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/smp_lock.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
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
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
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
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
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 lock_kernel();
123
124 for (i = 0; i < asb->s_map_size; i++)
125 brelse(asb->s_map[i].dm_bh);
126 kfree(asb->s_map);
127 kfree(asb);
128 sb->s_fs_info = NULL;
129
130 unlock_kernel();
131 }
132
133 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
134 {
135 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb);
136
137 if (asb->s_uid != 0)
138 seq_printf(seq, ",uid=%u", asb->s_uid);
139 if (asb->s_gid != 0)
140 seq_printf(seq, ",gid=%u", asb->s_gid);
141 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
142 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
143 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
144 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
145
146 return 0;
147 }
148
149 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
150
151 static const match_table_t tokens = {
152 {Opt_uid, "uid=%u"},
153 {Opt_gid, "gid=%u"},
154 {Opt_ownmask, "ownmask=%o"},
155 {Opt_othmask, "othmask=%o"},
156 {Opt_err, NULL}
157 };
158
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 = option;
180 break;
181 case Opt_gid:
182 if (match_int(args, &option))
183 return -EINVAL;
184 asb->s_gid = option;
185 break;
186 case Opt_ownmask:
187 if (match_octal(args, &option))
188 return -EINVAL;
189 asb->s_owner_mask = option;
190 break;
191 case Opt_othmask:
192 if (match_octal(args, &option))
193 return -EINVAL;
194 asb->s_other_mask = option;
195 break;
196 default:
197 printk("ADFS-fs: unrecognised mount option \"%s\" "
198 "or missing value\n", p);
199 return -EINVAL;
200 }
201 }
202 return 0;
203 }
204
205 static int adfs_remount(struct super_block *sb, int *flags, char *data)
206 {
207 *flags |= MS_NODIRATIME;
208 return parse_options(sb, data);
209 }
210
211 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
212 {
213 struct super_block *sb = dentry->d_sb;
214 struct adfs_sb_info *sbi = ADFS_SB(sb);
215 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
216
217 buf->f_type = ADFS_SUPER_MAGIC;
218 buf->f_namelen = sbi->s_namelen;
219 buf->f_bsize = sb->s_blocksize;
220 buf->f_blocks = sbi->s_size;
221 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
222 buf->f_bavail =
223 buf->f_bfree = adfs_map_free(sb);
224 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
225 buf->f_fsid.val[0] = (u32)id;
226 buf->f_fsid.val[1] = (u32)(id >> 32);
227
228 return 0;
229 }
230
231 static struct kmem_cache *adfs_inode_cachep;
232
233 static struct inode *adfs_alloc_inode(struct super_block *sb)
234 {
235 struct adfs_inode_info *ei;
236 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
237 if (!ei)
238 return NULL;
239 return &ei->vfs_inode;
240 }
241
242 static void adfs_destroy_inode(struct inode *inode)
243 {
244 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
245 }
246
247 static void init_once(void *foo)
248 {
249 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
250
251 inode_init_once(&ei->vfs_inode);
252 }
253
254 static int init_inodecache(void)
255 {
256 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
257 sizeof(struct adfs_inode_info),
258 0, (SLAB_RECLAIM_ACCOUNT|
259 SLAB_MEM_SPREAD),
260 init_once);
261 if (adfs_inode_cachep == NULL)
262 return -ENOMEM;
263 return 0;
264 }
265
266 static void destroy_inodecache(void)
267 {
268 kmem_cache_destroy(adfs_inode_cachep);
269 }
270
271 static const struct super_operations adfs_sops = {
272 .alloc_inode = adfs_alloc_inode,
273 .destroy_inode = adfs_destroy_inode,
274 .write_inode = adfs_write_inode,
275 .put_super = adfs_put_super,
276 .statfs = adfs_statfs,
277 .remount_fs = adfs_remount,
278 .show_options = adfs_show_options,
279 };
280
281 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
282 {
283 struct adfs_discmap *dm;
284 unsigned int map_addr, zone_size, nzones;
285 int i, zone;
286 struct adfs_sb_info *asb = ADFS_SB(sb);
287
288 nzones = asb->s_map_size;
289 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
290 map_addr = (nzones >> 1) * zone_size -
291 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
292 map_addr = signed_asl(map_addr, asb->s_map2blk);
293
294 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
295
296 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
297 if (dm == NULL) {
298 adfs_error(sb, "not enough memory");
299 return NULL;
300 }
301
302 for (zone = 0; zone < nzones; zone++, map_addr++) {
303 dm[zone].dm_startbit = 0;
304 dm[zone].dm_endbit = zone_size;
305 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
306 dm[zone].dm_bh = sb_bread(sb, map_addr);
307
308 if (!dm[zone].dm_bh) {
309 adfs_error(sb, "unable to read map");
310 goto error_free;
311 }
312 }
313
314 /* adjust the limits for the first and last map zones */
315 i = zone - 1;
316 dm[0].dm_startblk = 0;
317 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
318 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
319 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
320 (ADFS_DR_SIZE_BITS - i * zone_size);
321
322 if (adfs_checkmap(sb, dm))
323 return dm;
324
325 adfs_error(sb, "map corrupted");
326
327 error_free:
328 while (--zone >= 0)
329 brelse(dm[zone].dm_bh);
330
331 kfree(dm);
332 return NULL;
333 }
334
335 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
336 {
337 unsigned long discsize;
338
339 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
340 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
341
342 return discsize;
343 }
344
345 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
346 {
347 struct adfs_discrecord *dr;
348 struct buffer_head *bh;
349 struct object_info root_obj;
350 unsigned char *b_data;
351 struct adfs_sb_info *asb;
352 struct inode *root;
353
354 sb->s_flags |= MS_NODIRATIME;
355
356 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
357 if (!asb)
358 return -ENOMEM;
359 sb->s_fs_info = asb;
360
361 /* set default options */
362 asb->s_uid = 0;
363 asb->s_gid = 0;
364 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
365 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
366
367 if (parse_options(sb, data))
368 goto error;
369
370 sb_set_blocksize(sb, BLOCK_SIZE);
371 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
372 adfs_error(sb, "unable to read superblock");
373 goto error;
374 }
375
376 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
377
378 if (adfs_checkbblk(b_data)) {
379 if (!silent)
380 printk("VFS: Can't find an adfs filesystem on dev "
381 "%s.\n", sb->s_id);
382 goto error_free_bh;
383 }
384
385 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
386
387 /*
388 * Do some sanity checks on the ADFS disc record
389 */
390 if (adfs_checkdiscrecord(dr)) {
391 if (!silent)
392 printk("VPS: Can't find an adfs filesystem on dev "
393 "%s.\n", sb->s_id);
394 goto error_free_bh;
395 }
396
397 brelse(bh);
398 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
399 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
400 if (!bh) {
401 adfs_error(sb, "couldn't read superblock on "
402 "2nd try.");
403 goto error;
404 }
405 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
406 if (adfs_checkbblk(b_data)) {
407 adfs_error(sb, "disc record mismatch, very weird!");
408 goto error_free_bh;
409 }
410 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
411 } else {
412 if (!silent)
413 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
414 "%s.\n", sb->s_id);
415 goto error;
416 }
417
418 /*
419 * blocksize on this device should now be set to the ADFS log2secsize
420 */
421
422 sb->s_magic = ADFS_SUPER_MAGIC;
423 asb->s_idlen = dr->idlen;
424 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
425 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
426 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
427 asb->s_version = dr->format_version;
428 asb->s_log2sharesize = dr->log2sharesize;
429
430 asb->s_map = adfs_read_map(sb, dr);
431 if (!asb->s_map)
432 goto error_free_bh;
433
434 brelse(bh);
435
436 /*
437 * set up enough so that we can read an inode
438 */
439 sb->s_op = &adfs_sops;
440
441 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
442
443 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
444 root_obj.name_len = 0;
445 root_obj.loadaddr = 0;
446 root_obj.execaddr = 0;
447 root_obj.size = ADFS_NEWDIR_SIZE;
448 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
449 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
450
451 /*
452 * If this is a F+ disk with variable length directories,
453 * get the root_size from the disc record.
454 */
455 if (asb->s_version) {
456 root_obj.size = le32_to_cpu(dr->root_size);
457 asb->s_dir = &adfs_fplus_dir_ops;
458 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
459 } else {
460 asb->s_dir = &adfs_f_dir_ops;
461 asb->s_namelen = ADFS_F_NAME_LEN;
462 }
463
464 root = adfs_iget(sb, &root_obj);
465 sb->s_root = d_alloc_root(root);
466 if (!sb->s_root) {
467 int i;
468 iput(root);
469 for (i = 0; i < asb->s_map_size; i++)
470 brelse(asb->s_map[i].dm_bh);
471 kfree(asb->s_map);
472 adfs_error(sb, "get root inode failed\n");
473 goto error;
474 } else
475 sb->s_root->d_op = &adfs_dentry_operations;
476 return 0;
477
478 error_free_bh:
479 brelse(bh);
480 error:
481 sb->s_fs_info = NULL;
482 kfree(asb);
483 return -EINVAL;
484 }
485
486 static int adfs_get_sb(struct file_system_type *fs_type,
487 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
488 {
489 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
490 mnt);
491 }
492
493 static struct file_system_type adfs_fs_type = {
494 .owner = THIS_MODULE,
495 .name = "adfs",
496 .get_sb = adfs_get_sb,
497 .kill_sb = kill_block_super,
498 .fs_flags = FS_REQUIRES_DEV,
499 };
500
501 static int __init init_adfs_fs(void)
502 {
503 int err = init_inodecache();
504 if (err)
505 goto out1;
506 err = register_filesystem(&adfs_fs_type);
507 if (err)
508 goto out;
509 return 0;
510 out:
511 destroy_inodecache();
512 out1:
513 return err;
514 }
515
516 static void __exit exit_adfs_fs(void)
517 {
518 unregister_filesystem(&adfs_fs_type);
519 destroy_inodecache();
520 }
521
522 module_init(init_adfs_fs)
523 module_exit(exit_adfs_fs)
524 MODULE_LICENSE("GPL");
525
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