1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/adfs/super.c
4 *
5 * Copyright (C) 1997-1999 Russell King
6 */
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/parser.h>
10 #include <linux/mount.h>
11 #include <linux/seq_file.h>
12 #include <linux/slab.h>
13 #include <linux/statfs.h>
14 #include <linux/user_namespace.h>
15 #include <linux/blkdev.h>
16 #include "adfs.h"
17 #include "dir_f.h"
18 #include "dir_fplus.h"
19
20 #define ADFS_SB_FLAGS SB_NOATIME
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 struct va_format vaf;
28 va_list args;
29
30 va_start(args, fmt);
31 vaf.fmt = fmt;
32 vaf.va = &args;
33
34 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
35 sb->s_id, function ? ": " : "",
36 function ? function : "", &vaf);
37
38 va_end(args);
39 }
40
41 void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
42 {
43 struct va_format vaf;
44 va_list args;
45
46 va_start(args, fmt);
47 vaf.fmt = fmt;
48 vaf.va = &args;
49 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
50 va_end(args);
51 }
52
53 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
54 {
55 unsigned int max_idlen;
56 int i;
57
58 /* sector size must be 256, 512 or 1024 bytes */
59 if (dr->log2secsize != 8 &&
60 dr->log2secsize != 9 &&
61 dr->log2secsize != 10)
62 return 1;
63
64 /* idlen must be at least log2secsize + 3 */
65 if (dr->idlen < dr->log2secsize + 3)
66 return 1;
67
68 /* we cannot have such a large disc that we
69 * are unable to represent sector offsets in
70 * 32 bits. This works out at 2.0 TB.
71 */
72 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
73 return 1;
74
75 /*
76 * Maximum idlen is limited to 16 bits for new directories by
77 * the three-byte storage of an indirect disc address. For
78 * big directories, idlen must be no greater than 19 v2 [1.0]
79 */
80 max_idlen = dr->format_version ? 19 : 16;
81 if (dr->idlen > max_idlen)
82 return 1;
83
84 /* reserved bytes should be zero */
85 for (i = 0; i < sizeof(dr->unused52); i++)
86 if (dr->unused52[i] != 0)
87 return 1;
88
89 return 0;
90 }
91
92 static void adfs_put_super(struct super_block *sb)
93 {
94 struct adfs_sb_info *asb = ADFS_SB(sb);
95
96 adfs_free_map(sb);
97 kfree_rcu(asb, rcu);
98 }
99
100 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
101 {
102 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
103
104 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
105 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
106 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
107 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
108 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
109 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
110 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
111 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
112 if (asb->s_ftsuffix != 0)
113 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
114
115 return 0;
116 }
117
118 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
119
120 static const match_table_t tokens = {
121 {Opt_uid, "uid=%u"},
122 {Opt_gid, "gid=%u"},
123 {Opt_ownmask, "ownmask=%o"},
124 {Opt_othmask, "othmask=%o"},
125 {Opt_ftsuffix, "ftsuffix=%u"},
126 {Opt_err, NULL}
127 };
128
129 static int parse_options(struct super_block *sb, struct adfs_sb_info *asb,
130 char *options)
131 {
132 char *p;
133 int option;
134
135 if (!options)
136 return 0;
137
138 while ((p = strsep(&options, ",")) != NULL) {
139 substring_t args[MAX_OPT_ARGS];
140 int token;
141 if (!*p)
142 continue;
143
144 token = match_token(p, tokens, args);
145 switch (token) {
146 case Opt_uid:
147 if (match_int(args, &option))
148 return -EINVAL;
149 asb->s_uid = make_kuid(current_user_ns(), option);
150 if (!uid_valid(asb->s_uid))
151 return -EINVAL;
152 break;
153 case Opt_gid:
154 if (match_int(args, &option))
155 return -EINVAL;
156 asb->s_gid = make_kgid(current_user_ns(), option);
157 if (!gid_valid(asb->s_gid))
158 return -EINVAL;
159 break;
160 case Opt_ownmask:
161 if (match_octal(args, &option))
162 return -EINVAL;
163 asb->s_owner_mask = option;
164 break;
165 case Opt_othmask:
166 if (match_octal(args, &option))
167 return -EINVAL;
168 asb->s_other_mask = option;
169 break;
170 case Opt_ftsuffix:
171 if (match_int(args, &option))
172 return -EINVAL;
173 asb->s_ftsuffix = option;
174 break;
175 default:
176 adfs_msg(sb, KERN_ERR,
177 "unrecognised mount option \"%s\" or missing value",
178 p);
179 return -EINVAL;
180 }
181 }
182 return 0;
183 }
184
185 static int adfs_remount(struct super_block *sb, int *flags, char *data)
186 {
187 struct adfs_sb_info temp_asb;
188 int ret;
189
190 sync_filesystem(sb);
191 *flags |= ADFS_SB_FLAGS;
192
193 temp_asb = *ADFS_SB(sb);
194 ret = parse_options(sb, &temp_asb, data);
195 if (ret == 0)
196 *ADFS_SB(sb) = temp_asb;
197
198 return ret;
199 }
200
201 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
202 {
203 struct super_block *sb = dentry->d_sb;
204 struct adfs_sb_info *sbi = ADFS_SB(sb);
205 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
206
207 adfs_map_statfs(sb, buf);
208
209 buf->f_type = ADFS_SUPER_MAGIC;
210 buf->f_namelen = sbi->s_namelen;
211 buf->f_bsize = sb->s_blocksize;
212 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
213 buf->f_fsid = u64_to_fsid(id);
214
215 return 0;
216 }
217
218 static struct kmem_cache *adfs_inode_cachep;
219
220 static struct inode *adfs_alloc_inode(struct super_block *sb)
221 {
222 struct adfs_inode_info *ei;
223 ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);
224 if (!ei)
225 return NULL;
226 return &ei->vfs_inode;
227 }
228
229 static void adfs_free_inode(struct inode *inode)
230 {
231 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
232 }
233
234 static int adfs_drop_inode(struct inode *inode)
235 {
236 /* always drop inodes if we are read-only */
237 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);
238 }
239
240 static void init_once(void *foo)
241 {
242 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
243
244 inode_init_once(&ei->vfs_inode);
245 }
246
247 static int __init init_inodecache(void)
248 {
249 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
250 sizeof(struct adfs_inode_info),
251 0, (SLAB_RECLAIM_ACCOUNT|
252 SLAB_ACCOUNT),
253 init_once);
254 if (adfs_inode_cachep == NULL)
255 return -ENOMEM;
256 return 0;
257 }
258
259 static void destroy_inodecache(void)
260 {
261 /*
262 * Make sure all delayed rcu free inodes are flushed before we
263 * destroy cache.
264 */
265 rcu_barrier();
266 kmem_cache_destroy(adfs_inode_cachep);
267 }
268
269 static const struct super_operations adfs_sops = {
270 .alloc_inode = adfs_alloc_inode,
271 .free_inode = adfs_free_inode,
272 .drop_inode = adfs_drop_inode,
273 .write_inode = adfs_write_inode,
274 .put_super = adfs_put_super,
275 .statfs = adfs_statfs,
276 .remount_fs = adfs_remount,
277 .show_options = adfs_show_options,
278 };
279
280 static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
281 int (*validate)(struct super_block *sb,
282 struct buffer_head *bh,
283 struct adfs_discrecord **bhp))
284 {
285 struct adfs_sb_info *asb = ADFS_SB(sb);
286 struct adfs_discrecord *dr;
287 struct buffer_head *bh;
288 unsigned int blocksize = BLOCK_SIZE;
289 int ret, try;
290
291 for (try = 0; try < 2; try++) {
292 /* try to set the requested block size */
293 if (sb->s_blocksize != blocksize &&
294 !sb_set_blocksize(sb, blocksize)) {
295 if (!silent)
296 adfs_msg(sb, KERN_ERR,
297 "error: unsupported blocksize");
298 return -EINVAL;
299 }
300
301 /* read the buffer */
302 bh = sb_bread(sb, offset >> sb->s_blocksize_bits);
303 if (!bh) {
304 adfs_msg(sb, KERN_ERR,
305 "error: unable to read block %u, try %d",
306 offset >> sb->s_blocksize_bits, try);
307 return -EIO;
308 }
309
310 /* validate it */
311 ret = validate(sb, bh, &dr);
312 if (ret) {
313 brelse(bh);
314 return ret;
315 }
316
317 /* does the block size match the filesystem block size? */
318 blocksize = 1 << dr->log2secsize;
319 if (sb->s_blocksize == blocksize) {
320 asb->s_map = adfs_read_map(sb, dr);
321 brelse(bh);
322 return PTR_ERR_OR_ZERO(asb->s_map);
323 }
324
325 brelse(bh);
326 }
327
328 return -EIO;
329 }
330
331 static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
332 struct adfs_discrecord **drp)
333 {
334 struct adfs_discrecord *dr;
335 unsigned char *b_data;
336
337 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
338 if (adfs_checkbblk(b_data))
339 return -EILSEQ;
340
341 /* Do some sanity checks on the ADFS disc record */
342 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
343 if (adfs_checkdiscrecord(dr))
344 return -EILSEQ;
345
346 *drp = dr;
347 return 0;
348 }
349
350 static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,
351 struct adfs_discrecord **drp)
352 {
353 struct adfs_discrecord *dr;
354
355 /* Do some sanity checks on the ADFS disc record */
356 dr = (struct adfs_discrecord *)(bh->b_data + 4);
357 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)
358 return -EILSEQ;
359
360 *drp = dr;
361 return 0;
362 }
363
364 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
365 {
366 struct adfs_discrecord *dr;
367 struct object_info root_obj;
368 struct adfs_sb_info *asb;
369 struct inode *root;
370 int ret = -EINVAL;
371
372 sb->s_flags |= ADFS_SB_FLAGS;
373
374 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
375 if (!asb)
376 return -ENOMEM;
377
378 sb->s_fs_info = asb;
379 sb->s_magic = ADFS_SUPER_MAGIC;
380 sb->s_time_gran = 10000000;
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, asb, data))
390 goto error;
391
392 /* Try to probe the filesystem boot block */
393 ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk);
394 if (ret == -EILSEQ)
395 ret = adfs_probe(sb, 0, silent, adfs_validate_dr0);
396 if (ret == -EILSEQ) {
397 if (!silent)
398 adfs_msg(sb, KERN_ERR,
399 "error: can't find an ADFS filesystem on dev %s.",
400 sb->s_id);
401 ret = -EINVAL;
402 }
403 if (ret)
404 goto error;
405
406 /* set up enough so that we can read an inode */
407 sb->s_op = &adfs_sops;
408
409 dr = adfs_map_discrecord(asb->s_map);
410
411 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
412 root_obj.name_len = 0;
413 /* Set root object date as 01 Jan 1987 00:00:00 */
414 root_obj.loadaddr = 0xfff0003f;
415 root_obj.execaddr = 0xec22c000;
416 root_obj.size = ADFS_NEWDIR_SIZE;
417 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
418 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
419
420 /*
421 * If this is a F+ disk with variable length directories,
422 * get the root_size from the disc record.
423 */
424 if (dr->format_version) {
425 root_obj.size = le32_to_cpu(dr->root_size);
426 asb->s_dir = &adfs_fplus_dir_ops;
427 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
428 } else {
429 asb->s_dir = &adfs_f_dir_ops;
430 asb->s_namelen = ADFS_F_NAME_LEN;
431 }
432 /*
433 * ,xyz hex filetype suffix may be added by driver
434 * to files that have valid RISC OS filetype
435 */
436 if (asb->s_ftsuffix)
437 asb->s_namelen += 4;
438
439 sb->s_d_op = &adfs_dentry_operations;
440 root = adfs_iget(sb, &root_obj);
441 sb->s_root = d_make_root(root);
442 if (!sb->s_root) {
443 adfs_free_map(sb);
444 adfs_error(sb, "get root inode failed\n");
445 ret = -EIO;
446 goto error;
447 }
448 return 0;
449
450 error:
451 sb->s_fs_info = NULL;
452 kfree(asb);
453 return ret;
454 }
455
456 static struct dentry *adfs_mount(struct file_system_type *fs_type,
457 int flags, const char *dev_name, void *data)
458 {
459 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
460 }
461
462 static struct file_system_type adfs_fs_type = {
463 .owner = THIS_MODULE,
464 .name = "adfs",
465 .mount = adfs_mount,
466 .kill_sb = kill_block_super,
467 .fs_flags = FS_REQUIRES_DEV,
468 };
469 MODULE_ALIAS_FS("adfs");
470
471 static int __init init_adfs_fs(void)
472 {
473 int err = init_inodecache();
474 if (err)
475 goto out1;
476 err = register_filesystem(&adfs_fs_type);
477 if (err)
478 goto out;
479 return 0;
480 out:
481 destroy_inodecache();
482 out1:
483 return err;
484 }
485
486 static void __exit exit_adfs_fs(void)
487 {
488 unregister_filesystem(&adfs_fs_type);
489 destroy_inodecache();
490 }
491
492 module_init(init_adfs_fs)
493 module_exit(exit_adfs_fs)
494 MODULE_DESCRIPTION("Acorn Disc Filing System");
495 MODULE_LICENSE("GPL");
496
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