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Rev | Author | Line No. | Line |
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4265 | Serge | 1 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
2 | ;; ;; |
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3 | ;; Contains ext2 block handling code. ;; |
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4 | ;; ;; |
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5565 | serge | 5 | ;; Copyright (C) KolibriOS team 2013-2015. All rights reserved. ;; |
5201 | serge | 6 | ;; Distributed under terms of the GNU General Public License ;; |
4265 | Serge | 7 | ;; ;; |
8 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
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9 | |||
5201 | serge | 10 | $Revision: 4891 $ |
11 | |||
12 | |||
4265 | Serge | 13 | ;--------------------------------------------------------------------- |
14 | ; Write ext2 block from memory to disk. |
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15 | ; Input: eax = i_block (block number in ext2 terms); |
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16 | ; ebx = buffer address |
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17 | ; ebp = pointer to EXTFS |
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18 | ; Output: eax = error code (0 implies no error) |
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19 | ;--------------------------------------------------------------------- |
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20 | ext2_block_write: |
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21 | push edx ebx ecx |
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22 | |||
23 | mov edx, fs_write32_sys |
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24 | jmp ext2_block_modify |
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25 | |||
26 | ;--------------------------------------------------------------------- |
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27 | ; Read ext2 block from disk to memory. |
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28 | ; Input: eax = i_block (block number in ext2 terms); |
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29 | ; ebx = address of where to read block |
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30 | ; ebp = pointer to EXTFS |
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31 | ; Output: eax = error code (0 implies no error) |
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32 | ;--------------------------------------------------------------------- |
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33 | ext2_block_read: |
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34 | push edx ebx ecx |
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35 | |||
36 | mov edx, fs_read32_sys |
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37 | jmp ext2_block_modify |
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38 | |||
39 | ;--------------------------------------------------------------------- |
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40 | ; Modify ext2 block. |
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41 | ; Input: eax = i_block (block number in ext2 terms); |
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42 | ; ebx = I/O buffer address; |
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43 | ; edx = fs_read/write32_sys |
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44 | ; ebp = pointer to EXTFS |
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45 | ; edx, ebx, ecx on stack. |
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46 | ; Output: eax = error code (0 implies no error) |
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47 | ;--------------------------------------------------------------------- |
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48 | ext2_block_modify: |
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49 | ; Get block number in hard-disk terms in eax. |
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50 | mov ecx, [ebp + EXTFS.log_block_size] |
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51 | shl eax, cl |
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52 | mov ecx, eax |
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53 | push [ebp + EXTFS.count_block_in_block] |
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54 | |||
55 | @@: |
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56 | mov eax, ecx |
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57 | call edx |
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58 | test eax, eax |
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59 | jnz .fail |
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60 | |||
61 | inc ecx |
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62 | add ebx, 512 |
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63 | dec dword[esp] |
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64 | jnz @B |
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65 | |||
66 | xor eax, eax |
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67 | @@: |
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68 | pop ecx |
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69 | pop ecx ebx edx |
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70 | ret |
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71 | |||
72 | .fail: |
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73 | mov eax, ERROR_DEVICE |
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74 | jmp @B |
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75 | |||
76 | ;--------------------------------------------------------------------- |
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77 | ; Zeroes a block. |
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78 | ; Input: ebx = block ID. |
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79 | ; ebp = pointer to EXTFS. |
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80 | ; Output: eax = error code. |
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81 | ;--------------------------------------------------------------------- |
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82 | ext2_block_zero: |
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83 | push ebx |
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84 | |||
85 | mov eax, ebx |
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86 | mov ebx, [ebp + EXTFS.ext2_temp_block] |
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87 | |||
88 | call ext2_block_read |
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89 | test eax, eax |
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90 | jnz .return |
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91 | |||
92 | push edi ecx |
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93 | xor eax, eax |
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94 | mov ecx, [ebp + EXTFS.block_size] |
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95 | mov edi, [ebp + EXTFS.ext2_temp_block] |
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96 | rep stosb |
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97 | pop ecx edi |
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98 | |||
99 | mov eax, [esp] |
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100 | call ext2_block_write |
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101 | |||
102 | .return: |
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103 | pop ebx |
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104 | ret |
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105 | |||
106 | ;--------------------------------------------------------------------- |
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107 | ; Allocates a block. |
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108 | ; Input: eax = inode ID for "preference". |
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109 | ; ebp = pointer to EXTFS. |
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110 | ; Output: Block marked as set in block group. |
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111 | ; eax = error code. |
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112 | ; ebx = block ID. |
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113 | ;--------------------------------------------------------------------- |
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114 | ext2_block_alloc: |
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115 | push [ebp + EXTFS.superblock + EXT2_SB_STRUC.blocks_count] |
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116 | push EXT2_BLOCK_GROUP_DESC.free_blocks_count |
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117 | push [ebp + EXTFS.superblock + EXT2_SB_STRUC.blocks_per_group] |
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118 | |||
119 | lea ebx, [ebp + EXTFS.superblock + EXT2_SB_STRUC.free_block_count] |
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120 | push ebx |
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121 | |||
122 | push ext2_bg_read_blk_bitmap |
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123 | |||
124 | call ext2_resource_alloc |
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125 | |||
126 | ret |
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127 | |||
128 | ;--------------------------------------------------------------------- |
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129 | ; Zero-allocates a block. |
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130 | ; Input: eax = inode ID for "preference". |
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131 | ; ebp = pointer to EXTFS. |
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132 | ; Output: Block marked as set in block group. |
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133 | ; eax = error code. |
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134 | ; ebx = block ID. |
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135 | ;--------------------------------------------------------------------- |
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136 | ext2_block_calloc: |
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137 | call ext2_block_alloc |
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138 | test eax, eax |
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139 | jnz @F |
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140 | |||
141 | call ext2_block_zero |
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142 | @@: |
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143 | ret |
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144 | |||
145 | ;--------------------------------------------------------------------- |
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146 | ; Frees a block. |
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147 | ; Input: eax = block ID. |
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148 | ; ebp = pointer to EXTFS. |
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149 | ; Output: Block marked as free in block group. |
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150 | ; eax = error code. |
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151 | ;--------------------------------------------------------------------- |
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152 | ext2_block_free: |
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153 | push edi ecx |
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154 | |||
155 | mov edi, ext2_bg_read_blk_bitmap |
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156 | xor ecx, ecx |
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157 | call ext2_resource_free |
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158 | |||
159 | pop ecx edi |
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160 | ret |
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161 | |||
162 | ;--------------------------------------------------------------------- |
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163 | ; Find parent from file path in block. |
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164 | ; Input: esi = file path. |
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165 | ; ebx = pointer to directory block. |
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166 | ; ebp = pointer to EXTFS structure. |
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167 | ; Output: esi = name without parent, or not changed. |
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168 | ; ebx = directory record matched. |
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169 | ;--------------------------------------------------------------------- |
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170 | ext2_block_find_parent: |
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171 | sub esp, 256 ; Space for EXT2 filename. |
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172 | mov edx, ebx |
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173 | add edx, [ebp + EXTFS.block_size] ; Save block end. |
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174 | |||
175 | .start_rec: |
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176 | cmp [ebx + EXT2_DIR_STRUC.inode], 0 |
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177 | jz .next_rec |
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178 | |||
179 | mov edi, esp |
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180 | push esi |
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181 | movzx ecx, [ebx + EXT2_DIR_STRUC.name_len] |
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182 | lea esi, [ebx + EXT2_DIR_STRUC.name] |
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183 | call utf8_to_cp866 |
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184 | |||
185 | mov ecx, edi |
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186 | lea edi, [esp + 4] |
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187 | sub ecx, edi ; Number of bytes in resulting string. |
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188 | |||
189 | mov esi, [esp] |
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190 | |||
191 | ; esi: original file path. |
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192 | ; edi: converted string stored on stack. |
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193 | ; ecx: size of converted string. |
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194 | @@: |
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195 | ; If no bytes left in resulting string, test it. |
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196 | jecxz .test_find |
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197 | dec ecx |
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198 | |||
199 | lodsb |
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200 | call char_toupper |
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201 | |||
202 | mov ah, [edi] |
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203 | inc edi |
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204 | xchg al, ah |
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205 | call char_toupper |
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206 | |||
207 | ; If both are same, check next byte. |
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208 | cmp al, ah |
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209 | je @B |
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210 | @@: ; Doesn't match. |
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211 | pop esi |
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212 | |||
213 | .next_rec: |
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214 | movzx eax, [ebx + EXT2_DIR_STRUC.rec_len] |
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215 | add ebx, eax ; Go to next record. |
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216 | cmp ebx, edx ; Check if this is the end. |
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217 | jb .start_rec |
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218 | |||
219 | add esp, 256 |
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220 | ret |
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221 | |||
222 | .test_find: |
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223 | cmp byte [esi], 0 |
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224 | je .ret ; The end reached. |
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225 | cmp byte [esi], '/' ; If not end of directory name, not matched. |
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226 | jne @B |
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227 | inc esi |
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228 | |||
229 | .ret: |
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230 | add esp, 256 + 4 |
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231 | ret |
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232 | |||
233 | ;--------------------------------------------------------------------- |
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234 | ; Finds free space in a directory block, modifying last entry appropriately. |
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235 | ; Input: ebp = pointer to EXTFS. |
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236 | ; ecx = size of free space required. |
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237 | ; [EXTFS.ext2_temp_block] contains the block relevant. |
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238 | ; Output: edi = free entry. |
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239 | ; rec_len of free entry is set. |
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240 | ; eax = error code; if the block doesn't link to the next one, this is 0x00000001 on failure. |
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241 | ; ; else, 0xFFFFFFFF. |
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242 | ;--------------------------------------------------------------------- |
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243 | ext2_block_find_fspace: |
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244 | push ebx edx |
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245 | |||
246 | mov edi, [ebp + EXTFS.ext2_temp_block] |
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247 | mov edx, edi |
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248 | add edx, [ebp + EXTFS.block_size] |
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249 | |||
250 | @@: |
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251 | movzx eax, [edi + EXT2_DIR_STRUC.rec_len] |
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252 | test eax, eax |
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253 | jz .zero_len |
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254 | |||
255 | cmp [edi + EXT2_DIR_STRUC.inode], 0 |
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256 | je .unused_entry |
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257 | |||
258 | ; It's a used entry, so see if we can fit it between current one and next. |
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259 | ; Subtract the size used by the name and the structure from rec_len. |
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260 | movzx ebx, [edi + EXT2_DIR_STRUC.name_len] |
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261 | add ebx, 8 + 3 |
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262 | and ebx, 0xfffffffc ; Align it on the next 4-byte boundary. |
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263 | |||
264 | sub eax, ebx |
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265 | add edi, ebx |
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266 | cmp eax, ecx |
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267 | jb .next_iter |
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268 | |||
269 | sub edi, ebx |
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270 | mov [edi + EXT2_DIR_STRUC.rec_len], bx ; Make previous entry point to us. |
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271 | add edi, ebx |
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272 | |||
273 | mov [edi + EXT2_DIR_STRUC.rec_len], ax ; Make current entry point to next one. |
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274 | jmp .found |
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275 | |||
276 | .unused_entry: |
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277 | ; It's an unused inode. |
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278 | cmp eax, ecx |
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279 | jge .found |
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280 | |||
281 | .next_iter: |
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282 | add edi, eax |
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283 | cmp edi, edx |
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284 | jb @B |
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285 | |||
286 | .not_found: |
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287 | xor eax, eax |
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288 | not eax |
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289 | jmp .ret |
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290 | |||
291 | ; Zero length entry means we have the rest of the block for us. |
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292 | .zero_len: |
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293 | mov eax, edx |
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294 | sub eax, edi |
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295 | |||
296 | ; Point to next block. |
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297 | mov [edi + EXT2_DIR_STRUC.rec_len], ax |
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298 | |||
299 | cmp eax, ecx |
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300 | jge .fits |
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301 | |||
302 | mov [edi + EXT2_DIR_STRUC.inode], 0 |
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303 | |||
304 | ; It doesn't fit, but the block doesn't link to the next block. |
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305 | xor eax, eax |
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306 | inc eax |
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307 | jmp .ret |
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308 | |||
309 | .fits: |
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310 | mov [edi + EXT2_DIR_STRUC.rec_len], cx |
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311 | |||
312 | .found: |
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313 | xor eax, eax |
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314 | |||
315 | .ret: |
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316 | pop edx ebx |
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317 | ret |
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318 | |||
319 | ;--------------------------------------------------------------------- |
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320 | ; Gets the block group's descriptor. |
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321 | ; Input: eax = block group. |
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322 | ; Output: eax = if zero, error; else, points to block group descriptor. |
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323 | ; [EXTFS.ext2_temp_block] contains relevant block. |
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324 | ; ebp = pointer to EXTFS. |
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325 | ;--------------------------------------------------------------------- |
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326 | ext2_bg_read_desc: |
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327 | push edx ebx |
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328 | mov edx, 32 |
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329 | mul edx ; Get index of descriptor in global_desc_table. |
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330 | |||
331 | ; eax: block group descriptor offset relative to global descriptor table start |
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332 | ; Find the block this block descriptor is in. |
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333 | div [ebp + EXTFS.block_size] |
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334 | add eax, [ebp + EXTFS.superblock + EXT2_SB_STRUC.first_data_block] |
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335 | inc eax |
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336 | mov ebx, [ebp + EXTFS.ext2_temp_block] |
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337 | call ext2_block_read |
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338 | test eax, eax |
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339 | jnz .fail |
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340 | |||
341 | add ebx, edx ; edx: local index of descriptor inside block |
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342 | mov eax, ebx |
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343 | |||
344 | .return: |
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345 | pop ebx edx |
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346 | ret |
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347 | |||
348 | .fail: |
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349 | xor eax, eax |
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350 | jmp .return |
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351 | |||
352 | ;--------------------------------------------------------------------- |
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353 | ; Writes a block group's descriptor. |
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354 | ; Input: eax = block group. |
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355 | ; [EXTFS.ext2_temp_data] contains the block relevant. |
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356 | ; ebp = pointer to EXTFS. |
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357 | ; Output: eax = error code. |
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358 | ;--------------------------------------------------------------------- |
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359 | ext2_bg_write_desc: |
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360 | push edx ebx |
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361 | mov edx, 32 |
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362 | mul edx ; Get index of descriptor in global_desc_table. |
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363 | |||
364 | ; eax: block group descriptor offset relative to global descriptor table start |
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365 | ; Find the block this block descriptor is in. |
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366 | div [ebp + EXTFS.block_size] |
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367 | add eax, [ebp + EXTFS.superblock + EXT2_SB_STRUC.first_data_block] |
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368 | inc eax |
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369 | mov ebx, [ebp + EXTFS.ext2_temp_block] |
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370 | call ext2_block_write |
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371 | |||
372 | .return: |
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373 | pop ebx edx |
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374 | ret |
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375 | |||
376 | ;--------------------------------------------------------------------- |
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377 | ; Gets the block group's block bitmap. |
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378 | ; Input: eax = block group. |
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379 | ; Output: eax = if zero, error; else, points to block group descriptor. |
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380 | ; ebx = block bitmap's block (hard disk). |
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381 | ;--------------------------------------------------------------------- |
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382 | ext2_bg_read_blk_bitmap: |
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383 | push ecx |
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384 | |||
385 | call ext2_bg_read_desc |
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386 | test eax, eax |
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387 | jz .fail |
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388 | |||
389 | mov ebx, [eax + EXT2_BLOCK_GROUP_DESC.block_bitmap] ; Block number of block group bitmap - in ext2 terms. |
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390 | |||
391 | .return: |
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392 | pop ecx |
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393 | ret |
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394 | |||
395 | .fail: |
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396 | xor eax, eax |
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397 | jmp .return |
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398 | |||
399 | ;--------------------------------------------------------------------- |
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400 | ; Updates superblock, plus backups. |
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401 | ; Input: ebp = pointer to EXTFS. |
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402 | ; Output: eax = error code. |
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403 | ;--------------------------------------------------------------------- |
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404 | ext2_sb_update: |
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405 | push ebx |
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406 | |||
407 | mov eax, 2 |
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408 | lea ebx, [ebp + EXTFS.superblock] |
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409 | call fs_write32_sys |
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410 | |||
411 | pop ebx |
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412 | ret |