1 /*
2 * linux/fs/adfs/super.c
3 *
4 * Copyright (C) 1997-1999 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/buffer_head.h>
13 #include <linux/parser.h>
14 #include <linux/mount.h>
15 #include <linux/seq_file.h>
16 #include <linux/slab.h>
17 #include <linux/statfs.h>
18 #include "adfs.h"
19 #include "dir_f.h"
20 #include "dir_fplus.h"
21
22 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
23 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
24
__adfs_error(struct super_block * sb,const char * function,const char * fmt,...)25 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
26 {
27 char error_buf[128];
28 va_list args;
29
30 va_start(args, fmt);
31 vsnprintf(error_buf, sizeof(error_buf), fmt, args);
32 va_end(args);
33
34 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
35 sb->s_id, function ? ": " : "",
36 function ? function : "", error_buf);
37 }
38
adfs_checkdiscrecord(struct adfs_discrecord * dr)39 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
40 {
41 int i;
42
43 /* sector size must be 256, 512 or 1024 bytes */
44 if (dr->log2secsize != 8 &&
45 dr->log2secsize != 9 &&
46 dr->log2secsize != 10)
47 return 1;
48
49 /* idlen must be at least log2secsize + 3 */
50 if (dr->idlen < dr->log2secsize + 3)
51 return 1;
52
53 /* we cannot have such a large disc that we
54 * are unable to represent sector offsets in
55 * 32 bits. This works out at 2.0 TB.
56 */
57 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
58 return 1;
59
60 /* idlen must be no greater than 19 v2 [1.0] */
61 if (dr->idlen > 19)
62 return 1;
63
64 /* reserved bytes should be zero */
65 for (i = 0; i < sizeof(dr->unused52); i++)
66 if (dr->unused52[i] != 0)
67 return 1;
68
69 return 0;
70 }
71
adfs_calczonecheck(struct super_block * sb,unsigned char * map)72 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
73 {
74 unsigned int v0, v1, v2, v3;
75 int i;
76
77 v0 = v1 = v2 = v3 = 0;
78 for (i = sb->s_blocksize - 4; i; i -= 4) {
79 v0 += map[i] + (v3 >> 8);
80 v3 &= 0xff;
81 v1 += map[i + 1] + (v0 >> 8);
82 v0 &= 0xff;
83 v2 += map[i + 2] + (v1 >> 8);
84 v1 &= 0xff;
85 v3 += map[i + 3] + (v2 >> 8);
86 v2 &= 0xff;
87 }
88 v0 += v3 >> 8;
89 v1 += map[1] + (v0 >> 8);
90 v2 += map[2] + (v1 >> 8);
91 v3 += map[3] + (v2 >> 8);
92
93 return v0 ^ v1 ^ v2 ^ v3;
94 }
95
adfs_checkmap(struct super_block * sb,struct adfs_discmap * dm)96 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
97 {
98 unsigned char crosscheck = 0, zonecheck = 1;
99 int i;
100
101 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
102 unsigned char *map;
103
104 map = dm[i].dm_bh->b_data;
105
106 if (adfs_calczonecheck(sb, map) != map[0]) {
107 adfs_error(sb, "zone %d fails zonecheck", i);
108 zonecheck = 0;
109 }
110 crosscheck ^= map[3];
111 }
112 if (crosscheck != 0xff)
113 adfs_error(sb, "crosscheck != 0xff");
114 return crosscheck == 0xff && zonecheck;
115 }
116
adfs_put_super(struct super_block * sb)117 static void adfs_put_super(struct super_block *sb)
118 {
119 int i;
120 struct adfs_sb_info *asb = ADFS_SB(sb);
121
122 for (i = 0; i < asb->s_map_size; i++)
123 brelse(asb->s_map[i].dm_bh);
124 kfree(asb->s_map);
125 kfree(asb);
126 sb->s_fs_info = NULL;
127 }
128
adfs_show_options(struct seq_file * seq,struct dentry * root)129 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
130 {
131 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
132
133 if (asb->s_uid != 0)
134 seq_printf(seq, ",uid=%u", asb->s_uid);
135 if (asb->s_gid != 0)
136 seq_printf(seq, ",gid=%u", asb->s_gid);
137 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
138 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
139 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
140 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
141 if (asb->s_ftsuffix != 0)
142 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
143
144 return 0;
145 }
146
147 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
148
149 static const match_table_t tokens = {
150 {Opt_uid, "uid=%u"},
151 {Opt_gid, "gid=%u"},
152 {Opt_ownmask, "ownmask=%o"},
153 {Opt_othmask, "othmask=%o"},
154 {Opt_ftsuffix, "ftsuffix=%u"},
155 {Opt_err, NULL}
156 };
157
parse_options(struct super_block * sb,char * options)158 static int parse_options(struct super_block *sb, char *options)
159 {
160 char *p;
161 struct adfs_sb_info *asb = ADFS_SB(sb);
162 int option;
163
164 if (!options)
165 return 0;
166
167 while ((p = strsep(&options, ",")) != NULL) {
168 substring_t args[MAX_OPT_ARGS];
169 int token;
170 if (!*p)
171 continue;
172
173 token = match_token(p, tokens, args);
174 switch (token) {
175 case Opt_uid:
176 if (match_int(args, &option))
177 return -EINVAL;
178 asb->s_uid = option;
179 break;
180 case Opt_gid:
181 if (match_int(args, &option))
182 return -EINVAL;
183 asb->s_gid = option;
184 break;
185 case Opt_ownmask:
186 if (match_octal(args, &option))
187 return -EINVAL;
188 asb->s_owner_mask = option;
189 break;
190 case Opt_othmask:
191 if (match_octal(args, &option))
192 return -EINVAL;
193 asb->s_other_mask = option;
194 break;
195 case Opt_ftsuffix:
196 if (match_int(args, &option))
197 return -EINVAL;
198 asb->s_ftsuffix = option;
199 break;
200 default:
201 printk("ADFS-fs: unrecognised mount option \"%s\" "
202 "or missing value\n", p);
203 return -EINVAL;
204 }
205 }
206 return 0;
207 }
208
adfs_remount(struct super_block * sb,int * flags,char * data)209 static int adfs_remount(struct super_block *sb, int *flags, char *data)
210 {
211 *flags |= MS_NODIRATIME;
212 return parse_options(sb, data);
213 }
214
adfs_statfs(struct dentry * dentry,struct kstatfs * buf)215 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
216 {
217 struct super_block *sb = dentry->d_sb;
218 struct adfs_sb_info *sbi = ADFS_SB(sb);
219 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
220
221 buf->f_type = ADFS_SUPER_MAGIC;
222 buf->f_namelen = sbi->s_namelen;
223 buf->f_bsize = sb->s_blocksize;
224 buf->f_blocks = sbi->s_size;
225 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
226 buf->f_bavail =
227 buf->f_bfree = adfs_map_free(sb);
228 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
229 buf->f_fsid.val[0] = (u32)id;
230 buf->f_fsid.val[1] = (u32)(id >> 32);
231
232 return 0;
233 }
234
235 static struct kmem_cache *adfs_inode_cachep;
236
adfs_alloc_inode(struct super_block * sb)237 static struct inode *adfs_alloc_inode(struct super_block *sb)
238 {
239 struct adfs_inode_info *ei;
240 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
241 if (!ei)
242 return NULL;
243 return &ei->vfs_inode;
244 }
245
adfs_i_callback(struct rcu_head * head)246 static void adfs_i_callback(struct rcu_head *head)
247 {
248 struct inode *inode = container_of(head, struct inode, i_rcu);
249 INIT_LIST_HEAD(&inode->i_dentry);
250 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
251 }
252
adfs_destroy_inode(struct inode * inode)253 static void adfs_destroy_inode(struct inode *inode)
254 {
255 call_rcu(&inode->i_rcu, adfs_i_callback);
256 }
257
init_once(void * foo)258 static void init_once(void *foo)
259 {
260 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
261
262 inode_init_once(&ei->vfs_inode);
263 }
264
init_inodecache(void)265 static int init_inodecache(void)
266 {
267 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
268 sizeof(struct adfs_inode_info),
269 0, (SLAB_RECLAIM_ACCOUNT|
270 SLAB_MEM_SPREAD),
271 init_once);
272 if (adfs_inode_cachep == NULL)
273 return -ENOMEM;
274 return 0;
275 }
276
destroy_inodecache(void)277 static void destroy_inodecache(void)
278 {
279 kmem_cache_destroy(adfs_inode_cachep);
280 }
281
282 static const struct super_operations adfs_sops = {
283 .alloc_inode = adfs_alloc_inode,
284 .destroy_inode = adfs_destroy_inode,
285 .write_inode = adfs_write_inode,
286 .put_super = adfs_put_super,
287 .statfs = adfs_statfs,
288 .remount_fs = adfs_remount,
289 .show_options = adfs_show_options,
290 };
291
adfs_read_map(struct super_block * sb,struct adfs_discrecord * dr)292 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
293 {
294 struct adfs_discmap *dm;
295 unsigned int map_addr, zone_size, nzones;
296 int i, zone;
297 struct adfs_sb_info *asb = ADFS_SB(sb);
298
299 nzones = asb->s_map_size;
300 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
301 map_addr = (nzones >> 1) * zone_size -
302 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
303 map_addr = signed_asl(map_addr, asb->s_map2blk);
304
305 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
306
307 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
308 if (dm == NULL) {
309 adfs_error(sb, "not enough memory");
310 return NULL;
311 }
312
313 for (zone = 0; zone < nzones; zone++, map_addr++) {
314 dm[zone].dm_startbit = 0;
315 dm[zone].dm_endbit = zone_size;
316 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
317 dm[zone].dm_bh = sb_bread(sb, map_addr);
318
319 if (!dm[zone].dm_bh) {
320 adfs_error(sb, "unable to read map");
321 goto error_free;
322 }
323 }
324
325 /* adjust the limits for the first and last map zones */
326 i = zone - 1;
327 dm[0].dm_startblk = 0;
328 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
329 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
330 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
331 (ADFS_DR_SIZE_BITS - i * zone_size);
332
333 if (adfs_checkmap(sb, dm))
334 return dm;
335
336 adfs_error(sb, "map corrupted");
337
338 error_free:
339 while (--zone >= 0)
340 brelse(dm[zone].dm_bh);
341
342 kfree(dm);
343 return NULL;
344 }
345
adfs_discsize(struct adfs_discrecord * dr,int block_bits)346 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
347 {
348 unsigned long discsize;
349
350 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
351 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
352
353 return discsize;
354 }
355
adfs_fill_super(struct super_block * sb,void * data,int silent)356 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
357 {
358 struct adfs_discrecord *dr;
359 struct buffer_head *bh;
360 struct object_info root_obj;
361 unsigned char *b_data;
362 struct adfs_sb_info *asb;
363 struct inode *root;
364
365 sb->s_flags |= MS_NODIRATIME;
366
367 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
368 if (!asb)
369 return -ENOMEM;
370 sb->s_fs_info = asb;
371
372 /* set default options */
373 asb->s_uid = 0;
374 asb->s_gid = 0;
375 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
376 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
377 asb->s_ftsuffix = 0;
378
379 if (parse_options(sb, data))
380 goto error;
381
382 sb_set_blocksize(sb, BLOCK_SIZE);
383 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
384 adfs_error(sb, "unable to read superblock");
385 goto error;
386 }
387
388 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
389
390 if (adfs_checkbblk(b_data)) {
391 if (!silent)
392 printk("VFS: Can't find an adfs filesystem on dev "
393 "%s.\n", sb->s_id);
394 goto error_free_bh;
395 }
396
397 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
398
399 /*
400 * Do some sanity checks on the ADFS disc record
401 */
402 if (adfs_checkdiscrecord(dr)) {
403 if (!silent)
404 printk("VPS: Can't find an adfs filesystem on dev "
405 "%s.\n", sb->s_id);
406 goto error_free_bh;
407 }
408
409 brelse(bh);
410 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
411 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
412 if (!bh) {
413 adfs_error(sb, "couldn't read superblock on "
414 "2nd try.");
415 goto error;
416 }
417 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
418 if (adfs_checkbblk(b_data)) {
419 adfs_error(sb, "disc record mismatch, very weird!");
420 goto error_free_bh;
421 }
422 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
423 } else {
424 if (!silent)
425 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
426 "%s.\n", sb->s_id);
427 goto error;
428 }
429
430 /*
431 * blocksize on this device should now be set to the ADFS log2secsize
432 */
433
434 sb->s_magic = ADFS_SUPER_MAGIC;
435 asb->s_idlen = dr->idlen;
436 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
437 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
438 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
439 asb->s_version = dr->format_version;
440 asb->s_log2sharesize = dr->log2sharesize;
441
442 asb->s_map = adfs_read_map(sb, dr);
443 if (!asb->s_map)
444 goto error_free_bh;
445
446 brelse(bh);
447
448 /*
449 * set up enough so that we can read an inode
450 */
451 sb->s_op = &adfs_sops;
452
453 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
454
455 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
456 root_obj.name_len = 0;
457 /* Set root object date as 01 Jan 1987 00:00:00 */
458 root_obj.loadaddr = 0xfff0003f;
459 root_obj.execaddr = 0xec22c000;
460 root_obj.size = ADFS_NEWDIR_SIZE;
461 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
462 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
463 root_obj.filetype = -1;
464
465 /*
466 * If this is a F+ disk with variable length directories,
467 * get the root_size from the disc record.
468 */
469 if (asb->s_version) {
470 root_obj.size = le32_to_cpu(dr->root_size);
471 asb->s_dir = &adfs_fplus_dir_ops;
472 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
473 } else {
474 asb->s_dir = &adfs_f_dir_ops;
475 asb->s_namelen = ADFS_F_NAME_LEN;
476 }
477 /*
478 * ,xyz hex filetype suffix may be added by driver
479 * to files that have valid RISC OS filetype
480 */
481 if (asb->s_ftsuffix)
482 asb->s_namelen += 4;
483
484 sb->s_d_op = &adfs_dentry_operations;
485 root = adfs_iget(sb, &root_obj);
486 sb->s_root = d_make_root(root);
487 if (!sb->s_root) {
488 int i;
489 for (i = 0; i < asb->s_map_size; i++)
490 brelse(asb->s_map[i].dm_bh);
491 kfree(asb->s_map);
492 adfs_error(sb, "get root inode failed\n");
493 goto error;
494 }
495 return 0;
496
497 error_free_bh:
498 brelse(bh);
499 error:
500 sb->s_fs_info = NULL;
501 kfree(asb);
502 return -EINVAL;
503 }
504
adfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)505 static struct dentry *adfs_mount(struct file_system_type *fs_type,
506 int flags, const char *dev_name, void *data)
507 {
508 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
509 }
510
511 static struct file_system_type adfs_fs_type = {
512 .owner = THIS_MODULE,
513 .name = "adfs",
514 .mount = adfs_mount,
515 .kill_sb = kill_block_super,
516 .fs_flags = FS_REQUIRES_DEV,
517 };
518
init_adfs_fs(void)519 static int __init init_adfs_fs(void)
520 {
521 int err = init_inodecache();
522 if (err)
523 goto out1;
524 err = register_filesystem(&adfs_fs_type);
525 if (err)
526 goto out;
527 return 0;
528 out:
529 destroy_inodecache();
530 out1:
531 return err;
532 }
533
exit_adfs_fs(void)534 static void __exit exit_adfs_fs(void)
535 {
536 unregister_filesystem(&adfs_fs_type);
537 destroy_inodecache();
538 }
539
540 module_init(init_adfs_fs)
541 module_exit(exit_adfs_fs)
542 MODULE_LICENSE("GPL");
543