems_rfs_block_map_close (fs, &map); |
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412 | rtems_rfs_inode_close (fs, &inode); |
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413 | return rc; |
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414 | } |
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415 | |
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416 | rc = rtems_rfs_buffer_handle_open (fs, &buffer); |
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417 | if (rc > 0) |
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418 | { |
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419 | rtems_rfs_block_map_close (fs, &map); |
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420 | rtems_rfs_inode_close (fs, &inode); |
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421 | return rc; |
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422 | } |
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423 | |
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424 | rc = rtems_rfs_buffer_handle_request (fs, &buffer, block, false); |
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425 | if (rc > 0) |
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426 | { |
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427 | rtems_rfs_block_map_close (fs, &map); |
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428 | rtems_rfs_inode_close (fs, &inode); |
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429 | return rc; |
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430 | } |
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431 | |
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432 | data = rtems_rfs_buffer_data (&buffer); |
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433 | memcpy (path, data, *length); |
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434 | |
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435 | rc = rtems_rfs_buffer_handle_close (fs, &buffer); |
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436 | if (rc > 0) |
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437 | { |
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438 | rtems_rfs_block_map_close (fs, &map); |
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439 | rtems_rfs_inode_close (fs, &inode); |
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440 | return rc; |
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441 | } |
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442 | |
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443 | rc = rtems_rfs_block_map_close (fs, &map); |
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444 | if (rc > 0) |
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445 | { |
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446 | rtems_rfs_inode_close (fs, &inode); |
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447 | return rc; |
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448 | } |
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449 | } |
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450 | |
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451 | rc = rtems_rfs_inode_close (fs, &inode); |
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452 | |
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453 | return rc; |
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454 | } |
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