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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/isofs/rock.c | |
3 | * | |
4 | * (C) 1992, 1993 Eric Youngdale | |
5 | * | |
6 | * Rock Ridge Extensions to iso9660 | |
7 | */ | |
8 | ||
1da177e4 LT |
9 | #include <linux/slab.h> |
10 | #include <linux/pagemap.h> | |
11 | #include <linux/smp_lock.h> | |
1da177e4 | 12 | |
94f2f715 | 13 | #include "isofs.h" |
1da177e4 LT |
14 | #include "rock.h" |
15 | ||
7373909d AM |
16 | /* |
17 | * These functions are designed to read the system areas of a directory record | |
1da177e4 LT |
18 | * and extract relevant information. There are different functions provided |
19 | * depending upon what information we need at the time. One function fills | |
20 | * out an inode structure, a second one extracts a filename, a third one | |
21 | * returns a symbolic link name, and a fourth one returns the extent number | |
7373909d AM |
22 | * for the file. |
23 | */ | |
1da177e4 | 24 | |
1d372116 | 25 | #define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */ |
1da177e4 | 26 | |
ba40aaf0 AM |
27 | struct rock_state { |
28 | void *buffer; | |
29 | unsigned char *chr; | |
30 | int len; | |
31 | int cont_size; | |
32 | int cont_extent; | |
33 | int cont_offset; | |
34 | struct inode *inode; | |
35 | }; | |
36 | ||
12121714 AM |
37 | /* |
38 | * This is a way of ensuring that we have something in the system | |
7373909d | 39 | * use fields that is compatible with Rock Ridge. Return zero on success. |
12121714 AM |
40 | */ |
41 | ||
42 | static int check_sp(struct rock_ridge *rr, struct inode *inode) | |
43 | { | |
44 | if (rr->u.SP.magic[0] != 0xbe) | |
45 | return -1; | |
46 | if (rr->u.SP.magic[1] != 0xef) | |
47 | return -1; | |
48 | ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip; | |
49 | return 0; | |
50 | } | |
51 | ||
76ab07eb | 52 | static void setup_rock_ridge(struct iso_directory_record *de, |
ba40aaf0 | 53 | struct inode *inode, struct rock_state *rs) |
76ab07eb | 54 | { |
ba40aaf0 AM |
55 | rs->len = sizeof(struct iso_directory_record) + de->name_len[0]; |
56 | if (rs->len & 1) | |
57 | (rs->len)++; | |
58 | rs->chr = (unsigned char *)de + rs->len; | |
59 | rs->len = *((unsigned char *)de) - rs->len; | |
60 | if (rs->len < 0) | |
61 | rs->len = 0; | |
76ab07eb AM |
62 | |
63 | if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) { | |
ba40aaf0 AM |
64 | rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset; |
65 | rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset; | |
66 | if (rs->len < 0) | |
67 | rs->len = 0; | |
76ab07eb | 68 | } |
1d372116 | 69 | } |
1da177e4 | 70 | |
ba40aaf0 AM |
71 | static void init_rock_state(struct rock_state *rs, struct inode *inode) |
72 | { | |
73 | memset(rs, 0, sizeof(*rs)); | |
74 | rs->inode = inode; | |
75 | } | |
76 | ||
77 | /* | |
78 | * Returns 0 if the caller should continue scanning, 1 if the scan must end | |
79 | * and -ve on error. | |
80 | */ | |
81 | static int rock_continue(struct rock_state *rs) | |
82 | { | |
83 | int ret = 1; | |
84 | ||
85 | kfree(rs->buffer); | |
86 | rs->buffer = NULL; | |
87 | if (rs->cont_extent) { | |
88 | struct buffer_head *bh; | |
89 | ||
90 | rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL); | |
91 | if (!rs->buffer) { | |
92 | ret = -ENOMEM; | |
93 | goto out; | |
94 | } | |
95 | ret = -EIO; | |
96 | bh = sb_bread(rs->inode->i_sb, rs->cont_extent); | |
97 | if (bh) { | |
98 | memcpy(rs->buffer, bh->b_data + rs->cont_offset, | |
99 | rs->cont_size); | |
100 | put_bh(bh); | |
101 | rs->chr = rs->buffer; | |
102 | rs->len = rs->cont_size; | |
103 | rs->cont_extent = 0; | |
104 | rs->cont_size = 0; | |
105 | rs->cont_offset = 0; | |
106 | return 0; | |
107 | } | |
108 | printk("Unable to read rock-ridge attributes\n"); | |
109 | } | |
110 | out: | |
111 | kfree(rs->buffer); | |
112 | rs->buffer = NULL; | |
113 | return ret; | |
114 | } | |
1da177e4 | 115 | |
7373909d AM |
116 | /* |
117 | * return length of name field; 0: not found, -1: to be ignored | |
118 | */ | |
1d372116 AM |
119 | int get_rock_ridge_filename(struct iso_directory_record *de, |
120 | char *retname, struct inode *inode) | |
1da177e4 | 121 | { |
ba40aaf0 | 122 | struct rock_state rs; |
7fa393a1 AM |
123 | struct rock_ridge *rr; |
124 | int sig; | |
125 | int retnamlen = 0; | |
126 | int truncate = 0; | |
ba40aaf0 | 127 | int ret = 0; |
1da177e4 | 128 | |
1d372116 AM |
129 | if (!ISOFS_SB(inode->i_sb)->s_rock) |
130 | return 0; | |
131 | *retname = 0; | |
132 | ||
ba40aaf0 AM |
133 | init_rock_state(&rs, inode); |
134 | setup_rock_ridge(de, inode, &rs); | |
7fa393a1 AM |
135 | repeat: |
136 | ||
ba40aaf0 AM |
137 | while (rs.len > 2) { /* There may be one byte for padding somewhere */ |
138 | rr = (struct rock_ridge *)rs.chr; | |
7fa393a1 AM |
139 | if (rr->len < 3) |
140 | goto out; /* Something got screwed up here */ | |
ba40aaf0 AM |
141 | sig = isonum_721(rs.chr); |
142 | rs.chr += rr->len; | |
143 | rs.len -= rr->len; | |
144 | if (rs.len < 0) | |
7fa393a1 AM |
145 | goto out; /* corrupted isofs */ |
146 | ||
147 | switch (sig) { | |
148 | case SIG('R', 'R'): | |
149 | if ((rr->u.RR.flags[0] & RR_NM) == 0) | |
150 | goto out; | |
151 | break; | |
152 | case SIG('S', 'P'): | |
12121714 AM |
153 | if (check_sp(rr, inode)) |
154 | goto out; | |
7fa393a1 AM |
155 | break; |
156 | case SIG('C', 'E'): | |
ba40aaf0 AM |
157 | rs.cont_extent = isonum_733(rr->u.CE.extent); |
158 | rs.cont_offset = isonum_733(rr->u.CE.offset); | |
159 | rs.cont_size = isonum_733(rr->u.CE.size); | |
7fa393a1 AM |
160 | break; |
161 | case SIG('N', 'M'): | |
162 | if (truncate) | |
1d372116 | 163 | break; |
7fa393a1 | 164 | if (rr->len < 5) |
1d372116 | 165 | break; |
7fa393a1 AM |
166 | /* |
167 | * If the flags are 2 or 4, this indicates '.' or '..'. | |
168 | * We don't want to do anything with this, because it | |
169 | * screws up the code that calls us. We don't really | |
170 | * care anyways, since we can just use the non-RR | |
171 | * name. | |
172 | */ | |
173 | if (rr->u.NM.flags & 6) | |
1d372116 | 174 | break; |
1d372116 | 175 | |
7fa393a1 AM |
176 | if (rr->u.NM.flags & ~1) { |
177 | printk("Unsupported NM flag settings (%d)\n", | |
178 | rr->u.NM.flags); | |
1d372116 | 179 | break; |
7fa393a1 AM |
180 | } |
181 | if ((strlen(retname) + rr->len - 5) >= 254) { | |
182 | truncate = 1; | |
1d372116 AM |
183 | break; |
184 | } | |
7fa393a1 AM |
185 | strncat(retname, rr->u.NM.name, rr->len - 5); |
186 | retnamlen += rr->len - 5; | |
187 | break; | |
188 | case SIG('R', 'E'): | |
ba40aaf0 | 189 | kfree(rs.buffer); |
7fa393a1 AM |
190 | return -1; |
191 | default: | |
192 | break; | |
1d372116 | 193 | } |
1da177e4 | 194 | } |
ba40aaf0 AM |
195 | ret = rock_continue(&rs); |
196 | if (ret == 0) | |
197 | goto repeat; | |
198 | if (ret == 1) | |
199 | return retnamlen; /* If 0, this file did not have a NM field */ | |
7fa393a1 | 200 | out: |
ba40aaf0 AM |
201 | kfree(rs.buffer); |
202 | return ret; | |
1da177e4 LT |
203 | } |
204 | ||
205 | static int | |
206 | parse_rock_ridge_inode_internal(struct iso_directory_record *de, | |
207 | struct inode *inode, int regard_xa) | |
208 | { | |
1d372116 | 209 | int symlink_len = 0; |
7fa393a1 AM |
210 | int cnt, sig; |
211 | struct inode *reloc; | |
212 | struct rock_ridge *rr; | |
213 | int rootflag; | |
ba40aaf0 AM |
214 | struct rock_state rs; |
215 | int ret = 0; | |
1d372116 AM |
216 | |
217 | if (!ISOFS_SB(inode->i_sb)->s_rock) | |
218 | return 0; | |
219 | ||
ba40aaf0 AM |
220 | init_rock_state(&rs, inode); |
221 | setup_rock_ridge(de, inode, &rs); | |
1d372116 | 222 | if (regard_xa) { |
ba40aaf0 AM |
223 | rs.chr += 14; |
224 | rs.len -= 14; | |
225 | if (rs.len < 0) | |
226 | rs.len = 0; | |
1d372116 AM |
227 | } |
228 | ||
7fa393a1 | 229 | repeat: |
ba40aaf0 AM |
230 | while (rs.len > 2) { /* There may be one byte for padding somewhere */ |
231 | rr = (struct rock_ridge *)rs.chr; | |
7fa393a1 AM |
232 | if (rr->len < 3) |
233 | goto out; /* Something got screwed up here */ | |
ba40aaf0 AM |
234 | sig = isonum_721(rs.chr); |
235 | rs.chr += rr->len; | |
236 | rs.len -= rr->len; | |
237 | if (rs.len < 0) | |
7fa393a1 AM |
238 | goto out; /* corrupted isofs */ |
239 | ||
240 | switch (sig) { | |
1da177e4 | 241 | #ifndef CONFIG_ZISOFS /* No flag for SF or ZF */ |
7fa393a1 AM |
242 | case SIG('R', 'R'): |
243 | if ((rr->u.RR.flags[0] & | |
244 | (RR_PX | RR_TF | RR_SL | RR_CL)) == 0) | |
245 | goto out; | |
246 | break; | |
1da177e4 | 247 | #endif |
7fa393a1 | 248 | case SIG('S', 'P'): |
12121714 AM |
249 | if (check_sp(rr, inode)) |
250 | goto out; | |
7fa393a1 AM |
251 | break; |
252 | case SIG('C', 'E'): | |
ba40aaf0 AM |
253 | rs.cont_extent = isonum_733(rr->u.CE.extent); |
254 | rs.cont_offset = isonum_733(rr->u.CE.offset); | |
255 | rs.cont_size = isonum_733(rr->u.CE.size); | |
7fa393a1 AM |
256 | break; |
257 | case SIG('E', 'R'): | |
258 | ISOFS_SB(inode->i_sb)->s_rock = 1; | |
259 | printk(KERN_DEBUG "ISO 9660 Extensions: "); | |
260 | { | |
261 | int p; | |
262 | for (p = 0; p < rr->u.ER.len_id; p++) | |
263 | printk("%c", rr->u.ER.data[p]); | |
264 | } | |
265 | printk("\n"); | |
266 | break; | |
267 | case SIG('P', 'X'): | |
268 | inode->i_mode = isonum_733(rr->u.PX.mode); | |
269 | inode->i_nlink = isonum_733(rr->u.PX.n_links); | |
270 | inode->i_uid = isonum_733(rr->u.PX.uid); | |
271 | inode->i_gid = isonum_733(rr->u.PX.gid); | |
272 | break; | |
273 | case SIG('P', 'N'): | |
274 | { | |
275 | int high, low; | |
276 | high = isonum_733(rr->u.PN.dev_high); | |
277 | low = isonum_733(rr->u.PN.dev_low); | |
278 | /* | |
279 | * The Rock Ridge standard specifies that if | |
280 | * sizeof(dev_t) <= 4, then the high field is | |
281 | * unused, and the device number is completely | |
282 | * stored in the low field. Some writers may | |
283 | * ignore this subtlety, | |
284 | * and as a result we test to see if the entire | |
285 | * device number is | |
286 | * stored in the low field, and use that. | |
287 | */ | |
288 | if ((low & ~0xff) && high == 0) { | |
289 | inode->i_rdev = | |
290 | MKDEV(low >> 8, low & 0xff); | |
291 | } else { | |
292 | inode->i_rdev = | |
293 | MKDEV(high, low); | |
1d372116 | 294 | } |
7fa393a1 AM |
295 | } |
296 | break; | |
297 | case SIG('T', 'F'): | |
298 | /* | |
299 | * Some RRIP writers incorrectly place ctime in the | |
300 | * TF_CREATE field. Try to handle this correctly for | |
301 | * either case. | |
302 | */ | |
303 | /* Rock ridge never appears on a High Sierra disk */ | |
304 | cnt = 0; | |
305 | if (rr->u.TF.flags & TF_CREATE) { | |
306 | inode->i_ctime.tv_sec = | |
307 | iso_date(rr->u.TF.times[cnt++].time, | |
308 | 0); | |
309 | inode->i_ctime.tv_nsec = 0; | |
310 | } | |
311 | if (rr->u.TF.flags & TF_MODIFY) { | |
312 | inode->i_mtime.tv_sec = | |
313 | iso_date(rr->u.TF.times[cnt++].time, | |
314 | 0); | |
315 | inode->i_mtime.tv_nsec = 0; | |
316 | } | |
317 | if (rr->u.TF.flags & TF_ACCESS) { | |
318 | inode->i_atime.tv_sec = | |
319 | iso_date(rr->u.TF.times[cnt++].time, | |
320 | 0); | |
321 | inode->i_atime.tv_nsec = 0; | |
322 | } | |
323 | if (rr->u.TF.flags & TF_ATTRIBUTES) { | |
324 | inode->i_ctime.tv_sec = | |
325 | iso_date(rr->u.TF.times[cnt++].time, | |
326 | 0); | |
327 | inode->i_ctime.tv_nsec = 0; | |
328 | } | |
329 | break; | |
330 | case SIG('S', 'L'): | |
331 | { | |
332 | int slen; | |
333 | struct SL_component *slp; | |
334 | struct SL_component *oldslp; | |
335 | slen = rr->len - 5; | |
336 | slp = &rr->u.SL.link; | |
337 | inode->i_size = symlink_len; | |
338 | while (slen > 1) { | |
339 | rootflag = 0; | |
340 | switch (slp->flags & ~1) { | |
341 | case 0: | |
342 | inode->i_size += | |
343 | slp->len; | |
344 | break; | |
345 | case 2: | |
346 | inode->i_size += 1; | |
347 | break; | |
348 | case 4: | |
349 | inode->i_size += 2; | |
350 | break; | |
351 | case 8: | |
352 | rootflag = 1; | |
353 | inode->i_size += 1; | |
354 | break; | |
355 | default: | |
356 | printk("Symlink component flag " | |
357 | "not implemented\n"); | |
1d372116 | 358 | } |
7fa393a1 AM |
359 | slen -= slp->len + 2; |
360 | oldslp = slp; | |
361 | slp = (struct SL_component *) | |
362 | (((char *)slp) + slp->len + 2); | |
363 | ||
364 | if (slen < 2) { | |
365 | if (((rr->u.SL. | |
366 | flags & 1) != 0) | |
367 | && | |
368 | ((oldslp-> | |
369 | flags & 1) == 0)) | |
1d372116 | 370 | inode->i_size += |
7fa393a1 AM |
371 | 1; |
372 | break; | |
1d372116 | 373 | } |
7fa393a1 AM |
374 | |
375 | /* | |
376 | * If this component record isn't | |
377 | * continued, then append a '/'. | |
378 | */ | |
379 | if (!rootflag | |
380 | && (oldslp->flags & 1) == 0) | |
381 | inode->i_size += 1; | |
1d372116 | 382 | } |
7fa393a1 AM |
383 | } |
384 | symlink_len = inode->i_size; | |
385 | break; | |
386 | case SIG('R', 'E'): | |
387 | printk(KERN_WARNING "Attempt to read inode for " | |
388 | "relocated directory\n"); | |
389 | goto out; | |
390 | case SIG('C', 'L'): | |
391 | ISOFS_I(inode)->i_first_extent = | |
392 | isonum_733(rr->u.CL.location); | |
393 | reloc = | |
394 | isofs_iget(inode->i_sb, | |
395 | ISOFS_I(inode)->i_first_extent, | |
396 | 0); | |
397 | if (!reloc) | |
1d372116 | 398 | goto out; |
7fa393a1 AM |
399 | inode->i_mode = reloc->i_mode; |
400 | inode->i_nlink = reloc->i_nlink; | |
401 | inode->i_uid = reloc->i_uid; | |
402 | inode->i_gid = reloc->i_gid; | |
403 | inode->i_rdev = reloc->i_rdev; | |
404 | inode->i_size = reloc->i_size; | |
405 | inode->i_blocks = reloc->i_blocks; | |
406 | inode->i_atime = reloc->i_atime; | |
407 | inode->i_ctime = reloc->i_ctime; | |
408 | inode->i_mtime = reloc->i_mtime; | |
409 | iput(reloc); | |
410 | break; | |
1da177e4 | 411 | #ifdef CONFIG_ZISOFS |
7fa393a1 AM |
412 | case SIG('Z', 'F'): { |
413 | int algo; | |
414 | ||
415 | if (ISOFS_SB(inode->i_sb)->s_nocompress) | |
1d372116 | 416 | break; |
7fa393a1 AM |
417 | algo = isonum_721(rr->u.ZF.algorithm); |
418 | if (algo == SIG('p', 'z')) { | |
419 | int block_shift = | |
420 | isonum_711(&rr->u.ZF.parms[1]); | |
421 | if (block_shift < PAGE_CACHE_SHIFT | |
422 | || block_shift > 17) { | |
423 | printk(KERN_WARNING "isofs: " | |
424 | "Can't handle ZF block " | |
425 | "size of 2^%d\n", | |
426 | block_shift); | |
427 | } else { | |
428 | /* | |
429 | * Note: we don't change | |
430 | * i_blocks here | |
431 | */ | |
432 | ISOFS_I(inode)->i_file_format = | |
433 | isofs_file_compressed; | |
434 | /* | |
435 | * Parameters to compression | |
436 | * algorithm (header size, | |
437 | * block size) | |
438 | */ | |
439 | ISOFS_I(inode)->i_format_parm[0] = | |
440 | isonum_711(&rr->u.ZF.parms[0]); | |
441 | ISOFS_I(inode)->i_format_parm[1] = | |
442 | isonum_711(&rr->u.ZF.parms[1]); | |
443 | inode->i_size = | |
444 | isonum_733(rr->u.ZF. | |
445 | real_size); | |
446 | } | |
447 | } else { | |
448 | printk(KERN_WARNING | |
449 | "isofs: Unknown ZF compression " | |
450 | "algorithm: %c%c\n", | |
451 | rr->u.ZF.algorithm[0], | |
452 | rr->u.ZF.algorithm[1]); | |
1d372116 | 453 | } |
7fa393a1 AM |
454 | break; |
455 | } | |
456 | #endif | |
457 | default: | |
458 | break; | |
1d372116 AM |
459 | } |
460 | } | |
ba40aaf0 AM |
461 | ret = rock_continue(&rs); |
462 | if (ret == 0) | |
463 | goto repeat; | |
464 | if (ret == 1) | |
465 | ret = 0; | |
7fa393a1 | 466 | out: |
ba40aaf0 AM |
467 | kfree(rs.buffer); |
468 | return ret; | |
1da177e4 LT |
469 | } |
470 | ||
471 | static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit) | |
472 | { | |
473 | int slen; | |
474 | int rootflag; | |
475 | struct SL_component *oldslp; | |
476 | struct SL_component *slp; | |
477 | slen = rr->len - 5; | |
478 | slp = &rr->u.SL.link; | |
479 | while (slen > 1) { | |
480 | rootflag = 0; | |
481 | switch (slp->flags & ~1) { | |
482 | case 0: | |
483 | if (slp->len > plimit - rpnt) | |
484 | return NULL; | |
485 | memcpy(rpnt, slp->text, slp->len); | |
1d372116 | 486 | rpnt += slp->len; |
1da177e4 LT |
487 | break; |
488 | case 2: | |
489 | if (rpnt >= plimit) | |
490 | return NULL; | |
1d372116 | 491 | *rpnt++ = '.'; |
1da177e4 LT |
492 | break; |
493 | case 4: | |
494 | if (2 > plimit - rpnt) | |
495 | return NULL; | |
1d372116 AM |
496 | *rpnt++ = '.'; |
497 | *rpnt++ = '.'; | |
1da177e4 LT |
498 | break; |
499 | case 8: | |
500 | if (rpnt >= plimit) | |
501 | return NULL; | |
502 | rootflag = 1; | |
1d372116 | 503 | *rpnt++ = '/'; |
1da177e4 LT |
504 | break; |
505 | default: | |
506 | printk("Symlink component flag not implemented (%d)\n", | |
1d372116 | 507 | slp->flags); |
1da177e4 LT |
508 | } |
509 | slen -= slp->len + 2; | |
510 | oldslp = slp; | |
1d372116 | 511 | slp = (struct SL_component *)((char *)slp + slp->len + 2); |
1da177e4 LT |
512 | |
513 | if (slen < 2) { | |
514 | /* | |
515 | * If there is another SL record, and this component | |
516 | * record isn't continued, then add a slash. | |
517 | */ | |
518 | if ((!rootflag) && (rr->u.SL.flags & 1) && | |
519 | !(oldslp->flags & 1)) { | |
520 | if (rpnt >= plimit) | |
521 | return NULL; | |
1d372116 | 522 | *rpnt++ = '/'; |
1da177e4 LT |
523 | } |
524 | break; | |
525 | } | |
526 | ||
527 | /* | |
528 | * If this component record isn't continued, then append a '/'. | |
529 | */ | |
530 | if (!rootflag && !(oldslp->flags & 1)) { | |
531 | if (rpnt >= plimit) | |
532 | return NULL; | |
1d372116 | 533 | *rpnt++ = '/'; |
1da177e4 LT |
534 | } |
535 | } | |
536 | return rpnt; | |
537 | } | |
538 | ||
1d372116 | 539 | int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode) |
1da177e4 | 540 | { |
1d372116 | 541 | int result = parse_rock_ridge_inode_internal(de, inode, 0); |
7373909d AM |
542 | |
543 | /* | |
544 | * if rockridge flag was reset and we didn't look for attributes | |
545 | * behind eventual XA attributes, have a look there | |
546 | */ | |
1d372116 AM |
547 | if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1) |
548 | && (ISOFS_SB(inode->i_sb)->s_rock == 2)) { | |
549 | result = parse_rock_ridge_inode_internal(de, inode, 14); | |
550 | } | |
551 | return result; | |
1da177e4 LT |
552 | } |
553 | ||
7373909d AM |
554 | /* |
555 | * readpage() for symlinks: reads symlink contents into the page and either | |
556 | * makes it uptodate and returns 0 or returns error (-EIO) | |
557 | */ | |
1da177e4 LT |
558 | static int rock_ridge_symlink_readpage(struct file *file, struct page *page) |
559 | { | |
560 | struct inode *inode = page->mapping->host; | |
1d372116 | 561 | struct iso_inode_info *ei = ISOFS_I(inode); |
1da177e4 LT |
562 | char *link = kmap(page); |
563 | unsigned long bufsize = ISOFS_BUFFER_SIZE(inode); | |
564 | struct buffer_head *bh; | |
565 | char *rpnt = link; | |
566 | unsigned char *pnt; | |
76ab07eb | 567 | struct iso_directory_record *raw_de; |
1da177e4 LT |
568 | unsigned long block, offset; |
569 | int sig; | |
1da177e4 | 570 | struct rock_ridge *rr; |
ba40aaf0 AM |
571 | struct rock_state rs; |
572 | int ret; | |
1da177e4 LT |
573 | |
574 | if (!ISOFS_SB(inode->i_sb)->s_rock) | |
575 | goto error; | |
576 | ||
ba40aaf0 | 577 | init_rock_state(&rs, inode); |
1da177e4 LT |
578 | block = ei->i_iget5_block; |
579 | lock_kernel(); | |
580 | bh = sb_bread(inode->i_sb, block); | |
581 | if (!bh) | |
582 | goto out_noread; | |
583 | ||
1d372116 AM |
584 | offset = ei->i_iget5_offset; |
585 | pnt = (unsigned char *)bh->b_data + offset; | |
1da177e4 | 586 | |
76ab07eb | 587 | raw_de = (struct iso_directory_record *)pnt; |
1da177e4 LT |
588 | |
589 | /* | |
590 | * If we go past the end of the buffer, there is some sort of error. | |
591 | */ | |
592 | if (offset + *pnt > bufsize) | |
593 | goto out_bad_span; | |
594 | ||
7373909d AM |
595 | /* |
596 | * Now test for possible Rock Ridge extensions which will override | |
597 | * some of these numbers in the inode structure. | |
598 | */ | |
1da177e4 | 599 | |
ba40aaf0 | 600 | setup_rock_ridge(raw_de, inode, &rs); |
1da177e4 | 601 | |
7fa393a1 | 602 | repeat: |
ba40aaf0 AM |
603 | while (rs.len > 2) { /* There may be one byte for padding somewhere */ |
604 | rr = (struct rock_ridge *)rs.chr; | |
1da177e4 LT |
605 | if (rr->len < 3) |
606 | goto out; /* Something got screwed up here */ | |
ba40aaf0 AM |
607 | sig = isonum_721(rs.chr); |
608 | rs.chr += rr->len; | |
609 | rs.len -= rr->len; | |
610 | if (rs.len < 0) | |
1da177e4 LT |
611 | goto out; /* corrupted isofs */ |
612 | ||
613 | switch (sig) { | |
614 | case SIG('R', 'R'): | |
615 | if ((rr->u.RR.flags[0] & RR_SL) == 0) | |
616 | goto out; | |
617 | break; | |
618 | case SIG('S', 'P'): | |
12121714 AM |
619 | if (check_sp(rr, inode)) |
620 | goto out; | |
1da177e4 LT |
621 | break; |
622 | case SIG('S', 'L'): | |
623 | rpnt = get_symlink_chunk(rpnt, rr, | |
624 | link + (PAGE_SIZE - 1)); | |
625 | if (rpnt == NULL) | |
626 | goto out; | |
627 | break; | |
628 | case SIG('C', 'E'): | |
629 | /* This tells is if there is a continuation record */ | |
ba40aaf0 AM |
630 | rs.cont_extent = isonum_733(rr->u.CE.extent); |
631 | rs.cont_offset = isonum_733(rr->u.CE.offset); | |
632 | rs.cont_size = isonum_733(rr->u.CE.size); | |
1da177e4 LT |
633 | default: |
634 | break; | |
635 | } | |
636 | } | |
ba40aaf0 AM |
637 | ret = rock_continue(&rs); |
638 | if (ret == 0) | |
639 | goto repeat; | |
640 | if (ret < 0) | |
641 | goto fail; | |
1da177e4 LT |
642 | |
643 | if (rpnt == link) | |
644 | goto fail; | |
645 | brelse(bh); | |
646 | *rpnt = '\0'; | |
647 | unlock_kernel(); | |
648 | SetPageUptodate(page); | |
649 | kunmap(page); | |
650 | unlock_page(page); | |
651 | return 0; | |
652 | ||
653 | /* error exit from macro */ | |
7fa393a1 | 654 | out: |
ba40aaf0 | 655 | kfree(rs.buffer); |
1da177e4 | 656 | goto fail; |
7fa393a1 | 657 | out_noread: |
1da177e4 LT |
658 | printk("unable to read i-node block"); |
659 | goto fail; | |
7fa393a1 | 660 | out_bad_span: |
1da177e4 | 661 | printk("symlink spans iso9660 blocks\n"); |
7fa393a1 | 662 | fail: |
1da177e4 LT |
663 | brelse(bh); |
664 | unlock_kernel(); | |
7fa393a1 | 665 | error: |
1da177e4 LT |
666 | SetPageError(page); |
667 | kunmap(page); | |
668 | unlock_page(page); | |
669 | return -EIO; | |
670 | } | |
671 | ||
672 | struct address_space_operations isofs_symlink_aops = { | |
1d372116 | 673 | .readpage = rock_ridge_symlink_readpage |
1da177e4 | 674 | }; |