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 <linux/user_namespace.h>
19 #include "adfs.h"
20 #include "dir_f.h"
21 #include "dir_fplus.h"
22
23 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
24 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
25
__adfs_error(struct super_block * sb,const char * function,const char * fmt,...)26 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
27 {
28 char error_buf[128];
29 va_list args;
30
31 va_start(args, fmt);
32 vsnprintf(error_buf, sizeof(error_buf), fmt, args);
33 va_end(args);
34
35 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
36 sb->s_id, function ? ": " : "",
37 function ? function : "", error_buf);
38 }
39
adfs_checkdiscrecord(struct adfs_discrecord * dr)40 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
41 {
42 int i;
43
44 /* sector size must be 256, 512 or 1024 bytes */
45 if (dr->log2secsize != 8 &&
46 dr->log2secsize != 9 &&
47 dr->log2secsize != 10)
48 return 1;
49
50 /* idlen must be at least log2secsize + 3 */
51 if (dr->idlen < dr->log2secsize + 3)
52 return 1;
53
54 /* we cannot have such a large disc that we
55 * are unable to represent sector offsets in
56 * 32 bits. This works out at 2.0 TB.
57 */
58 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
59 return 1;
60
61 /* idlen must be no greater than 19 v2 [1.0] */
62 if (dr->idlen > 19)
63 return 1;
64
65 /* reserved bytes should be zero */
66 for (i = 0; i < sizeof(dr->unused52); i++)
67 if (dr->unused52[i] != 0)
68 return 1;
69
70 return 0;
71 }
72
adfs_calczonecheck(struct super_block * sb,unsigned char * map)73 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
74 {
75 unsigned int v0, v1, v2, v3;
76 int i;
77
78 v0 = v1 = v2 = v3 = 0;
79 for (i = sb->s_blocksize - 4; i; i -= 4) {
80 v0 += map[i] + (v3 >> 8);
81 v3 &= 0xff;
82 v1 += map[i + 1] + (v0 >> 8);
83 v0 &= 0xff;
84 v2 += map[i + 2] + (v1 >> 8);
85 v1 &= 0xff;
86 v3 += map[i + 3] + (v2 >> 8);
87 v2 &= 0xff;
88 }
89 v0 += v3 >> 8;
90 v1 += map[1] + (v0 >> 8);
91 v2 += map[2] + (v1 >> 8);
92 v3 += map[3] + (v2 >> 8);
93
94 return v0 ^ v1 ^ v2 ^ v3;
95 }
96
adfs_checkmap(struct super_block * sb,struct adfs_discmap * dm)97 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
98 {
99 unsigned char crosscheck = 0, zonecheck = 1;
100 int i;
101
102 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
103 unsigned char *map;
104
105 map = dm[i].dm_bh->b_data;
106
107 if (adfs_calczonecheck(sb, map) != map[0]) {
108 adfs_error(sb, "zone %d fails zonecheck", i);
109 zonecheck = 0;
110 }
111 crosscheck ^= map[3];
112 }
113 if (crosscheck != 0xff)
114 adfs_error(sb, "crosscheck != 0xff");
115 return crosscheck == 0xff && zonecheck;
116 }
117
adfs_put_super(struct super_block * sb)118 static void adfs_put_super(struct super_block *sb)
119 {
120 int i;
121 struct adfs_sb_info *asb = ADFS_SB(sb);
122
123 for (i = 0; i < asb->s_map_size; i++)
124 brelse(asb->s_map[i].dm_bh);
125 kfree(asb->s_map);
126 kfree(asb);
127 sb->s_fs_info = NULL;
128 }
129
adfs_show_options(struct seq_file * seq,struct dentry * root)130 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
131 {
132 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
133
134 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
135 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
136 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
137 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
138 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
139 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
140 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
141 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
142 if (asb->s_ftsuffix != 0)
143 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
144
145 return 0;
146 }
147
148 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
149
150 static const match_table_t tokens = {
151 {Opt_uid, "uid=%u"},
152 {Opt_gid, "gid=%u"},
153 {Opt_ownmask, "ownmask=%o"},
154 {Opt_othmask, "othmask=%o"},
155 {Opt_ftsuffix, "ftsuffix=%u"},
156 {Opt_err, NULL}
157 };
158
parse_options(struct super_block * sb,char * options)159 static int parse_options(struct super_block *sb, char *options)
160 {
161 char *p;
162 struct adfs_sb_info *asb = ADFS_SB(sb);
163 int option;
164
165 if (!options)
166 return 0;
167
168 while ((p = strsep(&options, ",")) != NULL) {
169 substring_t args[MAX_OPT_ARGS];
170 int token;
171 if (!*p)
172 continue;
173
174 token = match_token(p, tokens, args);
175 switch (token) {
176 case Opt_uid:
177 if (match_int(args, &option))
178 return -EINVAL;
179 asb->s_uid = make_kuid(current_user_ns(), option);
180 if (!uid_valid(asb->s_uid))
181 return -EINVAL;
182 break;
183 case Opt_gid:
184 if (match_int(args, &option))
185 return -EINVAL;
186 asb->s_gid = make_kgid(current_user_ns(), option);
187 if (!gid_valid(asb->s_gid))
188 return -EINVAL;
189 break;
190 case Opt_ownmask:
191 if (match_octal(args, &option))
192 return -EINVAL;
193 asb->s_owner_mask = option;
194 break;
195 case Opt_othmask:
196 if (match_octal(args, &option))
197 return -EINVAL;
198 asb->s_other_mask = option;
199 break;
200 case Opt_ftsuffix:
201 if (match_int(args, &option))
202 return -EINVAL;
203 asb->s_ftsuffix = option;
204 break;
205 default:
206 printk("ADFS-fs: unrecognised mount option \"%s\" "
207 "or missing value\n", p);
208 return -EINVAL;
209 }
210 }
211 return 0;
212 }
213
adfs_remount(struct super_block * sb,int * flags,char * data)214 static int adfs_remount(struct super_block *sb, int *flags, char *data)
215 {
216 sync_filesystem(sb);
217 *flags |= MS_NODIRATIME;
218 return parse_options(sb, data);
219 }
220
adfs_statfs(struct dentry * dentry,struct kstatfs * buf)221 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
222 {
223 struct super_block *sb = dentry->d_sb;
224 struct adfs_sb_info *sbi = ADFS_SB(sb);
225 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
226
227 buf->f_type = ADFS_SUPER_MAGIC;
228 buf->f_namelen = sbi->s_namelen;
229 buf->f_bsize = sb->s_blocksize;
230 buf->f_blocks = sbi->s_size;
231 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
232 buf->f_bavail =
233 buf->f_bfree = adfs_map_free(sb);
234 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
235 buf->f_fsid.val[0] = (u32)id;
236 buf->f_fsid.val[1] = (u32)(id >> 32);
237
238 return 0;
239 }
240
241 static struct kmem_cache *adfs_inode_cachep;
242
adfs_alloc_inode(struct super_block * sb)243 static struct inode *adfs_alloc_inode(struct super_block *sb)
244 {
245 struct adfs_inode_info *ei;
246 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
247 if (!ei)
248 return NULL;
249 return &ei->vfs_inode;
250 }
251
adfs_i_callback(struct rcu_head * head)252 static void adfs_i_callback(struct rcu_head *head)
253 {
254 struct inode *inode = container_of(head, struct inode, i_rcu);
255 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
256 }
257
adfs_destroy_inode(struct inode * inode)258 static void adfs_destroy_inode(struct inode *inode)
259 {
260 call_rcu(&inode->i_rcu, adfs_i_callback);
261 }
262
init_once(void * foo)263 static void init_once(void *foo)
264 {
265 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
266
267 inode_init_once(&ei->vfs_inode);
268 }
269
init_inodecache(void)270 static int init_inodecache(void)
271 {
272 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
273 sizeof(struct adfs_inode_info),
274 0, (SLAB_RECLAIM_ACCOUNT|
275 SLAB_MEM_SPREAD),
276 init_once);
277 if (adfs_inode_cachep == NULL)
278 return -ENOMEM;
279 return 0;
280 }
281
destroy_inodecache(void)282 static void destroy_inodecache(void)
283 {
284 /*
285 * Make sure all delayed rcu free inodes are flushed before we
286 * destroy cache.
287 */
288 rcu_barrier();
289 kmem_cache_destroy(adfs_inode_cachep);
290 }
291
292 static const struct super_operations adfs_sops = {
293 .alloc_inode = adfs_alloc_inode,
294 .destroy_inode = adfs_destroy_inode,
295 .write_inode = adfs_write_inode,
296 .put_super = adfs_put_super,
297 .statfs = adfs_statfs,
298 .remount_fs = adfs_remount,
299 .show_options = adfs_show_options,
300 };
301
adfs_read_map(struct super_block * sb,struct adfs_discrecord * dr)302 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
303 {
304 struct adfs_discmap *dm;
305 unsigned int map_addr, zone_size, nzones;
306 int i, zone;
307 struct adfs_sb_info *asb = ADFS_SB(sb);
308
309 nzones = asb->s_map_size;
310 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
311 map_addr = (nzones >> 1) * zone_size -
312 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
313 map_addr = signed_asl(map_addr, asb->s_map2blk);
314
315 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
316
317 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
318 if (dm == NULL) {
319 adfs_error(sb, "not enough memory");
320 return NULL;
321 }
322
323 for (zone = 0; zone < nzones; zone++, map_addr++) {
324 dm[zone].dm_startbit = 0;
325 dm[zone].dm_endbit = zone_size;
326 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
327 dm[zone].dm_bh = sb_bread(sb, map_addr);
328
329 if (!dm[zone].dm_bh) {
330 adfs_error(sb, "unable to read map");
331 goto error_free;
332 }
333 }
334
335 /* adjust the limits for the first and last map zones */
336 i = zone - 1;
337 dm[0].dm_startblk = 0;
338 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
339 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
340 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
341 (ADFS_DR_SIZE_BITS - i * zone_size);
342
343 if (adfs_checkmap(sb, dm))
344 return dm;
345
346 adfs_error(sb, "map corrupted");
347
348 error_free:
349 while (--zone >= 0)
350 brelse(dm[zone].dm_bh);
351
352 kfree(dm);
353 return NULL;
354 }
355
adfs_discsize(struct adfs_discrecord * dr,int block_bits)356 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
357 {
358 unsigned long discsize;
359
360 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
361 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
362
363 return discsize;
364 }
365
adfs_fill_super(struct super_block * sb,void * data,int silent)366 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
367 {
368 struct adfs_discrecord *dr;
369 struct buffer_head *bh;
370 struct object_info root_obj;
371 unsigned char *b_data;
372 struct adfs_sb_info *asb;
373 struct inode *root;
374
375 sb->s_flags |= MS_NODIRATIME;
376
377 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
378 if (!asb)
379 return -ENOMEM;
380 sb->s_fs_info = asb;
381
382 /* set default options */
383 asb->s_uid = GLOBAL_ROOT_UID;
384 asb->s_gid = GLOBAL_ROOT_GID;
385 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
386 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
387 asb->s_ftsuffix = 0;
388
389 if (parse_options(sb, data))
390 goto error;
391
392 sb_set_blocksize(sb, BLOCK_SIZE);
393 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
394 adfs_error(sb, "unable to read superblock");
395 goto error;
396 }
397
398 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
399
400 if (adfs_checkbblk(b_data)) {
401 if (!silent)
402 printk("VFS: Can't find an adfs filesystem on dev "
403 "%s.\n", sb->s_id);
404 goto error_free_bh;
405 }
406
407 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
408
409 /*
410 * Do some sanity checks on the ADFS disc record
411 */
412 if (adfs_checkdiscrecord(dr)) {
413 if (!silent)
414 printk("VPS: Can't find an adfs filesystem on dev "
415 "%s.\n", sb->s_id);
416 goto error_free_bh;
417 }
418
419 brelse(bh);
420 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
421 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
422 if (!bh) {
423 adfs_error(sb, "couldn't read superblock on "
424 "2nd try.");
425 goto error;
426 }
427 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
428 if (adfs_checkbblk(b_data)) {
429 adfs_error(sb, "disc record mismatch, very weird!");
430 goto error_free_bh;
431 }
432 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
433 } else {
434 if (!silent)
435 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
436 "%s.\n", sb->s_id);
437 goto error;
438 }
439
440 /*
441 * blocksize on this device should now be set to the ADFS log2secsize
442 */
443
444 sb->s_magic = ADFS_SUPER_MAGIC;
445 asb->s_idlen = dr->idlen;
446 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
447 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
448 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
449 asb->s_version = dr->format_version;
450 asb->s_log2sharesize = dr->log2sharesize;
451
452 asb->s_map = adfs_read_map(sb, dr);
453 if (!asb->s_map)
454 goto error_free_bh;
455
456 brelse(bh);
457
458 /*
459 * set up enough so that we can read an inode
460 */
461 sb->s_op = &adfs_sops;
462
463 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
464
465 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
466 root_obj.name_len = 0;
467 /* Set root object date as 01 Jan 1987 00:00:00 */
468 root_obj.loadaddr = 0xfff0003f;
469 root_obj.execaddr = 0xec22c000;
470 root_obj.size = ADFS_NEWDIR_SIZE;
471 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
472 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
473 root_obj.filetype = -1;
474
475 /*
476 * If this is a F+ disk with variable length directories,
477 * get the root_size from the disc record.
478 */
479 if (asb->s_version) {
480 root_obj.size = le32_to_cpu(dr->root_size);
481 asb->s_dir = &adfs_fplus_dir_ops;
482 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
483 } else {
484 asb->s_dir = &adfs_f_dir_ops;
485 asb->s_namelen = ADFS_F_NAME_LEN;
486 }
487 /*
488 * ,xyz hex filetype suffix may be added by driver
489 * to files that have valid RISC OS filetype
490 */
491 if (asb->s_ftsuffix)
492 asb->s_namelen += 4;
493
494 sb->s_d_op = &adfs_dentry_operations;
495 root = adfs_iget(sb, &root_obj);
496 sb->s_root = d_make_root(root);
497 if (!sb->s_root) {
498 int i;
499 for (i = 0; i < asb->s_map_size; i++)
500 brelse(asb->s_map[i].dm_bh);
501 kfree(asb->s_map);
502 adfs_error(sb, "get root inode failed\n");
503 goto error;
504 }
505 return 0;
506
507 error_free_bh:
508 brelse(bh);
509 error:
510 sb->s_fs_info = NULL;
511 kfree(asb);
512 return -EINVAL;
513 }
514
adfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)515 static struct dentry *adfs_mount(struct file_system_type *fs_type,
516 int flags, const char *dev_name, void *data)
517 {
518 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
519 }
520
521 static struct file_system_type adfs_fs_type = {
522 .owner = THIS_MODULE,
523 .name = "adfs",
524 .mount = adfs_mount,
525 .kill_sb = kill_block_super,
526 .fs_flags = FS_REQUIRES_DEV,
527 };
528 MODULE_ALIAS_FS("adfs");
529
init_adfs_fs(void)530 static int __init init_adfs_fs(void)
531 {
532 int err = init_inodecache();
533 if (err)
534 goto out1;
535 err = register_filesystem(&adfs_fs_type);
536 if (err)
537 goto out;
538 return 0;
539 out:
540 destroy_inodecache();
541 out1:
542 return err;
543 }
544
exit_adfs_fs(void)545 static void __exit exit_adfs_fs(void)
546 {
547 unregister_filesystem(&adfs_fs_type);
548 destroy_inodecache();
549 }
550
551 module_init(init_adfs_fs)
552 module_exit(exit_adfs_fs)
553 MODULE_LICENSE("GPL");
554