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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / fs / adfs / super.c
blob9e421eeb672bed6ae53f85ff9a4eaf7cdcf92c92
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/errno.h>
12 #include <linux/fs.h>
13 #include <linux/adfs_fs.h>
14 #include <linux/slab.h>
15 #include <linux/time.h>
16 #include <linux/stat.h>
17 #include <linux/string.h>
18 #include <linux/init.h>
19 #include <linux/buffer_head.h>
20 #include <linux/vfs.h>
21 #include <linux/parser.h>
22 #include <linux/bitops.h>
23 #include <linux/mount.h>
24 #include <linux/seq_file.h>
25
26 #include <asm/uaccess.h>
27 #include <asm/system.h>
28
29 #include <stdarg.h>
30
31 #include "adfs.h"
32 #include "dir_f.h"
33 #include "dir_fplus.h"
34
35 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
36 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
37
38 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
39 {
40 char error_buf[128];
41 va_list args;
42
43 va_start(args, fmt);
44 vsnprintf(error_buf, sizeof(error_buf), fmt, args);
45 va_end(args);
46
47 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
48 sb->s_id, function ? ": " : "",
49 function ? function : "", error_buf);
50 }
51
52 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
53 {
54 int i;
55
56 /* sector size must be 256, 512 or 1024 bytes */
57 if (dr->log2secsize != 8 &&
58 dr->log2secsize != 9 &&
59 dr->log2secsize != 10)
60 return 1;
61
62 /* idlen must be at least log2secsize + 3 */
63 if (dr->idlen < dr->log2secsize + 3)
64 return 1;
65
66 /* we cannot have such a large disc that we
67 * are unable to represent sector offsets in
68 * 32 bits. This works out at 2.0 TB.
69 */
70 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
71 return 1;
72
73 /* idlen must be no greater than 19 v2 [1.0] */
74 if (dr->idlen > 19)
75 return 1;
76
77 /* reserved bytes should be zero */
78 for (i = 0; i < sizeof(dr->unused52); i++)
79 if (dr->unused52[i] != 0)
80 return 1;
81
82 return 0;
83 }
84
85 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
86 {
87 unsigned int v0, v1, v2, v3;
88 int i;
89
90 v0 = v1 = v2 = v3 = 0;
91 for (i = sb->s_blocksize - 4; i; i -= 4) {
92 v0 += map[i] + (v3 >> 8);
93 v3 &= 0xff;
94 v1 += map[i + 1] + (v0 >> 8);
95 v0 &= 0xff;
96 v2 += map[i + 2] + (v1 >> 8);
97 v1 &= 0xff;
98 v3 += map[i + 3] + (v2 >> 8);
99 v2 &= 0xff;
100 }
101 v0 += v3 >> 8;
102 v1 += map[1] + (v0 >> 8);
103 v2 += map[2] + (v1 >> 8);
104 v3 += map[3] + (v2 >> 8);
105
106 return v0 ^ v1 ^ v2 ^ v3;
107 }
108
109 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
110 {
111 unsigned char crosscheck = 0, zonecheck = 1;
112 int i;
113
114 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
115 unsigned char *map;
116
117 map = dm[i].dm_bh->b_data;
118
119 if (adfs_calczonecheck(sb, map) != map[0]) {
120 adfs_error(sb, "zone %d fails zonecheck", i);
121 zonecheck = 0;
122 }
123 crosscheck ^= map[3];
124 }
125 if (crosscheck != 0xff)
126 adfs_error(sb, "crosscheck != 0xff");
127 return crosscheck == 0xff && zonecheck;
128 }
129
130 static void adfs_put_super(struct super_block *sb)
131 {
132 int i;
133 struct adfs_sb_info *asb = ADFS_SB(sb);
134
135 for (i = 0; i < asb->s_map_size; i++)
136 brelse(asb->s_map[i].dm_bh);
137 kfree(asb->s_map);
138 kfree(asb);
139 sb->s_fs_info = NULL;
140 }
141
142 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
143 {
144 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb);
145
146 if (asb->s_uid != 0)
147 seq_printf(seq, ",uid=%u", asb->s_uid);
148 if (asb->s_gid != 0)
149 seq_printf(seq, ",gid=%u", asb->s_gid);
150 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
151 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
152 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
153 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
154
155 return 0;
156 }
157
158 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
159
160 static match_table_t tokens = {
161 {Opt_uid, "uid=%u"},
162 {Opt_gid, "gid=%u"},
163 {Opt_ownmask, "ownmask=%o"},
164 {Opt_othmask, "othmask=%o"},
165 {Opt_err, NULL}
166 };
167
168 static int parse_options(struct super_block *sb, char *options)
169 {
170 char *p;
171 struct adfs_sb_info *asb = ADFS_SB(sb);
172 int option;
173
174 if (!options)
175 return 0;
176
177 while ((p = strsep(&options, ",")) != NULL) {
178 substring_t args[MAX_OPT_ARGS];
179 int token;
180 if (!*p)
181 continue;
182
183 token = match_token(p, tokens, args);
184 switch (token) {
185 case Opt_uid:
186 if (match_int(args, &option))
187 return -EINVAL;
188 asb->s_uid = option;
189 break;
190 case Opt_gid:
191 if (match_int(args, &option))
192 return -EINVAL;
193 asb->s_gid = option;
194 break;
195 case Opt_ownmask:
196 if (match_octal(args, &option))
197 return -EINVAL;
198 asb->s_owner_mask = option;
199 break;
200 case Opt_othmask:
201 if (match_octal(args, &option))
202 return -EINVAL;
203 asb->s_other_mask = 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
214 static int adfs_remount(struct super_block *sb, int *flags, char *data)
215 {
216 *flags |= MS_NODIRATIME;
217 return parse_options(sb, data);
218 }
219
220 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
221 {
222 struct adfs_sb_info *asb = ADFS_SB(dentry->d_sb);
223
224 buf->f_type = ADFS_SUPER_MAGIC;
225 buf->f_namelen = asb->s_namelen;
226 buf->f_bsize = dentry->d_sb->s_blocksize;
227 buf->f_blocks = asb->s_size;
228 buf->f_files = asb->s_ids_per_zone * asb->s_map_size;
229 buf->f_bavail =
230 buf->f_bfree = adfs_map_free(dentry->d_sb);
231 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
232
233 return 0;
234 }
235
236 static struct kmem_cache *adfs_inode_cachep;
237
238 static struct inode *adfs_alloc_inode(struct super_block *sb)
239 {
240 struct adfs_inode_info *ei;
241 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
242 if (!ei)
243 return NULL;
244 return &ei->vfs_inode;
245 }
246
247 static void adfs_destroy_inode(struct inode *inode)
248 {
249 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
250 }
251
252 static void init_once(struct kmem_cache *cachep, void *foo)
253 {
254 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
255
256 inode_init_once(&ei->vfs_inode);
257 }
258
259 static int init_inodecache(void)
260 {
261 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
262 sizeof(struct adfs_inode_info),
263 0, (SLAB_RECLAIM_ACCOUNT|
264 SLAB_MEM_SPREAD),
265 init_once);
266 if (adfs_inode_cachep == NULL)
267 return -ENOMEM;
268 return 0;
269 }
270
271 static void destroy_inodecache(void)
272 {
273 kmem_cache_destroy(adfs_inode_cachep);
274 }
275
276 static const struct super_operations adfs_sops = {
277 .alloc_inode = adfs_alloc_inode,
278 .destroy_inode = adfs_destroy_inode,
279 .write_inode = adfs_write_inode,
280 .put_super = adfs_put_super,
281 .statfs = adfs_statfs,
282 .remount_fs = adfs_remount,
283 .show_options = adfs_show_options,
284 };
285
286 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
287 {
288 struct adfs_discmap *dm;
289 unsigned int map_addr, zone_size, nzones;
290 int i, zone;
291 struct adfs_sb_info *asb = ADFS_SB(sb);
292
293 nzones = asb->s_map_size;
294 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
295 map_addr = (nzones >> 1) * zone_size -
296 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
297 map_addr = signed_asl(map_addr, asb->s_map2blk);
298
299 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
300
301 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
302 if (dm == NULL) {
303 adfs_error(sb, "not enough memory");
304 return NULL;
305 }
306
307 for (zone = 0; zone < nzones; zone++, map_addr++) {
308 dm[zone].dm_startbit = 0;
309 dm[zone].dm_endbit = zone_size;
310 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
311 dm[zone].dm_bh = sb_bread(sb, map_addr);
312
313 if (!dm[zone].dm_bh) {
314 adfs_error(sb, "unable to read map");
315 goto error_free;
316 }
317 }
318
319 /* adjust the limits for the first and last map zones */
320 i = zone - 1;
321 dm[0].dm_startblk = 0;
322 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
323 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
324 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
325 (ADFS_DR_SIZE_BITS - i * zone_size);
326
327 if (adfs_checkmap(sb, dm))
328 return dm;
329
330 adfs_error(sb, "map corrupted");
331
332 error_free:
333 while (--zone >= 0)
334 brelse(dm[zone].dm_bh);
335
336 kfree(dm);
337 return NULL;
338 }
339
340 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
341 {
342 unsigned long discsize;
343
344 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
345 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
346
347 return discsize;
348 }
349
350 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
351 {
352 struct adfs_discrecord *dr;
353 struct buffer_head *bh;
354 struct object_info root_obj;
355 unsigned char *b_data;
356 struct adfs_sb_info *asb;
357 struct inode *root;
358
359 sb->s_flags |= MS_NODIRATIME;
360
361 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
362 if (!asb)
363 return -ENOMEM;
364 sb->s_fs_info = asb;
365
366 /* set default options */
367 asb->s_uid = 0;
368 asb->s_gid = 0;
369 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
370 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
371
372 if (parse_options(sb, data))
373 goto error;
374
375 sb_set_blocksize(sb, BLOCK_SIZE);
376 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
377 adfs_error(sb, "unable to read superblock");
378 goto error;
379 }
380
381 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
382
383 if (adfs_checkbblk(b_data)) {
384 if (!silent)
385 printk("VFS: Can't find an adfs filesystem on dev "
386 "%s.\n", sb->s_id);
387 goto error_free_bh;
388 }
389
390 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
391
392 /*
393 * Do some sanity checks on the ADFS disc record
394 */
395 if (adfs_checkdiscrecord(dr)) {
396 if (!silent)
397 printk("VPS: Can't find an adfs filesystem on dev "
398 "%s.\n", sb->s_id);
399 goto error_free_bh;
400 }
401
402 brelse(bh);
403 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
404 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
405 if (!bh) {
406 adfs_error(sb, "couldn't read superblock on "
407 "2nd try.");
408 goto error;
409 }
410 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
411 if (adfs_checkbblk(b_data)) {
412 adfs_error(sb, "disc record mismatch, very weird!");
413 goto error_free_bh;
414 }
415 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
416 } else {
417 if (!silent)
418 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
419 "%s.\n", sb->s_id);
420 goto error;
421 }
422
423 /*
424 * blocksize on this device should now be set to the ADFS log2secsize
425 */
426
427 sb->s_magic = ADFS_SUPER_MAGIC;
428 asb->s_idlen = dr->idlen;
429 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
430 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
431 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
432 asb->s_version = dr->format_version;
433 asb->s_log2sharesize = dr->log2sharesize;
434
435 asb->s_map = adfs_read_map(sb, dr);
436 if (!asb->s_map)
437 goto error_free_bh;
438
439 brelse(bh);
440
441 /*
442 * set up enough so that we can read an inode
443 */
444 sb->s_op = &adfs_sops;
445
446 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
447
448 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
449 root_obj.name_len = 0;
450 root_obj.loadaddr = 0;
451 root_obj.execaddr = 0;
452 root_obj.size = ADFS_NEWDIR_SIZE;
453 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
454 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
455
456 /*
457 * If this is a F+ disk with variable length directories,
458 * get the root_size from the disc record.
459 */
460 if (asb->s_version) {
461 root_obj.size = le32_to_cpu(dr->root_size);
462 asb->s_dir = &adfs_fplus_dir_ops;
463 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
464 } else {
465 asb->s_dir = &adfs_f_dir_ops;
466 asb->s_namelen = ADFS_F_NAME_LEN;
467 }
468
469 root = adfs_iget(sb, &root_obj);
470 sb->s_root = d_alloc_root(root);
471 if (!sb->s_root) {
472 int i;
473 iput(root);
474 for (i = 0; i < asb->s_map_size; i++)
475 brelse(asb->s_map[i].dm_bh);
476 kfree(asb->s_map);
477 adfs_error(sb, "get root inode failed\n");
478 goto error;
479 } else
480 sb->s_root->d_op = &adfs_dentry_operations;
481 return 0;
482
483 error_free_bh:
484 brelse(bh);
485 error:
486 sb->s_fs_info = NULL;
487 kfree(asb);
488 return -EINVAL;
489 }
490
491 static int adfs_get_sb(struct file_system_type *fs_type,
492 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
493 {
494 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
495 mnt);
496 }
497
498 static struct file_system_type adfs_fs_type = {
499 .owner = THIS_MODULE,
500 .name = "adfs",
501 .get_sb = adfs_get_sb,
502 .kill_sb = kill_block_super,
503 .fs_flags = FS_REQUIRES_DEV,
504 };
505
506 static int __init init_adfs_fs(void)
507 {
508 int err = init_inodecache();
509 if (err)
510 goto out1;
511 err = register_filesystem(&adfs_fs_type);
512 if (err)
513 goto out;
514 return 0;
515 out:
516 destroy_inodecache();
517 out1:
518 return err;
519 }
520
521 static void __exit exit_adfs_fs(void)
522 {
523 unregister_filesystem(&adfs_fs_type);
524 destroy_inodecache();
525 }
526
527 module_init(init_adfs_fs)
528 module_exit(exit_adfs_fs)
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