1 /*
2  *  linux/fs/isofs/inode.c
3  *
4  *  (C) 1991  Linus Torvalds - minix filesystem
5  *      1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
6  *      1994  Eberhard Mönkeberg - multi session handling.
7  *      1995  Mark Dobie - allow mounting of some weird VideoCDs and PhotoCDs.
8  *	1997  Gordon Chaffee - Joliet CDs
9  *	1998  Eric Lammerts - ISO 9660 Level 3
10  *	2004  Paul Serice - Inode Support pushed out from 4GB to 128GB
11  *	2004  Paul Serice - NFS Export Operations
12  */
13 
14 #include <linux/init.h>
15 #include <linux/module.h>
16 
17 #include <linux/slab.h>
18 #include <linux/nls.h>
19 #include <linux/ctype.h>
20 #include <linux/statfs.h>
21 #include <linux/cdrom.h>
22 #include <linux/parser.h>
23 #include <linux/mpage.h>
24 
25 #include "isofs.h"
26 #include "zisofs.h"
27 
28 #define BEQUIET
29 
30 static int isofs_hashi(const struct dentry *parent, const struct inode *inode,
31 		struct qstr *qstr);
32 static int isofs_hash(const struct dentry *parent, const struct inode *inode,
33 		struct qstr *qstr);
34 static int isofs_dentry_cmpi(const struct dentry *parent,
35 		const struct inode *pinode,
36 		const struct dentry *dentry, const struct inode *inode,
37 		unsigned int len, const char *str, const struct qstr *name);
38 static int isofs_dentry_cmp(const struct dentry *parent,
39 		const struct inode *pinode,
40 		const struct dentry *dentry, const struct inode *inode,
41 		unsigned int len, const char *str, const struct qstr *name);
42 
43 #ifdef CONFIG_JOLIET
44 static int isofs_hashi_ms(const struct dentry *parent, const struct inode *inode,
45 		struct qstr *qstr);
46 static int isofs_hash_ms(const struct dentry *parent, const struct inode *inode,
47 		struct qstr *qstr);
48 static int isofs_dentry_cmpi_ms(const struct dentry *parent,
49 		const struct inode *pinode,
50 		const struct dentry *dentry, const struct inode *inode,
51 		unsigned int len, const char *str, const struct qstr *name);
52 static int isofs_dentry_cmp_ms(const struct dentry *parent,
53 		const struct inode *pinode,
54 		const struct dentry *dentry, const struct inode *inode,
55 		unsigned int len, const char *str, const struct qstr *name);
56 #endif
57 
isofs_put_super(struct super_block * sb)58 static void isofs_put_super(struct super_block *sb)
59 {
60 	struct isofs_sb_info *sbi = ISOFS_SB(sb);
61 
62 #ifdef CONFIG_JOLIET
63 	unload_nls(sbi->s_nls_iocharset);
64 #endif
65 
66 	kfree(sbi);
67 	sb->s_fs_info = NULL;
68 	return;
69 }
70 
71 static int isofs_read_inode(struct inode *);
72 static int isofs_statfs (struct dentry *, struct kstatfs *);
73 
74 static struct kmem_cache *isofs_inode_cachep;
75 
isofs_alloc_inode(struct super_block * sb)76 static struct inode *isofs_alloc_inode(struct super_block *sb)
77 {
78 	struct iso_inode_info *ei;
79 	ei = kmem_cache_alloc(isofs_inode_cachep, GFP_KERNEL);
80 	if (!ei)
81 		return NULL;
82 	return &ei->vfs_inode;
83 }
84 
isofs_i_callback(struct rcu_head * head)85 static void isofs_i_callback(struct rcu_head *head)
86 {
87 	struct inode *inode = container_of(head, struct inode, i_rcu);
88 	kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));
89 }
90 
isofs_destroy_inode(struct inode * inode)91 static void isofs_destroy_inode(struct inode *inode)
92 {
93 	call_rcu(&inode->i_rcu, isofs_i_callback);
94 }
95 
init_once(void * foo)96 static void init_once(void *foo)
97 {
98 	struct iso_inode_info *ei = foo;
99 
100 	inode_init_once(&ei->vfs_inode);
101 }
102 
init_inodecache(void)103 static int init_inodecache(void)
104 {
105 	isofs_inode_cachep = kmem_cache_create("isofs_inode_cache",
106 					sizeof(struct iso_inode_info),
107 					0, (SLAB_RECLAIM_ACCOUNT|
108 					SLAB_MEM_SPREAD),
109 					init_once);
110 	if (isofs_inode_cachep == NULL)
111 		return -ENOMEM;
112 	return 0;
113 }
114 
destroy_inodecache(void)115 static void destroy_inodecache(void)
116 {
117 	kmem_cache_destroy(isofs_inode_cachep);
118 }
119 
isofs_remount(struct super_block * sb,int * flags,char * data)120 static int isofs_remount(struct super_block *sb, int *flags, char *data)
121 {
122 	if (!(*flags & MS_RDONLY))
123 		return -EROFS;
124 	return 0;
125 }
126 
127 static const struct super_operations isofs_sops = {
128 	.alloc_inode	= isofs_alloc_inode,
129 	.destroy_inode	= isofs_destroy_inode,
130 	.put_super	= isofs_put_super,
131 	.statfs		= isofs_statfs,
132 	.remount_fs	= isofs_remount,
133 	.show_options	= generic_show_options,
134 };
135 
136 
137 static const struct dentry_operations isofs_dentry_ops[] = {
138 	{
139 		.d_hash		= isofs_hash,
140 		.d_compare	= isofs_dentry_cmp,
141 	},
142 	{
143 		.d_hash		= isofs_hashi,
144 		.d_compare	= isofs_dentry_cmpi,
145 	},
146 #ifdef CONFIG_JOLIET
147 	{
148 		.d_hash		= isofs_hash_ms,
149 		.d_compare	= isofs_dentry_cmp_ms,
150 	},
151 	{
152 		.d_hash		= isofs_hashi_ms,
153 		.d_compare	= isofs_dentry_cmpi_ms,
154 	},
155 #endif
156 };
157 
158 struct iso9660_options{
159 	unsigned int rock:1;
160 	unsigned int joliet:1;
161 	unsigned int cruft:1;
162 	unsigned int hide:1;
163 	unsigned int showassoc:1;
164 	unsigned int nocompress:1;
165 	unsigned int overriderockperm:1;
166 	unsigned int uid_set:1;
167 	unsigned int gid_set:1;
168 	unsigned int utf8:1;
169 	unsigned char map;
170 	unsigned char check;
171 	unsigned int blocksize;
172 	umode_t fmode;
173 	umode_t dmode;
174 	gid_t gid;
175 	uid_t uid;
176 	char *iocharset;
177 	/* LVE */
178 	s32 session;
179 	s32 sbsector;
180 };
181 
182 /*
183  * Compute the hash for the isofs name corresponding to the dentry.
184  */
185 static int
isofs_hash_common(const struct dentry * dentry,struct qstr * qstr,int ms)186 isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms)
187 {
188 	const char *name;
189 	int len;
190 
191 	len = qstr->len;
192 	name = qstr->name;
193 	if (ms) {
194 		while (len && name[len-1] == '.')
195 			len--;
196 	}
197 
198 	qstr->hash = full_name_hash(name, len);
199 
200 	return 0;
201 }
202 
203 /*
204  * Compute the hash for the isofs name corresponding to the dentry.
205  */
206 static int
isofs_hashi_common(const struct dentry * dentry,struct qstr * qstr,int ms)207 isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms)
208 {
209 	const char *name;
210 	int len;
211 	char c;
212 	unsigned long hash;
213 
214 	len = qstr->len;
215 	name = qstr->name;
216 	if (ms) {
217 		while (len && name[len-1] == '.')
218 			len--;
219 	}
220 
221 	hash = init_name_hash();
222 	while (len--) {
223 		c = tolower(*name++);
224 		hash = partial_name_hash(c, hash);
225 	}
226 	qstr->hash = end_name_hash(hash);
227 
228 	return 0;
229 }
230 
231 /*
232  * Compare of two isofs names.
233  */
isofs_dentry_cmp_common(unsigned int len,const char * str,const struct qstr * name,int ms,int ci)234 static int isofs_dentry_cmp_common(
235 		unsigned int len, const char *str,
236 		const struct qstr *name, int ms, int ci)
237 {
238 	int alen, blen;
239 
240 	/* A filename cannot end in '.' or we treat it like it has none */
241 	alen = name->len;
242 	blen = len;
243 	if (ms) {
244 		while (alen && name->name[alen-1] == '.')
245 			alen--;
246 		while (blen && str[blen-1] == '.')
247 			blen--;
248 	}
249 	if (alen == blen) {
250 		if (ci) {
251 			if (strnicmp(name->name, str, alen) == 0)
252 				return 0;
253 		} else {
254 			if (strncmp(name->name, str, alen) == 0)
255 				return 0;
256 		}
257 	}
258 	return 1;
259 }
260 
261 static int
isofs_hash(const struct dentry * dentry,const struct inode * inode,struct qstr * qstr)262 isofs_hash(const struct dentry *dentry, const struct inode *inode,
263 		struct qstr *qstr)
264 {
265 	return isofs_hash_common(dentry, qstr, 0);
266 }
267 
268 static int
isofs_hashi(const struct dentry * dentry,const struct inode * inode,struct qstr * qstr)269 isofs_hashi(const struct dentry *dentry, const struct inode *inode,
270 		struct qstr *qstr)
271 {
272 	return isofs_hashi_common(dentry, qstr, 0);
273 }
274 
275 static int
isofs_dentry_cmp(const struct dentry * parent,const struct inode * pinode,const struct dentry * dentry,const struct inode * inode,unsigned int len,const char * str,const struct qstr * name)276 isofs_dentry_cmp(const struct dentry *parent, const struct inode *pinode,
277 		const struct dentry *dentry, const struct inode *inode,
278 		unsigned int len, const char *str, const struct qstr *name)
279 {
280 	return isofs_dentry_cmp_common(len, str, name, 0, 0);
281 }
282 
283 static int
isofs_dentry_cmpi(const struct dentry * parent,const struct inode * pinode,const struct dentry * dentry,const struct inode * inode,unsigned int len,const char * str,const struct qstr * name)284 isofs_dentry_cmpi(const struct dentry *parent, const struct inode *pinode,
285 		const struct dentry *dentry, const struct inode *inode,
286 		unsigned int len, const char *str, const struct qstr *name)
287 {
288 	return isofs_dentry_cmp_common(len, str, name, 0, 1);
289 }
290 
291 #ifdef CONFIG_JOLIET
292 static int
isofs_hash_ms(const struct dentry * dentry,const struct inode * inode,struct qstr * qstr)293 isofs_hash_ms(const struct dentry *dentry, const struct inode *inode,
294 		struct qstr *qstr)
295 {
296 	return isofs_hash_common(dentry, qstr, 1);
297 }
298 
299 static int
isofs_hashi_ms(const struct dentry * dentry,const struct inode * inode,struct qstr * qstr)300 isofs_hashi_ms(const struct dentry *dentry, const struct inode *inode,
301 		struct qstr *qstr)
302 {
303 	return isofs_hashi_common(dentry, qstr, 1);
304 }
305 
306 static int
isofs_dentry_cmp_ms(const struct dentry * parent,const struct inode * pinode,const struct dentry * dentry,const struct inode * inode,unsigned int len,const char * str,const struct qstr * name)307 isofs_dentry_cmp_ms(const struct dentry *parent, const struct inode *pinode,
308 		const struct dentry *dentry, const struct inode *inode,
309 		unsigned int len, const char *str, const struct qstr *name)
310 {
311 	return isofs_dentry_cmp_common(len, str, name, 1, 0);
312 }
313 
314 static int
isofs_dentry_cmpi_ms(const struct dentry * parent,const struct inode * pinode,const struct dentry * dentry,const struct inode * inode,unsigned int len,const char * str,const struct qstr * name)315 isofs_dentry_cmpi_ms(const struct dentry *parent, const struct inode *pinode,
316 		const struct dentry *dentry, const struct inode *inode,
317 		unsigned int len, const char *str, const struct qstr *name)
318 {
319 	return isofs_dentry_cmp_common(len, str, name, 1, 1);
320 }
321 #endif
322 
323 enum {
324 	Opt_block, Opt_check_r, Opt_check_s, Opt_cruft, Opt_gid, Opt_ignore,
325 	Opt_iocharset, Opt_map_a, Opt_map_n, Opt_map_o, Opt_mode, Opt_nojoliet,
326 	Opt_norock, Opt_sb, Opt_session, Opt_uid, Opt_unhide, Opt_utf8, Opt_err,
327 	Opt_nocompress, Opt_hide, Opt_showassoc, Opt_dmode, Opt_overriderockperm,
328 };
329 
330 static const match_table_t tokens = {
331 	{Opt_norock, "norock"},
332 	{Opt_nojoliet, "nojoliet"},
333 	{Opt_unhide, "unhide"},
334 	{Opt_hide, "hide"},
335 	{Opt_showassoc, "showassoc"},
336 	{Opt_cruft, "cruft"},
337 	{Opt_utf8, "utf8"},
338 	{Opt_iocharset, "iocharset=%s"},
339 	{Opt_map_a, "map=acorn"},
340 	{Opt_map_a, "map=a"},
341 	{Opt_map_n, "map=normal"},
342 	{Opt_map_n, "map=n"},
343 	{Opt_map_o, "map=off"},
344 	{Opt_map_o, "map=o"},
345 	{Opt_session, "session=%u"},
346 	{Opt_sb, "sbsector=%u"},
347 	{Opt_check_r, "check=relaxed"},
348 	{Opt_check_r, "check=r"},
349 	{Opt_check_s, "check=strict"},
350 	{Opt_check_s, "check=s"},
351 	{Opt_uid, "uid=%u"},
352 	{Opt_gid, "gid=%u"},
353 	{Opt_mode, "mode=%u"},
354 	{Opt_dmode, "dmode=%u"},
355 	{Opt_overriderockperm, "overriderockperm"},
356 	{Opt_block, "block=%u"},
357 	{Opt_ignore, "conv=binary"},
358 	{Opt_ignore, "conv=b"},
359 	{Opt_ignore, "conv=text"},
360 	{Opt_ignore, "conv=t"},
361 	{Opt_ignore, "conv=mtext"},
362 	{Opt_ignore, "conv=m"},
363 	{Opt_ignore, "conv=auto"},
364 	{Opt_ignore, "conv=a"},
365 	{Opt_nocompress, "nocompress"},
366 	{Opt_err, NULL}
367 };
368 
parse_options(char * options,struct iso9660_options * popt)369 static int parse_options(char *options, struct iso9660_options *popt)
370 {
371 	char *p;
372 	int option;
373 
374 	popt->map = 'n';
375 	popt->rock = 1;
376 	popt->joliet = 1;
377 	popt->cruft = 0;
378 	popt->hide = 0;
379 	popt->showassoc = 0;
380 	popt->check = 'u';		/* unset */
381 	popt->nocompress = 0;
382 	popt->blocksize = 1024;
383 	popt->fmode = popt->dmode = ISOFS_INVALID_MODE;
384 	popt->uid_set = 0;
385 	popt->gid_set = 0;
386 	popt->gid = 0;
387 	popt->uid = 0;
388 	popt->iocharset = NULL;
389 	popt->utf8 = 0;
390 	popt->overriderockperm = 0;
391 	popt->session=-1;
392 	popt->sbsector=-1;
393 	if (!options)
394 		return 1;
395 
396 	while ((p = strsep(&options, ",")) != NULL) {
397 		int token;
398 		substring_t args[MAX_OPT_ARGS];
399 		unsigned n;
400 
401 		if (!*p)
402 			continue;
403 
404 		token = match_token(p, tokens, args);
405 		switch (token) {
406 		case Opt_norock:
407 			popt->rock = 0;
408 			break;
409 		case Opt_nojoliet:
410 			popt->joliet = 0;
411 			break;
412 		case Opt_hide:
413 			popt->hide = 1;
414 			break;
415 		case Opt_unhide:
416 		case Opt_showassoc:
417 			popt->showassoc = 1;
418 			break;
419 		case Opt_cruft:
420 			popt->cruft = 1;
421 			break;
422 		case Opt_utf8:
423 			popt->utf8 = 1;
424 			break;
425 #ifdef CONFIG_JOLIET
426 		case Opt_iocharset:
427 			popt->iocharset = match_strdup(&args[0]);
428 			break;
429 #endif
430 		case Opt_map_a:
431 			popt->map = 'a';
432 			break;
433 		case Opt_map_o:
434 			popt->map = 'o';
435 			break;
436 		case Opt_map_n:
437 			popt->map = 'n';
438 			break;
439 		case Opt_session:
440 			if (match_int(&args[0], &option))
441 				return 0;
442 			n = option;
443 			if (n > 99)
444 				return 0;
445 			popt->session = n + 1;
446 			break;
447 		case Opt_sb:
448 			if (match_int(&args[0], &option))
449 				return 0;
450 			popt->sbsector = option;
451 			break;
452 		case Opt_check_r:
453 			popt->check = 'r';
454 			break;
455 		case Opt_check_s:
456 			popt->check = 's';
457 			break;
458 		case Opt_ignore:
459 			break;
460 		case Opt_uid:
461 			if (match_int(&args[0], &option))
462 				return 0;
463 			popt->uid = option;
464 			popt->uid_set = 1;
465 			break;
466 		case Opt_gid:
467 			if (match_int(&args[0], &option))
468 				return 0;
469 			popt->gid = option;
470 			popt->gid_set = 1;
471 			break;
472 		case Opt_mode:
473 			if (match_int(&args[0], &option))
474 				return 0;
475 			popt->fmode = option;
476 			break;
477 		case Opt_dmode:
478 			if (match_int(&args[0], &option))
479 				return 0;
480 			popt->dmode = option;
481 			break;
482 		case Opt_overriderockperm:
483 			popt->overriderockperm = 1;
484 			break;
485 		case Opt_block:
486 			if (match_int(&args[0], &option))
487 				return 0;
488 			n = option;
489 			if (n != 512 && n != 1024 && n != 2048)
490 				return 0;
491 			popt->blocksize = n;
492 			break;
493 		case Opt_nocompress:
494 			popt->nocompress = 1;
495 			break;
496 		default:
497 			return 0;
498 		}
499 	}
500 	return 1;
501 }
502 
503 /*
504  * look if the driver can tell the multi session redirection value
505  *
506  * don't change this if you don't know what you do, please!
507  * Multisession is legal only with XA disks.
508  * A non-XA disk with more than one volume descriptor may do it right, but
509  * usually is written in a nowhere standardized "multi-partition" manner.
510  * Multisession uses absolute addressing (solely the first frame of the whole
511  * track is #0), multi-partition uses relative addressing (each first frame of
512  * each track is #0), and a track is not a session.
513  *
514  * A broken CDwriter software or drive firmware does not set new standards,
515  * at least not if conflicting with the existing ones.
516  *
517  * emoenke@gwdg.de
518  */
519 #define WE_OBEY_THE_WRITTEN_STANDARDS 1
520 
isofs_get_last_session(struct super_block * sb,s32 session)521 static unsigned int isofs_get_last_session(struct super_block *sb, s32 session)
522 {
523 	struct cdrom_multisession ms_info;
524 	unsigned int vol_desc_start;
525 	struct block_device *bdev = sb->s_bdev;
526 	int i;
527 
528 	vol_desc_start=0;
529 	ms_info.addr_format=CDROM_LBA;
530 	if(session >= 0 && session <= 99) {
531 		struct cdrom_tocentry Te;
532 		Te.cdte_track=session;
533 		Te.cdte_format=CDROM_LBA;
534 		i = ioctl_by_bdev(bdev, CDROMREADTOCENTRY, (unsigned long) &Te);
535 		if (!i) {
536 			printk(KERN_DEBUG "ISOFS: Session %d start %d type %d\n",
537 				session, Te.cdte_addr.lba,
538 				Te.cdte_ctrl&CDROM_DATA_TRACK);
539 			if ((Te.cdte_ctrl&CDROM_DATA_TRACK) == 4)
540 				return Te.cdte_addr.lba;
541 		}
542 
543 		printk(KERN_ERR "ISOFS: Invalid session number or type of track\n");
544 	}
545 	i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long) &ms_info);
546 	if (session > 0)
547 		printk(KERN_ERR "ISOFS: Invalid session number\n");
548 #if 0
549 	printk(KERN_DEBUG "isofs.inode: CDROMMULTISESSION: rc=%d\n",i);
550 	if (i==0) {
551 		printk(KERN_DEBUG "isofs.inode: XA disk: %s\n",ms_info.xa_flag?"yes":"no");
552 		printk(KERN_DEBUG "isofs.inode: vol_desc_start = %d\n", ms_info.addr.lba);
553 	}
554 #endif
555 	if (i==0)
556 #if WE_OBEY_THE_WRITTEN_STANDARDS
557 		if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
558 #endif
559 			vol_desc_start=ms_info.addr.lba;
560 	return vol_desc_start;
561 }
562 
563 /*
564  * Check if root directory is empty (has less than 3 files).
565  *
566  * Used to detect broken CDs where ISO root directory is empty but Joliet root
567  * directory is OK. If such CD has Rock Ridge extensions, they will be disabled
568  * (and Joliet used instead) or else no files would be visible.
569  */
rootdir_empty(struct super_block * sb,unsigned long block)570 static bool rootdir_empty(struct super_block *sb, unsigned long block)
571 {
572 	int offset = 0, files = 0, de_len;
573 	struct iso_directory_record *de;
574 	struct buffer_head *bh;
575 
576 	bh = sb_bread(sb, block);
577 	if (!bh)
578 		return true;
579 	while (files < 3) {
580 		de = (struct iso_directory_record *) (bh->b_data + offset);
581 		de_len = *(unsigned char *) de;
582 		if (de_len == 0)
583 			break;
584 		files++;
585 		offset += de_len;
586 	}
587 	brelse(bh);
588 	return files < 3;
589 }
590 
591 /*
592  * Initialize the superblock and read the root inode.
593  *
594  * Note: a check_disk_change() has been done immediately prior
595  * to this call, so we don't need to check again.
596  */
isofs_fill_super(struct super_block * s,void * data,int silent)597 static int isofs_fill_super(struct super_block *s, void *data, int silent)
598 {
599 	struct buffer_head *bh = NULL, *pri_bh = NULL;
600 	struct hs_primary_descriptor *h_pri = NULL;
601 	struct iso_primary_descriptor *pri = NULL;
602 	struct iso_supplementary_descriptor *sec = NULL;
603 	struct iso_directory_record *rootp;
604 	struct inode *inode;
605 	struct iso9660_options opt;
606 	struct isofs_sb_info *sbi;
607 	unsigned long first_data_zone;
608 	int joliet_level = 0;
609 	int iso_blknum, block;
610 	int orig_zonesize;
611 	int table, error = -EINVAL;
612 	unsigned int vol_desc_start;
613 
614 	save_mount_options(s, data);
615 
616 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
617 	if (!sbi)
618 		return -ENOMEM;
619 	s->s_fs_info = sbi;
620 
621 	if (!parse_options((char *)data, &opt))
622 		goto out_freesbi;
623 
624 	/*
625 	 * First of all, get the hardware blocksize for this device.
626 	 * If we don't know what it is, or the hardware blocksize is
627 	 * larger than the blocksize the user specified, then use
628 	 * that value.
629 	 */
630 	/*
631 	 * What if bugger tells us to go beyond page size?
632 	 */
633 	opt.blocksize = sb_min_blocksize(s, opt.blocksize);
634 
635 	sbi->s_high_sierra = 0; /* default is iso9660 */
636 
637 	vol_desc_start = (opt.sbsector != -1) ?
638 		opt.sbsector : isofs_get_last_session(s,opt.session);
639 
640 	for (iso_blknum = vol_desc_start+16;
641 		iso_blknum < vol_desc_start+100; iso_blknum++) {
642 		struct hs_volume_descriptor *hdp;
643 		struct iso_volume_descriptor  *vdp;
644 
645 		block = iso_blknum << (ISOFS_BLOCK_BITS - s->s_blocksize_bits);
646 		if (!(bh = sb_bread(s, block)))
647 			goto out_no_read;
648 
649 		vdp = (struct iso_volume_descriptor *)bh->b_data;
650 		hdp = (struct hs_volume_descriptor *)bh->b_data;
651 
652 		/*
653 		 * Due to the overlapping physical location of the descriptors,
654 		 * ISO CDs can match hdp->id==HS_STANDARD_ID as well. To ensure
655 		 * proper identification in this case, we first check for ISO.
656 		 */
657 		if (strncmp (vdp->id, ISO_STANDARD_ID, sizeof vdp->id) == 0) {
658 			if (isonum_711(vdp->type) == ISO_VD_END)
659 				break;
660 			if (isonum_711(vdp->type) == ISO_VD_PRIMARY) {
661 				if (pri == NULL) {
662 					pri = (struct iso_primary_descriptor *)vdp;
663 					/* Save the buffer in case we need it ... */
664 					pri_bh = bh;
665 					bh = NULL;
666 				}
667 			}
668 #ifdef CONFIG_JOLIET
669 			else if (isonum_711(vdp->type) == ISO_VD_SUPPLEMENTARY) {
670 				sec = (struct iso_supplementary_descriptor *)vdp;
671 				if (sec->escape[0] == 0x25 && sec->escape[1] == 0x2f) {
672 					if (opt.joliet) {
673 						if (sec->escape[2] == 0x40)
674 							joliet_level = 1;
675 						else if (sec->escape[2] == 0x43)
676 							joliet_level = 2;
677 						else if (sec->escape[2] == 0x45)
678 							joliet_level = 3;
679 
680 						printk(KERN_DEBUG "ISO 9660 Extensions: "
681 							"Microsoft Joliet Level %d\n",
682 							joliet_level);
683 					}
684 					goto root_found;
685 				} else {
686 				/* Unknown supplementary volume descriptor */
687 				sec = NULL;
688 				}
689 			}
690 #endif
691 		} else {
692 			if (strncmp (hdp->id, HS_STANDARD_ID, sizeof hdp->id) == 0) {
693 				if (isonum_711(hdp->type) != ISO_VD_PRIMARY)
694 					goto out_freebh;
695 
696 				sbi->s_high_sierra = 1;
697 				opt.rock = 0;
698 				h_pri = (struct hs_primary_descriptor *)vdp;
699 				goto root_found;
700 			}
701 		}
702 
703 		/* Just skip any volume descriptors we don't recognize */
704 
705 		brelse(bh);
706 		bh = NULL;
707 	}
708 	/*
709 	 * If we fall through, either no volume descriptor was found,
710 	 * or else we passed a primary descriptor looking for others.
711 	 */
712 	if (!pri)
713 		goto out_unknown_format;
714 	brelse(bh);
715 	bh = pri_bh;
716 	pri_bh = NULL;
717 
718 root_found:
719 
720 	if (joliet_level && (pri == NULL || !opt.rock)) {
721 		/* This is the case of Joliet with the norock mount flag.
722 		 * A disc with both Joliet and Rock Ridge is handled later
723 		 */
724 		pri = (struct iso_primary_descriptor *) sec;
725 	}
726 
727 	if(sbi->s_high_sierra){
728 		rootp = (struct iso_directory_record *) h_pri->root_directory_record;
729 		sbi->s_nzones = isonum_733(h_pri->volume_space_size);
730 		sbi->s_log_zone_size = isonum_723(h_pri->logical_block_size);
731 		sbi->s_max_size = isonum_733(h_pri->volume_space_size);
732 	} else {
733 		if (!pri)
734 			goto out_freebh;
735 		rootp = (struct iso_directory_record *) pri->root_directory_record;
736 		sbi->s_nzones = isonum_733(pri->volume_space_size);
737 		sbi->s_log_zone_size = isonum_723(pri->logical_block_size);
738 		sbi->s_max_size = isonum_733(pri->volume_space_size);
739 	}
740 
741 	sbi->s_ninodes = 0; /* No way to figure this out easily */
742 
743 	orig_zonesize = sbi->s_log_zone_size;
744 	/*
745 	 * If the zone size is smaller than the hardware sector size,
746 	 * this is a fatal error.  This would occur if the disc drive
747 	 * had sectors that were 2048 bytes, but the filesystem had
748 	 * blocks that were 512 bytes (which should only very rarely
749 	 * happen.)
750 	 */
751 	if (orig_zonesize < opt.blocksize)
752 		goto out_bad_size;
753 
754 	/* RDE: convert log zone size to bit shift */
755 	switch (sbi->s_log_zone_size) {
756 	case  512: sbi->s_log_zone_size =  9; break;
757 	case 1024: sbi->s_log_zone_size = 10; break;
758 	case 2048: sbi->s_log_zone_size = 11; break;
759 
760 	default:
761 		goto out_bad_zone_size;
762 	}
763 
764 	s->s_magic = ISOFS_SUPER_MAGIC;
765 
766 	/*
767 	 * With multi-extent files, file size is only limited by the maximum
768 	 * size of a file system, which is 8 TB.
769 	 */
770 	s->s_maxbytes = 0x80000000000LL;
771 
772 	/* Set this for reference. Its not currently used except on write
773 	   which we don't have .. */
774 
775 	first_data_zone = isonum_733(rootp->extent) +
776 			  isonum_711(rootp->ext_attr_length);
777 	sbi->s_firstdatazone = first_data_zone;
778 #ifndef BEQUIET
779 	printk(KERN_DEBUG "ISOFS: Max size:%ld   Log zone size:%ld\n",
780 		sbi->s_max_size, 1UL << sbi->s_log_zone_size);
781 	printk(KERN_DEBUG "ISOFS: First datazone:%ld\n", sbi->s_firstdatazone);
782 	if(sbi->s_high_sierra)
783 		printk(KERN_DEBUG "ISOFS: Disc in High Sierra format.\n");
784 #endif
785 
786 	/*
787 	 * If the Joliet level is set, we _may_ decide to use the
788 	 * secondary descriptor, but can't be sure until after we
789 	 * read the root inode. But before reading the root inode
790 	 * we may need to change the device blocksize, and would
791 	 * rather release the old buffer first. So, we cache the
792 	 * first_data_zone value from the secondary descriptor.
793 	 */
794 	if (joliet_level) {
795 		pri = (struct iso_primary_descriptor *) sec;
796 		rootp = (struct iso_directory_record *)
797 			pri->root_directory_record;
798 		first_data_zone = isonum_733(rootp->extent) +
799 				isonum_711(rootp->ext_attr_length);
800 	}
801 
802 	/*
803 	 * We're all done using the volume descriptor, and may need
804 	 * to change the device blocksize, so release the buffer now.
805 	 */
806 	brelse(pri_bh);
807 	brelse(bh);
808 
809 	/*
810 	 * Force the blocksize to 512 for 512 byte sectors.  The file
811 	 * read primitives really get it wrong in a bad way if we don't
812 	 * do this.
813 	 *
814 	 * Note - we should never be setting the blocksize to something
815 	 * less than the hardware sector size for the device.  If we
816 	 * do, we would end up having to read larger buffers and split
817 	 * out portions to satisfy requests.
818 	 *
819 	 * Note2- the idea here is that we want to deal with the optimal
820 	 * zonesize in the filesystem.  If we have it set to something less,
821 	 * then we have horrible problems with trying to piece together
822 	 * bits of adjacent blocks in order to properly read directory
823 	 * entries.  By forcing the blocksize in this way, we ensure
824 	 * that we will never be required to do this.
825 	 */
826 	sb_set_blocksize(s, orig_zonesize);
827 
828 	sbi->s_nls_iocharset = NULL;
829 
830 #ifdef CONFIG_JOLIET
831 	if (joliet_level && opt.utf8 == 0) {
832 		char *p = opt.iocharset ? opt.iocharset : CONFIG_NLS_DEFAULT;
833 		sbi->s_nls_iocharset = load_nls(p);
834 		if (! sbi->s_nls_iocharset) {
835 			/* Fail only if explicit charset specified */
836 			if (opt.iocharset)
837 				goto out_freesbi;
838 			sbi->s_nls_iocharset = load_nls_default();
839 		}
840 	}
841 #endif
842 	s->s_op = &isofs_sops;
843 	s->s_export_op = &isofs_export_ops;
844 	sbi->s_mapping = opt.map;
845 	sbi->s_rock = (opt.rock ? 2 : 0);
846 	sbi->s_rock_offset = -1; /* initial offset, will guess until SP is found*/
847 	sbi->s_cruft = opt.cruft;
848 	sbi->s_hide = opt.hide;
849 	sbi->s_showassoc = opt.showassoc;
850 	sbi->s_uid = opt.uid;
851 	sbi->s_gid = opt.gid;
852 	sbi->s_uid_set = opt.uid_set;
853 	sbi->s_gid_set = opt.gid_set;
854 	sbi->s_utf8 = opt.utf8;
855 	sbi->s_nocompress = opt.nocompress;
856 	sbi->s_overriderockperm = opt.overriderockperm;
857 	/*
858 	 * It would be incredibly stupid to allow people to mark every file
859 	 * on the disk as suid, so we merely allow them to set the default
860 	 * permissions.
861 	 */
862 	if (opt.fmode != ISOFS_INVALID_MODE)
863 		sbi->s_fmode = opt.fmode & 0777;
864 	else
865 		sbi->s_fmode = ISOFS_INVALID_MODE;
866 	if (opt.dmode != ISOFS_INVALID_MODE)
867 		sbi->s_dmode = opt.dmode & 0777;
868 	else
869 		sbi->s_dmode = ISOFS_INVALID_MODE;
870 
871 	/*
872 	 * Read the root inode, which _may_ result in changing
873 	 * the s_rock flag. Once we have the final s_rock value,
874 	 * we then decide whether to use the Joliet descriptor.
875 	 */
876 	inode = isofs_iget(s, sbi->s_firstdatazone, 0);
877 	if (IS_ERR(inode))
878 		goto out_no_root;
879 
880 	/*
881 	 * Fix for broken CDs with Rock Ridge and empty ISO root directory but
882 	 * correct Joliet root directory.
883 	 */
884 	if (sbi->s_rock == 1 && joliet_level &&
885 				rootdir_empty(s, sbi->s_firstdatazone)) {
886 		printk(KERN_NOTICE
887 			"ISOFS: primary root directory is empty. "
888 			"Disabling Rock Ridge and switching to Joliet.");
889 		sbi->s_rock = 0;
890 	}
891 
892 	/*
893 	 * If this disk has both Rock Ridge and Joliet on it, then we
894 	 * want to use Rock Ridge by default.  This can be overridden
895 	 * by using the norock mount option.  There is still one other
896 	 * possibility that is not taken into account: a Rock Ridge
897 	 * CD with Unicode names.  Until someone sees such a beast, it
898 	 * will not be supported.
899 	 */
900 	if (sbi->s_rock == 1) {
901 		joliet_level = 0;
902 	} else if (joliet_level) {
903 		sbi->s_rock = 0;
904 		if (sbi->s_firstdatazone != first_data_zone) {
905 			sbi->s_firstdatazone = first_data_zone;
906 			printk(KERN_DEBUG
907 				"ISOFS: changing to secondary root\n");
908 			iput(inode);
909 			inode = isofs_iget(s, sbi->s_firstdatazone, 0);
910 			if (IS_ERR(inode))
911 				goto out_no_root;
912 		}
913 	}
914 
915 	if (opt.check == 'u') {
916 		/* Only Joliet is case insensitive by default */
917 		if (joliet_level)
918 			opt.check = 'r';
919 		else
920 			opt.check = 's';
921 	}
922 	sbi->s_joliet_level = joliet_level;
923 
924 	/* Make sure the root inode is a directory */
925 	if (!S_ISDIR(inode->i_mode)) {
926 		printk(KERN_WARNING
927 			"isofs_fill_super: root inode is not a directory. "
928 			"Corrupted media?\n");
929 		goto out_iput;
930 	}
931 
932 	table = 0;
933 	if (joliet_level)
934 		table += 2;
935 	if (opt.check == 'r')
936 		table++;
937 
938 	s->s_d_op = &isofs_dentry_ops[table];
939 
940 	/* get the root dentry */
941 	s->s_root = d_make_root(inode);
942 	if (!(s->s_root)) {
943 		error = -ENOMEM;
944 		goto out_no_inode;
945 	}
946 
947 	kfree(opt.iocharset);
948 
949 	return 0;
950 
951 	/*
952 	 * Display error messages and free resources.
953 	 */
954 out_iput:
955 	iput(inode);
956 	goto out_no_inode;
957 out_no_root:
958 	error = PTR_ERR(inode);
959 	if (error != -ENOMEM)
960 		printk(KERN_WARNING "%s: get root inode failed\n", __func__);
961 out_no_inode:
962 #ifdef CONFIG_JOLIET
963 	unload_nls(sbi->s_nls_iocharset);
964 #endif
965 	goto out_freesbi;
966 out_no_read:
967 	printk(KERN_WARNING "%s: bread failed, dev=%s, iso_blknum=%d, block=%d\n",
968 		__func__, s->s_id, iso_blknum, block);
969 	goto out_freebh;
970 out_bad_zone_size:
971 	printk(KERN_WARNING "ISOFS: Bad logical zone size %ld\n",
972 		sbi->s_log_zone_size);
973 	goto out_freebh;
974 out_bad_size:
975 	printk(KERN_WARNING "ISOFS: Logical zone size(%d) < hardware blocksize(%u)\n",
976 		orig_zonesize, opt.blocksize);
977 	goto out_freebh;
978 out_unknown_format:
979 	if (!silent)
980 		printk(KERN_WARNING "ISOFS: Unable to identify CD-ROM format.\n");
981 
982 out_freebh:
983 	brelse(bh);
984 	brelse(pri_bh);
985 out_freesbi:
986 	kfree(opt.iocharset);
987 	kfree(sbi);
988 	s->s_fs_info = NULL;
989 	return error;
990 }
991 
isofs_statfs(struct dentry * dentry,struct kstatfs * buf)992 static int isofs_statfs (struct dentry *dentry, struct kstatfs *buf)
993 {
994 	struct super_block *sb = dentry->d_sb;
995 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
996 
997 	buf->f_type = ISOFS_SUPER_MAGIC;
998 	buf->f_bsize = sb->s_blocksize;
999 	buf->f_blocks = (ISOFS_SB(sb)->s_nzones
1000 		<< (ISOFS_SB(sb)->s_log_zone_size - sb->s_blocksize_bits));
1001 	buf->f_bfree = 0;
1002 	buf->f_bavail = 0;
1003 	buf->f_files = ISOFS_SB(sb)->s_ninodes;
1004 	buf->f_ffree = 0;
1005 	buf->f_fsid.val[0] = (u32)id;
1006 	buf->f_fsid.val[1] = (u32)(id >> 32);
1007 	buf->f_namelen = NAME_MAX;
1008 	return 0;
1009 }
1010 
1011 /*
1012  * Get a set of blocks; filling in buffer_heads if already allocated
1013  * or getblk() if they are not.  Returns the number of blocks inserted
1014  * (-ve == error.)
1015  */
isofs_get_blocks(struct inode * inode,sector_t iblock,struct buffer_head ** bh,unsigned long nblocks)1016 int isofs_get_blocks(struct inode *inode, sector_t iblock,
1017 		     struct buffer_head **bh, unsigned long nblocks)
1018 {
1019 	unsigned long b_off = iblock;
1020 	unsigned offset, sect_size;
1021 	unsigned int firstext;
1022 	unsigned long nextblk, nextoff;
1023 	int section, rv, error;
1024 	struct iso_inode_info *ei = ISOFS_I(inode);
1025 
1026 	error = -EIO;
1027 	rv = 0;
1028 	if (iblock != b_off) {
1029 		printk(KERN_DEBUG "%s: block number too large\n", __func__);
1030 		goto abort;
1031 	}
1032 
1033 
1034 	offset = 0;
1035 	firstext = ei->i_first_extent;
1036 	sect_size = ei->i_section_size >> ISOFS_BUFFER_BITS(inode);
1037 	nextblk = ei->i_next_section_block;
1038 	nextoff = ei->i_next_section_offset;
1039 	section = 0;
1040 
1041 	while (nblocks) {
1042 		/* If we are *way* beyond the end of the file, print a message.
1043 		 * Access beyond the end of the file up to the next page boundary
1044 		 * is normal, however because of the way the page cache works.
1045 		 * In this case, we just return 0 so that we can properly fill
1046 		 * the page with useless information without generating any
1047 		 * I/O errors.
1048 		 */
1049 		if (b_off > ((inode->i_size + PAGE_CACHE_SIZE - 1) >> ISOFS_BUFFER_BITS(inode))) {
1050 			printk(KERN_DEBUG "%s: block >= EOF (%lu, %llu)\n",
1051 				__func__, b_off,
1052 				(unsigned long long)inode->i_size);
1053 			goto abort;
1054 		}
1055 
1056 		/* On the last section, nextblk == 0, section size is likely to
1057 		 * exceed sect_size by a partial block, and access beyond the
1058 		 * end of the file will reach beyond the section size, too.
1059 		 */
1060 		while (nextblk && (b_off >= (offset + sect_size))) {
1061 			struct inode *ninode;
1062 
1063 			offset += sect_size;
1064 			ninode = isofs_iget(inode->i_sb, nextblk, nextoff);
1065 			if (IS_ERR(ninode)) {
1066 				error = PTR_ERR(ninode);
1067 				goto abort;
1068 			}
1069 			firstext  = ISOFS_I(ninode)->i_first_extent;
1070 			sect_size = ISOFS_I(ninode)->i_section_size >> ISOFS_BUFFER_BITS(ninode);
1071 			nextblk   = ISOFS_I(ninode)->i_next_section_block;
1072 			nextoff   = ISOFS_I(ninode)->i_next_section_offset;
1073 			iput(ninode);
1074 
1075 			if (++section > 100) {
1076 				printk(KERN_DEBUG "%s: More than 100 file sections ?!?"
1077 					" aborting...\n", __func__);
1078 				printk(KERN_DEBUG "%s: block=%lu firstext=%u sect_size=%u "
1079 					"nextblk=%lu nextoff=%lu\n", __func__,
1080 					b_off, firstext, (unsigned) sect_size,
1081 					nextblk, nextoff);
1082 				goto abort;
1083 			}
1084 		}
1085 
1086 		if (*bh) {
1087 			map_bh(*bh, inode->i_sb, firstext + b_off - offset);
1088 		} else {
1089 			*bh = sb_getblk(inode->i_sb, firstext+b_off-offset);
1090 			if (!*bh)
1091 				goto abort;
1092 		}
1093 		bh++;	/* Next buffer head */
1094 		b_off++;	/* Next buffer offset */
1095 		nblocks--;
1096 		rv++;
1097 	}
1098 
1099 	error = 0;
1100 abort:
1101 	return rv != 0 ? rv : error;
1102 }
1103 
1104 /*
1105  * Used by the standard interfaces.
1106  */
isofs_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)1107 static int isofs_get_block(struct inode *inode, sector_t iblock,
1108 		    struct buffer_head *bh_result, int create)
1109 {
1110 	int ret;
1111 
1112 	if (create) {
1113 		printk(KERN_DEBUG "%s: Kernel tries to allocate a block\n", __func__);
1114 		return -EROFS;
1115 	}
1116 
1117 	ret = isofs_get_blocks(inode, iblock, &bh_result, 1);
1118 	return ret < 0 ? ret : 0;
1119 }
1120 
isofs_bmap(struct inode * inode,sector_t block)1121 static int isofs_bmap(struct inode *inode, sector_t block)
1122 {
1123 	struct buffer_head dummy;
1124 	int error;
1125 
1126 	dummy.b_state = 0;
1127 	dummy.b_blocknr = -1000;
1128 	error = isofs_get_block(inode, block, &dummy, 0);
1129 	if (!error)
1130 		return dummy.b_blocknr;
1131 	return 0;
1132 }
1133 
isofs_bread(struct inode * inode,sector_t block)1134 struct buffer_head *isofs_bread(struct inode *inode, sector_t block)
1135 {
1136 	sector_t blknr = isofs_bmap(inode, block);
1137 	if (!blknr)
1138 		return NULL;
1139 	return sb_bread(inode->i_sb, blknr);
1140 }
1141 
isofs_readpage(struct file * file,struct page * page)1142 static int isofs_readpage(struct file *file, struct page *page)
1143 {
1144 	return mpage_readpage(page, isofs_get_block);
1145 }
1146 
isofs_readpages(struct file * file,struct address_space * mapping,struct list_head * pages,unsigned nr_pages)1147 static int isofs_readpages(struct file *file, struct address_space *mapping,
1148 			struct list_head *pages, unsigned nr_pages)
1149 {
1150 	return mpage_readpages(mapping, pages, nr_pages, isofs_get_block);
1151 }
1152 
_isofs_bmap(struct address_space * mapping,sector_t block)1153 static sector_t _isofs_bmap(struct address_space *mapping, sector_t block)
1154 {
1155 	return generic_block_bmap(mapping,block,isofs_get_block);
1156 }
1157 
1158 static const struct address_space_operations isofs_aops = {
1159 	.readpage = isofs_readpage,
1160 	.readpages = isofs_readpages,
1161 	.bmap = _isofs_bmap
1162 };
1163 
isofs_read_level3_size(struct inode * inode)1164 static int isofs_read_level3_size(struct inode *inode)
1165 {
1166 	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
1167 	int high_sierra = ISOFS_SB(inode->i_sb)->s_high_sierra;
1168 	struct buffer_head *bh = NULL;
1169 	unsigned long block, offset, block_saved, offset_saved;
1170 	int i = 0;
1171 	int more_entries = 0;
1172 	struct iso_directory_record *tmpde = NULL;
1173 	struct iso_inode_info *ei = ISOFS_I(inode);
1174 
1175 	inode->i_size = 0;
1176 
1177 	/* The first 16 blocks are reserved as the System Area.  Thus,
1178 	 * no inodes can appear in block 0.  We use this to flag that
1179 	 * this is the last section. */
1180 	ei->i_next_section_block = 0;
1181 	ei->i_next_section_offset = 0;
1182 
1183 	block = ei->i_iget5_block;
1184 	offset = ei->i_iget5_offset;
1185 
1186 	do {
1187 		struct iso_directory_record *de;
1188 		unsigned int de_len;
1189 
1190 		if (!bh) {
1191 			bh = sb_bread(inode->i_sb, block);
1192 			if (!bh)
1193 				goto out_noread;
1194 		}
1195 		de = (struct iso_directory_record *) (bh->b_data + offset);
1196 		de_len = *(unsigned char *) de;
1197 
1198 		if (de_len == 0) {
1199 			brelse(bh);
1200 			bh = NULL;
1201 			++block;
1202 			offset = 0;
1203 			continue;
1204 		}
1205 
1206 		block_saved = block;
1207 		offset_saved = offset;
1208 		offset += de_len;
1209 
1210 		/* Make sure we have a full directory entry */
1211 		if (offset >= bufsize) {
1212 			int slop = bufsize - offset + de_len;
1213 			if (!tmpde) {
1214 				tmpde = kmalloc(256, GFP_KERNEL);
1215 				if (!tmpde)
1216 					goto out_nomem;
1217 			}
1218 			memcpy(tmpde, de, slop);
1219 			offset &= bufsize - 1;
1220 			block++;
1221 			brelse(bh);
1222 			bh = NULL;
1223 			if (offset) {
1224 				bh = sb_bread(inode->i_sb, block);
1225 				if (!bh)
1226 					goto out_noread;
1227 				memcpy((void *)tmpde+slop, bh->b_data, offset);
1228 			}
1229 			de = tmpde;
1230 		}
1231 
1232 		inode->i_size += isonum_733(de->size);
1233 		if (i == 1) {
1234 			ei->i_next_section_block = block_saved;
1235 			ei->i_next_section_offset = offset_saved;
1236 		}
1237 
1238 		more_entries = de->flags[-high_sierra] & 0x80;
1239 
1240 		i++;
1241 		if (i > 100)
1242 			goto out_toomany;
1243 	} while (more_entries);
1244 out:
1245 	kfree(tmpde);
1246 	if (bh)
1247 		brelse(bh);
1248 	return 0;
1249 
1250 out_nomem:
1251 	if (bh)
1252 		brelse(bh);
1253 	return -ENOMEM;
1254 
1255 out_noread:
1256 	printk(KERN_INFO "ISOFS: unable to read i-node block %lu\n", block);
1257 	kfree(tmpde);
1258 	return -EIO;
1259 
1260 out_toomany:
1261 	printk(KERN_INFO "%s: More than 100 file sections ?!?, aborting...\n"
1262 		"isofs_read_level3_size: inode=%lu\n",
1263 		__func__, inode->i_ino);
1264 	goto out;
1265 }
1266 
isofs_read_inode(struct inode * inode)1267 static int isofs_read_inode(struct inode *inode)
1268 {
1269 	struct super_block *sb = inode->i_sb;
1270 	struct isofs_sb_info *sbi = ISOFS_SB(sb);
1271 	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
1272 	unsigned long block;
1273 	int high_sierra = sbi->s_high_sierra;
1274 	struct buffer_head *bh = NULL;
1275 	struct iso_directory_record *de;
1276 	struct iso_directory_record *tmpde = NULL;
1277 	unsigned int de_len;
1278 	unsigned long offset;
1279 	struct iso_inode_info *ei = ISOFS_I(inode);
1280 	int ret = -EIO;
1281 
1282 	block = ei->i_iget5_block;
1283 	bh = sb_bread(inode->i_sb, block);
1284 	if (!bh)
1285 		goto out_badread;
1286 
1287 	offset = ei->i_iget5_offset;
1288 
1289 	de = (struct iso_directory_record *) (bh->b_data + offset);
1290 	de_len = *(unsigned char *) de;
1291 
1292 	if (offset + de_len > bufsize) {
1293 		int frag1 = bufsize - offset;
1294 
1295 		tmpde = kmalloc(de_len, GFP_KERNEL);
1296 		if (tmpde == NULL) {
1297 			printk(KERN_INFO "%s: out of memory\n", __func__);
1298 			ret = -ENOMEM;
1299 			goto fail;
1300 		}
1301 		memcpy(tmpde, bh->b_data + offset, frag1);
1302 		brelse(bh);
1303 		bh = sb_bread(inode->i_sb, ++block);
1304 		if (!bh)
1305 			goto out_badread;
1306 		memcpy((char *)tmpde+frag1, bh->b_data, de_len - frag1);
1307 		de = tmpde;
1308 	}
1309 
1310 	inode->i_ino = isofs_get_ino(ei->i_iget5_block,
1311 					ei->i_iget5_offset,
1312 					ISOFS_BUFFER_BITS(inode));
1313 
1314 	/* Assume it is a normal-format file unless told otherwise */
1315 	ei->i_file_format = isofs_file_normal;
1316 
1317 	if (de->flags[-high_sierra] & 2) {
1318 		if (sbi->s_dmode != ISOFS_INVALID_MODE)
1319 			inode->i_mode = S_IFDIR | sbi->s_dmode;
1320 		else
1321 			inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
1322 		set_nlink(inode, 1);	/*
1323 					 * Set to 1.  We know there are 2, but
1324 					 * the find utility tries to optimize
1325 					 * if it is 2, and it screws up.  It is
1326 					 * easier to give 1 which tells find to
1327 					 * do it the hard way.
1328 					 */
1329 	} else {
1330 		if (sbi->s_fmode != ISOFS_INVALID_MODE) {
1331 			inode->i_mode = S_IFREG | sbi->s_fmode;
1332 		} else {
1333 			/*
1334 			 * Set default permissions: r-x for all.  The disc
1335 			 * could be shared with DOS machines so virtually
1336 			 * anything could be a valid executable.
1337 			 */
1338 			inode->i_mode = S_IFREG | S_IRUGO | S_IXUGO;
1339 		}
1340 		set_nlink(inode, 1);
1341 	}
1342 	inode->i_uid = sbi->s_uid;
1343 	inode->i_gid = sbi->s_gid;
1344 	inode->i_blocks = 0;
1345 
1346 	ei->i_format_parm[0] = 0;
1347 	ei->i_format_parm[1] = 0;
1348 	ei->i_format_parm[2] = 0;
1349 
1350 	ei->i_section_size = isonum_733(de->size);
1351 	if (de->flags[-high_sierra] & 0x80) {
1352 		ret = isofs_read_level3_size(inode);
1353 		if (ret < 0)
1354 			goto fail;
1355 		ret = -EIO;
1356 	} else {
1357 		ei->i_next_section_block = 0;
1358 		ei->i_next_section_offset = 0;
1359 		inode->i_size = isonum_733(de->size);
1360 	}
1361 
1362 	/*
1363 	 * Some dipshit decided to store some other bit of information
1364 	 * in the high byte of the file length.  Truncate size in case
1365 	 * this CDROM was mounted with the cruft option.
1366 	 */
1367 
1368 	if (sbi->s_cruft)
1369 		inode->i_size &= 0x00ffffff;
1370 
1371 	if (de->interleave[0]) {
1372 		printk(KERN_DEBUG "ISOFS: Interleaved files not (yet) supported.\n");
1373 		inode->i_size = 0;
1374 	}
1375 
1376 	/* I have no idea what file_unit_size is used for, so
1377 	   we will flag it for now */
1378 	if (de->file_unit_size[0] != 0) {
1379 		printk(KERN_DEBUG "ISOFS: File unit size != 0 for ISO file (%ld).\n",
1380 			inode->i_ino);
1381 	}
1382 
1383 	/* I have no idea what other flag bits are used for, so
1384 	   we will flag it for now */
1385 #ifdef DEBUG
1386 	if((de->flags[-high_sierra] & ~2)!= 0){
1387 		printk(KERN_DEBUG "ISOFS: Unusual flag settings for ISO file "
1388 				"(%ld %x).\n",
1389 			inode->i_ino, de->flags[-high_sierra]);
1390 	}
1391 #endif
1392 
1393 	inode->i_mtime.tv_sec =
1394 	inode->i_atime.tv_sec =
1395 	inode->i_ctime.tv_sec = iso_date(de->date, high_sierra);
1396 	inode->i_mtime.tv_nsec =
1397 	inode->i_atime.tv_nsec =
1398 	inode->i_ctime.tv_nsec = 0;
1399 
1400 	ei->i_first_extent = (isonum_733(de->extent) +
1401 			isonum_711(de->ext_attr_length));
1402 
1403 	/* Set the number of blocks for stat() - should be done before RR */
1404 	inode->i_blocks = (inode->i_size + 511) >> 9;
1405 
1406 	/*
1407 	 * Now test for possible Rock Ridge extensions which will override
1408 	 * some of these numbers in the inode structure.
1409 	 */
1410 
1411 	if (!high_sierra) {
1412 		parse_rock_ridge_inode(de, inode);
1413 		/* if we want uid/gid set, override the rock ridge setting */
1414 		if (sbi->s_uid_set)
1415 			inode->i_uid = sbi->s_uid;
1416 		if (sbi->s_gid_set)
1417 			inode->i_gid = sbi->s_gid;
1418 	}
1419 	/* Now set final access rights if overriding rock ridge setting */
1420 	if (S_ISDIR(inode->i_mode) && sbi->s_overriderockperm &&
1421 	    sbi->s_dmode != ISOFS_INVALID_MODE)
1422 		inode->i_mode = S_IFDIR | sbi->s_dmode;
1423 	if (S_ISREG(inode->i_mode) && sbi->s_overriderockperm &&
1424 	    sbi->s_fmode != ISOFS_INVALID_MODE)
1425 		inode->i_mode = S_IFREG | sbi->s_fmode;
1426 
1427 	/* Install the inode operations vector */
1428 	if (S_ISREG(inode->i_mode)) {
1429 		inode->i_fop = &generic_ro_fops;
1430 		switch (ei->i_file_format) {
1431 #ifdef CONFIG_ZISOFS
1432 		case isofs_file_compressed:
1433 			inode->i_data.a_ops = &zisofs_aops;
1434 			break;
1435 #endif
1436 		default:
1437 			inode->i_data.a_ops = &isofs_aops;
1438 			break;
1439 		}
1440 	} else if (S_ISDIR(inode->i_mode)) {
1441 		inode->i_op = &isofs_dir_inode_operations;
1442 		inode->i_fop = &isofs_dir_operations;
1443 	} else if (S_ISLNK(inode->i_mode)) {
1444 		inode->i_op = &page_symlink_inode_operations;
1445 		inode->i_data.a_ops = &isofs_symlink_aops;
1446 	} else
1447 		/* XXX - parse_rock_ridge_inode() had already set i_rdev. */
1448 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1449 
1450 	ret = 0;
1451 out:
1452 	kfree(tmpde);
1453 	if (bh)
1454 		brelse(bh);
1455 	return ret;
1456 
1457 out_badread:
1458 	printk(KERN_WARNING "ISOFS: unable to read i-node block\n");
1459 fail:
1460 	goto out;
1461 }
1462 
1463 struct isofs_iget5_callback_data {
1464 	unsigned long block;
1465 	unsigned long offset;
1466 };
1467 
isofs_iget5_test(struct inode * ino,void * data)1468 static int isofs_iget5_test(struct inode *ino, void *data)
1469 {
1470 	struct iso_inode_info *i = ISOFS_I(ino);
1471 	struct isofs_iget5_callback_data *d =
1472 		(struct isofs_iget5_callback_data*)data;
1473 	return (i->i_iget5_block == d->block)
1474 		&& (i->i_iget5_offset == d->offset);
1475 }
1476 
isofs_iget5_set(struct inode * ino,void * data)1477 static int isofs_iget5_set(struct inode *ino, void *data)
1478 {
1479 	struct iso_inode_info *i = ISOFS_I(ino);
1480 	struct isofs_iget5_callback_data *d =
1481 		(struct isofs_iget5_callback_data*)data;
1482 	i->i_iget5_block = d->block;
1483 	i->i_iget5_offset = d->offset;
1484 	return 0;
1485 }
1486 
1487 /* Store, in the inode's containing structure, the block and block
1488  * offset that point to the underlying meta-data for the inode.  The
1489  * code below is otherwise similar to the iget() code in
1490  * include/linux/fs.h */
isofs_iget(struct super_block * sb,unsigned long block,unsigned long offset)1491 struct inode *isofs_iget(struct super_block *sb,
1492 			 unsigned long block,
1493 			 unsigned long offset)
1494 {
1495 	unsigned long hashval;
1496 	struct inode *inode;
1497 	struct isofs_iget5_callback_data data;
1498 	long ret;
1499 
1500 	if (offset >= 1ul << sb->s_blocksize_bits)
1501 		return ERR_PTR(-EINVAL);
1502 
1503 	data.block = block;
1504 	data.offset = offset;
1505 
1506 	hashval = (block << sb->s_blocksize_bits) | offset;
1507 
1508 	inode = iget5_locked(sb, hashval, &isofs_iget5_test,
1509 				&isofs_iget5_set, &data);
1510 
1511 	if (!inode)
1512 		return ERR_PTR(-ENOMEM);
1513 
1514 	if (inode->i_state & I_NEW) {
1515 		ret = isofs_read_inode(inode);
1516 		if (ret < 0) {
1517 			iget_failed(inode);
1518 			inode = ERR_PTR(ret);
1519 		} else {
1520 			unlock_new_inode(inode);
1521 		}
1522 	}
1523 
1524 	return inode;
1525 }
1526 
isofs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1527 static struct dentry *isofs_mount(struct file_system_type *fs_type,
1528 	int flags, const char *dev_name, void *data)
1529 {
1530 	/* We don't support read-write mounts */
1531 	if (!(flags & MS_RDONLY))
1532 		return ERR_PTR(-EACCES);
1533 	return mount_bdev(fs_type, flags, dev_name, data, isofs_fill_super);
1534 }
1535 
1536 static struct file_system_type iso9660_fs_type = {
1537 	.owner		= THIS_MODULE,
1538 	.name		= "iso9660",
1539 	.mount		= isofs_mount,
1540 	.kill_sb	= kill_block_super,
1541 	.fs_flags	= FS_REQUIRES_DEV,
1542 };
1543 
init_iso9660_fs(void)1544 static int __init init_iso9660_fs(void)
1545 {
1546 	int err = init_inodecache();
1547 	if (err)
1548 		goto out;
1549 #ifdef CONFIG_ZISOFS
1550 	err = zisofs_init();
1551 	if (err)
1552 		goto out1;
1553 #endif
1554 	err = register_filesystem(&iso9660_fs_type);
1555 	if (err)
1556 		goto out2;
1557 	return 0;
1558 out2:
1559 #ifdef CONFIG_ZISOFS
1560 	zisofs_cleanup();
1561 out1:
1562 #endif
1563 	destroy_inodecache();
1564 out:
1565 	return err;
1566 }
1567 
exit_iso9660_fs(void)1568 static void __exit exit_iso9660_fs(void)
1569 {
1570         unregister_filesystem(&iso9660_fs_type);
1571 #ifdef CONFIG_ZISOFS
1572 	zisofs_cleanup();
1573 #endif
1574 	destroy_inodecache();
1575 }
1576 
1577 module_init(init_iso9660_fs)
1578 module_exit(exit_iso9660_fs)
1579 MODULE_LICENSE("GPL");
1580 /* Actual filesystem name is iso9660, as requested in filesystems.c */
1581 MODULE_ALIAS("iso9660");
1582