xref: /openbmc/linux/fs/isofs/inode.c (revision 61c6065e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/isofs/inode.c
4  *
5  *  (C) 1991  Linus Torvalds - minix filesystem
6  *      1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
7  *      1994  Eberhard Mönkeberg - multi session handling.
8  *      1995  Mark Dobie - allow mounting of some weird VideoCDs and PhotoCDs.
9  *	1997  Gordon Chaffee - Joliet CDs
10  *	1998  Eric Lammerts - ISO 9660 Level 3
11  *	2004  Paul Serice - Inode Support pushed out from 4GB to 128GB
12  *	2004  Paul Serice - NFS Export Operations
13  */
14 
15 #include <linux/init.h>
16 #include <linux/module.h>
17 
18 #include <linux/slab.h>
19 #include <linux/cred.h>
20 #include <linux/nls.h>
21 #include <linux/ctype.h>
22 #include <linux/statfs.h>
23 #include <linux/cdrom.h>
24 #include <linux/parser.h>
25 #include <linux/mpage.h>
26 #include <linux/user_namespace.h>
27 #include <linux/seq_file.h>
28 #include <linux/blkdev.h>
29 
30 #include "isofs.h"
31 #include "zisofs.h"
32 
33 /* max tz offset is 13 hours */
34 #define MAX_TZ_OFFSET (52*15*60)
35 
36 #define BEQUIET
37 
38 static int isofs_hashi(const struct dentry *parent, struct qstr *qstr);
39 static int isofs_dentry_cmpi(const struct dentry *dentry,
40 		unsigned int len, const char *str, const struct qstr *name);
41 
42 #ifdef CONFIG_JOLIET
43 static int isofs_hashi_ms(const struct dentry *parent, struct qstr *qstr);
44 static int isofs_hash_ms(const struct dentry *parent, struct qstr *qstr);
45 static int isofs_dentry_cmpi_ms(const struct dentry *dentry,
46 		unsigned int len, const char *str, const struct qstr *name);
47 static int isofs_dentry_cmp_ms(const struct dentry *dentry,
48 		unsigned int len, const char *str, const struct qstr *name);
49 #endif
50 
51 static void isofs_put_super(struct super_block *sb)
52 {
53 	struct isofs_sb_info *sbi = ISOFS_SB(sb);
54 
55 #ifdef CONFIG_JOLIET
56 	unload_nls(sbi->s_nls_iocharset);
57 #endif
58 
59 	kfree(sbi);
60 	sb->s_fs_info = NULL;
61 	return;
62 }
63 
64 static int isofs_read_inode(struct inode *, int relocated);
65 static int isofs_statfs (struct dentry *, struct kstatfs *);
66 static int isofs_show_options(struct seq_file *, struct dentry *);
67 
68 static struct kmem_cache *isofs_inode_cachep;
69 
70 static struct inode *isofs_alloc_inode(struct super_block *sb)
71 {
72 	struct iso_inode_info *ei;
73 	ei = alloc_inode_sb(sb, isofs_inode_cachep, GFP_KERNEL);
74 	if (!ei)
75 		return NULL;
76 	return &ei->vfs_inode;
77 }
78 
79 static void isofs_free_inode(struct inode *inode)
80 {
81 	kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));
82 }
83 
84 static void init_once(void *foo)
85 {
86 	struct iso_inode_info *ei = foo;
87 
88 	inode_init_once(&ei->vfs_inode);
89 }
90 
91 static int __init init_inodecache(void)
92 {
93 	isofs_inode_cachep = kmem_cache_create("isofs_inode_cache",
94 					sizeof(struct iso_inode_info),
95 					0, (SLAB_RECLAIM_ACCOUNT|
96 					SLAB_MEM_SPREAD|SLAB_ACCOUNT),
97 					init_once);
98 	if (!isofs_inode_cachep)
99 		return -ENOMEM;
100 	return 0;
101 }
102 
103 static void destroy_inodecache(void)
104 {
105 	/*
106 	 * Make sure all delayed rcu free inodes are flushed before we
107 	 * destroy cache.
108 	 */
109 	rcu_barrier();
110 	kmem_cache_destroy(isofs_inode_cachep);
111 }
112 
113 static int isofs_remount(struct super_block *sb, int *flags, char *data)
114 {
115 	sync_filesystem(sb);
116 	if (!(*flags & SB_RDONLY))
117 		return -EROFS;
118 	return 0;
119 }
120 
121 static const struct super_operations isofs_sops = {
122 	.alloc_inode	= isofs_alloc_inode,
123 	.free_inode	= isofs_free_inode,
124 	.put_super	= isofs_put_super,
125 	.statfs		= isofs_statfs,
126 	.remount_fs	= isofs_remount,
127 	.show_options	= isofs_show_options,
128 };
129 
130 
131 static const struct dentry_operations isofs_dentry_ops[] = {
132 	{
133 		.d_hash		= isofs_hashi,
134 		.d_compare	= isofs_dentry_cmpi,
135 	},
136 #ifdef CONFIG_JOLIET
137 	{
138 		.d_hash		= isofs_hash_ms,
139 		.d_compare	= isofs_dentry_cmp_ms,
140 	},
141 	{
142 		.d_hash		= isofs_hashi_ms,
143 		.d_compare	= isofs_dentry_cmpi_ms,
144 	},
145 #endif
146 };
147 
148 struct iso9660_options{
149 	unsigned int rock:1;
150 	unsigned int joliet:1;
151 	unsigned int cruft:1;
152 	unsigned int hide:1;
153 	unsigned int showassoc:1;
154 	unsigned int nocompress:1;
155 	unsigned int overriderockperm:1;
156 	unsigned int uid_set:1;
157 	unsigned int gid_set:1;
158 	unsigned char map;
159 	unsigned char check;
160 	unsigned int blocksize;
161 	umode_t fmode;
162 	umode_t dmode;
163 	kgid_t gid;
164 	kuid_t uid;
165 	char *iocharset;
166 	/* LVE */
167 	s32 session;
168 	s32 sbsector;
169 };
170 
171 /*
172  * Compute the hash for the isofs name corresponding to the dentry.
173  */
174 static int
175 isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms)
176 {
177 	const char *name;
178 	int len;
179 	char c;
180 	unsigned long hash;
181 
182 	len = qstr->len;
183 	name = qstr->name;
184 	if (ms) {
185 		while (len && name[len-1] == '.')
186 			len--;
187 	}
188 
189 	hash = init_name_hash(dentry);
190 	while (len--) {
191 		c = tolower(*name++);
192 		hash = partial_name_hash(c, hash);
193 	}
194 	qstr->hash = end_name_hash(hash);
195 
196 	return 0;
197 }
198 
199 /*
200  * Compare of two isofs names.
201  */
202 static int isofs_dentry_cmp_common(
203 		unsigned int len, const char *str,
204 		const struct qstr *name, int ms, int ci)
205 {
206 	int alen, blen;
207 
208 	/* A filename cannot end in '.' or we treat it like it has none */
209 	alen = name->len;
210 	blen = len;
211 	if (ms) {
212 		while (alen && name->name[alen-1] == '.')
213 			alen--;
214 		while (blen && str[blen-1] == '.')
215 			blen--;
216 	}
217 	if (alen == blen) {
218 		if (ci) {
219 			if (strncasecmp(name->name, str, alen) == 0)
220 				return 0;
221 		} else {
222 			if (strncmp(name->name, str, alen) == 0)
223 				return 0;
224 		}
225 	}
226 	return 1;
227 }
228 
229 static int
230 isofs_hashi(const struct dentry *dentry, struct qstr *qstr)
231 {
232 	return isofs_hashi_common(dentry, qstr, 0);
233 }
234 
235 static int
236 isofs_dentry_cmpi(const struct dentry *dentry,
237 		unsigned int len, const char *str, const struct qstr *name)
238 {
239 	return isofs_dentry_cmp_common(len, str, name, 0, 1);
240 }
241 
242 #ifdef CONFIG_JOLIET
243 /*
244  * Compute the hash for the isofs name corresponding to the dentry.
245  */
246 static int
247 isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms)
248 {
249 	const char *name;
250 	int len;
251 
252 	len = qstr->len;
253 	name = qstr->name;
254 	if (ms) {
255 		while (len && name[len-1] == '.')
256 			len--;
257 	}
258 
259 	qstr->hash = full_name_hash(dentry, name, len);
260 
261 	return 0;
262 }
263 
264 static int
265 isofs_hash_ms(const struct dentry *dentry, struct qstr *qstr)
266 {
267 	return isofs_hash_common(dentry, qstr, 1);
268 }
269 
270 static int
271 isofs_hashi_ms(const struct dentry *dentry, struct qstr *qstr)
272 {
273 	return isofs_hashi_common(dentry, qstr, 1);
274 }
275 
276 static int
277 isofs_dentry_cmp_ms(const struct dentry *dentry,
278 		unsigned int len, const char *str, const struct qstr *name)
279 {
280 	return isofs_dentry_cmp_common(len, str, name, 1, 0);
281 }
282 
283 static int
284 isofs_dentry_cmpi_ms(const struct dentry *dentry,
285 		unsigned int len, const char *str, const struct qstr *name)
286 {
287 	return isofs_dentry_cmp_common(len, str, name, 1, 1);
288 }
289 #endif
290 
291 enum {
292 	Opt_block, Opt_check_r, Opt_check_s, Opt_cruft, Opt_gid, Opt_ignore,
293 	Opt_iocharset, Opt_map_a, Opt_map_n, Opt_map_o, Opt_mode, Opt_nojoliet,
294 	Opt_norock, Opt_sb, Opt_session, Opt_uid, Opt_unhide, Opt_utf8, Opt_err,
295 	Opt_nocompress, Opt_hide, Opt_showassoc, Opt_dmode, Opt_overriderockperm,
296 };
297 
298 static const match_table_t tokens = {
299 	{Opt_norock, "norock"},
300 	{Opt_nojoliet, "nojoliet"},
301 	{Opt_unhide, "unhide"},
302 	{Opt_hide, "hide"},
303 	{Opt_showassoc, "showassoc"},
304 	{Opt_cruft, "cruft"},
305 	{Opt_utf8, "utf8"},
306 	{Opt_iocharset, "iocharset=%s"},
307 	{Opt_map_a, "map=acorn"},
308 	{Opt_map_a, "map=a"},
309 	{Opt_map_n, "map=normal"},
310 	{Opt_map_n, "map=n"},
311 	{Opt_map_o, "map=off"},
312 	{Opt_map_o, "map=o"},
313 	{Opt_session, "session=%u"},
314 	{Opt_sb, "sbsector=%u"},
315 	{Opt_check_r, "check=relaxed"},
316 	{Opt_check_r, "check=r"},
317 	{Opt_check_s, "check=strict"},
318 	{Opt_check_s, "check=s"},
319 	{Opt_uid, "uid=%u"},
320 	{Opt_gid, "gid=%u"},
321 	{Opt_mode, "mode=%u"},
322 	{Opt_dmode, "dmode=%u"},
323 	{Opt_overriderockperm, "overriderockperm"},
324 	{Opt_block, "block=%u"},
325 	{Opt_ignore, "conv=binary"},
326 	{Opt_ignore, "conv=b"},
327 	{Opt_ignore, "conv=text"},
328 	{Opt_ignore, "conv=t"},
329 	{Opt_ignore, "conv=mtext"},
330 	{Opt_ignore, "conv=m"},
331 	{Opt_ignore, "conv=auto"},
332 	{Opt_ignore, "conv=a"},
333 	{Opt_nocompress, "nocompress"},
334 	{Opt_err, NULL}
335 };
336 
337 static int parse_options(char *options, struct iso9660_options *popt)
338 {
339 	char *p;
340 	int option;
341 	unsigned int uv;
342 
343 	popt->map = 'n';
344 	popt->rock = 1;
345 	popt->joliet = 1;
346 	popt->cruft = 0;
347 	popt->hide = 0;
348 	popt->showassoc = 0;
349 	popt->check = 'u';		/* unset */
350 	popt->nocompress = 0;
351 	popt->blocksize = 1024;
352 	popt->fmode = popt->dmode = ISOFS_INVALID_MODE;
353 	popt->uid_set = 0;
354 	popt->gid_set = 0;
355 	popt->gid = GLOBAL_ROOT_GID;
356 	popt->uid = GLOBAL_ROOT_UID;
357 	popt->iocharset = NULL;
358 	popt->overriderockperm = 0;
359 	popt->session=-1;
360 	popt->sbsector=-1;
361 	if (!options)
362 		return 1;
363 
364 	while ((p = strsep(&options, ",")) != NULL) {
365 		int token;
366 		substring_t args[MAX_OPT_ARGS];
367 		unsigned n;
368 
369 		if (!*p)
370 			continue;
371 
372 		token = match_token(p, tokens, args);
373 		switch (token) {
374 		case Opt_norock:
375 			popt->rock = 0;
376 			break;
377 		case Opt_nojoliet:
378 			popt->joliet = 0;
379 			break;
380 		case Opt_hide:
381 			popt->hide = 1;
382 			break;
383 		case Opt_unhide:
384 		case Opt_showassoc:
385 			popt->showassoc = 1;
386 			break;
387 		case Opt_cruft:
388 			popt->cruft = 1;
389 			break;
390 #ifdef CONFIG_JOLIET
391 		case Opt_utf8:
392 			kfree(popt->iocharset);
393 			popt->iocharset = kstrdup("utf8", GFP_KERNEL);
394 			if (!popt->iocharset)
395 				return 0;
396 			break;
397 		case Opt_iocharset:
398 			kfree(popt->iocharset);
399 			popt->iocharset = match_strdup(&args[0]);
400 			if (!popt->iocharset)
401 				return 0;
402 			break;
403 #endif
404 		case Opt_map_a:
405 			popt->map = 'a';
406 			break;
407 		case Opt_map_o:
408 			popt->map = 'o';
409 			break;
410 		case Opt_map_n:
411 			popt->map = 'n';
412 			break;
413 		case Opt_session:
414 			if (match_int(&args[0], &option))
415 				return 0;
416 			n = option;
417 			/*
418 			 * Track numbers are supposed to be in range 1-99, the
419 			 * mount option starts indexing at 0.
420 			 */
421 			if (n >= 99)
422 				return 0;
423 			popt->session = n + 1;
424 			break;
425 		case Opt_sb:
426 			if (match_int(&args[0], &option))
427 				return 0;
428 			popt->sbsector = option;
429 			break;
430 		case Opt_check_r:
431 			popt->check = 'r';
432 			break;
433 		case Opt_check_s:
434 			popt->check = 's';
435 			break;
436 		case Opt_ignore:
437 			break;
438 		case Opt_uid:
439 			if (match_uint(&args[0], &uv))
440 				return 0;
441 			popt->uid = make_kuid(current_user_ns(), uv);
442 			if (!uid_valid(popt->uid))
443 				return 0;
444 			popt->uid_set = 1;
445 			break;
446 		case Opt_gid:
447 			if (match_uint(&args[0], &uv))
448 				return 0;
449 			popt->gid = make_kgid(current_user_ns(), uv);
450 			if (!gid_valid(popt->gid))
451 				return 0;
452 			popt->gid_set = 1;
453 			break;
454 		case Opt_mode:
455 			if (match_int(&args[0], &option))
456 				return 0;
457 			popt->fmode = option;
458 			break;
459 		case Opt_dmode:
460 			if (match_int(&args[0], &option))
461 				return 0;
462 			popt->dmode = option;
463 			break;
464 		case Opt_overriderockperm:
465 			popt->overriderockperm = 1;
466 			break;
467 		case Opt_block:
468 			if (match_int(&args[0], &option))
469 				return 0;
470 			n = option;
471 			if (n != 512 && n != 1024 && n != 2048)
472 				return 0;
473 			popt->blocksize = n;
474 			break;
475 		case Opt_nocompress:
476 			popt->nocompress = 1;
477 			break;
478 		default:
479 			return 0;
480 		}
481 	}
482 	return 1;
483 }
484 
485 /*
486  * Display the mount options in /proc/mounts.
487  */
488 static int isofs_show_options(struct seq_file *m, struct dentry *root)
489 {
490 	struct isofs_sb_info *sbi = ISOFS_SB(root->d_sb);
491 
492 	if (!sbi->s_rock)		seq_puts(m, ",norock");
493 	else if (!sbi->s_joliet_level)	seq_puts(m, ",nojoliet");
494 	if (sbi->s_cruft)		seq_puts(m, ",cruft");
495 	if (sbi->s_hide)		seq_puts(m, ",hide");
496 	if (sbi->s_nocompress)		seq_puts(m, ",nocompress");
497 	if (sbi->s_overriderockperm)	seq_puts(m, ",overriderockperm");
498 	if (sbi->s_showassoc)		seq_puts(m, ",showassoc");
499 
500 	if (sbi->s_check)		seq_printf(m, ",check=%c", sbi->s_check);
501 	if (sbi->s_mapping)		seq_printf(m, ",map=%c", sbi->s_mapping);
502 	if (sbi->s_session != 255)	seq_printf(m, ",session=%u", sbi->s_session - 1);
503 	if (sbi->s_sbsector != -1)	seq_printf(m, ",sbsector=%u", sbi->s_sbsector);
504 
505 	if (root->d_sb->s_blocksize != 1024)
506 		seq_printf(m, ",blocksize=%lu", root->d_sb->s_blocksize);
507 
508 	if (sbi->s_uid_set)
509 		seq_printf(m, ",uid=%u",
510 			   from_kuid_munged(&init_user_ns, sbi->s_uid));
511 	if (sbi->s_gid_set)
512 		seq_printf(m, ",gid=%u",
513 			   from_kgid_munged(&init_user_ns, sbi->s_gid));
514 
515 	if (sbi->s_dmode != ISOFS_INVALID_MODE)
516 		seq_printf(m, ",dmode=%o", sbi->s_dmode);
517 	if (sbi->s_fmode != ISOFS_INVALID_MODE)
518 		seq_printf(m, ",fmode=%o", sbi->s_fmode);
519 
520 #ifdef CONFIG_JOLIET
521 	if (sbi->s_nls_iocharset)
522 		seq_printf(m, ",iocharset=%s", sbi->s_nls_iocharset->charset);
523 	else
524 		seq_puts(m, ",iocharset=utf8");
525 #endif
526 	return 0;
527 }
528 
529 /*
530  * look if the driver can tell the multi session redirection value
531  *
532  * don't change this if you don't know what you do, please!
533  * Multisession is legal only with XA disks.
534  * A non-XA disk with more than one volume descriptor may do it right, but
535  * usually is written in a nowhere standardized "multi-partition" manner.
536  * Multisession uses absolute addressing (solely the first frame of the whole
537  * track is #0), multi-partition uses relative addressing (each first frame of
538  * each track is #0), and a track is not a session.
539  *
540  * A broken CDwriter software or drive firmware does not set new standards,
541  * at least not if conflicting with the existing ones.
542  *
543  * emoenke@gwdg.de
544  */
545 #define WE_OBEY_THE_WRITTEN_STANDARDS 1
546 
547 static unsigned int isofs_get_last_session(struct super_block *sb, s32 session)
548 {
549 	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
550 	unsigned int vol_desc_start = 0;
551 
552 	if (session > 0) {
553 		struct cdrom_tocentry te;
554 
555 		if (!cdi)
556 			return 0;
557 
558 		te.cdte_track = session;
559 		te.cdte_format = CDROM_LBA;
560 		if (cdrom_read_tocentry(cdi, &te) == 0) {
561 			printk(KERN_DEBUG "ISOFS: Session %d start %d type %d\n",
562 				session, te.cdte_addr.lba,
563 				te.cdte_ctrl & CDROM_DATA_TRACK);
564 			if ((te.cdte_ctrl & CDROM_DATA_TRACK) == 4)
565 				return te.cdte_addr.lba;
566 		}
567 
568 		printk(KERN_ERR "ISOFS: Invalid session number or type of track\n");
569 	}
570 
571 	if (cdi) {
572 		struct cdrom_multisession ms_info;
573 
574 		ms_info.addr_format = CDROM_LBA;
575 		if (cdrom_multisession(cdi, &ms_info) == 0) {
576 #if WE_OBEY_THE_WRITTEN_STANDARDS
577 			/* necessary for a valid ms_info.addr */
578 			if (ms_info.xa_flag)
579 #endif
580 				vol_desc_start = ms_info.addr.lba;
581 		}
582 	}
583 
584 	return vol_desc_start;
585 }
586 
587 /*
588  * Check if root directory is empty (has less than 3 files).
589  *
590  * Used to detect broken CDs where ISO root directory is empty but Joliet root
591  * directory is OK. If such CD has Rock Ridge extensions, they will be disabled
592  * (and Joliet used instead) or else no files would be visible.
593  */
594 static bool rootdir_empty(struct super_block *sb, unsigned long block)
595 {
596 	int offset = 0, files = 0, de_len;
597 	struct iso_directory_record *de;
598 	struct buffer_head *bh;
599 
600 	bh = sb_bread(sb, block);
601 	if (!bh)
602 		return true;
603 	while (files < 3) {
604 		de = (struct iso_directory_record *) (bh->b_data + offset);
605 		de_len = *(unsigned char *) de;
606 		if (de_len == 0)
607 			break;
608 		files++;
609 		offset += de_len;
610 	}
611 	brelse(bh);
612 	return files < 3;
613 }
614 
615 /*
616  * Initialize the superblock and read the root inode.
617  */
618 static int isofs_fill_super(struct super_block *s, void *data, int silent)
619 {
620 	struct buffer_head *bh = NULL, *pri_bh = NULL;
621 	struct hs_primary_descriptor *h_pri = NULL;
622 	struct iso_primary_descriptor *pri = NULL;
623 	struct iso_supplementary_descriptor *sec = NULL;
624 	struct iso_directory_record *rootp;
625 	struct inode *inode;
626 	struct iso9660_options opt;
627 	struct isofs_sb_info *sbi;
628 	unsigned long first_data_zone;
629 	int joliet_level = 0;
630 	int iso_blknum, block;
631 	int orig_zonesize;
632 	int table, error = -EINVAL;
633 	unsigned int vol_desc_start;
634 
635 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
636 	if (!sbi)
637 		return -ENOMEM;
638 	s->s_fs_info = sbi;
639 
640 	if (!parse_options((char *)data, &opt))
641 		goto out_freesbi;
642 
643 	/*
644 	 * First of all, get the hardware blocksize for this device.
645 	 * If we don't know what it is, or the hardware blocksize is
646 	 * larger than the blocksize the user specified, then use
647 	 * that value.
648 	 */
649 	/*
650 	 * What if bugger tells us to go beyond page size?
651 	 */
652 	if (bdev_logical_block_size(s->s_bdev) > 2048) {
653 		printk(KERN_WARNING
654 		       "ISOFS: unsupported/invalid hardware sector size %d\n",
655 			bdev_logical_block_size(s->s_bdev));
656 		goto out_freesbi;
657 	}
658 	opt.blocksize = sb_min_blocksize(s, opt.blocksize);
659 
660 	sbi->s_high_sierra = 0; /* default is iso9660 */
661 	sbi->s_session = opt.session;
662 	sbi->s_sbsector = opt.sbsector;
663 
664 	vol_desc_start = (opt.sbsector != -1) ?
665 		opt.sbsector : isofs_get_last_session(s,opt.session);
666 
667 	for (iso_blknum = vol_desc_start+16;
668 		iso_blknum < vol_desc_start+100; iso_blknum++) {
669 		struct hs_volume_descriptor *hdp;
670 		struct iso_volume_descriptor  *vdp;
671 
672 		block = iso_blknum << (ISOFS_BLOCK_BITS - s->s_blocksize_bits);
673 		if (!(bh = sb_bread(s, block)))
674 			goto out_no_read;
675 
676 		vdp = (struct iso_volume_descriptor *)bh->b_data;
677 		hdp = (struct hs_volume_descriptor *)bh->b_data;
678 
679 		/*
680 		 * Due to the overlapping physical location of the descriptors,
681 		 * ISO CDs can match hdp->id==HS_STANDARD_ID as well. To ensure
682 		 * proper identification in this case, we first check for ISO.
683 		 */
684 		if (strncmp (vdp->id, ISO_STANDARD_ID, sizeof vdp->id) == 0) {
685 			if (isonum_711(vdp->type) == ISO_VD_END)
686 				break;
687 			if (isonum_711(vdp->type) == ISO_VD_PRIMARY) {
688 				if (!pri) {
689 					pri = (struct iso_primary_descriptor *)vdp;
690 					/* Save the buffer in case we need it ... */
691 					pri_bh = bh;
692 					bh = NULL;
693 				}
694 			}
695 #ifdef CONFIG_JOLIET
696 			else if (isonum_711(vdp->type) == ISO_VD_SUPPLEMENTARY) {
697 				sec = (struct iso_supplementary_descriptor *)vdp;
698 				if (sec->escape[0] == 0x25 && sec->escape[1] == 0x2f) {
699 					if (opt.joliet) {
700 						if (sec->escape[2] == 0x40)
701 							joliet_level = 1;
702 						else if (sec->escape[2] == 0x43)
703 							joliet_level = 2;
704 						else if (sec->escape[2] == 0x45)
705 							joliet_level = 3;
706 
707 						printk(KERN_DEBUG "ISO 9660 Extensions: "
708 							"Microsoft Joliet Level %d\n",
709 							joliet_level);
710 					}
711 					goto root_found;
712 				} else {
713 				/* Unknown supplementary volume descriptor */
714 				sec = NULL;
715 				}
716 			}
717 #endif
718 		} else {
719 			if (strncmp (hdp->id, HS_STANDARD_ID, sizeof hdp->id) == 0) {
720 				if (isonum_711(hdp->type) != ISO_VD_PRIMARY)
721 					goto out_freebh;
722 
723 				sbi->s_high_sierra = 1;
724 				opt.rock = 0;
725 				h_pri = (struct hs_primary_descriptor *)vdp;
726 				goto root_found;
727 			}
728 		}
729 
730 		/* Just skip any volume descriptors we don't recognize */
731 
732 		brelse(bh);
733 		bh = NULL;
734 	}
735 	/*
736 	 * If we fall through, either no volume descriptor was found,
737 	 * or else we passed a primary descriptor looking for others.
738 	 */
739 	if (!pri)
740 		goto out_unknown_format;
741 	brelse(bh);
742 	bh = pri_bh;
743 	pri_bh = NULL;
744 
745 root_found:
746 	/* We don't support read-write mounts */
747 	if (!sb_rdonly(s)) {
748 		error = -EACCES;
749 		goto out_freebh;
750 	}
751 
752 	if (joliet_level && (!pri || !opt.rock)) {
753 		/* This is the case of Joliet with the norock mount flag.
754 		 * A disc with both Joliet and Rock Ridge is handled later
755 		 */
756 		pri = (struct iso_primary_descriptor *) sec;
757 	}
758 
759 	if(sbi->s_high_sierra){
760 		rootp = (struct iso_directory_record *) h_pri->root_directory_record;
761 		sbi->s_nzones = isonum_733(h_pri->volume_space_size);
762 		sbi->s_log_zone_size = isonum_723(h_pri->logical_block_size);
763 		sbi->s_max_size = isonum_733(h_pri->volume_space_size);
764 	} else {
765 		if (!pri)
766 			goto out_freebh;
767 		rootp = (struct iso_directory_record *) pri->root_directory_record;
768 		sbi->s_nzones = isonum_733(pri->volume_space_size);
769 		sbi->s_log_zone_size = isonum_723(pri->logical_block_size);
770 		sbi->s_max_size = isonum_733(pri->volume_space_size);
771 	}
772 
773 	sbi->s_ninodes = 0; /* No way to figure this out easily */
774 
775 	orig_zonesize = sbi->s_log_zone_size;
776 	/*
777 	 * If the zone size is smaller than the hardware sector size,
778 	 * this is a fatal error.  This would occur if the disc drive
779 	 * had sectors that were 2048 bytes, but the filesystem had
780 	 * blocks that were 512 bytes (which should only very rarely
781 	 * happen.)
782 	 */
783 	if (orig_zonesize < opt.blocksize)
784 		goto out_bad_size;
785 
786 	/* RDE: convert log zone size to bit shift */
787 	switch (sbi->s_log_zone_size) {
788 	case  512: sbi->s_log_zone_size =  9; break;
789 	case 1024: sbi->s_log_zone_size = 10; break;
790 	case 2048: sbi->s_log_zone_size = 11; break;
791 
792 	default:
793 		goto out_bad_zone_size;
794 	}
795 
796 	s->s_magic = ISOFS_SUPER_MAGIC;
797 
798 	/*
799 	 * With multi-extent files, file size is only limited by the maximum
800 	 * size of a file system, which is 8 TB.
801 	 */
802 	s->s_maxbytes = 0x80000000000LL;
803 
804 	/* ECMA-119 timestamp from 1900/1/1 with tz offset */
805 	s->s_time_min = mktime64(1900, 1, 1, 0, 0, 0) - MAX_TZ_OFFSET;
806 	s->s_time_max = mktime64(U8_MAX+1900, 12, 31, 23, 59, 59) + MAX_TZ_OFFSET;
807 
808 	/* Set this for reference. Its not currently used except on write
809 	   which we don't have .. */
810 
811 	first_data_zone = isonum_733(rootp->extent) +
812 			  isonum_711(rootp->ext_attr_length);
813 	sbi->s_firstdatazone = first_data_zone;
814 #ifndef BEQUIET
815 	printk(KERN_DEBUG "ISOFS: Max size:%ld   Log zone size:%ld\n",
816 		sbi->s_max_size, 1UL << sbi->s_log_zone_size);
817 	printk(KERN_DEBUG "ISOFS: First datazone:%ld\n", sbi->s_firstdatazone);
818 	if(sbi->s_high_sierra)
819 		printk(KERN_DEBUG "ISOFS: Disc in High Sierra format.\n");
820 #endif
821 
822 	/*
823 	 * If the Joliet level is set, we _may_ decide to use the
824 	 * secondary descriptor, but can't be sure until after we
825 	 * read the root inode. But before reading the root inode
826 	 * we may need to change the device blocksize, and would
827 	 * rather release the old buffer first. So, we cache the
828 	 * first_data_zone value from the secondary descriptor.
829 	 */
830 	if (joliet_level) {
831 		pri = (struct iso_primary_descriptor *) sec;
832 		rootp = (struct iso_directory_record *)
833 			pri->root_directory_record;
834 		first_data_zone = isonum_733(rootp->extent) +
835 				isonum_711(rootp->ext_attr_length);
836 	}
837 
838 	/*
839 	 * We're all done using the volume descriptor, and may need
840 	 * to change the device blocksize, so release the buffer now.
841 	 */
842 	brelse(pri_bh);
843 	brelse(bh);
844 
845 	/*
846 	 * Force the blocksize to 512 for 512 byte sectors.  The file
847 	 * read primitives really get it wrong in a bad way if we don't
848 	 * do this.
849 	 *
850 	 * Note - we should never be setting the blocksize to something
851 	 * less than the hardware sector size for the device.  If we
852 	 * do, we would end up having to read larger buffers and split
853 	 * out portions to satisfy requests.
854 	 *
855 	 * Note2- the idea here is that we want to deal with the optimal
856 	 * zonesize in the filesystem.  If we have it set to something less,
857 	 * then we have horrible problems with trying to piece together
858 	 * bits of adjacent blocks in order to properly read directory
859 	 * entries.  By forcing the blocksize in this way, we ensure
860 	 * that we will never be required to do this.
861 	 */
862 	sb_set_blocksize(s, orig_zonesize);
863 
864 	sbi->s_nls_iocharset = NULL;
865 
866 #ifdef CONFIG_JOLIET
867 	if (joliet_level) {
868 		char *p = opt.iocharset ? opt.iocharset : CONFIG_NLS_DEFAULT;
869 		if (strcmp(p, "utf8") != 0) {
870 			sbi->s_nls_iocharset = opt.iocharset ?
871 				load_nls(opt.iocharset) : load_nls_default();
872 			if (!sbi->s_nls_iocharset)
873 				goto out_freesbi;
874 		}
875 	}
876 #endif
877 	s->s_op = &isofs_sops;
878 	s->s_export_op = &isofs_export_ops;
879 	sbi->s_mapping = opt.map;
880 	sbi->s_rock = (opt.rock ? 2 : 0);
881 	sbi->s_rock_offset = -1; /* initial offset, will guess until SP is found*/
882 	sbi->s_cruft = opt.cruft;
883 	sbi->s_hide = opt.hide;
884 	sbi->s_showassoc = opt.showassoc;
885 	sbi->s_uid = opt.uid;
886 	sbi->s_gid = opt.gid;
887 	sbi->s_uid_set = opt.uid_set;
888 	sbi->s_gid_set = opt.gid_set;
889 	sbi->s_nocompress = opt.nocompress;
890 	sbi->s_overriderockperm = opt.overriderockperm;
891 	/*
892 	 * It would be incredibly stupid to allow people to mark every file
893 	 * on the disk as suid, so we merely allow them to set the default
894 	 * permissions.
895 	 */
896 	if (opt.fmode != ISOFS_INVALID_MODE)
897 		sbi->s_fmode = opt.fmode & 0777;
898 	else
899 		sbi->s_fmode = ISOFS_INVALID_MODE;
900 	if (opt.dmode != ISOFS_INVALID_MODE)
901 		sbi->s_dmode = opt.dmode & 0777;
902 	else
903 		sbi->s_dmode = ISOFS_INVALID_MODE;
904 
905 	/*
906 	 * Read the root inode, which _may_ result in changing
907 	 * the s_rock flag. Once we have the final s_rock value,
908 	 * we then decide whether to use the Joliet descriptor.
909 	 */
910 	inode = isofs_iget(s, sbi->s_firstdatazone, 0);
911 	if (IS_ERR(inode))
912 		goto out_no_root;
913 
914 	/*
915 	 * Fix for broken CDs with Rock Ridge and empty ISO root directory but
916 	 * correct Joliet root directory.
917 	 */
918 	if (sbi->s_rock == 1 && joliet_level &&
919 				rootdir_empty(s, sbi->s_firstdatazone)) {
920 		printk(KERN_NOTICE
921 			"ISOFS: primary root directory is empty. "
922 			"Disabling Rock Ridge and switching to Joliet.");
923 		sbi->s_rock = 0;
924 	}
925 
926 	/*
927 	 * If this disk has both Rock Ridge and Joliet on it, then we
928 	 * want to use Rock Ridge by default.  This can be overridden
929 	 * by using the norock mount option.  There is still one other
930 	 * possibility that is not taken into account: a Rock Ridge
931 	 * CD with Unicode names.  Until someone sees such a beast, it
932 	 * will not be supported.
933 	 */
934 	if (sbi->s_rock == 1) {
935 		joliet_level = 0;
936 	} else if (joliet_level) {
937 		sbi->s_rock = 0;
938 		if (sbi->s_firstdatazone != first_data_zone) {
939 			sbi->s_firstdatazone = first_data_zone;
940 			printk(KERN_DEBUG
941 				"ISOFS: changing to secondary root\n");
942 			iput(inode);
943 			inode = isofs_iget(s, sbi->s_firstdatazone, 0);
944 			if (IS_ERR(inode))
945 				goto out_no_root;
946 		}
947 	}
948 
949 	if (opt.check == 'u') {
950 		/* Only Joliet is case insensitive by default */
951 		if (joliet_level)
952 			opt.check = 'r';
953 		else
954 			opt.check = 's';
955 	}
956 	sbi->s_joliet_level = joliet_level;
957 
958 	/* Make sure the root inode is a directory */
959 	if (!S_ISDIR(inode->i_mode)) {
960 		printk(KERN_WARNING
961 			"isofs_fill_super: root inode is not a directory. "
962 			"Corrupted media?\n");
963 		goto out_iput;
964 	}
965 
966 	table = 0;
967 	if (joliet_level)
968 		table += 2;
969 	if (opt.check == 'r')
970 		table++;
971 	sbi->s_check = opt.check;
972 
973 	if (table)
974 		s->s_d_op = &isofs_dentry_ops[table - 1];
975 
976 	/* get the root dentry */
977 	s->s_root = d_make_root(inode);
978 	if (!(s->s_root)) {
979 		error = -ENOMEM;
980 		goto out_no_inode;
981 	}
982 
983 	kfree(opt.iocharset);
984 
985 	return 0;
986 
987 	/*
988 	 * Display error messages and free resources.
989 	 */
990 out_iput:
991 	iput(inode);
992 	goto out_no_inode;
993 out_no_root:
994 	error = PTR_ERR(inode);
995 	if (error != -ENOMEM)
996 		printk(KERN_WARNING "%s: get root inode failed\n", __func__);
997 out_no_inode:
998 #ifdef CONFIG_JOLIET
999 	unload_nls(sbi->s_nls_iocharset);
1000 #endif
1001 	goto out_freesbi;
1002 out_no_read:
1003 	printk(KERN_WARNING "%s: bread failed, dev=%s, iso_blknum=%d, block=%d\n",
1004 		__func__, s->s_id, iso_blknum, block);
1005 	goto out_freebh;
1006 out_bad_zone_size:
1007 	printk(KERN_WARNING "ISOFS: Bad logical zone size %ld\n",
1008 		sbi->s_log_zone_size);
1009 	goto out_freebh;
1010 out_bad_size:
1011 	printk(KERN_WARNING "ISOFS: Logical zone size(%d) < hardware blocksize(%u)\n",
1012 		orig_zonesize, opt.blocksize);
1013 	goto out_freebh;
1014 out_unknown_format:
1015 	if (!silent)
1016 		printk(KERN_WARNING "ISOFS: Unable to identify CD-ROM format.\n");
1017 
1018 out_freebh:
1019 	brelse(bh);
1020 	brelse(pri_bh);
1021 out_freesbi:
1022 	kfree(opt.iocharset);
1023 	kfree(sbi);
1024 	s->s_fs_info = NULL;
1025 	return error;
1026 }
1027 
1028 static int isofs_statfs (struct dentry *dentry, struct kstatfs *buf)
1029 {
1030 	struct super_block *sb = dentry->d_sb;
1031 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
1032 
1033 	buf->f_type = ISOFS_SUPER_MAGIC;
1034 	buf->f_bsize = sb->s_blocksize;
1035 	buf->f_blocks = (ISOFS_SB(sb)->s_nzones
1036 		<< (ISOFS_SB(sb)->s_log_zone_size - sb->s_blocksize_bits));
1037 	buf->f_bfree = 0;
1038 	buf->f_bavail = 0;
1039 	buf->f_files = ISOFS_SB(sb)->s_ninodes;
1040 	buf->f_ffree = 0;
1041 	buf->f_fsid = u64_to_fsid(id);
1042 	buf->f_namelen = NAME_MAX;
1043 	return 0;
1044 }
1045 
1046 /*
1047  * Get a set of blocks; filling in buffer_heads if already allocated
1048  * or getblk() if they are not.  Returns the number of blocks inserted
1049  * (-ve == error.)
1050  */
1051 int isofs_get_blocks(struct inode *inode, sector_t iblock,
1052 		     struct buffer_head **bh, unsigned long nblocks)
1053 {
1054 	unsigned long b_off = iblock;
1055 	unsigned offset, sect_size;
1056 	unsigned int firstext;
1057 	unsigned long nextblk, nextoff;
1058 	int section, rv, error;
1059 	struct iso_inode_info *ei = ISOFS_I(inode);
1060 
1061 	error = -EIO;
1062 	rv = 0;
1063 	if (iblock != b_off) {
1064 		printk(KERN_DEBUG "%s: block number too large\n", __func__);
1065 		goto abort;
1066 	}
1067 
1068 
1069 	offset = 0;
1070 	firstext = ei->i_first_extent;
1071 	sect_size = ei->i_section_size >> ISOFS_BUFFER_BITS(inode);
1072 	nextblk = ei->i_next_section_block;
1073 	nextoff = ei->i_next_section_offset;
1074 	section = 0;
1075 
1076 	while (nblocks) {
1077 		/* If we are *way* beyond the end of the file, print a message.
1078 		 * Access beyond the end of the file up to the next page boundary
1079 		 * is normal, however because of the way the page cache works.
1080 		 * In this case, we just return 0 so that we can properly fill
1081 		 * the page with useless information without generating any
1082 		 * I/O errors.
1083 		 */
1084 		if (b_off > ((inode->i_size + PAGE_SIZE - 1) >> ISOFS_BUFFER_BITS(inode))) {
1085 			printk(KERN_DEBUG "%s: block >= EOF (%lu, %llu)\n",
1086 				__func__, b_off,
1087 				(unsigned long long)inode->i_size);
1088 			goto abort;
1089 		}
1090 
1091 		/* On the last section, nextblk == 0, section size is likely to
1092 		 * exceed sect_size by a partial block, and access beyond the
1093 		 * end of the file will reach beyond the section size, too.
1094 		 */
1095 		while (nextblk && (b_off >= (offset + sect_size))) {
1096 			struct inode *ninode;
1097 
1098 			offset += sect_size;
1099 			ninode = isofs_iget(inode->i_sb, nextblk, nextoff);
1100 			if (IS_ERR(ninode)) {
1101 				error = PTR_ERR(ninode);
1102 				goto abort;
1103 			}
1104 			firstext  = ISOFS_I(ninode)->i_first_extent;
1105 			sect_size = ISOFS_I(ninode)->i_section_size >> ISOFS_BUFFER_BITS(ninode);
1106 			nextblk   = ISOFS_I(ninode)->i_next_section_block;
1107 			nextoff   = ISOFS_I(ninode)->i_next_section_offset;
1108 			iput(ninode);
1109 
1110 			if (++section > 100) {
1111 				printk(KERN_DEBUG "%s: More than 100 file sections ?!?"
1112 					" aborting...\n", __func__);
1113 				printk(KERN_DEBUG "%s: block=%lu firstext=%u sect_size=%u "
1114 					"nextblk=%lu nextoff=%lu\n", __func__,
1115 					b_off, firstext, (unsigned) sect_size,
1116 					nextblk, nextoff);
1117 				goto abort;
1118 			}
1119 		}
1120 
1121 		if (*bh) {
1122 			map_bh(*bh, inode->i_sb, firstext + b_off - offset);
1123 		} else {
1124 			*bh = sb_getblk(inode->i_sb, firstext+b_off-offset);
1125 			if (!*bh)
1126 				goto abort;
1127 		}
1128 		bh++;	/* Next buffer head */
1129 		b_off++;	/* Next buffer offset */
1130 		nblocks--;
1131 		rv++;
1132 	}
1133 
1134 	error = 0;
1135 abort:
1136 	return rv != 0 ? rv : error;
1137 }
1138 
1139 /*
1140  * Used by the standard interfaces.
1141  */
1142 static int isofs_get_block(struct inode *inode, sector_t iblock,
1143 		    struct buffer_head *bh_result, int create)
1144 {
1145 	int ret;
1146 
1147 	if (create) {
1148 		printk(KERN_DEBUG "%s: Kernel tries to allocate a block\n", __func__);
1149 		return -EROFS;
1150 	}
1151 
1152 	ret = isofs_get_blocks(inode, iblock, &bh_result, 1);
1153 	return ret < 0 ? ret : 0;
1154 }
1155 
1156 static int isofs_bmap(struct inode *inode, sector_t block)
1157 {
1158 	struct buffer_head dummy;
1159 	int error;
1160 
1161 	dummy.b_state = 0;
1162 	dummy.b_blocknr = -1000;
1163 	error = isofs_get_block(inode, block, &dummy, 0);
1164 	if (!error)
1165 		return dummy.b_blocknr;
1166 	return 0;
1167 }
1168 
1169 struct buffer_head *isofs_bread(struct inode *inode, sector_t block)
1170 {
1171 	sector_t blknr = isofs_bmap(inode, block);
1172 	if (!blknr)
1173 		return NULL;
1174 	return sb_bread(inode->i_sb, blknr);
1175 }
1176 
1177 static int isofs_read_folio(struct file *file, struct folio *folio)
1178 {
1179 	return mpage_read_folio(folio, isofs_get_block);
1180 }
1181 
1182 static void isofs_readahead(struct readahead_control *rac)
1183 {
1184 	mpage_readahead(rac, isofs_get_block);
1185 }
1186 
1187 static sector_t _isofs_bmap(struct address_space *mapping, sector_t block)
1188 {
1189 	return generic_block_bmap(mapping,block,isofs_get_block);
1190 }
1191 
1192 static const struct address_space_operations isofs_aops = {
1193 	.read_folio = isofs_read_folio,
1194 	.readahead = isofs_readahead,
1195 	.bmap = _isofs_bmap
1196 };
1197 
1198 static int isofs_read_level3_size(struct inode *inode)
1199 {
1200 	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
1201 	int high_sierra = ISOFS_SB(inode->i_sb)->s_high_sierra;
1202 	struct buffer_head *bh = NULL;
1203 	unsigned long block, offset, block_saved, offset_saved;
1204 	int i = 0;
1205 	int more_entries = 0;
1206 	struct iso_directory_record *tmpde = NULL;
1207 	struct iso_inode_info *ei = ISOFS_I(inode);
1208 
1209 	inode->i_size = 0;
1210 
1211 	/* The first 16 blocks are reserved as the System Area.  Thus,
1212 	 * no inodes can appear in block 0.  We use this to flag that
1213 	 * this is the last section. */
1214 	ei->i_next_section_block = 0;
1215 	ei->i_next_section_offset = 0;
1216 
1217 	block = ei->i_iget5_block;
1218 	offset = ei->i_iget5_offset;
1219 
1220 	do {
1221 		struct iso_directory_record *de;
1222 		unsigned int de_len;
1223 
1224 		if (!bh) {
1225 			bh = sb_bread(inode->i_sb, block);
1226 			if (!bh)
1227 				goto out_noread;
1228 		}
1229 		de = (struct iso_directory_record *) (bh->b_data + offset);
1230 		de_len = *(unsigned char *) de;
1231 
1232 		if (de_len == 0) {
1233 			brelse(bh);
1234 			bh = NULL;
1235 			++block;
1236 			offset = 0;
1237 			continue;
1238 		}
1239 
1240 		block_saved = block;
1241 		offset_saved = offset;
1242 		offset += de_len;
1243 
1244 		/* Make sure we have a full directory entry */
1245 		if (offset >= bufsize) {
1246 			int slop = bufsize - offset + de_len;
1247 			if (!tmpde) {
1248 				tmpde = kmalloc(256, GFP_KERNEL);
1249 				if (!tmpde)
1250 					goto out_nomem;
1251 			}
1252 			memcpy(tmpde, de, slop);
1253 			offset &= bufsize - 1;
1254 			block++;
1255 			brelse(bh);
1256 			bh = NULL;
1257 			if (offset) {
1258 				bh = sb_bread(inode->i_sb, block);
1259 				if (!bh)
1260 					goto out_noread;
1261 				memcpy((void *)tmpde+slop, bh->b_data, offset);
1262 			}
1263 			de = tmpde;
1264 		}
1265 
1266 		inode->i_size += isonum_733(de->size);
1267 		if (i == 1) {
1268 			ei->i_next_section_block = block_saved;
1269 			ei->i_next_section_offset = offset_saved;
1270 		}
1271 
1272 		more_entries = de->flags[-high_sierra] & 0x80;
1273 
1274 		i++;
1275 		if (i > 100)
1276 			goto out_toomany;
1277 	} while (more_entries);
1278 out:
1279 	kfree(tmpde);
1280 	brelse(bh);
1281 	return 0;
1282 
1283 out_nomem:
1284 	brelse(bh);
1285 	return -ENOMEM;
1286 
1287 out_noread:
1288 	printk(KERN_INFO "ISOFS: unable to read i-node block %lu\n", block);
1289 	kfree(tmpde);
1290 	return -EIO;
1291 
1292 out_toomany:
1293 	printk(KERN_INFO "%s: More than 100 file sections ?!?, aborting...\n"
1294 		"isofs_read_level3_size: inode=%lu\n",
1295 		__func__, inode->i_ino);
1296 	goto out;
1297 }
1298 
1299 static int isofs_read_inode(struct inode *inode, int relocated)
1300 {
1301 	struct super_block *sb = inode->i_sb;
1302 	struct isofs_sb_info *sbi = ISOFS_SB(sb);
1303 	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
1304 	unsigned long block;
1305 	int high_sierra = sbi->s_high_sierra;
1306 	struct buffer_head *bh;
1307 	struct iso_directory_record *de;
1308 	struct iso_directory_record *tmpde = NULL;
1309 	unsigned int de_len;
1310 	unsigned long offset;
1311 	struct iso_inode_info *ei = ISOFS_I(inode);
1312 	int ret = -EIO;
1313 
1314 	block = ei->i_iget5_block;
1315 	bh = sb_bread(inode->i_sb, block);
1316 	if (!bh)
1317 		goto out_badread;
1318 
1319 	offset = ei->i_iget5_offset;
1320 
1321 	de = (struct iso_directory_record *) (bh->b_data + offset);
1322 	de_len = *(unsigned char *) de;
1323 	if (de_len < sizeof(struct iso_directory_record))
1324 		goto fail;
1325 
1326 	if (offset + de_len > bufsize) {
1327 		int frag1 = bufsize - offset;
1328 
1329 		tmpde = kmalloc(de_len, GFP_KERNEL);
1330 		if (!tmpde) {
1331 			ret = -ENOMEM;
1332 			goto fail;
1333 		}
1334 		memcpy(tmpde, bh->b_data + offset, frag1);
1335 		brelse(bh);
1336 		bh = sb_bread(inode->i_sb, ++block);
1337 		if (!bh)
1338 			goto out_badread;
1339 		memcpy((char *)tmpde+frag1, bh->b_data, de_len - frag1);
1340 		de = tmpde;
1341 	}
1342 
1343 	inode->i_ino = isofs_get_ino(ei->i_iget5_block,
1344 					ei->i_iget5_offset,
1345 					ISOFS_BUFFER_BITS(inode));
1346 
1347 	/* Assume it is a normal-format file unless told otherwise */
1348 	ei->i_file_format = isofs_file_normal;
1349 
1350 	if (de->flags[-high_sierra] & 2) {
1351 		if (sbi->s_dmode != ISOFS_INVALID_MODE)
1352 			inode->i_mode = S_IFDIR | sbi->s_dmode;
1353 		else
1354 			inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
1355 		set_nlink(inode, 1);	/*
1356 					 * Set to 1.  We know there are 2, but
1357 					 * the find utility tries to optimize
1358 					 * if it is 2, and it screws up.  It is
1359 					 * easier to give 1 which tells find to
1360 					 * do it the hard way.
1361 					 */
1362 	} else {
1363 		if (sbi->s_fmode != ISOFS_INVALID_MODE) {
1364 			inode->i_mode = S_IFREG | sbi->s_fmode;
1365 		} else {
1366 			/*
1367 			 * Set default permissions: r-x for all.  The disc
1368 			 * could be shared with DOS machines so virtually
1369 			 * anything could be a valid executable.
1370 			 */
1371 			inode->i_mode = S_IFREG | S_IRUGO | S_IXUGO;
1372 		}
1373 		set_nlink(inode, 1);
1374 	}
1375 	inode->i_uid = sbi->s_uid;
1376 	inode->i_gid = sbi->s_gid;
1377 	inode->i_blocks = 0;
1378 
1379 	ei->i_format_parm[0] = 0;
1380 	ei->i_format_parm[1] = 0;
1381 	ei->i_format_parm[2] = 0;
1382 
1383 	ei->i_section_size = isonum_733(de->size);
1384 	if (de->flags[-high_sierra] & 0x80) {
1385 		ret = isofs_read_level3_size(inode);
1386 		if (ret < 0)
1387 			goto fail;
1388 		ret = -EIO;
1389 	} else {
1390 		ei->i_next_section_block = 0;
1391 		ei->i_next_section_offset = 0;
1392 		inode->i_size = isonum_733(de->size);
1393 	}
1394 
1395 	/*
1396 	 * Some dipshit decided to store some other bit of information
1397 	 * in the high byte of the file length.  Truncate size in case
1398 	 * this CDROM was mounted with the cruft option.
1399 	 */
1400 
1401 	if (sbi->s_cruft)
1402 		inode->i_size &= 0x00ffffff;
1403 
1404 	if (de->interleave[0]) {
1405 		printk(KERN_DEBUG "ISOFS: Interleaved files not (yet) supported.\n");
1406 		inode->i_size = 0;
1407 	}
1408 
1409 	/* I have no idea what file_unit_size is used for, so
1410 	   we will flag it for now */
1411 	if (de->file_unit_size[0] != 0) {
1412 		printk(KERN_DEBUG "ISOFS: File unit size != 0 for ISO file (%ld).\n",
1413 			inode->i_ino);
1414 	}
1415 
1416 	/* I have no idea what other flag bits are used for, so
1417 	   we will flag it for now */
1418 #ifdef DEBUG
1419 	if((de->flags[-high_sierra] & ~2)!= 0){
1420 		printk(KERN_DEBUG "ISOFS: Unusual flag settings for ISO file "
1421 				"(%ld %x).\n",
1422 			inode->i_ino, de->flags[-high_sierra]);
1423 	}
1424 #endif
1425 
1426 	inode->i_mtime.tv_sec =
1427 	inode->i_atime.tv_sec =
1428 	inode->i_ctime.tv_sec = iso_date(de->date, high_sierra);
1429 	inode->i_mtime.tv_nsec =
1430 	inode->i_atime.tv_nsec =
1431 	inode->i_ctime.tv_nsec = 0;
1432 
1433 	ei->i_first_extent = (isonum_733(de->extent) +
1434 			isonum_711(de->ext_attr_length));
1435 
1436 	/* Set the number of blocks for stat() - should be done before RR */
1437 	inode->i_blocks = (inode->i_size + 511) >> 9;
1438 
1439 	/*
1440 	 * Now test for possible Rock Ridge extensions which will override
1441 	 * some of these numbers in the inode structure.
1442 	 */
1443 
1444 	if (!high_sierra) {
1445 		parse_rock_ridge_inode(de, inode, relocated);
1446 		/* if we want uid/gid set, override the rock ridge setting */
1447 		if (sbi->s_uid_set)
1448 			inode->i_uid = sbi->s_uid;
1449 		if (sbi->s_gid_set)
1450 			inode->i_gid = sbi->s_gid;
1451 	}
1452 	/* Now set final access rights if overriding rock ridge setting */
1453 	if (S_ISDIR(inode->i_mode) && sbi->s_overriderockperm &&
1454 	    sbi->s_dmode != ISOFS_INVALID_MODE)
1455 		inode->i_mode = S_IFDIR | sbi->s_dmode;
1456 	if (S_ISREG(inode->i_mode) && sbi->s_overriderockperm &&
1457 	    sbi->s_fmode != ISOFS_INVALID_MODE)
1458 		inode->i_mode = S_IFREG | sbi->s_fmode;
1459 
1460 	/* Install the inode operations vector */
1461 	if (S_ISREG(inode->i_mode)) {
1462 		inode->i_fop = &generic_ro_fops;
1463 		switch (ei->i_file_format) {
1464 #ifdef CONFIG_ZISOFS
1465 		case isofs_file_compressed:
1466 			inode->i_data.a_ops = &zisofs_aops;
1467 			break;
1468 #endif
1469 		default:
1470 			inode->i_data.a_ops = &isofs_aops;
1471 			break;
1472 		}
1473 	} else if (S_ISDIR(inode->i_mode)) {
1474 		inode->i_op = &isofs_dir_inode_operations;
1475 		inode->i_fop = &isofs_dir_operations;
1476 	} else if (S_ISLNK(inode->i_mode)) {
1477 		inode->i_op = &page_symlink_inode_operations;
1478 		inode_nohighmem(inode);
1479 		inode->i_data.a_ops = &isofs_symlink_aops;
1480 	} else
1481 		/* XXX - parse_rock_ridge_inode() had already set i_rdev. */
1482 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1483 
1484 	ret = 0;
1485 out:
1486 	kfree(tmpde);
1487 	brelse(bh);
1488 	return ret;
1489 
1490 out_badread:
1491 	printk(KERN_WARNING "ISOFS: unable to read i-node block\n");
1492 fail:
1493 	goto out;
1494 }
1495 
1496 struct isofs_iget5_callback_data {
1497 	unsigned long block;
1498 	unsigned long offset;
1499 };
1500 
1501 static int isofs_iget5_test(struct inode *ino, void *data)
1502 {
1503 	struct iso_inode_info *i = ISOFS_I(ino);
1504 	struct isofs_iget5_callback_data *d =
1505 		(struct isofs_iget5_callback_data*)data;
1506 	return (i->i_iget5_block == d->block)
1507 		&& (i->i_iget5_offset == d->offset);
1508 }
1509 
1510 static int isofs_iget5_set(struct inode *ino, void *data)
1511 {
1512 	struct iso_inode_info *i = ISOFS_I(ino);
1513 	struct isofs_iget5_callback_data *d =
1514 		(struct isofs_iget5_callback_data*)data;
1515 	i->i_iget5_block = d->block;
1516 	i->i_iget5_offset = d->offset;
1517 	return 0;
1518 }
1519 
1520 /* Store, in the inode's containing structure, the block and block
1521  * offset that point to the underlying meta-data for the inode.  The
1522  * code below is otherwise similar to the iget() code in
1523  * include/linux/fs.h */
1524 struct inode *__isofs_iget(struct super_block *sb,
1525 			   unsigned long block,
1526 			   unsigned long offset,
1527 			   int relocated)
1528 {
1529 	unsigned long hashval;
1530 	struct inode *inode;
1531 	struct isofs_iget5_callback_data data;
1532 	long ret;
1533 
1534 	if (offset >= 1ul << sb->s_blocksize_bits)
1535 		return ERR_PTR(-EINVAL);
1536 
1537 	data.block = block;
1538 	data.offset = offset;
1539 
1540 	hashval = (block << sb->s_blocksize_bits) | offset;
1541 
1542 	inode = iget5_locked(sb, hashval, &isofs_iget5_test,
1543 				&isofs_iget5_set, &data);
1544 
1545 	if (!inode)
1546 		return ERR_PTR(-ENOMEM);
1547 
1548 	if (inode->i_state & I_NEW) {
1549 		ret = isofs_read_inode(inode, relocated);
1550 		if (ret < 0) {
1551 			iget_failed(inode);
1552 			inode = ERR_PTR(ret);
1553 		} else {
1554 			unlock_new_inode(inode);
1555 		}
1556 	}
1557 
1558 	return inode;
1559 }
1560 
1561 static struct dentry *isofs_mount(struct file_system_type *fs_type,
1562 	int flags, const char *dev_name, void *data)
1563 {
1564 	return mount_bdev(fs_type, flags, dev_name, data, isofs_fill_super);
1565 }
1566 
1567 static struct file_system_type iso9660_fs_type = {
1568 	.owner		= THIS_MODULE,
1569 	.name		= "iso9660",
1570 	.mount		= isofs_mount,
1571 	.kill_sb	= kill_block_super,
1572 	.fs_flags	= FS_REQUIRES_DEV,
1573 };
1574 MODULE_ALIAS_FS("iso9660");
1575 MODULE_ALIAS("iso9660");
1576 
1577 static int __init init_iso9660_fs(void)
1578 {
1579 	int err = init_inodecache();
1580 	if (err)
1581 		goto out;
1582 #ifdef CONFIG_ZISOFS
1583 	err = zisofs_init();
1584 	if (err)
1585 		goto out1;
1586 #endif
1587 	err = register_filesystem(&iso9660_fs_type);
1588 	if (err)
1589 		goto out2;
1590 	return 0;
1591 out2:
1592 #ifdef CONFIG_ZISOFS
1593 	zisofs_cleanup();
1594 out1:
1595 #endif
1596 	destroy_inodecache();
1597 out:
1598 	return err;
1599 }
1600 
1601 static void __exit exit_iso9660_fs(void)
1602 {
1603         unregister_filesystem(&iso9660_fs_type);
1604 #ifdef CONFIG_ZISOFS
1605 	zisofs_cleanup();
1606 #endif
1607 	destroy_inodecache();
1608 }
1609 
1610 module_init(init_iso9660_fs)
1611 module_exit(exit_iso9660_fs)
1612 MODULE_LICENSE("GPL");
1613