]> err.no Git - linux-2.6/blob - fs/isofs/rock.c
isofs: fix minor filesystem corruption
[linux-2.6] / fs / isofs / rock.c
1 /*
2  *  linux/fs/isofs/rock.c
3  *
4  *  (C) 1992, 1993  Eric Youngdale
5  *
6  *  Rock Ridge Extensions to iso9660
7  */
8
9 #include <linux/slab.h>
10 #include <linux/pagemap.h>
11 #include <linux/smp_lock.h>
12
13 #include "isofs.h"
14 #include "rock.h"
15
16 /*
17  * These functions are designed to read the system areas of a directory record
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
22  * for the file.
23  */
24
25 #define SIG(A,B) ((A) | ((B) << 8))     /* isonum_721() */
26
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
37 /*
38  * This is a way of ensuring that we have something in the system
39  * use fields that is compatible with Rock Ridge.  Return zero on success.
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
52 static void setup_rock_ridge(struct iso_directory_record *de,
53                         struct inode *inode, struct rock_state *rs)
54 {
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;
62
63         if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
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;
68         }
69 }
70
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         int blocksize = 1 << rs->inode->i_blkbits;
85         const int min_de_size = offsetof(struct rock_ridge, u);
86
87         kfree(rs->buffer);
88         rs->buffer = NULL;
89
90         if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
91             (unsigned)rs->cont_size > blocksize ||
92             (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
93                 printk(KERN_NOTICE "rock: corrupted directory entry. "
94                         "extent=%d, offset=%d, size=%d\n",
95                         rs->cont_extent, rs->cont_offset, rs->cont_size);
96                 ret = -EIO;
97                 goto out;
98         }
99
100         if (rs->cont_extent) {
101                 struct buffer_head *bh;
102
103                 rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
104                 if (!rs->buffer) {
105                         ret = -ENOMEM;
106                         goto out;
107                 }
108                 ret = -EIO;
109                 bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
110                 if (bh) {
111                         memcpy(rs->buffer, bh->b_data + rs->cont_offset,
112                                         rs->cont_size);
113                         put_bh(bh);
114                         rs->chr = rs->buffer;
115                         rs->len = rs->cont_size;
116                         rs->cont_extent = 0;
117                         rs->cont_size = 0;
118                         rs->cont_offset = 0;
119                         return 0;
120                 }
121                 printk("Unable to read rock-ridge attributes\n");
122         }
123 out:
124         kfree(rs->buffer);
125         rs->buffer = NULL;
126         return ret;
127 }
128
129 /*
130  * We think there's a record of type `sig' at rs->chr.  Parse the signature
131  * and make sure that there's really room for a record of that type.
132  */
133 static int rock_check_overflow(struct rock_state *rs, int sig)
134 {
135         int len;
136
137         switch (sig) {
138         case SIG('S', 'P'):
139                 len = sizeof(struct SU_SP_s);
140                 break;
141         case SIG('C', 'E'):
142                 len = sizeof(struct SU_CE_s);
143                 break;
144         case SIG('E', 'R'):
145                 len = sizeof(struct SU_ER_s);
146                 break;
147         case SIG('R', 'R'):
148                 len = sizeof(struct RR_RR_s);
149                 break;
150         case SIG('P', 'X'):
151                 len = sizeof(struct RR_PX_s);
152                 break;
153         case SIG('P', 'N'):
154                 len = sizeof(struct RR_PN_s);
155                 break;
156         case SIG('S', 'L'):
157                 len = sizeof(struct RR_SL_s);
158                 break;
159         case SIG('N', 'M'):
160                 len = sizeof(struct RR_NM_s);
161                 break;
162         case SIG('C', 'L'):
163                 len = sizeof(struct RR_CL_s);
164                 break;
165         case SIG('P', 'L'):
166                 len = sizeof(struct RR_PL_s);
167                 break;
168         case SIG('T', 'F'):
169                 len = sizeof(struct RR_TF_s);
170                 break;
171         case SIG('Z', 'F'):
172                 len = sizeof(struct RR_ZF_s);
173                 break;
174         default:
175                 len = 0;
176                 break;
177         }
178         len += offsetof(struct rock_ridge, u);
179         if (len > rs->len) {
180                 printk(KERN_NOTICE "rock: directory entry would overflow "
181                                 "storage\n");
182                 printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
183                                 sig, len, rs->len);
184                 return -EIO;
185         }
186         return 0;
187 }
188
189 /*
190  * return length of name field; 0: not found, -1: to be ignored
191  */
192 int get_rock_ridge_filename(struct iso_directory_record *de,
193                             char *retname, struct inode *inode)
194 {
195         struct rock_state rs;
196         struct rock_ridge *rr;
197         int sig;
198         int retnamlen = 0;
199         int truncate = 0;
200         int ret = 0;
201
202         if (!ISOFS_SB(inode->i_sb)->s_rock)
203                 return 0;
204         *retname = 0;
205
206         init_rock_state(&rs, inode);
207         setup_rock_ridge(de, inode, &rs);
208 repeat:
209
210         while (rs.len > 2) { /* There may be one byte for padding somewhere */
211                 rr = (struct rock_ridge *)rs.chr;
212                 /*
213                  * Ignore rock ridge info if rr->len is out of range, but
214                  * don't return -EIO because that would make the file
215                  * invisible.
216                  */
217                 if (rr->len < 3)
218                         goto out;       /* Something got screwed up here */
219                 sig = isonum_721(rs.chr);
220                 if (rock_check_overflow(&rs, sig))
221                         goto eio;
222                 rs.chr += rr->len;
223                 rs.len -= rr->len;
224                 /*
225                  * As above, just ignore the rock ridge info if rr->len
226                  * is bogus.
227                  */
228                 if (rs.len < 0)
229                         goto out;       /* Something got screwed up here */
230
231                 switch (sig) {
232                 case SIG('R', 'R'):
233                         if ((rr->u.RR.flags[0] & RR_NM) == 0)
234                                 goto out;
235                         break;
236                 case SIG('S', 'P'):
237                         if (check_sp(rr, inode))
238                                 goto out;
239                         break;
240                 case SIG('C', 'E'):
241                         rs.cont_extent = isonum_733(rr->u.CE.extent);
242                         rs.cont_offset = isonum_733(rr->u.CE.offset);
243                         rs.cont_size = isonum_733(rr->u.CE.size);
244                         break;
245                 case SIG('N', 'M'):
246                         if (truncate)
247                                 break;
248                         if (rr->len < 5)
249                                 break;
250                         /*
251                          * If the flags are 2 or 4, this indicates '.' or '..'.
252                          * We don't want to do anything with this, because it
253                          * screws up the code that calls us.  We don't really
254                          * care anyways, since we can just use the non-RR
255                          * name.
256                          */
257                         if (rr->u.NM.flags & 6)
258                                 break;
259
260                         if (rr->u.NM.flags & ~1) {
261                                 printk("Unsupported NM flag settings (%d)\n",
262                                         rr->u.NM.flags);
263                                 break;
264                         }
265                         if ((strlen(retname) + rr->len - 5) >= 254) {
266                                 truncate = 1;
267                                 break;
268                         }
269                         strncat(retname, rr->u.NM.name, rr->len - 5);
270                         retnamlen += rr->len - 5;
271                         break;
272                 case SIG('R', 'E'):
273                         kfree(rs.buffer);
274                         return -1;
275                 default:
276                         break;
277                 }
278         }
279         ret = rock_continue(&rs);
280         if (ret == 0)
281                 goto repeat;
282         if (ret == 1)
283                 return retnamlen; /* If 0, this file did not have a NM field */
284 out:
285         kfree(rs.buffer);
286         return ret;
287 eio:
288         ret = -EIO;
289         goto out;
290 }
291
292 static int
293 parse_rock_ridge_inode_internal(struct iso_directory_record *de,
294                                 struct inode *inode, int regard_xa)
295 {
296         int symlink_len = 0;
297         int cnt, sig;
298         struct inode *reloc;
299         struct rock_ridge *rr;
300         int rootflag;
301         struct rock_state rs;
302         int ret = 0;
303
304         if (!ISOFS_SB(inode->i_sb)->s_rock)
305                 return 0;
306
307         init_rock_state(&rs, inode);
308         setup_rock_ridge(de, inode, &rs);
309         if (regard_xa) {
310                 rs.chr += 14;
311                 rs.len -= 14;
312                 if (rs.len < 0)
313                         rs.len = 0;
314         }
315
316 repeat:
317         while (rs.len > 2) { /* There may be one byte for padding somewhere */
318                 rr = (struct rock_ridge *)rs.chr;
319                 /*
320                  * Ignore rock ridge info if rr->len is out of range, but
321                  * don't return -EIO because that would make the file
322                  * invisible.
323                  */
324                 if (rr->len < 3)
325                         goto out;       /* Something got screwed up here */
326                 sig = isonum_721(rs.chr);
327                 if (rock_check_overflow(&rs, sig))
328                         goto eio;
329                 rs.chr += rr->len;
330                 rs.len -= rr->len;
331                 /*
332                  * As above, just ignore the rock ridge info if rr->len
333                  * is bogus.
334                  */
335                 if (rs.len < 0)
336                         goto out;       /* Something got screwed up here */
337
338                 switch (sig) {
339 #ifndef CONFIG_ZISOFS           /* No flag for SF or ZF */
340                 case SIG('R', 'R'):
341                         if ((rr->u.RR.flags[0] &
342                              (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
343                                 goto out;
344                         break;
345 #endif
346                 case SIG('S', 'P'):
347                         if (check_sp(rr, inode))
348                                 goto out;
349                         break;
350                 case SIG('C', 'E'):
351                         rs.cont_extent = isonum_733(rr->u.CE.extent);
352                         rs.cont_offset = isonum_733(rr->u.CE.offset);
353                         rs.cont_size = isonum_733(rr->u.CE.size);
354                         break;
355                 case SIG('E', 'R'):
356                         ISOFS_SB(inode->i_sb)->s_rock = 1;
357                         printk(KERN_DEBUG "ISO 9660 Extensions: ");
358                         {
359                                 int p;
360                                 for (p = 0; p < rr->u.ER.len_id; p++)
361                                         printk("%c", rr->u.ER.data[p]);
362                         }
363                         printk("\n");
364                         break;
365                 case SIG('P', 'X'):
366                         inode->i_mode = isonum_733(rr->u.PX.mode);
367                         inode->i_nlink = isonum_733(rr->u.PX.n_links);
368                         inode->i_uid = isonum_733(rr->u.PX.uid);
369                         inode->i_gid = isonum_733(rr->u.PX.gid);
370                         break;
371                 case SIG('P', 'N'):
372                         {
373                                 int high, low;
374                                 high = isonum_733(rr->u.PN.dev_high);
375                                 low = isonum_733(rr->u.PN.dev_low);
376                                 /*
377                                  * The Rock Ridge standard specifies that if
378                                  * sizeof(dev_t) <= 4, then the high field is
379                                  * unused, and the device number is completely
380                                  * stored in the low field.  Some writers may
381                                  * ignore this subtlety,
382                                  * and as a result we test to see if the entire
383                                  * device number is
384                                  * stored in the low field, and use that.
385                                  */
386                                 if ((low & ~0xff) && high == 0) {
387                                         inode->i_rdev =
388                                             MKDEV(low >> 8, low & 0xff);
389                                 } else {
390                                         inode->i_rdev =
391                                             MKDEV(high, low);
392                                 }
393                         }
394                         break;
395                 case SIG('T', 'F'):
396                         /*
397                          * Some RRIP writers incorrectly place ctime in the
398                          * TF_CREATE field. Try to handle this correctly for
399                          * either case.
400                          */
401                         /* Rock ridge never appears on a High Sierra disk */
402                         cnt = 0;
403                         if (rr->u.TF.flags & TF_CREATE) {
404                                 inode->i_ctime.tv_sec =
405                                     iso_date(rr->u.TF.times[cnt++].time,
406                                              0);
407                                 inode->i_ctime.tv_nsec = 0;
408                         }
409                         if (rr->u.TF.flags & TF_MODIFY) {
410                                 inode->i_mtime.tv_sec =
411                                     iso_date(rr->u.TF.times[cnt++].time,
412                                              0);
413                                 inode->i_mtime.tv_nsec = 0;
414                         }
415                         if (rr->u.TF.flags & TF_ACCESS) {
416                                 inode->i_atime.tv_sec =
417                                     iso_date(rr->u.TF.times[cnt++].time,
418                                              0);
419                                 inode->i_atime.tv_nsec = 0;
420                         }
421                         if (rr->u.TF.flags & TF_ATTRIBUTES) {
422                                 inode->i_ctime.tv_sec =
423                                     iso_date(rr->u.TF.times[cnt++].time,
424                                              0);
425                                 inode->i_ctime.tv_nsec = 0;
426                         }
427                         break;
428                 case SIG('S', 'L'):
429                         {
430                                 int slen;
431                                 struct SL_component *slp;
432                                 struct SL_component *oldslp;
433                                 slen = rr->len - 5;
434                                 slp = &rr->u.SL.link;
435                                 inode->i_size = symlink_len;
436                                 while (slen > 1) {
437                                         rootflag = 0;
438                                         switch (slp->flags & ~1) {
439                                         case 0:
440                                                 inode->i_size +=
441                                                     slp->len;
442                                                 break;
443                                         case 2:
444                                                 inode->i_size += 1;
445                                                 break;
446                                         case 4:
447                                                 inode->i_size += 2;
448                                                 break;
449                                         case 8:
450                                                 rootflag = 1;
451                                                 inode->i_size += 1;
452                                                 break;
453                                         default:
454                                                 printk("Symlink component flag "
455                                                         "not implemented\n");
456                                         }
457                                         slen -= slp->len + 2;
458                                         oldslp = slp;
459                                         slp = (struct SL_component *)
460                                                 (((char *)slp) + slp->len + 2);
461
462                                         if (slen < 2) {
463                                                 if (((rr->u.SL.
464                                                       flags & 1) != 0)
465                                                     &&
466                                                     ((oldslp->
467                                                       flags & 1) == 0))
468                                                         inode->i_size +=
469                                                             1;
470                                                 break;
471                                         }
472
473                                         /*
474                                          * If this component record isn't
475                                          * continued, then append a '/'.
476                                          */
477                                         if (!rootflag
478                                             && (oldslp->flags & 1) == 0)
479                                                 inode->i_size += 1;
480                                 }
481                         }
482                         symlink_len = inode->i_size;
483                         break;
484                 case SIG('R', 'E'):
485                         printk(KERN_WARNING "Attempt to read inode for "
486                                         "relocated directory\n");
487                         goto out;
488                 case SIG('C', 'L'):
489                         ISOFS_I(inode)->i_first_extent =
490                             isonum_733(rr->u.CL.location);
491                         reloc =
492                             isofs_iget(inode->i_sb,
493                                        ISOFS_I(inode)->i_first_extent,
494                                        0);
495                         if (IS_ERR(reloc)) {
496                                 ret = PTR_ERR(reloc);
497                                 goto out;
498                         }
499                         inode->i_mode = reloc->i_mode;
500                         inode->i_nlink = reloc->i_nlink;
501                         inode->i_uid = reloc->i_uid;
502                         inode->i_gid = reloc->i_gid;
503                         inode->i_rdev = reloc->i_rdev;
504                         inode->i_size = reloc->i_size;
505                         inode->i_blocks = reloc->i_blocks;
506                         inode->i_atime = reloc->i_atime;
507                         inode->i_ctime = reloc->i_ctime;
508                         inode->i_mtime = reloc->i_mtime;
509                         iput(reloc);
510                         break;
511 #ifdef CONFIG_ZISOFS
512                 case SIG('Z', 'F'): {
513                         int algo;
514
515                         if (ISOFS_SB(inode->i_sb)->s_nocompress)
516                                 break;
517                         algo = isonum_721(rr->u.ZF.algorithm);
518                         if (algo == SIG('p', 'z')) {
519                                 int block_shift =
520                                         isonum_711(&rr->u.ZF.parms[1]);
521                                 if (block_shift < PAGE_CACHE_SHIFT
522                                                 || block_shift > 17) {
523                                         printk(KERN_WARNING "isofs: "
524                                                 "Can't handle ZF block "
525                                                 "size of 2^%d\n",
526                                                 block_shift);
527                                 } else {
528                                         /*
529                                          * Note: we don't change
530                                          * i_blocks here
531                                          */
532                                         ISOFS_I(inode)->i_file_format =
533                                                 isofs_file_compressed;
534                                         /*
535                                          * Parameters to compression
536                                          * algorithm (header size,
537                                          * block size)
538                                          */
539                                         ISOFS_I(inode)->i_format_parm[0] =
540                                                 isonum_711(&rr->u.ZF.parms[0]);
541                                         ISOFS_I(inode)->i_format_parm[1] =
542                                                 isonum_711(&rr->u.ZF.parms[1]);
543                                         inode->i_size =
544                                             isonum_733(rr->u.ZF.
545                                                        real_size);
546                                 }
547                         } else {
548                                 printk(KERN_WARNING
549                                        "isofs: Unknown ZF compression "
550                                                 "algorithm: %c%c\n",
551                                        rr->u.ZF.algorithm[0],
552                                        rr->u.ZF.algorithm[1]);
553                         }
554                         break;
555                 }
556 #endif
557                 default:
558                         break;
559                 }
560         }
561         ret = rock_continue(&rs);
562         if (ret == 0)
563                 goto repeat;
564         if (ret == 1)
565                 ret = 0;
566 out:
567         kfree(rs.buffer);
568         return ret;
569 eio:
570         ret = -EIO;
571         goto out;
572 }
573
574 static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
575 {
576         int slen;
577         int rootflag;
578         struct SL_component *oldslp;
579         struct SL_component *slp;
580         slen = rr->len - 5;
581         slp = &rr->u.SL.link;
582         while (slen > 1) {
583                 rootflag = 0;
584                 switch (slp->flags & ~1) {
585                 case 0:
586                         if (slp->len > plimit - rpnt)
587                                 return NULL;
588                         memcpy(rpnt, slp->text, slp->len);
589                         rpnt += slp->len;
590                         break;
591                 case 2:
592                         if (rpnt >= plimit)
593                                 return NULL;
594                         *rpnt++ = '.';
595                         break;
596                 case 4:
597                         if (2 > plimit - rpnt)
598                                 return NULL;
599                         *rpnt++ = '.';
600                         *rpnt++ = '.';
601                         break;
602                 case 8:
603                         if (rpnt >= plimit)
604                                 return NULL;
605                         rootflag = 1;
606                         *rpnt++ = '/';
607                         break;
608                 default:
609                         printk("Symlink component flag not implemented (%d)\n",
610                                slp->flags);
611                 }
612                 slen -= slp->len + 2;
613                 oldslp = slp;
614                 slp = (struct SL_component *)((char *)slp + slp->len + 2);
615
616                 if (slen < 2) {
617                         /*
618                          * If there is another SL record, and this component
619                          * record isn't continued, then add a slash.
620                          */
621                         if ((!rootflag) && (rr->u.SL.flags & 1) &&
622                             !(oldslp->flags & 1)) {
623                                 if (rpnt >= plimit)
624                                         return NULL;
625                                 *rpnt++ = '/';
626                         }
627                         break;
628                 }
629
630                 /*
631                  * If this component record isn't continued, then append a '/'.
632                  */
633                 if (!rootflag && !(oldslp->flags & 1)) {
634                         if (rpnt >= plimit)
635                                 return NULL;
636                         *rpnt++ = '/';
637                 }
638         }
639         return rpnt;
640 }
641
642 int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode)
643 {
644         int result = parse_rock_ridge_inode_internal(de, inode, 0);
645
646         /*
647          * if rockridge flag was reset and we didn't look for attributes
648          * behind eventual XA attributes, have a look there
649          */
650         if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
651             && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
652                 result = parse_rock_ridge_inode_internal(de, inode, 14);
653         }
654         return result;
655 }
656
657 /*
658  * readpage() for symlinks: reads symlink contents into the page and either
659  * makes it uptodate and returns 0 or returns error (-EIO)
660  */
661 static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
662 {
663         struct inode *inode = page->mapping->host;
664         struct iso_inode_info *ei = ISOFS_I(inode);
665         char *link = kmap(page);
666         unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
667         struct buffer_head *bh;
668         char *rpnt = link;
669         unsigned char *pnt;
670         struct iso_directory_record *raw_de;
671         unsigned long block, offset;
672         int sig;
673         struct rock_ridge *rr;
674         struct rock_state rs;
675         int ret;
676
677         if (!ISOFS_SB(inode->i_sb)->s_rock)
678                 goto error;
679
680         init_rock_state(&rs, inode);
681         block = ei->i_iget5_block;
682         lock_kernel();
683         bh = sb_bread(inode->i_sb, block);
684         if (!bh)
685                 goto out_noread;
686
687         offset = ei->i_iget5_offset;
688         pnt = (unsigned char *)bh->b_data + offset;
689
690         raw_de = (struct iso_directory_record *)pnt;
691
692         /*
693          * If we go past the end of the buffer, there is some sort of error.
694          */
695         if (offset + *pnt > bufsize)
696                 goto out_bad_span;
697
698         /*
699          * Now test for possible Rock Ridge extensions which will override
700          * some of these numbers in the inode structure.
701          */
702
703         setup_rock_ridge(raw_de, inode, &rs);
704
705 repeat:
706         while (rs.len > 2) { /* There may be one byte for padding somewhere */
707                 rr = (struct rock_ridge *)rs.chr;
708                 if (rr->len < 3)
709                         goto out;       /* Something got screwed up here */
710                 sig = isonum_721(rs.chr);
711                 if (rock_check_overflow(&rs, sig))
712                         goto out;
713                 rs.chr += rr->len;
714                 rs.len -= rr->len;
715                 if (rs.len < 0)
716                         goto out;       /* corrupted isofs */
717
718                 switch (sig) {
719                 case SIG('R', 'R'):
720                         if ((rr->u.RR.flags[0] & RR_SL) == 0)
721                                 goto out;
722                         break;
723                 case SIG('S', 'P'):
724                         if (check_sp(rr, inode))
725                                 goto out;
726                         break;
727                 case SIG('S', 'L'):
728                         rpnt = get_symlink_chunk(rpnt, rr,
729                                                  link + (PAGE_SIZE - 1));
730                         if (rpnt == NULL)
731                                 goto out;
732                         break;
733                 case SIG('C', 'E'):
734                         /* This tells is if there is a continuation record */
735                         rs.cont_extent = isonum_733(rr->u.CE.extent);
736                         rs.cont_offset = isonum_733(rr->u.CE.offset);
737                         rs.cont_size = isonum_733(rr->u.CE.size);
738                 default:
739                         break;
740                 }
741         }
742         ret = rock_continue(&rs);
743         if (ret == 0)
744                 goto repeat;
745         if (ret < 0)
746                 goto fail;
747
748         if (rpnt == link)
749                 goto fail;
750         brelse(bh);
751         *rpnt = '\0';
752         unlock_kernel();
753         SetPageUptodate(page);
754         kunmap(page);
755         unlock_page(page);
756         return 0;
757
758         /* error exit from macro */
759 out:
760         kfree(rs.buffer);
761         goto fail;
762 out_noread:
763         printk("unable to read i-node block");
764         goto fail;
765 out_bad_span:
766         printk("symlink spans iso9660 blocks\n");
767 fail:
768         brelse(bh);
769         unlock_kernel();
770 error:
771         SetPageError(page);
772         kunmap(page);
773         unlock_page(page);
774         return -EIO;
775 }
776
777 const struct address_space_operations isofs_symlink_aops = {
778         .readpage = rock_ridge_symlink_readpage
779 };