1 | /*␊ |
2 | * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.␊ |
3 | *␊ |
4 | * @APPLE_LICENSE_HEADER_START@␊ |
5 | * ␊ |
6 | * The contents of this file constitute Original Code as defined in and␊ |
7 | * are subject to the Apple Public Source License Version 2.0 (the␊ |
8 | * "License"). You may not use this file except in compliance with the␊ |
9 | * License. Please obtain a copy of the License at␊ |
10 | * http://www.apple.com/publicsource and read it before using this file.␊ |
11 | * ␊ |
12 | * This Original Code and all software distributed under the License are␊ |
13 | * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER␊ |
14 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,␊ |
15 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,␊ |
16 | * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the␊ |
17 | * License for the specific language governing rights and limitations␊ |
18 | * under the License.␊ |
19 | * ␊ |
20 | * @APPLE_LICENSE_HEADER_END@␊ |
21 | */␊ |
22 | /*␊ |
23 | * ufs.c - File System Module for UFS.␊ |
24 | *␊ |
25 | * Copyright (c) 1998-2002 Apple Computer, Inc.␊ |
26 | *␊ |
27 | * DRI: Josh de Cesare␊ |
28 | */␊ |
29 | ␊ |
30 | //#include <sl.h>␊ |
31 | #include "sl.h" //Azi:???␊ |
32 | ␊ |
33 | #include "ufs.h"␊ |
34 | #include "ufs_byteorder.h"␊ |
35 | ␊ |
36 | #if !defined(MAXNAMLEN) && defined(UFSMAXNAMLEN)␊ |
37 | #define MAXNAMLEN UFSMAXNAMLEN␊ |
38 | #endif␊ |
39 | ␊ |
40 | typedef struct dinode Inode, *InodePtr;␊ |
41 | ␊ |
42 | // Private function prototypes␊ |
43 | ␊ |
44 | static char *ReadBlock(long fragNum, long fragOffset, long length,␊ |
45 | char *buffer, long cache);␊ |
46 | static long ReadInode(long inodeNum, InodePtr inode, long *flags, long *time);␊ |
47 | static long ResolvePathToInode(char *filePath, long *flags,␊ |
48 | InodePtr fileInode, InodePtr dirInode);␊ |
49 | static long ReadDirEntry(InodePtr dirInode, long *fileInodeNum,␊ |
50 | long long *dirIndex, char **name);␊ |
51 | static long FindFileInDir(char *fileName, long *flags,␊ |
52 | InodePtr fileInode, InodePtr dirInode);␊ |
53 | static char *ReadFileBlock(InodePtr fileInode, long fragNum, long blockOffset,␊ |
54 | long length, char *buffer, long cache);␊ |
55 | static long ReadFile(InodePtr fileInode, uint64_t *length, void *base, uint64_t offset);␊ |
56 | ␊ |
57 | #define kDevBlockSize (0x200) // Size of each disk block.␊ |
58 | #define kDiskLabelBlock (15) // Block the DL is in.␊ |
59 | ␊ |
60 | #ifdef __i386__␊ |
61 | ␊ |
62 | static CICell gCurrentIH;␊ |
63 | static long long gPartitionBase;␊ |
64 | static char *gULBuf;␊ |
65 | static char *gFSBuf;␊ |
66 | static struct fs *gFS;␊ |
67 | #if !BOOT1␊ |
68 | static struct ufslabel gUFSLabel; // for UUID␊ |
69 | #endif␊ |
70 | static long gBlockSize;␊ |
71 | static long gFragSize;␊ |
72 | static long gFragsPerBlock;␊ |
73 | static char *gTempBlock;␊ |
74 | static char *gTempName;␊ |
75 | static char *gTempName2;␊ |
76 | static InodePtr gRootInodePtr;␊ |
77 | static InodePtr gFileInodePtr;␊ |
78 | ␊ |
79 | #else /* !__i386__ */␊ |
80 | ␊ |
81 | static CICell gCurrentIH;␊ |
82 | static long long gPartitionBase;␊ |
83 | static char gDLBuf[8192];␊ |
84 | static char gFSBuf[SBSIZE];␊ |
85 | static struct fs *gFS;␊ |
86 | #if !BOOT1␊ |
87 | static struct ufslabel gUFSLabel; // for UUID␊ |
88 | #endif␊ |
89 | static long gBlockSize;␊ |
90 | static long gFragSize;␊ |
91 | static long gFragsPerBlock;␊ |
92 | static char *gTempBlock;␊ |
93 | static char gTempName[MAXNAMLEN + 1];␊ |
94 | static char gTempName2[MAXNAMLEN + 1];␊ |
95 | static Inode _gRootInode;␊ |
96 | static Inode _gFileInode;␊ |
97 | static InodePtr gRootInodePtr = &_gRootInode;␊ |
98 | static InodePtr gFileInodePtr = &_gFileInode;␊ |
99 | ␊ |
100 | #endif /* !__i386__ */␊ |
101 | ␊ |
102 | // Public functions␊ |
103 | ␊ |
104 | void UFSFree(CICell ih)␊ |
105 | {␊ |
106 | if(gCurrentIH == ih)␊ |
107 | gCurrentIH = 0;␊ |
108 | free(ih);␊ |
109 | }␊ |
110 | ␊ |
111 | long UFSInitPartition( CICell ih )␊ |
112 | {␊ |
113 | #if !BOOT1␊ |
114 | long ret;␊ |
115 | #endif␊ |
116 | ␊ |
117 | if (ih == gCurrentIH) {␊ |
118 | #ifdef __i386__␊ |
119 | CacheInit(ih, gBlockSize);␊ |
120 | #endif␊ |
121 | return 0;␊ |
122 | }␊ |
123 | ␊ |
124 | #if !BOOT1␊ |
125 | verbose("UFSInitPartition: %x\n", ih);␊ |
126 | #endif␊ |
127 | ␊ |
128 | gCurrentIH = 0;␊ |
129 | ␊ |
130 | #ifdef __i386__␊ |
131 | if (!gULBuf) gULBuf = (char *) malloc(UFS_LABEL_SIZE);␊ |
132 | if (!gFSBuf) gFSBuf = (char *) malloc(SBSIZE);␊ |
133 | if (!gTempName) gTempName = (char *) malloc(MAXNAMLEN + 1);␊ |
134 | if (!gTempName2) gTempName2 = (char *) malloc(MAXNAMLEN + 1);␊ |
135 | if (!gRootInodePtr) gRootInodePtr = (InodePtr) malloc(sizeof(Inode));␊ |
136 | if (!gFileInodePtr) gFileInodePtr = (InodePtr) malloc(sizeof(Inode));␊ |
137 | if (!gULBuf || !gFSBuf || !gTempName || !gTempName2 ||␊ |
138 | !gRootInodePtr || !gFileInodePtr) return -1;␊ |
139 | #endif␊ |
140 | ␊ |
141 | // Assume there is no Disk Label␊ |
142 | gPartitionBase = 0;␊ |
143 | ␊ |
144 | #if !BOOT1␊ |
145 | // read the disk label to get the UUID␊ |
146 | // (rumor has it that UFS headers can be either-endian on disk; hopefully␊ |
147 | // that isn't true for this UUID field).␊ |
148 | Seek(ih, gPartitionBase + UFS_LABEL_OFFSET);␊ |
149 | ret = Read(ih, (long)&gUFSLabel, UFS_LABEL_SIZE);␊ |
150 | if(ret != 0)␊ |
151 | bzero(&gUFSLabel, UFS_LABEL_SIZE);␊ |
152 | #endif /* !BOOT1 */␊ |
153 | ␊ |
154 | // Look for the Super Block␊ |
155 | Seek(ih, gPartitionBase + SBOFF);␊ |
156 | Read(ih, (long)gFSBuf, SBSIZE);␊ |
157 | ␊ |
158 | gFS = (struct fs *)gFSBuf;␊ |
159 | byte_swap_superblock(gFS);␊ |
160 | ␊ |
161 | if (gFS->fs_magic != FS_MAGIC) {␊ |
162 | return -1;␊ |
163 | }␊ |
164 | ␊ |
165 | ␉ih->modTime = gFS->fs_time;␊ |
166 | ␉␊ |
167 | // Calculate the block size and set up the block cache.␊ |
168 | gBlockSize = gFS->fs_bsize;␊ |
169 | gFragSize = gFS->fs_fsize;␊ |
170 | gFragsPerBlock = gBlockSize / gFragSize;␊ |
171 | if (gTempBlock != 0) free(gTempBlock);␊ |
172 | gTempBlock = malloc(gBlockSize);␊ |
173 | CacheInit(ih, gBlockSize);␊ |
174 | ␊ |
175 | gCurrentIH = ih;␊ |
176 | ␊ |
177 | // Read the Root Inode␊ |
178 | ReadInode(ROOTINO, gRootInodePtr, 0, 0);␊ |
179 | ␊ |
180 | return 0;␊ |
181 | }␊ |
182 | ␊ |
183 | #if !BOOT1␊ |
184 | ␊ |
185 | long UFSGetUUID(CICell ih, char *uuidStr)␊ |
186 | {␊ |
187 | long long uuid = gUFSLabel.ul_uuid;␊ |
188 | ␊ |
189 | if (UFSInitPartition(ih) == -1) return -1;␊ |
190 | if (uuid == 0LL) return -1;␊ |
191 | ␊ |
192 | return CreateUUIDString((uint8_t*)(&uuid), sizeof(uuid), uuidStr);␊ |
193 | }␊ |
194 | ␊ |
195 | #endif /* !BOOT1 */␊ |
196 | ␊ |
197 | long UFSLoadFile( CICell ih, char * filePath )␊ |
198 | {␊ |
199 | return UFSReadFile(ih, filePath, (void *)gFSLoadAddress, 0, 0);␊ |
200 | }␊ |
201 | ␊ |
202 | long UFSReadFile( CICell ih, char * filePath, void * base, uint64_t offset, uint64_t length )␊ |
203 | {␊ |
204 | long ret, flags;␊ |
205 | ␊ |
206 | #if !BOOT1␊ |
207 | verbose("Loading UFS file: [%s] from %x.\n", filePath, (unsigned)ih);␊ |
208 | #endif␊ |
209 | ␊ |
210 | if (UFSInitPartition(ih) == -1) return -1;␊ |
211 | ␊ |
212 | // Skip one or two leading '/'.␊ |
213 | if (*filePath == '/') filePath++;␊ |
214 | if (*filePath == '/') filePath++;␊ |
215 | ␊ |
216 | ret = ResolvePathToInode(filePath, &flags, gFileInodePtr, gRootInodePtr);␊ |
217 | if ((ret == -1) || ((flags & kFileTypeMask) != kFileTypeFlat)) return -1;␊ |
218 | ␊ |
219 | ret = ReadFile(gFileInodePtr, &length, base, offset);␊ |
220 | if (ret == -1) return -1;␊ |
221 | ␊ |
222 | return length;␊ |
223 | }␊ |
224 | ␊ |
225 | #ifndef BOOT1␊ |
226 | ␊ |
227 | long UFSGetDirEntry( CICell ih, char * dirPath, long long * dirIndex,␊ |
228 | char ** name, long * flags, long * time,␊ |
229 | FinderInfo * finderInfo, long * infoValid)␊ |
230 | {␊ |
231 | long ret, fileInodeNum, dirFlags;␊ |
232 | Inode tmpInode;␊ |
233 | ␊ |
234 | if (UFSInitPartition(ih) == -1) return -1;␊ |
235 | ␊ |
236 | if (infoValid) *infoValid = 0;␊ |
237 | ␊ |
238 | // Skip a leading '/' if present␊ |
239 | if (*dirPath == '/') dirPath++;␊ |
240 | if (*dirPath == '/') dirPath++;␊ |
241 | ␊ |
242 | ret = ResolvePathToInode(dirPath, &dirFlags, gFileInodePtr, gRootInodePtr);␊ |
243 | if ((ret == -1) || ((dirFlags & kFileTypeMask) != kFileTypeDirectory))␊ |
244 | return -1;␊ |
245 | ␊ |
246 | ret = ReadDirEntry(gFileInodePtr, &fileInodeNum, dirIndex, name);␊ |
247 | if (ret != 0) return ret;␊ |
248 | ␊ |
249 | ReadInode(fileInodeNum, &tmpInode, flags, time);␊ |
250 | ␊ |
251 | return 0;␊ |
252 | }␊ |
253 | ␊ |
254 | void␊ |
255 | UFSGetDescription(CICell ih, char *str, long strMaxLen)␊ |
256 | {␊ |
257 | if (UFSInitPartition(ih) == -1) { return; }␊ |
258 | ␊ |
259 | struct ufslabel *ul;␊ |
260 | ␊ |
261 | // Look for the Disk Label␊ |
262 | Seek(ih, 1ULL * UFS_LABEL_OFFSET);␊ |
263 | Read(ih, (long)gULBuf, UFS_LABEL_SIZE);␊ |
264 | ␊ |
265 | ul = (struct ufslabel *)gULBuf;␊ |
266 | ␊ |
267 | unsigned char magic_bytes[] = UFS_LABEL_MAGIC;␊ |
268 | int i;␊ |
269 | unsigned char *p = (unsigned char *)&ul->ul_magic;␊ |
270 | ␊ |
271 | for (i=0; i<sizeof(magic_bytes); i++, p++) {␊ |
272 | if (*p != magic_bytes[i])␊ |
273 | return;␊ |
274 | }␊ |
275 | strncpy(str, (const char *)ul->ul_name, strMaxLen);␊ |
276 | }␊ |
277 | ␊ |
278 | long␊ |
279 | UFSGetFileBlock(CICell ih, char *filePath, unsigned long long *firstBlock)␊ |
280 | {␊ |
281 | long ret, flags;␊ |
282 | ␊ |
283 | if (UFSInitPartition(ih) == -1) return -1;␊ |
284 | ␊ |
285 | // Skip one or two leading '/'.␊ |
286 | if (*filePath == '/') filePath++;␊ |
287 | if (*filePath == '/') filePath++;␊ |
288 | ␊ |
289 | ret = ResolvePathToInode(filePath, &flags, gFileInodePtr, gRootInodePtr);␊ |
290 | if ((ret == -1) || ((flags & kFileTypeMask) != kFileTypeFlat)) return -1;␊ |
291 | ␊ |
292 | *firstBlock = (gPartitionBase + 1ULL * gFileInodePtr->di_db[0] * gBlockSize) / 512ULL;␊ |
293 | ␊ |
294 | return 0;␊ |
295 | }␊ |
296 | ␊ |
297 | ␊ |
298 | #endif /* !BOOT1 */␊ |
299 | ␊ |
300 | // Private functions␊ |
301 | ␊ |
302 | static char * ReadBlock( long fragNum, long blockOffset, long length,␊ |
303 | char * buffer, long cache )␊ |
304 | {␊ |
305 | long long offset;␊ |
306 | long blockNum;␊ |
307 | ␊ |
308 | blockNum = fragNum / gFragsPerBlock;␊ |
309 | fragNum -= blockNum * gFragsPerBlock;␊ |
310 | ␊ |
311 | blockOffset += fragNum * gFragSize;␊ |
312 | ␊ |
313 | offset = gPartitionBase + 1ULL * blockNum * gBlockSize;␊ |
314 | ␊ |
315 | if (cache && ((blockOffset + length) <= gBlockSize)) {␊ |
316 | CacheRead(gCurrentIH, gTempBlock, offset, gBlockSize, 1);␊ |
317 | if (buffer != 0) bcopy(gTempBlock + blockOffset, buffer, length);␊ |
318 | else buffer = gTempBlock + blockOffset;␊ |
319 | } else {␊ |
320 | offset += blockOffset;␊ |
321 | CacheRead(gCurrentIH, buffer, offset, length, 0);␊ |
322 | }␊ |
323 | ␊ |
324 | return buffer;␊ |
325 | }␊ |
326 | ␊ |
327 | static long ReadInode( long inodeNum, InodePtr inode, long * flags, long * time )␊ |
328 | {␊ |
329 | long fragNum = ino_to_fsba(gFS, inodeNum);␊ |
330 | long blockOffset = ino_to_fsbo(gFS, inodeNum) * sizeof(Inode);␊ |
331 | ␊ |
332 | ReadBlock(fragNum, blockOffset, sizeof(Inode), (char *)inode, 1);␊ |
333 | byte_swap_dinode_in(inode);␊ |
334 | ␊ |
335 | if (time != 0) *time = inode->di_mtime;␊ |
336 | ␊ |
337 | if (flags != 0) {␊ |
338 | switch (inode->di_mode & IFMT) {␊ |
339 | case IFREG: *flags = kFileTypeFlat; break;␊ |
340 | case IFDIR: *flags = kFileTypeDirectory; break;␊ |
341 | case IFLNK: *flags = kFileTypeLink; break;␊ |
342 | default : *flags = kFileTypeUnknown; break;␊ |
343 | }␊ |
344 | ␊ |
345 | *flags |= inode->di_mode & kPermMask;␊ |
346 | ␊ |
347 | if (inode->di_uid != 0) *flags |= kOwnerNotRoot;␊ |
348 | }␊ |
349 | ␊ |
350 | return 0;␊ |
351 | }␊ |
352 | ␊ |
353 | static long ResolvePathToInode( char * filePath, long * flags,␊ |
354 | InodePtr fileInode, InodePtr dirInode )␊ |
355 | {␊ |
356 | char * restPath;␊ |
357 | long ret, cnt;␊ |
358 | ␊ |
359 | // if filePath is empty the we want this directory.␊ |
360 | if (*filePath == '\0') {␊ |
361 | bcopy((char *)dirInode, (char *)fileInode, sizeof(Inode));␊ |
362 | return 0;␊ |
363 | }␊ |
364 | ␊ |
365 | // Copy the file name to gTempName␊ |
366 | cnt = 0;␊ |
367 | while ((filePath[cnt] != '/') && (filePath[cnt] != '\0')) cnt++;␊ |
368 | strlcpy(gTempName, filePath, cnt+1);␊ |
369 | ␊ |
370 | // Move restPath to the right place.␊ |
371 | if (filePath[cnt] != '\0') cnt++;␊ |
372 | restPath = filePath + cnt;␊ |
373 | ␊ |
374 | // gTempName is a name in the current Dir.␊ |
375 | // restPath is the rest of the path if any.␊ |
376 | ␊ |
377 | ret = FindFileInDir(gTempName, flags, fileInode, dirInode);␊ |
378 | if (ret == -1) return -1;␊ |
379 | ␊ |
380 | if ((*restPath != '\0') && ((*flags & kFileTypeMask) == kFileTypeDirectory))␊ |
381 | ret = ResolvePathToInode(restPath, flags, fileInode, fileInode);␊ |
382 | ␊ |
383 | return ret;␊ |
384 | }␊ |
385 | ␊ |
386 | static long ReadDirEntry( InodePtr dirInode, long * fileInodeNum,␊ |
387 | long long * dirIndex, char ** name )␊ |
388 | {␊ |
389 | struct direct *dir;␊ |
390 | char *buffer;␊ |
391 | long long index;␊ |
392 | long dirBlockNum, dirBlockOffset;␊ |
393 | ␊ |
394 | while (1) {␊ |
395 | index = *dirIndex;␊ |
396 | ␊ |
397 | dirBlockOffset = (long) (index % DIRBLKSIZ);␊ |
398 | dirBlockNum = (long) (index / DIRBLKSIZ);␊ |
399 | ␊ |
400 | buffer = ReadFileBlock(dirInode, dirBlockNum, 0, DIRBLKSIZ, 0, 1);␊ |
401 | if (buffer == 0) return -1;␊ |
402 | ␊ |
403 | dir = (struct direct *)(buffer + dirBlockOffset);␊ |
404 | byte_swap_dir_block_in((char *)dir, 1);␊ |
405 | ␊ |
406 | *dirIndex += dir->d_reclen;␊ |
407 | ␊ |
408 | if (dir->d_ino != 0) break;␊ |
409 | ␊ |
410 | if (dirBlockOffset != 0) return -1;␊ |
411 | }␊ |
412 | ␊ |
413 | *fileInodeNum = dir->d_ino;␊ |
414 | *name = strlcpy(gTempName2, dir->d_name, dir->d_namlen+1);␊ |
415 | ␊ |
416 | return 0;␊ |
417 | }␊ |
418 | ␊ |
419 | static long FindFileInDir( char * fileName, long * flags,␊ |
420 | InodePtr fileInode, InodePtr dirInode )␊ |
421 | {␊ |
422 | long ret, inodeNum;␊ |
423 | long long index = 0;␊ |
424 | char *name;␊ |
425 | ␊ |
426 | while (1) {␊ |
427 | ret = ReadDirEntry(dirInode, &inodeNum, &index, &name);␊ |
428 | if (ret == -1) return -1;␊ |
429 | ␊ |
430 | if (strcmp(fileName, name) == 0) break;␊ |
431 | }␊ |
432 | ␊ |
433 | ReadInode(inodeNum, fileInode, flags, 0);␊ |
434 | ␊ |
435 | return 0;␊ |
436 | }␊ |
437 | ␊ |
438 | static char * ReadFileBlock( InodePtr fileInode, long fragNum, long blockOffset,␊ |
439 | long length, char * buffer, long cache )␊ |
440 | {␊ |
441 | long fragCount, blockNum;␊ |
442 | long diskFragNum, indFragNum, indBlockOff, refsPerBlock;␊ |
443 | char *indBlock;␊ |
444 | ␊ |
445 | fragCount = (fileInode->di_size + gFragSize - 1) / gFragSize;␊ |
446 | if (fragNum >= fragCount) return 0;␊ |
447 | ␊ |
448 | refsPerBlock = gBlockSize / sizeof(ufs_daddr_t);␊ |
449 | ␊ |
450 | blockNum = fragNum / gFragsPerBlock;␊ |
451 | fragNum -= blockNum * gFragsPerBlock;␊ |
452 | ␊ |
453 | // Get Direct Block Number.␊ |
454 | if (blockNum < NDADDR) {␊ |
455 | diskFragNum = fileInode->di_db[blockNum];␊ |
456 | } else {␊ |
457 | blockNum -= NDADDR;␊ |
458 | ␊ |
459 | // Get Single Indirect Fragment Number.␊ |
460 | if (blockNum < refsPerBlock) {␊ |
461 | indFragNum = fileInode->di_ib[0];␊ |
462 | } else {␊ |
463 | blockNum -= refsPerBlock;␊ |
464 | ␊ |
465 | // Get Double Indirect Fragment Number.␊ |
466 | if (blockNum < (refsPerBlock * refsPerBlock)) {␊ |
467 | indFragNum = fileInode->di_ib[1];␊ |
468 | } else {␊ |
469 | blockNum -= refsPerBlock * refsPerBlock;␊ |
470 | ␊ |
471 | // Get Triple Indirect Fragment Number.␊ |
472 | indFragNum = fileInode->di_ib[2];␊ |
473 | ␊ |
474 | indBlock = ReadBlock(indFragNum, 0, gBlockSize, 0, 1);␊ |
475 | indBlockOff = blockNum / (refsPerBlock * refsPerBlock);␊ |
476 | blockNum %= (refsPerBlock * refsPerBlock);␊ |
477 | indFragNum = SWAP_BE32(((ufs_daddr_t *)indBlock)[indBlockOff]);␊ |
478 | }␊ |
479 | ␊ |
480 | indBlock = ReadBlock(indFragNum, 0, gBlockSize, 0, 1);␊ |
481 | indBlockOff = blockNum / refsPerBlock;␊ |
482 | blockNum %= refsPerBlock;␊ |
483 | indFragNum = SWAP_BE32(((ufs_daddr_t *)indBlock)[indBlockOff]);␊ |
484 | }␊ |
485 | ␊ |
486 | indBlock = ReadBlock(indFragNum, 0, gBlockSize, 0, 1);␊ |
487 | diskFragNum = SWAP_BE32(((ufs_daddr_t *)indBlock)[blockNum]);␊ |
488 | }␊ |
489 | ␊ |
490 | buffer = ReadBlock(diskFragNum+fragNum, blockOffset, length, buffer, cache);␊ |
491 | ␊ |
492 | return buffer;␊ |
493 | }␊ |
494 | ␊ |
495 | static long ReadFile( InodePtr fileInode, uint64_t * length, void * base, uint64_t offset )␊ |
496 | {␊ |
497 | long bytesLeft, curSize, curFrag;␊ |
498 | char *buffer, *curAddr = (char *)base;␊ |
499 | ␊ |
500 | bytesLeft = fileInode->di_size;␊ |
501 | ␊ |
502 | if (offset > bytesLeft) {␊ |
503 | printf("Offset is too large.\n");␊ |
504 | return -1;␊ |
505 | }␊ |
506 | ␊ |
507 | if ((*length == 0) || ((offset + *length) > bytesLeft)) {␊ |
508 | *length = bytesLeft - offset;␊ |
509 | }␊ |
510 | /*␊ |
511 | if (bytesLeft > kLoadSize) {␊ |
512 | printf("File is too large.\n");␊ |
513 | return -1;␊ |
514 | }␊ |
515 | */␊ |
516 | bytesLeft = *length;␊ |
517 | curFrag = (offset / gBlockSize) * gFragsPerBlock;␊ |
518 | offset %= gBlockSize;␊ |
519 | ␊ |
520 | while (bytesLeft) {␊ |
521 | curSize = gBlockSize;␊ |
522 | if (curSize > bytesLeft) curSize = bytesLeft;␊ |
523 | if ((offset + curSize) > gBlockSize) curSize = (gBlockSize - offset);␊ |
524 | ␊ |
525 | buffer = ReadFileBlock(fileInode, curFrag, offset, curSize, curAddr, 0);␊ |
526 | if (buffer == 0) break;␊ |
527 | ␊ |
528 | if (offset != 0) offset = 0;␊ |
529 | ␊ |
530 | curFrag += gFragsPerBlock;␊ |
531 | curAddr += curSize;␊ |
532 | bytesLeft -= curSize;␊ |
533 | }␊ |
534 | ␊ |
535 | return bytesLeft;␊ |
536 | }␊ |
537 | |