blob: 243963228d10e98572fa8d7de34effc412bc0129 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
24#include <asm/uaccess.h>
25#include <asm/system.h>
26
27#include <stdarg.h>
28
29#include "adfs.h"
30#include "dir_f.h"
31#include "dir_fplus.h"
32
33void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
34{
35 char error_buf[128];
36 va_list args;
37
38 va_start(args, fmt);
39 vsprintf(error_buf, fmt, args);
40 va_end(args);
41
42 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
43 sb->s_id, function ? ": " : "",
44 function ? function : "", error_buf);
45}
46
47static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
48{
49 int i;
50
51 /* sector size must be 256, 512 or 1024 bytes */
52 if (dr->log2secsize != 8 &&
53 dr->log2secsize != 9 &&
54 dr->log2secsize != 10)
55 return 1;
56
57 /* idlen must be at least log2secsize + 3 */
58 if (dr->idlen < dr->log2secsize + 3)
59 return 1;
60
61 /* we cannot have such a large disc that we
62 * are unable to represent sector offsets in
63 * 32 bits. This works out at 2.0 TB.
64 */
65 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
66 return 1;
67
68 /* idlen must be no greater than 19 v2 [1.0] */
69 if (dr->idlen > 19)
70 return 1;
71
72 /* reserved bytes should be zero */
73 for (i = 0; i < sizeof(dr->unused52); i++)
74 if (dr->unused52[i] != 0)
75 return 1;
76
77 return 0;
78}
79
80static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
81{
82 unsigned int v0, v1, v2, v3;
83 int i;
84
85 v0 = v1 = v2 = v3 = 0;
86 for (i = sb->s_blocksize - 4; i; i -= 4) {
87 v0 += map[i] + (v3 >> 8);
88 v3 &= 0xff;
89 v1 += map[i + 1] + (v0 >> 8);
90 v0 &= 0xff;
91 v2 += map[i + 2] + (v1 >> 8);
92 v1 &= 0xff;
93 v3 += map[i + 3] + (v2 >> 8);
94 v2 &= 0xff;
95 }
96 v0 += v3 >> 8;
97 v1 += map[1] + (v0 >> 8);
98 v2 += map[2] + (v1 >> 8);
99 v3 += map[3] + (v2 >> 8);
100
101 return v0 ^ v1 ^ v2 ^ v3;
102}
103
104static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
105{
106 unsigned char crosscheck = 0, zonecheck = 1;
107 int i;
108
109 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
110 unsigned char *map;
111
112 map = dm[i].dm_bh->b_data;
113
114 if (adfs_calczonecheck(sb, map) != map[0]) {
115 adfs_error(sb, "zone %d fails zonecheck", i);
116 zonecheck = 0;
117 }
118 crosscheck ^= map[3];
119 }
120 if (crosscheck != 0xff)
121 adfs_error(sb, "crosscheck != 0xff");
122 return crosscheck == 0xff && zonecheck;
123}
124
125static void adfs_put_super(struct super_block *sb)
126{
127 int i;
128 struct adfs_sb_info *asb = ADFS_SB(sb);
129
130 for (i = 0; i < asb->s_map_size; i++)
131 brelse(asb->s_map[i].dm_bh);
132 kfree(asb->s_map);
133 kfree(asb);
134 sb->s_fs_info = NULL;
135}
136
137enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
138
139static match_table_t tokens = {
140 {Opt_uid, "uid=%u"},
141 {Opt_gid, "gid=%u"},
142 {Opt_ownmask, "ownmask=%o"},
143 {Opt_othmask, "othmask=%o"},
144 {Opt_err, NULL}
145};
146
147static int parse_options(struct super_block *sb, char *options)
148{
149 char *p;
150 struct adfs_sb_info *asb = ADFS_SB(sb);
151 int option;
152
153 if (!options)
154 return 0;
155
156 while ((p = strsep(&options, ",")) != NULL) {
157 substring_t args[MAX_OPT_ARGS];
158 int token;
159 if (!*p)
160 continue;
161
162 token = match_token(p, tokens, args);
163 switch (token) {
164 case Opt_uid:
165 if (match_int(args, &option))
166 return -EINVAL;
167 asb->s_uid = option;
168 break;
169 case Opt_gid:
170 if (match_int(args, &option))
171 return -EINVAL;
172 asb->s_gid = option;
173 break;
174 case Opt_ownmask:
175 if (match_octal(args, &option))
176 return -EINVAL;
177 asb->s_owner_mask = option;
178 break;
179 case Opt_othmask:
180 if (match_octal(args, &option))
181 return -EINVAL;
182 asb->s_other_mask = option;
183 break;
184 default:
185 printk("ADFS-fs: unrecognised mount option \"%s\" "
186 "or missing value\n", p);
187 return -EINVAL;
188 }
189 }
190 return 0;
191}
192
193static int adfs_remount(struct super_block *sb, int *flags, char *data)
194{
195 *flags |= MS_NODIRATIME;
196 return parse_options(sb, data);
197}
198
199static int adfs_statfs(struct super_block *sb, struct kstatfs *buf)
200{
201 struct adfs_sb_info *asb = ADFS_SB(sb);
202
203 buf->f_type = ADFS_SUPER_MAGIC;
204 buf->f_namelen = asb->s_namelen;
205 buf->f_bsize = sb->s_blocksize;
206 buf->f_blocks = asb->s_size;
207 buf->f_files = asb->s_ids_per_zone * asb->s_map_size;
208 buf->f_bavail =
209 buf->f_bfree = adfs_map_free(sb);
210 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
211
212 return 0;
213}
214
215static kmem_cache_t *adfs_inode_cachep;
216
217static struct inode *adfs_alloc_inode(struct super_block *sb)
218{
219 struct adfs_inode_info *ei;
220 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, SLAB_KERNEL);
221 if (!ei)
222 return NULL;
223 return &ei->vfs_inode;
224}
225
226static void adfs_destroy_inode(struct inode *inode)
227{
228 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
229}
230
231static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
232{
233 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
234
235 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
236 SLAB_CTOR_CONSTRUCTOR)
237 inode_init_once(&ei->vfs_inode);
238}
239
240static int init_inodecache(void)
241{
242 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
243 sizeof(struct adfs_inode_info),
244 0, SLAB_RECLAIM_ACCOUNT,
245 init_once, NULL);
246 if (adfs_inode_cachep == NULL)
247 return -ENOMEM;
248 return 0;
249}
250
251static void destroy_inodecache(void)
252{
253 if (kmem_cache_destroy(adfs_inode_cachep))
254 printk(KERN_INFO "adfs_inode_cache: not all structures were freed\n");
255}
256
257static struct super_operations adfs_sops = {
258 .alloc_inode = adfs_alloc_inode,
259 .destroy_inode = adfs_destroy_inode,
260 .write_inode = adfs_write_inode,
261 .put_super = adfs_put_super,
262 .statfs = adfs_statfs,
263 .remount_fs = adfs_remount,
264};
265
266static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
267{
268 struct adfs_discmap *dm;
269 unsigned int map_addr, zone_size, nzones;
270 int i, zone;
271 struct adfs_sb_info *asb = ADFS_SB(sb);
272
273 nzones = asb->s_map_size;
274 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
275 map_addr = (nzones >> 1) * zone_size -
276 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
277 map_addr = signed_asl(map_addr, asb->s_map2blk);
278
279 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
280
281 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
282 if (dm == NULL) {
283 adfs_error(sb, "not enough memory");
284 return NULL;
285 }
286
287 for (zone = 0; zone < nzones; zone++, map_addr++) {
288 dm[zone].dm_startbit = 0;
289 dm[zone].dm_endbit = zone_size;
290 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
291 dm[zone].dm_bh = sb_bread(sb, map_addr);
292
293 if (!dm[zone].dm_bh) {
294 adfs_error(sb, "unable to read map");
295 goto error_free;
296 }
297 }
298
299 /* adjust the limits for the first and last map zones */
300 i = zone - 1;
301 dm[0].dm_startblk = 0;
302 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
303 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
304 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
305 (ADFS_DR_SIZE_BITS - i * zone_size);
306
307 if (adfs_checkmap(sb, dm))
308 return dm;
309
310 adfs_error(sb, NULL, "map corrupted");
311
312error_free:
313 while (--zone >= 0)
314 brelse(dm[zone].dm_bh);
315
316 kfree(dm);
317 return NULL;
318}
319
320static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
321{
322 unsigned long discsize;
323
324 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
325 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
326
327 return discsize;
328}
329
330static int adfs_fill_super(struct super_block *sb, void *data, int silent)
331{
332 struct adfs_discrecord *dr;
333 struct buffer_head *bh;
334 struct object_info root_obj;
335 unsigned char *b_data;
336 struct adfs_sb_info *asb;
337 struct inode *root;
338
339 sb->s_flags |= MS_NODIRATIME;
340
341 asb = kmalloc(sizeof(*asb), GFP_KERNEL);
342 if (!asb)
343 return -ENOMEM;
344 sb->s_fs_info = asb;
345 memset(asb, 0, sizeof(*asb));
346
347 /* set default options */
348 asb->s_uid = 0;
349 asb->s_gid = 0;
350 asb->s_owner_mask = S_IRWXU;
351 asb->s_other_mask = S_IRWXG | S_IRWXO;
352
353 if (parse_options(sb, data))
354 goto error;
355
356 sb_set_blocksize(sb, BLOCK_SIZE);
357 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
358 adfs_error(sb, "unable to read superblock");
359 goto error;
360 }
361
362 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
363
364 if (adfs_checkbblk(b_data)) {
365 if (!silent)
366 printk("VFS: Can't find an adfs filesystem on dev "
367 "%s.\n", sb->s_id);
368 goto error_free_bh;
369 }
370
371 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
372
373 /*
374 * Do some sanity checks on the ADFS disc record
375 */
376 if (adfs_checkdiscrecord(dr)) {
377 if (!silent)
378 printk("VPS: Can't find an adfs filesystem on dev "
379 "%s.\n", sb->s_id);
380 goto error_free_bh;
381 }
382
383 brelse(bh);
384 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
385 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
386 if (!bh) {
387 adfs_error(sb, "couldn't read superblock on "
388 "2nd try.");
389 goto error;
390 }
391 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
392 if (adfs_checkbblk(b_data)) {
393 adfs_error(sb, "disc record mismatch, very weird!");
394 goto error_free_bh;
395 }
396 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
397 } else {
398 if (!silent)
399 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
400 "%s.\n", sb->s_id);
401 goto error;
402 }
403
404 /*
405 * blocksize on this device should now be set to the ADFS log2secsize
406 */
407
408 sb->s_magic = ADFS_SUPER_MAGIC;
409 asb->s_idlen = dr->idlen;
410 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
411 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
412 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
413 asb->s_version = dr->format_version;
414 asb->s_log2sharesize = dr->log2sharesize;
415
416 asb->s_map = adfs_read_map(sb, dr);
417 if (!asb->s_map)
418 goto error_free_bh;
419
420 brelse(bh);
421
422 /*
423 * set up enough so that we can read an inode
424 */
425 sb->s_op = &adfs_sops;
426
427 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
428
429 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
430 root_obj.name_len = 0;
431 root_obj.loadaddr = 0;
432 root_obj.execaddr = 0;
433 root_obj.size = ADFS_NEWDIR_SIZE;
434 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
435 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
436
437 /*
438 * If this is a F+ disk with variable length directories,
439 * get the root_size from the disc record.
440 */
441 if (asb->s_version) {
442 root_obj.size = le32_to_cpu(dr->root_size);
443 asb->s_dir = &adfs_fplus_dir_ops;
444 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
445 } else {
446 asb->s_dir = &adfs_f_dir_ops;
447 asb->s_namelen = ADFS_F_NAME_LEN;
448 }
449
450 root = adfs_iget(sb, &root_obj);
451 sb->s_root = d_alloc_root(root);
452 if (!sb->s_root) {
453 int i;
454 iput(root);
455 for (i = 0; i < asb->s_map_size; i++)
456 brelse(asb->s_map[i].dm_bh);
457 kfree(asb->s_map);
458 adfs_error(sb, "get root inode failed\n");
459 goto error;
460 } else
461 sb->s_root->d_op = &adfs_dentry_operations;
462 return 0;
463
464error_free_bh:
465 brelse(bh);
466error:
467 sb->s_fs_info = NULL;
468 kfree(asb);
469 return -EINVAL;
470}
471
472static struct super_block *adfs_get_sb(struct file_system_type *fs_type,
473 int flags, const char *dev_name, void *data)
474{
475 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
476}
477
478static struct file_system_type adfs_fs_type = {
479 .owner = THIS_MODULE,
480 .name = "adfs",
481 .get_sb = adfs_get_sb,
482 .kill_sb = kill_block_super,
483 .fs_flags = FS_REQUIRES_DEV,
484};
485
486static int __init init_adfs_fs(void)
487{
488 int err = init_inodecache();
489 if (err)
490 goto out1;
491 err = register_filesystem(&adfs_fs_type);
492 if (err)
493 goto out;
494 return 0;
495out:
496 destroy_inodecache();
497out1:
498 return err;
499}
500
501static void __exit exit_adfs_fs(void)
502{
503 unregister_filesystem(&adfs_fs_type);
504 destroy_inodecache();
505}
506
507module_init(init_adfs_fs)
508module_exit(exit_adfs_fs)