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(sb: root->d_sb); |
103 | |
104 | if (!uid_eq(left: 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, table: tokens, args); |
145 | switch (token) { |
146 | case Opt_uid: |
147 | if (match_int(args, result: &option)) |
148 | return -EINVAL; |
149 | asb->s_uid = make_kuid(current_user_ns(), uid: option); |
150 | if (!uid_valid(uid: asb->s_uid)) |
151 | return -EINVAL; |
152 | break; |
153 | case Opt_gid: |
154 | if (match_int(args, result: &option)) |
155 | return -EINVAL; |
156 | asb->s_gid = make_kgid(current_user_ns(), gid: option); |
157 | if (!gid_valid(gid: asb->s_gid)) |
158 | return -EINVAL; |
159 | break; |
160 | case Opt_ownmask: |
161 | if (match_octal(args, result: &option)) |
162 | return -EINVAL; |
163 | asb->s_owner_mask = option; |
164 | break; |
165 | case Opt_othmask: |
166 | if (match_octal(args, result: &option)) |
167 | return -EINVAL; |
168 | asb->s_other_mask = option; |
169 | break; |
170 | case Opt_ftsuffix: |
171 | if (match_int(args, result: &option)) |
172 | return -EINVAL; |
173 | asb->s_ftsuffix = option; |
174 | break; |
175 | default: |
176 | adfs_msg(sb, KERN_ERR, |
177 | fmt: "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, asb: &temp_asb, options: 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(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(v: 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, cache: 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(s: adfs_inode_cachep, objp: 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(name: "adfs_inode_cache" , |
250 | size: sizeof(struct adfs_inode_info), |
251 | align: 0, flags: (SLAB_RECLAIM_ACCOUNT| |
252 | SLAB_MEM_SPREAD|SLAB_ACCOUNT), |
253 | ctor: 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(s: 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 | fmt: "error: unsupported blocksize" ); |
298 | return -EINVAL; |
299 | } |
300 | |
301 | /* read the buffer */ |
302 | bh = sb_bread(sb, block: offset >> sb->s_blocksize_bits); |
303 | if (!bh) { |
304 | adfs_msg(sb, KERN_ERR, |
305 | fmt: "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(ptr: 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(ptr: 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(size: 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, fill_super: 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_LICENSE("GPL" ); |
495 | |