xref: /kernel/linux/linux-6.6/fs/isofs/rock.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  linux/fs/isofs/rock.c
4 *
5 *  (C) 1992, 1993  Eric Youngdale
6 *
7 *  Rock Ridge Extensions to iso9660
8 */
9
10#include <linux/slab.h>
11#include <linux/pagemap.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
27struct 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	int cont_loops;
35	struct inode *inode;
36};
37
38/*
39 * This is a way of ensuring that we have something in the system
40 * use fields that is compatible with Rock Ridge.  Return zero on success.
41 */
42
43static int check_sp(struct rock_ridge *rr, struct inode *inode)
44{
45	if (rr->u.SP.magic[0] != 0xbe)
46		return -1;
47	if (rr->u.SP.magic[1] != 0xef)
48		return -1;
49	ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
50	return 0;
51}
52
53static void setup_rock_ridge(struct iso_directory_record *de,
54			struct inode *inode, struct rock_state *rs)
55{
56	rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
57	if (rs->len & 1)
58		(rs->len)++;
59	rs->chr = (unsigned char *)de + rs->len;
60	rs->len = *((unsigned char *)de) - rs->len;
61	if (rs->len < 0)
62		rs->len = 0;
63
64	if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
65		rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
66		rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
67		if (rs->len < 0)
68			rs->len = 0;
69	}
70}
71
72static void init_rock_state(struct rock_state *rs, struct inode *inode)
73{
74	memset(rs, 0, sizeof(*rs));
75	rs->inode = inode;
76}
77
78/* Maximum number of Rock Ridge continuation entries */
79#define RR_MAX_CE_ENTRIES 32
80
81/*
82 * Returns 0 if the caller should continue scanning, 1 if the scan must end
83 * and -ve on error.
84 */
85static int rock_continue(struct rock_state *rs)
86{
87	int ret = 1;
88	int blocksize = 1 << rs->inode->i_blkbits;
89	const int min_de_size = offsetof(struct rock_ridge, u);
90
91	kfree(rs->buffer);
92	rs->buffer = NULL;
93
94	if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
95	    (unsigned)rs->cont_size > blocksize ||
96	    (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
97		printk(KERN_NOTICE "rock: corrupted directory entry. "
98			"extent=%d, offset=%d, size=%d\n",
99			rs->cont_extent, rs->cont_offset, rs->cont_size);
100		ret = -EIO;
101		goto out;
102	}
103
104	if (rs->cont_extent) {
105		struct buffer_head *bh;
106
107		rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
108		if (!rs->buffer) {
109			ret = -ENOMEM;
110			goto out;
111		}
112		ret = -EIO;
113		if (++rs->cont_loops >= RR_MAX_CE_ENTRIES)
114			goto out;
115		bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
116		if (bh) {
117			memcpy(rs->buffer, bh->b_data + rs->cont_offset,
118					rs->cont_size);
119			put_bh(bh);
120			rs->chr = rs->buffer;
121			rs->len = rs->cont_size;
122			rs->cont_extent = 0;
123			rs->cont_size = 0;
124			rs->cont_offset = 0;
125			return 0;
126		}
127		printk("Unable to read rock-ridge attributes\n");
128	}
129out:
130	kfree(rs->buffer);
131	rs->buffer = NULL;
132	return ret;
133}
134
135/*
136 * We think there's a record of type `sig' at rs->chr.  Parse the signature
137 * and make sure that there's really room for a record of that type.
138 */
139static int rock_check_overflow(struct rock_state *rs, int sig)
140{
141	int len;
142
143	switch (sig) {
144	case SIG('S', 'P'):
145		len = sizeof(struct SU_SP_s);
146		break;
147	case SIG('C', 'E'):
148		len = sizeof(struct SU_CE_s);
149		break;
150	case SIG('E', 'R'):
151		len = sizeof(struct SU_ER_s);
152		break;
153	case SIG('R', 'R'):
154		len = sizeof(struct RR_RR_s);
155		break;
156	case SIG('P', 'X'):
157		len = sizeof(struct RR_PX_s);
158		break;
159	case SIG('P', 'N'):
160		len = sizeof(struct RR_PN_s);
161		break;
162	case SIG('S', 'L'):
163		len = sizeof(struct RR_SL_s);
164		break;
165	case SIG('N', 'M'):
166		len = sizeof(struct RR_NM_s);
167		break;
168	case SIG('C', 'L'):
169		len = sizeof(struct RR_CL_s);
170		break;
171	case SIG('P', 'L'):
172		len = sizeof(struct RR_PL_s);
173		break;
174	case SIG('T', 'F'):
175		len = sizeof(struct RR_TF_s);
176		break;
177	case SIG('Z', 'F'):
178		len = sizeof(struct RR_ZF_s);
179		break;
180	default:
181		len = 0;
182		break;
183	}
184	len += offsetof(struct rock_ridge, u);
185	if (len > rs->len) {
186		printk(KERN_NOTICE "rock: directory entry would overflow "
187				"storage\n");
188		printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
189				sig, len, rs->len);
190		return -EIO;
191	}
192	return 0;
193}
194
195/*
196 * return length of name field; 0: not found, -1: to be ignored
197 */
198int get_rock_ridge_filename(struct iso_directory_record *de,
199			    char *retname, struct inode *inode)
200{
201	struct rock_state rs;
202	struct rock_ridge *rr;
203	int sig;
204	int retnamlen = 0;
205	int truncate = 0;
206	int ret = 0;
207	char *p;
208	int len;
209
210	if (!ISOFS_SB(inode->i_sb)->s_rock)
211		return 0;
212	*retname = 0;
213
214	init_rock_state(&rs, inode);
215	setup_rock_ridge(de, inode, &rs);
216repeat:
217
218	while (rs.len > 2) { /* There may be one byte for padding somewhere */
219		rr = (struct rock_ridge *)rs.chr;
220		/*
221		 * Ignore rock ridge info if rr->len is out of range, but
222		 * don't return -EIO because that would make the file
223		 * invisible.
224		 */
225		if (rr->len < 3)
226			goto out;	/* Something got screwed up here */
227		sig = isonum_721(rs.chr);
228		if (rock_check_overflow(&rs, sig))
229			goto eio;
230		rs.chr += rr->len;
231		rs.len -= rr->len;
232		/*
233		 * As above, just ignore the rock ridge info if rr->len
234		 * is bogus.
235		 */
236		if (rs.len < 0)
237			goto out;	/* Something got screwed up here */
238
239		switch (sig) {
240		case SIG('R', 'R'):
241			if ((rr->u.RR.flags[0] & RR_NM) == 0)
242				goto out;
243			break;
244		case SIG('S', 'P'):
245			if (check_sp(rr, inode))
246				goto out;
247			break;
248		case SIG('C', 'E'):
249			rs.cont_extent = isonum_733(rr->u.CE.extent);
250			rs.cont_offset = isonum_733(rr->u.CE.offset);
251			rs.cont_size = isonum_733(rr->u.CE.size);
252			break;
253		case SIG('N', 'M'):
254			if (truncate)
255				break;
256			if (rr->len < 5)
257				break;
258			/*
259			 * If the flags are 2 or 4, this indicates '.' or '..'.
260			 * We don't want to do anything with this, because it
261			 * screws up the code that calls us.  We don't really
262			 * care anyways, since we can just use the non-RR
263			 * name.
264			 */
265			if (rr->u.NM.flags & 6)
266				break;
267
268			if (rr->u.NM.flags & ~1) {
269				printk("Unsupported NM flag settings (%d)\n",
270					rr->u.NM.flags);
271				break;
272			}
273			len = rr->len - 5;
274			if (retnamlen + len >= 254) {
275				truncate = 1;
276				break;
277			}
278			p = memchr(rr->u.NM.name, '\0', len);
279			if (unlikely(p))
280				len = p - rr->u.NM.name;
281			memcpy(retname + retnamlen, rr->u.NM.name, len);
282			retnamlen += len;
283			retname[retnamlen] = '\0';
284			break;
285		case SIG('R', 'E'):
286			kfree(rs.buffer);
287			return -1;
288		default:
289			break;
290		}
291	}
292	ret = rock_continue(&rs);
293	if (ret == 0)
294		goto repeat;
295	if (ret == 1)
296		return retnamlen; /* If 0, this file did not have a NM field */
297out:
298	kfree(rs.buffer);
299	return ret;
300eio:
301	ret = -EIO;
302	goto out;
303}
304
305#define RR_REGARD_XA 1
306#define RR_RELOC_DE 2
307
308static int
309parse_rock_ridge_inode_internal(struct iso_directory_record *de,
310				struct inode *inode, int flags)
311{
312	int symlink_len = 0;
313	int cnt, sig;
314	unsigned int reloc_block;
315	struct inode *reloc;
316	struct rock_ridge *rr;
317	int rootflag;
318	struct rock_state rs;
319	int ret = 0;
320
321	if (!ISOFS_SB(inode->i_sb)->s_rock)
322		return 0;
323
324	init_rock_state(&rs, inode);
325	setup_rock_ridge(de, inode, &rs);
326	if (flags & RR_REGARD_XA) {
327		rs.chr += 14;
328		rs.len -= 14;
329		if (rs.len < 0)
330			rs.len = 0;
331	}
332
333repeat:
334	while (rs.len > 2) { /* There may be one byte for padding somewhere */
335		rr = (struct rock_ridge *)rs.chr;
336		/*
337		 * Ignore rock ridge info if rr->len is out of range, but
338		 * don't return -EIO because that would make the file
339		 * invisible.
340		 */
341		if (rr->len < 3)
342			goto out;	/* Something got screwed up here */
343		sig = isonum_721(rs.chr);
344		if (rock_check_overflow(&rs, sig))
345			goto eio;
346		rs.chr += rr->len;
347		rs.len -= rr->len;
348		/*
349		 * As above, just ignore the rock ridge info if rr->len
350		 * is bogus.
351		 */
352		if (rs.len < 0)
353			goto out;	/* Something got screwed up here */
354
355		switch (sig) {
356#ifndef CONFIG_ZISOFS		/* No flag for SF or ZF */
357		case SIG('R', 'R'):
358			if ((rr->u.RR.flags[0] &
359			     (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
360				goto out;
361			break;
362#endif
363		case SIG('S', 'P'):
364			if (check_sp(rr, inode))
365				goto out;
366			break;
367		case SIG('C', 'E'):
368			rs.cont_extent = isonum_733(rr->u.CE.extent);
369			rs.cont_offset = isonum_733(rr->u.CE.offset);
370			rs.cont_size = isonum_733(rr->u.CE.size);
371			break;
372		case SIG('E', 'R'):
373			/* Invalid length of ER tag id? */
374			if (rr->u.ER.len_id + offsetof(struct rock_ridge, u.ER.data) > rr->len)
375				goto out;
376			ISOFS_SB(inode->i_sb)->s_rock = 1;
377			printk(KERN_DEBUG "ISO 9660 Extensions: ");
378			{
379				int p;
380				for (p = 0; p < rr->u.ER.len_id; p++)
381					printk(KERN_CONT "%c", rr->u.ER.data[p]);
382			}
383			printk(KERN_CONT "\n");
384			break;
385		case SIG('P', 'X'):
386			inode->i_mode = isonum_733(rr->u.PX.mode);
387			set_nlink(inode, isonum_733(rr->u.PX.n_links));
388			i_uid_write(inode, isonum_733(rr->u.PX.uid));
389			i_gid_write(inode, isonum_733(rr->u.PX.gid));
390			break;
391		case SIG('P', 'N'):
392			{
393				int high, low;
394				high = isonum_733(rr->u.PN.dev_high);
395				low = isonum_733(rr->u.PN.dev_low);
396				/*
397				 * The Rock Ridge standard specifies that if
398				 * sizeof(dev_t) <= 4, then the high field is
399				 * unused, and the device number is completely
400				 * stored in the low field.  Some writers may
401				 * ignore this subtlety,
402				 * and as a result we test to see if the entire
403				 * device number is
404				 * stored in the low field, and use that.
405				 */
406				if ((low & ~0xff) && high == 0) {
407					inode->i_rdev =
408					    MKDEV(low >> 8, low & 0xff);
409				} else {
410					inode->i_rdev =
411					    MKDEV(high, low);
412				}
413			}
414			break;
415		case SIG('T', 'F'):
416			/*
417			 * Some RRIP writers incorrectly place ctime in the
418			 * TF_CREATE field. Try to handle this correctly for
419			 * either case.
420			 */
421			/* Rock ridge never appears on a High Sierra disk */
422			cnt = 0;
423			if (rr->u.TF.flags & TF_CREATE) {
424				inode_set_ctime(inode,
425						iso_date(rr->u.TF.times[cnt++].time, 0),
426						0);
427			}
428			if (rr->u.TF.flags & TF_MODIFY) {
429				inode->i_mtime.tv_sec =
430				    iso_date(rr->u.TF.times[cnt++].time,
431					     0);
432				inode->i_mtime.tv_nsec = 0;
433			}
434			if (rr->u.TF.flags & TF_ACCESS) {
435				inode->i_atime.tv_sec =
436				    iso_date(rr->u.TF.times[cnt++].time,
437					     0);
438				inode->i_atime.tv_nsec = 0;
439			}
440			if (rr->u.TF.flags & TF_ATTRIBUTES) {
441				inode_set_ctime(inode,
442						iso_date(rr->u.TF.times[cnt++].time, 0),
443						0);
444			}
445			break;
446		case SIG('S', 'L'):
447			{
448				int slen;
449				struct SL_component *slp;
450				struct SL_component *oldslp;
451				slen = rr->len - 5;
452				slp = &rr->u.SL.link;
453				inode->i_size = symlink_len;
454				while (slen > 1) {
455					rootflag = 0;
456					switch (slp->flags & ~1) {
457					case 0:
458						inode->i_size +=
459						    slp->len;
460						break;
461					case 2:
462						inode->i_size += 1;
463						break;
464					case 4:
465						inode->i_size += 2;
466						break;
467					case 8:
468						rootflag = 1;
469						inode->i_size += 1;
470						break;
471					default:
472						printk("Symlink component flag "
473							"not implemented\n");
474					}
475					slen -= slp->len + 2;
476					oldslp = slp;
477					slp = (struct SL_component *)
478						(((char *)slp) + slp->len + 2);
479
480					if (slen < 2) {
481						if (((rr->u.SL.
482						      flags & 1) != 0)
483						    &&
484						    ((oldslp->
485						      flags & 1) == 0))
486							inode->i_size +=
487							    1;
488						break;
489					}
490
491					/*
492					 * If this component record isn't
493					 * continued, then append a '/'.
494					 */
495					if (!rootflag
496					    && (oldslp->flags & 1) == 0)
497						inode->i_size += 1;
498				}
499			}
500			symlink_len = inode->i_size;
501			break;
502		case SIG('R', 'E'):
503			printk(KERN_WARNING "Attempt to read inode for "
504					"relocated directory\n");
505			goto out;
506		case SIG('C', 'L'):
507			if (flags & RR_RELOC_DE) {
508				printk(KERN_ERR
509				       "ISOFS: Recursive directory relocation "
510				       "is not supported\n");
511				goto eio;
512			}
513			reloc_block = isonum_733(rr->u.CL.location);
514			if (reloc_block == ISOFS_I(inode)->i_iget5_block &&
515			    ISOFS_I(inode)->i_iget5_offset == 0) {
516				printk(KERN_ERR
517				       "ISOFS: Directory relocation points to "
518				       "itself\n");
519				goto eio;
520			}
521			ISOFS_I(inode)->i_first_extent = reloc_block;
522			reloc = isofs_iget_reloc(inode->i_sb, reloc_block, 0);
523			if (IS_ERR(reloc)) {
524				ret = PTR_ERR(reloc);
525				goto out;
526			}
527			inode->i_mode = reloc->i_mode;
528			set_nlink(inode, reloc->i_nlink);
529			inode->i_uid = reloc->i_uid;
530			inode->i_gid = reloc->i_gid;
531			inode->i_rdev = reloc->i_rdev;
532			inode->i_size = reloc->i_size;
533			inode->i_blocks = reloc->i_blocks;
534			inode->i_atime = reloc->i_atime;
535			inode_set_ctime_to_ts(inode, inode_get_ctime(reloc));
536			inode->i_mtime = reloc->i_mtime;
537			iput(reloc);
538			break;
539#ifdef CONFIG_ZISOFS
540		case SIG('Z', 'F'): {
541			int algo;
542
543			if (ISOFS_SB(inode->i_sb)->s_nocompress)
544				break;
545			algo = isonum_721(rr->u.ZF.algorithm);
546			if (algo == SIG('p', 'z')) {
547				int block_shift =
548					isonum_711(&rr->u.ZF.parms[1]);
549				if (block_shift > 17) {
550					printk(KERN_WARNING "isofs: "
551						"Can't handle ZF block "
552						"size of 2^%d\n",
553						block_shift);
554				} else {
555					/*
556					 * Note: we don't change
557					 * i_blocks here
558					 */
559					ISOFS_I(inode)->i_file_format =
560						isofs_file_compressed;
561					/*
562					 * Parameters to compression
563					 * algorithm (header size,
564					 * block size)
565					 */
566					ISOFS_I(inode)->i_format_parm[0] =
567						isonum_711(&rr->u.ZF.parms[0]);
568					ISOFS_I(inode)->i_format_parm[1] =
569						isonum_711(&rr->u.ZF.parms[1]);
570					inode->i_size =
571					    isonum_733(rr->u.ZF.
572						       real_size);
573				}
574			} else {
575				printk(KERN_WARNING
576				       "isofs: Unknown ZF compression "
577						"algorithm: %c%c\n",
578				       rr->u.ZF.algorithm[0],
579				       rr->u.ZF.algorithm[1]);
580			}
581			break;
582		}
583#endif
584		default:
585			break;
586		}
587	}
588	ret = rock_continue(&rs);
589	if (ret == 0)
590		goto repeat;
591	if (ret == 1)
592		ret = 0;
593out:
594	kfree(rs.buffer);
595	return ret;
596eio:
597	ret = -EIO;
598	goto out;
599}
600
601static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
602{
603	int slen;
604	int rootflag;
605	struct SL_component *oldslp;
606	struct SL_component *slp;
607	slen = rr->len - 5;
608	slp = &rr->u.SL.link;
609	while (slen > 1) {
610		rootflag = 0;
611		switch (slp->flags & ~1) {
612		case 0:
613			if (slp->len > plimit - rpnt)
614				return NULL;
615			memcpy(rpnt, slp->text, slp->len);
616			rpnt += slp->len;
617			break;
618		case 2:
619			if (rpnt >= plimit)
620				return NULL;
621			*rpnt++ = '.';
622			break;
623		case 4:
624			if (2 > plimit - rpnt)
625				return NULL;
626			*rpnt++ = '.';
627			*rpnt++ = '.';
628			break;
629		case 8:
630			if (rpnt >= plimit)
631				return NULL;
632			rootflag = 1;
633			*rpnt++ = '/';
634			break;
635		default:
636			printk("Symlink component flag not implemented (%d)\n",
637			       slp->flags);
638		}
639		slen -= slp->len + 2;
640		oldslp = slp;
641		slp = (struct SL_component *)((char *)slp + slp->len + 2);
642
643		if (slen < 2) {
644			/*
645			 * If there is another SL record, and this component
646			 * record isn't continued, then add a slash.
647			 */
648			if ((!rootflag) && (rr->u.SL.flags & 1) &&
649			    !(oldslp->flags & 1)) {
650				if (rpnt >= plimit)
651					return NULL;
652				*rpnt++ = '/';
653			}
654			break;
655		}
656
657		/*
658		 * If this component record isn't continued, then append a '/'.
659		 */
660		if (!rootflag && !(oldslp->flags & 1)) {
661			if (rpnt >= plimit)
662				return NULL;
663			*rpnt++ = '/';
664		}
665	}
666	return rpnt;
667}
668
669int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode,
670			   int relocated)
671{
672	int flags = relocated ? RR_RELOC_DE : 0;
673	int result = parse_rock_ridge_inode_internal(de, inode, flags);
674
675	/*
676	 * if rockridge flag was reset and we didn't look for attributes
677	 * behind eventual XA attributes, have a look there
678	 */
679	if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
680	    && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
681		result = parse_rock_ridge_inode_internal(de, inode,
682							 flags | RR_REGARD_XA);
683	}
684	return result;
685}
686
687/*
688 * read_folio() for symlinks: reads symlink contents into the folio and either
689 * makes it uptodate and returns 0 or returns error (-EIO)
690 */
691static int rock_ridge_symlink_read_folio(struct file *file, struct folio *folio)
692{
693	struct page *page = &folio->page;
694	struct inode *inode = page->mapping->host;
695	struct iso_inode_info *ei = ISOFS_I(inode);
696	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
697	char *link = page_address(page);
698	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
699	struct buffer_head *bh;
700	char *rpnt = link;
701	unsigned char *pnt;
702	struct iso_directory_record *raw_de;
703	unsigned long block, offset;
704	int sig;
705	struct rock_ridge *rr;
706	struct rock_state rs;
707	int ret;
708
709	if (!sbi->s_rock)
710		goto error;
711
712	init_rock_state(&rs, inode);
713	block = ei->i_iget5_block;
714	bh = sb_bread(inode->i_sb, block);
715	if (!bh)
716		goto out_noread;
717
718	offset = ei->i_iget5_offset;
719	pnt = (unsigned char *)bh->b_data + offset;
720
721	raw_de = (struct iso_directory_record *)pnt;
722
723	/*
724	 * If we go past the end of the buffer, there is some sort of error.
725	 */
726	if (offset + *pnt > bufsize)
727		goto out_bad_span;
728
729	/*
730	 * Now test for possible Rock Ridge extensions which will override
731	 * some of these numbers in the inode structure.
732	 */
733
734	setup_rock_ridge(raw_de, inode, &rs);
735
736repeat:
737	while (rs.len > 2) { /* There may be one byte for padding somewhere */
738		rr = (struct rock_ridge *)rs.chr;
739		if (rr->len < 3)
740			goto out;	/* Something got screwed up here */
741		sig = isonum_721(rs.chr);
742		if (rock_check_overflow(&rs, sig))
743			goto out;
744		rs.chr += rr->len;
745		rs.len -= rr->len;
746		if (rs.len < 0)
747			goto out;	/* corrupted isofs */
748
749		switch (sig) {
750		case SIG('R', 'R'):
751			if ((rr->u.RR.flags[0] & RR_SL) == 0)
752				goto out;
753			break;
754		case SIG('S', 'P'):
755			if (check_sp(rr, inode))
756				goto out;
757			break;
758		case SIG('S', 'L'):
759			rpnt = get_symlink_chunk(rpnt, rr,
760						 link + (PAGE_SIZE - 1));
761			if (rpnt == NULL)
762				goto out;
763			break;
764		case SIG('C', 'E'):
765			/* This tells is if there is a continuation record */
766			rs.cont_extent = isonum_733(rr->u.CE.extent);
767			rs.cont_offset = isonum_733(rr->u.CE.offset);
768			rs.cont_size = isonum_733(rr->u.CE.size);
769			break;
770		default:
771			break;
772		}
773	}
774	ret = rock_continue(&rs);
775	if (ret == 0)
776		goto repeat;
777	if (ret < 0)
778		goto fail;
779
780	if (rpnt == link)
781		goto fail;
782	brelse(bh);
783	*rpnt = '\0';
784	SetPageUptodate(page);
785	unlock_page(page);
786	return 0;
787
788	/* error exit from macro */
789out:
790	kfree(rs.buffer);
791	goto fail;
792out_noread:
793	printk("unable to read i-node block");
794	goto fail;
795out_bad_span:
796	printk("symlink spans iso9660 blocks\n");
797fail:
798	brelse(bh);
799error:
800	SetPageError(page);
801	unlock_page(page);
802	return -EIO;
803}
804
805const struct address_space_operations isofs_symlink_aops = {
806	.read_folio = rock_ridge_symlink_read_folio
807};
808