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1 | /** @file\r | |
2 | Routines dealing with disk spaces and FAT table entries.\r | |
3 | \r | |
4 | Copyright (c) 2005 - 2013, Intel Corporation. All rights reserved.<BR>\r | |
5 | SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
6 | \r | |
7 | \r | |
8 | \r | |
9 | **/\r | |
10 | \r | |
11 | #include "Fat.h"\r | |
12 | \r | |
13 | \r | |
14 | /**\r | |
15 | \r | |
16 | Get the FAT entry of the volume, which is identified with the Index.\r | |
17 | \r | |
18 | @param Volume - FAT file system volume.\r | |
19 | @param Index - The index of the FAT entry of the volume.\r | |
20 | \r | |
21 | @return The buffer of the FAT entry\r | |
22 | \r | |
23 | **/\r | |
24 | STATIC\r | |
25 | VOID *\r | |
26 | FatLoadFatEntry (\r | |
27 | IN FAT_VOLUME *Volume,\r | |
28 | IN UINTN Index\r | |
29 | )\r | |
30 | {\r | |
31 | UINTN Pos;\r | |
32 | EFI_STATUS Status;\r | |
33 | \r | |
34 | if (Index > (Volume->MaxCluster + 1)) {\r | |
35 | Volume->FatEntryBuffer = (UINT32) -1;\r | |
36 | return &Volume->FatEntryBuffer;\r | |
37 | }\r | |
38 | //\r | |
39 | // Compute buffer position needed\r | |
40 | //\r | |
41 | switch (Volume->FatType) {\r | |
42 | case Fat12:\r | |
43 | Pos = FAT_POS_FAT12 (Index);\r | |
44 | break;\r | |
45 | \r | |
46 | case Fat16:\r | |
47 | Pos = FAT_POS_FAT16 (Index);\r | |
48 | break;\r | |
49 | \r | |
50 | default:\r | |
51 | Pos = FAT_POS_FAT32 (Index);\r | |
52 | }\r | |
53 | //\r | |
54 | // Set the position and read the buffer\r | |
55 | //\r | |
56 | Volume->FatEntryPos = Volume->FatPos + Pos;\r | |
57 | Status = FatDiskIo (\r | |
58 | Volume,\r | |
59 | ReadFat,\r | |
60 | Volume->FatEntryPos,\r | |
61 | Volume->FatEntrySize,\r | |
62 | &Volume->FatEntryBuffer,\r | |
63 | NULL\r | |
64 | );\r | |
65 | if (EFI_ERROR (Status)) {\r | |
66 | Volume->FatEntryBuffer = (UINT32) -1;\r | |
67 | }\r | |
68 | \r | |
69 | return &Volume->FatEntryBuffer;\r | |
70 | }\r | |
71 | \r | |
72 | /**\r | |
73 | \r | |
74 | Get the FAT entry value of the volume, which is identified with the Index.\r | |
75 | \r | |
76 | @param Volume - FAT file system volume.\r | |
77 | @param Index - The index of the FAT entry of the volume.\r | |
78 | \r | |
79 | @return The value of the FAT entry.\r | |
80 | \r | |
81 | **/\r | |
82 | STATIC\r | |
83 | UINTN\r | |
84 | FatGetFatEntry (\r | |
85 | IN FAT_VOLUME *Volume,\r | |
86 | IN UINTN Index\r | |
87 | )\r | |
88 | {\r | |
89 | VOID *Pos;\r | |
90 | UINT8 *En12;\r | |
91 | UINT16 *En16;\r | |
92 | UINT32 *En32;\r | |
93 | UINTN Accum;\r | |
94 | \r | |
95 | Pos = FatLoadFatEntry (Volume, Index);\r | |
96 | \r | |
97 | if (Index > (Volume->MaxCluster + 1)) {\r | |
98 | return (UINTN) -1;\r | |
99 | }\r | |
100 | \r | |
101 | switch (Volume->FatType) {\r | |
102 | case Fat12:\r | |
103 | En12 = Pos;\r | |
104 | Accum = En12[0] | (En12[1] << 8);\r | |
105 | Accum = FAT_ODD_CLUSTER_FAT12 (Index) ? (Accum >> 4) : (Accum & FAT_CLUSTER_MASK_FAT12);\r | |
106 | Accum = Accum | ((Accum >= FAT_CLUSTER_SPECIAL_FAT12) ? FAT_CLUSTER_SPECIAL_EXT : 0);\r | |
107 | break;\r | |
108 | \r | |
109 | case Fat16:\r | |
110 | En16 = Pos;\r | |
111 | Accum = *En16;\r | |
112 | Accum = Accum | ((Accum >= FAT_CLUSTER_SPECIAL_FAT16) ? FAT_CLUSTER_SPECIAL_EXT : 0);\r | |
113 | break;\r | |
114 | \r | |
115 | default:\r | |
116 | En32 = Pos;\r | |
117 | Accum = *En32 & FAT_CLUSTER_MASK_FAT32;\r | |
118 | Accum = Accum | ((Accum >= FAT_CLUSTER_SPECIAL_FAT32) ? FAT_CLUSTER_SPECIAL_EXT : 0);\r | |
119 | }\r | |
120 | \r | |
121 | return Accum;\r | |
122 | }\r | |
123 | \r | |
124 | /**\r | |
125 | \r | |
126 | Set the FAT entry value of the volume, which is identified with the Index.\r | |
127 | \r | |
128 | @param Volume - FAT file system volume.\r | |
129 | @param Index - The index of the FAT entry of the volume.\r | |
130 | @param Value - The new value of the FAT entry.\r | |
131 | \r | |
132 | @retval EFI_SUCCESS - Set the new FAT entry value successfully.\r | |
133 | @retval EFI_VOLUME_CORRUPTED - The FAT type of the volume is error.\r | |
134 | @return other - An error occurred when operation the FAT entries.\r | |
135 | \r | |
136 | **/\r | |
137 | STATIC\r | |
138 | EFI_STATUS\r | |
139 | FatSetFatEntry (\r | |
140 | IN FAT_VOLUME *Volume,\r | |
141 | IN UINTN Index,\r | |
142 | IN UINTN Value\r | |
143 | )\r | |
144 | {\r | |
145 | VOID *Pos;\r | |
146 | UINT8 *En12;\r | |
147 | UINT16 *En16;\r | |
148 | UINT32 *En32;\r | |
149 | UINTN Accum;\r | |
150 | EFI_STATUS Status;\r | |
151 | UINTN OriginalVal;\r | |
152 | \r | |
153 | if (Index < FAT_MIN_CLUSTER) {\r | |
154 | return EFI_VOLUME_CORRUPTED;\r | |
155 | }\r | |
156 | \r | |
157 | OriginalVal = FatGetFatEntry (Volume, Index);\r | |
158 | if (Value == FAT_CLUSTER_FREE && OriginalVal != FAT_CLUSTER_FREE) {\r | |
159 | Volume->FatInfoSector.FreeInfo.ClusterCount += 1;\r | |
160 | if (Index < Volume->FatInfoSector.FreeInfo.NextCluster) {\r | |
161 | Volume->FatInfoSector.FreeInfo.NextCluster = (UINT32) Index;\r | |
162 | }\r | |
163 | } else if (Value != FAT_CLUSTER_FREE && OriginalVal == FAT_CLUSTER_FREE) {\r | |
164 | if (Volume->FatInfoSector.FreeInfo.ClusterCount != 0) {\r | |
165 | Volume->FatInfoSector.FreeInfo.ClusterCount -= 1;\r | |
166 | }\r | |
167 | }\r | |
168 | //\r | |
169 | // Make sure the entry is in memory\r | |
170 | //\r | |
171 | Pos = FatLoadFatEntry (Volume, Index);\r | |
172 | \r | |
173 | //\r | |
174 | // Update the value\r | |
175 | //\r | |
176 | switch (Volume->FatType) {\r | |
177 | case Fat12:\r | |
178 | En12 = Pos;\r | |
179 | Accum = En12[0] | (En12[1] << 8);\r | |
180 | Value = Value & FAT_CLUSTER_MASK_FAT12;\r | |
181 | \r | |
182 | if (FAT_ODD_CLUSTER_FAT12 (Index)) {\r | |
183 | Accum = (Value << 4) | (Accum & 0xF);\r | |
184 | } else {\r | |
185 | Accum = Value | (Accum & FAT_CLUSTER_UNMASK_FAT12);\r | |
186 | }\r | |
187 | \r | |
188 | En12[0] = (UINT8) (Accum & 0xFF);\r | |
189 | En12[1] = (UINT8) (Accum >> 8);\r | |
190 | break;\r | |
191 | \r | |
192 | case Fat16:\r | |
193 | En16 = Pos;\r | |
194 | *En16 = (UINT16) Value;\r | |
195 | break;\r | |
196 | \r | |
197 | default:\r | |
198 | En32 = Pos;\r | |
199 | *En32 = (*En32 & FAT_CLUSTER_UNMASK_FAT32) | (UINT32) (Value & FAT_CLUSTER_MASK_FAT32);\r | |
200 | }\r | |
201 | //\r | |
202 | // If the volume's dirty bit is not set, set it now\r | |
203 | //\r | |
204 | if (!Volume->FatDirty && Volume->FatType != Fat12) {\r | |
205 | Volume->FatDirty = TRUE;\r | |
206 | FatAccessVolumeDirty (Volume, WriteFat, &Volume->DirtyValue);\r | |
207 | }\r | |
208 | //\r | |
209 | // Write the updated fat entry value to the volume\r | |
210 | // The fat is the first fat, and other fat will be in sync\r | |
211 | // when the FAT cache flush back.\r | |
212 | //\r | |
213 | Status = FatDiskIo (\r | |
214 | Volume,\r | |
215 | WriteFat,\r | |
216 | Volume->FatEntryPos,\r | |
217 | Volume->FatEntrySize,\r | |
218 | &Volume->FatEntryBuffer,\r | |
219 | NULL\r | |
220 | );\r | |
221 | return Status;\r | |
222 | }\r | |
223 | \r | |
224 | /**\r | |
225 | \r | |
226 | Free the cluster chain.\r | |
227 | \r | |
228 | @param Volume - FAT file system volume.\r | |
229 | @param Cluster - The first cluster of cluster chain.\r | |
230 | \r | |
231 | @retval EFI_SUCCESS - The cluster chain is freed successfully.\r | |
232 | @retval EFI_VOLUME_CORRUPTED - There are errors in the file's clusters.\r | |
233 | \r | |
234 | **/\r | |
235 | STATIC\r | |
236 | EFI_STATUS\r | |
237 | FatFreeClusters (\r | |
238 | IN FAT_VOLUME *Volume,\r | |
239 | IN UINTN Cluster\r | |
240 | )\r | |
241 | {\r | |
242 | UINTN LastCluster;\r | |
243 | \r | |
244 | while (!FAT_END_OF_FAT_CHAIN (Cluster)) {\r | |
245 | if (Cluster == FAT_CLUSTER_FREE || Cluster >= FAT_CLUSTER_SPECIAL) {\r | |
246 | \r | |
247 | DEBUG ((EFI_D_INIT | EFI_D_ERROR, "FatShrinkEof: cluster chain corrupt\n"));\r | |
248 | return EFI_VOLUME_CORRUPTED;\r | |
249 | }\r | |
250 | \r | |
251 | LastCluster = Cluster;\r | |
252 | Cluster = FatGetFatEntry (Volume, Cluster);\r | |
253 | FatSetFatEntry (Volume, LastCluster, FAT_CLUSTER_FREE);\r | |
254 | }\r | |
255 | \r | |
256 | return EFI_SUCCESS;\r | |
257 | }\r | |
258 | \r | |
259 | /**\r | |
260 | \r | |
261 | Allocate a free cluster and return the cluster index.\r | |
262 | \r | |
263 | @param Volume - FAT file system volume.\r | |
264 | \r | |
265 | @return The index of the free cluster\r | |
266 | \r | |
267 | **/\r | |
268 | STATIC\r | |
269 | UINTN\r | |
270 | FatAllocateCluster (\r | |
271 | IN FAT_VOLUME *Volume\r | |
272 | )\r | |
273 | {\r | |
274 | UINTN Cluster;\r | |
275 | \r | |
276 | //\r | |
277 | // Start looking at FatFreePos for the next unallocated cluster\r | |
278 | //\r | |
279 | if (Volume->DiskError) {\r | |
280 | return (UINTN) FAT_CLUSTER_LAST;\r | |
281 | }\r | |
282 | \r | |
283 | for (;;) {\r | |
284 | //\r | |
285 | // If the end of the list, return no available cluster\r | |
286 | //\r | |
287 | if (Volume->FatInfoSector.FreeInfo.NextCluster > (Volume->MaxCluster + 1)) {\r | |
288 | if (Volume->FreeInfoValid && 0 < (INT32) (Volume->FatInfoSector.FreeInfo.ClusterCount)) {\r | |
289 | Volume->FreeInfoValid = FALSE;\r | |
290 | }\r | |
291 | \r | |
292 | FatComputeFreeInfo (Volume);\r | |
293 | if (Volume->FatInfoSector.FreeInfo.NextCluster > (Volume->MaxCluster + 1)) {\r | |
294 | return (UINTN) FAT_CLUSTER_LAST;\r | |
295 | }\r | |
296 | }\r | |
297 | \r | |
298 | Cluster = FatGetFatEntry (Volume, Volume->FatInfoSector.FreeInfo.NextCluster);\r | |
299 | if (Cluster == FAT_CLUSTER_FREE) {\r | |
300 | break;\r | |
301 | }\r | |
302 | //\r | |
303 | // Try the next cluster\r | |
304 | //\r | |
305 | Volume->FatInfoSector.FreeInfo.NextCluster += 1;\r | |
306 | }\r | |
307 | \r | |
308 | Cluster = Volume->FatInfoSector.FreeInfo.NextCluster;\r | |
309 | Volume->FatInfoSector.FreeInfo.NextCluster += 1;\r | |
310 | return Cluster;\r | |
311 | }\r | |
312 | \r | |
313 | /**\r | |
314 | \r | |
315 | Count the number of clusters given a size.\r | |
316 | \r | |
317 | @param Volume - The file system volume.\r | |
318 | @param Size - The size in bytes.\r | |
319 | \r | |
320 | @return The number of the clusters.\r | |
321 | \r | |
322 | **/\r | |
323 | STATIC\r | |
324 | UINTN\r | |
325 | FatSizeToClusters (\r | |
326 | IN FAT_VOLUME *Volume,\r | |
327 | IN UINTN Size\r | |
328 | )\r | |
329 | {\r | |
330 | UINTN Clusters;\r | |
331 | \r | |
332 | Clusters = Size >> Volume->ClusterAlignment;\r | |
333 | if ((Size & (Volume->ClusterSize - 1)) > 0) {\r | |
334 | Clusters += 1;\r | |
335 | }\r | |
336 | \r | |
337 | return Clusters;\r | |
338 | }\r | |
339 | \r | |
340 | /**\r | |
341 | \r | |
342 | Shrink the end of the open file base on the file size.\r | |
343 | \r | |
344 | @param OFile - The open file.\r | |
345 | \r | |
346 | @retval EFI_SUCCESS - Shrinked successfully.\r | |
347 | @retval EFI_VOLUME_CORRUPTED - There are errors in the file's clusters.\r | |
348 | \r | |
349 | **/\r | |
350 | EFI_STATUS\r | |
351 | FatShrinkEof (\r | |
352 | IN FAT_OFILE *OFile\r | |
353 | )\r | |
354 | {\r | |
355 | FAT_VOLUME *Volume;\r | |
356 | UINTN NewSize;\r | |
357 | UINTN CurSize;\r | |
358 | UINTN Cluster;\r | |
359 | UINTN LastCluster;\r | |
360 | \r | |
361 | Volume = OFile->Volume;\r | |
362 | ASSERT_VOLUME_LOCKED (Volume);\r | |
363 | \r | |
364 | NewSize = FatSizeToClusters (Volume, OFile->FileSize);\r | |
365 | \r | |
366 | //\r | |
367 | // Find the address of the last cluster\r | |
368 | //\r | |
369 | Cluster = OFile->FileCluster;\r | |
370 | LastCluster = FAT_CLUSTER_FREE;\r | |
371 | \r | |
372 | if (NewSize != 0) {\r | |
373 | \r | |
374 | for (CurSize = 0; CurSize < NewSize; CurSize++) {\r | |
375 | if (Cluster == FAT_CLUSTER_FREE || Cluster >= FAT_CLUSTER_SPECIAL) {\r | |
376 | \r | |
377 | DEBUG ((EFI_D_INIT | EFI_D_ERROR, "FatShrinkEof: cluster chain corrupt\n"));\r | |
378 | return EFI_VOLUME_CORRUPTED;\r | |
379 | }\r | |
380 | \r | |
381 | LastCluster = Cluster;\r | |
382 | Cluster = FatGetFatEntry (Volume, Cluster);\r | |
383 | }\r | |
384 | \r | |
385 | FatSetFatEntry (Volume, LastCluster, (UINTN) FAT_CLUSTER_LAST);\r | |
386 | \r | |
387 | } else {\r | |
388 | //\r | |
389 | // Check to see if the file is already completely truncated\r | |
390 | //\r | |
391 | if (Cluster == FAT_CLUSTER_FREE) {\r | |
392 | return EFI_SUCCESS;\r | |
393 | }\r | |
394 | //\r | |
395 | // The file is being completely truncated.\r | |
396 | //\r | |
397 | OFile->FileCluster = FAT_CLUSTER_FREE;\r | |
398 | }\r | |
399 | //\r | |
400 | // Set CurrentCluster == FileCluster\r | |
401 | // to force a recalculation of Position related stuffs\r | |
402 | //\r | |
403 | OFile->FileCurrentCluster = OFile->FileCluster;\r | |
404 | OFile->FileLastCluster = LastCluster;\r | |
405 | OFile->Dirty = TRUE;\r | |
406 | //\r | |
407 | // Free the remaining cluster chain\r | |
408 | //\r | |
409 | return FatFreeClusters (Volume, Cluster);\r | |
410 | }\r | |
411 | \r | |
412 | /**\r | |
413 | \r | |
414 | Grow the end of the open file base on the NewSizeInBytes.\r | |
415 | \r | |
416 | @param OFile - The open file.\r | |
417 | @param NewSizeInBytes - The new size in bytes of the open file.\r | |
418 | \r | |
419 | @retval EFI_SUCCESS - The file is grown successfully.\r | |
420 | @retval EFI_UNSUPPORTED - The file size is larger than 4GB.\r | |
421 | @retval EFI_VOLUME_CORRUPTED - There are errors in the files' clusters.\r | |
422 | @retval EFI_VOLUME_FULL - The volume is full and can not grow the file.\r | |
423 | \r | |
424 | **/\r | |
425 | EFI_STATUS\r | |
426 | FatGrowEof (\r | |
427 | IN FAT_OFILE *OFile,\r | |
428 | IN UINT64 NewSizeInBytes\r | |
429 | )\r | |
430 | {\r | |
431 | FAT_VOLUME *Volume;\r | |
432 | EFI_STATUS Status;\r | |
433 | UINTN Cluster;\r | |
434 | UINTN CurSize;\r | |
435 | UINTN NewSize;\r | |
436 | UINTN LastCluster;\r | |
437 | UINTN NewCluster;\r | |
438 | UINTN ClusterCount;\r | |
439 | \r | |
440 | //\r | |
441 | // For FAT file system, the max file is 4GB.\r | |
442 | //\r | |
443 | if (NewSizeInBytes > 0x0FFFFFFFFL) {\r | |
444 | return EFI_UNSUPPORTED;\r | |
445 | }\r | |
446 | \r | |
447 | Volume = OFile->Volume;\r | |
448 | ASSERT_VOLUME_LOCKED (Volume);\r | |
449 | //\r | |
450 | // If the file is already large enough, do nothing\r | |
451 | //\r | |
452 | CurSize = FatSizeToClusters (Volume, OFile->FileSize);\r | |
453 | NewSize = FatSizeToClusters (Volume, (UINTN) NewSizeInBytes);\r | |
454 | \r | |
455 | if (CurSize < NewSize) {\r | |
456 | //\r | |
457 | // If we haven't found the files last cluster do it now\r | |
458 | //\r | |
459 | if ((OFile->FileCluster != 0) && (OFile->FileLastCluster == 0)) {\r | |
460 | Cluster = OFile->FileCluster;\r | |
461 | ClusterCount = 0;\r | |
462 | \r | |
463 | while (!FAT_END_OF_FAT_CHAIN (Cluster)) {\r | |
464 | if (Cluster < FAT_MIN_CLUSTER || Cluster > Volume->MaxCluster + 1) {\r | |
465 | \r | |
466 | DEBUG (\r | |
467 | (EFI_D_INIT | EFI_D_ERROR,\r | |
468 | "FatGrowEof: cluster chain corrupt\n")\r | |
469 | );\r | |
470 | Status = EFI_VOLUME_CORRUPTED;\r | |
471 | goto Done;\r | |
472 | }\r | |
473 | \r | |
474 | ClusterCount++;\r | |
475 | OFile->FileLastCluster = Cluster;\r | |
476 | Cluster = FatGetFatEntry (Volume, Cluster);\r | |
477 | }\r | |
478 | \r | |
479 | if (ClusterCount != CurSize) {\r | |
480 | DEBUG (\r | |
481 | (EFI_D_INIT | EFI_D_ERROR,\r | |
482 | "FatGrowEof: cluster chain size does not match file size\n")\r | |
483 | );\r | |
484 | Status = EFI_VOLUME_CORRUPTED;\r | |
485 | goto Done;\r | |
486 | }\r | |
487 | \r | |
488 | }\r | |
489 | //\r | |
490 | // Loop until we've allocated enough space\r | |
491 | //\r | |
492 | LastCluster = OFile->FileLastCluster;\r | |
493 | \r | |
494 | while (CurSize < NewSize) {\r | |
495 | NewCluster = FatAllocateCluster (Volume);\r | |
496 | if (FAT_END_OF_FAT_CHAIN (NewCluster)) {\r | |
497 | if (LastCluster != FAT_CLUSTER_FREE) {\r | |
498 | FatSetFatEntry (Volume, LastCluster, (UINTN) FAT_CLUSTER_LAST);\r | |
499 | OFile->FileLastCluster = LastCluster;\r | |
500 | }\r | |
501 | \r | |
502 | Status = EFI_VOLUME_FULL;\r | |
503 | goto Done;\r | |
504 | }\r | |
505 | \r | |
506 | if (NewCluster < FAT_MIN_CLUSTER || NewCluster > Volume->MaxCluster + 1) {\r | |
507 | Status = EFI_VOLUME_CORRUPTED;\r | |
508 | goto Done;\r | |
509 | }\r | |
510 | \r | |
511 | if (LastCluster != 0) {\r | |
512 | FatSetFatEntry (Volume, LastCluster, NewCluster);\r | |
513 | } else {\r | |
514 | OFile->FileCluster = NewCluster;\r | |
515 | OFile->FileCurrentCluster = NewCluster;\r | |
516 | }\r | |
517 | \r | |
518 | LastCluster = NewCluster;\r | |
519 | CurSize += 1;\r | |
520 | \r | |
521 | //\r | |
522 | // Terminate the cluster list\r | |
523 | //\r | |
524 | // Note that we must do this EVERY time we allocate a cluster, because\r | |
525 | // FatAllocateCluster scans the FAT looking for a free cluster and\r | |
526 | // "LastCluster" is no longer free! Usually, FatAllocateCluster will\r | |
527 | // start looking with the cluster after "LastCluster"; however, when\r | |
528 | // there is only one free cluster left, it will find "LastCluster"\r | |
529 | // a second time. There are other, less predictable scenarios\r | |
530 | // where this could happen, as well.\r | |
531 | //\r | |
532 | FatSetFatEntry (Volume, LastCluster, (UINTN) FAT_CLUSTER_LAST);\r | |
533 | OFile->FileLastCluster = LastCluster;\r | |
534 | }\r | |
535 | }\r | |
536 | \r | |
537 | OFile->FileSize = (UINTN) NewSizeInBytes;\r | |
538 | OFile->Dirty = TRUE;\r | |
539 | return EFI_SUCCESS;\r | |
540 | \r | |
541 | Done:\r | |
542 | FatShrinkEof (OFile);\r | |
543 | return Status;\r | |
544 | }\r | |
545 | \r | |
546 | /**\r | |
547 | \r | |
548 | Seek OFile to requested position, and calculate the number of\r | |
549 | consecutive clusters from the position in the file\r | |
550 | \r | |
551 | @param OFile - The open file.\r | |
552 | @param Position - The file's position which will be accessed.\r | |
553 | @param PosLimit - The maximum length current reading/writing may access\r | |
554 | \r | |
555 | @retval EFI_SUCCESS - Set the info successfully.\r | |
556 | @retval EFI_VOLUME_CORRUPTED - Cluster chain corrupt.\r | |
557 | \r | |
558 | **/\r | |
559 | EFI_STATUS\r | |
560 | FatOFilePosition (\r | |
561 | IN FAT_OFILE *OFile,\r | |
562 | IN UINTN Position,\r | |
563 | IN UINTN PosLimit\r | |
564 | )\r | |
565 | {\r | |
566 | FAT_VOLUME *Volume;\r | |
567 | UINTN ClusterSize;\r | |
568 | UINTN Cluster;\r | |
569 | UINTN StartPos;\r | |
570 | UINTN Run;\r | |
571 | \r | |
572 | Volume = OFile->Volume;\r | |
573 | ClusterSize = Volume->ClusterSize;\r | |
574 | \r | |
575 | ASSERT_VOLUME_LOCKED (Volume);\r | |
576 | \r | |
577 | //\r | |
578 | // If this is the fixed root dir, then compute its position\r | |
579 | // from its fixed info in the fat bpb\r | |
580 | //\r | |
581 | if (OFile->IsFixedRootDir) {\r | |
582 | OFile->PosDisk = Volume->RootPos + Position;\r | |
583 | Run = OFile->FileSize - Position;\r | |
584 | } else {\r | |
585 | //\r | |
586 | // Run the file's cluster chain to find the current position\r | |
587 | // If possible, run from the current cluster rather than\r | |
588 | // start from beginning\r | |
589 | // Assumption: OFile->Position is always consistent with\r | |
590 | // OFile->FileCurrentCluster.\r | |
591 | // OFile->Position is not modified outside this function;\r | |
592 | // OFile->FileCurrentCluster is modified outside this function\r | |
593 | // to be the same as OFile->FileCluster\r | |
594 | // when OFile->FileCluster is updated, so make a check of this\r | |
595 | // and invalidate the original OFile->Position in this case\r | |
596 | //\r | |
597 | Cluster = OFile->FileCurrentCluster;\r | |
598 | StartPos = OFile->Position;\r | |
599 | if (Position < StartPos || OFile->FileCluster == Cluster) {\r | |
600 | StartPos = 0;\r | |
601 | Cluster = OFile->FileCluster;\r | |
602 | }\r | |
603 | \r | |
604 | while (StartPos + ClusterSize <= Position) {\r | |
605 | StartPos += ClusterSize;\r | |
606 | if (Cluster == FAT_CLUSTER_FREE || (Cluster >= FAT_CLUSTER_SPECIAL)) {\r | |
607 | DEBUG ((EFI_D_INIT | EFI_D_ERROR, "FatOFilePosition:"" cluster chain corrupt\n"));\r | |
608 | return EFI_VOLUME_CORRUPTED;\r | |
609 | }\r | |
610 | \r | |
611 | Cluster = FatGetFatEntry (Volume, Cluster);\r | |
612 | }\r | |
613 | \r | |
614 | if (Cluster < FAT_MIN_CLUSTER || Cluster > Volume->MaxCluster + 1) {\r | |
615 | return EFI_VOLUME_CORRUPTED;\r | |
616 | }\r | |
617 | \r | |
618 | OFile->PosDisk = Volume->FirstClusterPos +\r | |
619 | LShiftU64 (Cluster - FAT_MIN_CLUSTER, Volume->ClusterAlignment) +\r | |
620 | Position - StartPos;\r | |
621 | OFile->FileCurrentCluster = Cluster;\r | |
622 | OFile->Position = StartPos;\r | |
623 | \r | |
624 | //\r | |
625 | // Compute the number of consecutive clusters in the file\r | |
626 | //\r | |
627 | Run = StartPos + ClusterSize - Position;\r | |
628 | if (!FAT_END_OF_FAT_CHAIN (Cluster)) {\r | |
629 | while ((FatGetFatEntry (Volume, Cluster) == Cluster + 1) && Run < PosLimit) {\r | |
630 | Run += ClusterSize;\r | |
631 | Cluster += 1;\r | |
632 | }\r | |
633 | }\r | |
634 | }\r | |
635 | \r | |
636 | OFile->PosRem = Run;\r | |
637 | return EFI_SUCCESS;\r | |
638 | }\r | |
639 | \r | |
640 | /**\r | |
641 | \r | |
642 | Get the size of directory of the open file.\r | |
643 | \r | |
644 | @param Volume - The File System Volume.\r | |
645 | @param Cluster - The Starting cluster.\r | |
646 | \r | |
647 | @return The physical size of the file starting at the input cluster, if there is error in the\r | |
648 | cluster chain, the return value is 0.\r | |
649 | \r | |
650 | **/\r | |
651 | UINTN\r | |
652 | FatPhysicalDirSize (\r | |
653 | IN FAT_VOLUME *Volume,\r | |
654 | IN UINTN Cluster\r | |
655 | )\r | |
656 | {\r | |
657 | UINTN Size;\r | |
658 | ASSERT_VOLUME_LOCKED (Volume);\r | |
659 | //\r | |
660 | // Run the cluster chain for the OFile\r | |
661 | //\r | |
662 | Size = 0;\r | |
663 | //\r | |
664 | // N.B. ".." directories on some media do not contain a starting\r | |
665 | // cluster. In the case of "." or ".." we don't need the size anyway.\r | |
666 | //\r | |
667 | if (Cluster != 0) {\r | |
668 | while (!FAT_END_OF_FAT_CHAIN (Cluster)) {\r | |
669 | if (Cluster == FAT_CLUSTER_FREE || Cluster >= FAT_CLUSTER_SPECIAL) {\r | |
670 | DEBUG (\r | |
671 | (EFI_D_INIT | EFI_D_ERROR,\r | |
672 | "FATDirSize: cluster chain corrupt\n")\r | |
673 | );\r | |
674 | return 0;\r | |
675 | }\r | |
676 | \r | |
677 | Size += Volume->ClusterSize;\r | |
678 | Cluster = FatGetFatEntry (Volume, Cluster);\r | |
679 | }\r | |
680 | }\r | |
681 | \r | |
682 | return Size;\r | |
683 | }\r | |
684 | \r | |
685 | /**\r | |
686 | \r | |
687 | Get the physical size of a file on the disk.\r | |
688 | \r | |
689 | @param Volume - The file system volume.\r | |
690 | @param RealSize - The real size of a file.\r | |
691 | \r | |
692 | @return The physical size of a file on the disk.\r | |
693 | \r | |
694 | **/\r | |
695 | UINT64\r | |
696 | FatPhysicalFileSize (\r | |
697 | IN FAT_VOLUME *Volume,\r | |
698 | IN UINTN RealSize\r | |
699 | )\r | |
700 | {\r | |
701 | UINTN ClusterSizeMask;\r | |
702 | UINT64 PhysicalSize;\r | |
703 | ClusterSizeMask = Volume->ClusterSize - 1;\r | |
704 | PhysicalSize = (RealSize + ClusterSizeMask) & (~((UINT64) ClusterSizeMask));\r | |
705 | return PhysicalSize;\r | |
706 | }\r | |
707 | \r | |
708 | /**\r | |
709 | \r | |
710 | Update the free cluster info of FatInfoSector of the volume.\r | |
711 | \r | |
712 | @param Volume - FAT file system volume.\r | |
713 | \r | |
714 | **/\r | |
715 | VOID\r | |
716 | FatComputeFreeInfo (\r | |
717 | IN FAT_VOLUME *Volume\r | |
718 | )\r | |
719 | {\r | |
720 | UINTN Index;\r | |
721 | \r | |
722 | //\r | |
723 | // If we don't have valid info, compute it now\r | |
724 | //\r | |
725 | if (!Volume->FreeInfoValid) {\r | |
726 | \r | |
727 | Volume->FreeInfoValid = TRUE;\r | |
728 | Volume->FatInfoSector.FreeInfo.ClusterCount = 0;\r | |
729 | for (Index = Volume->MaxCluster + 1; Index >= FAT_MIN_CLUSTER; Index--) {\r | |
730 | if (Volume->DiskError) {\r | |
731 | break;\r | |
732 | }\r | |
733 | \r | |
734 | if (FatGetFatEntry (Volume, Index) == FAT_CLUSTER_FREE) {\r | |
735 | Volume->FatInfoSector.FreeInfo.ClusterCount += 1;\r | |
736 | Volume->FatInfoSector.FreeInfo.NextCluster = (UINT32) Index;\r | |
737 | }\r | |
738 | }\r | |
739 | \r | |
740 | Volume->FatInfoSector.Signature = FAT_INFO_SIGNATURE;\r | |
741 | Volume->FatInfoSector.InfoBeginSignature = FAT_INFO_BEGIN_SIGNATURE;\r | |
742 | Volume->FatInfoSector.InfoEndSignature = FAT_INFO_END_SIGNATURE;\r | |
743 | }\r | |
744 | }\r |