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/fs_parser.h>
10#include <linux/fs_context.h>
11#include <linux/mount.h>
12#include <linux/seq_file.h>
13#include <linux/slab.h>
14#include <linux/statfs.h>
15#include <linux/user_namespace.h>
16#include <linux/blkdev.h>
17#include "adfs.h"
18#include "dir_f.h"
19#include "dir_fplus.h"
20
21#define ADFS_SB_FLAGS SB_NOATIME
22
23#define ADFS_DEFAULT_OWNER_MASK S_IRWXU
24#define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
25
26void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
27{
28 struct va_format vaf;
29 va_list args;
30
31 va_start(args, fmt);
32 vaf.fmt = fmt;
33 vaf.va = &args;
34
35 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
36 sb->s_id, function ? ": " : "",
37 function ? function : "", &vaf);
38
39 va_end(args);
40}
41
42void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
43{
44 struct va_format vaf;
45 va_list args;
46
47 va_start(args, fmt);
48 vaf.fmt = fmt;
49 vaf.va = &args;
50 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
51 va_end(args);
52}
53
54static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
55{
56 unsigned int max_idlen;
57 int i;
58
59 /* sector size must be 256, 512 or 1024 bytes */
60 if (dr->log2secsize != 8 &&
61 dr->log2secsize != 9 &&
62 dr->log2secsize != 10)
63 return 1;
64
65 /* idlen must be at least log2secsize + 3 */
66 if (dr->idlen < dr->log2secsize + 3)
67 return 1;
68
69 /* we cannot have such a large disc that we
70 * are unable to represent sector offsets in
71 * 32 bits. This works out at 2.0 TB.
72 */
73 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
74 return 1;
75
76 /*
77 * Maximum idlen is limited to 16 bits for new directories by
78 * the three-byte storage of an indirect disc address. For
79 * big directories, idlen must be no greater than 19 v2 [1.0]
80 */
81 max_idlen = dr->format_version ? 19 : 16;
82 if (dr->idlen > max_idlen)
83 return 1;
84
85 /* reserved bytes should be zero */
86 for (i = 0; i < sizeof(dr->unused52); i++)
87 if (dr->unused52[i] != 0)
88 return 1;
89
90 return 0;
91}
92
93static void adfs_put_super(struct super_block *sb)
94{
95 struct adfs_sb_info *asb = ADFS_SB(sb);
96
97 adfs_free_map(sb);
98 kfree_rcu(asb, rcu);
99}
100
101static int adfs_show_options(struct seq_file *seq, struct dentry *root)
102{
103 struct adfs_sb_info *asb = ADFS_SB(sb: root->d_sb);
104
105 if (!uid_eq(left: asb->s_uid, GLOBAL_ROOT_UID))
106 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
107 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
108 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
109 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
110 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
111 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
112 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
113 if (asb->s_ftsuffix != 0)
114 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
115
116 return 0;
117}
118
119enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix};
120
121static const struct fs_parameter_spec adfs_param_spec[] = {
122 fsparam_uid ("uid", Opt_uid),
123 fsparam_gid ("gid", Opt_gid),
124 fsparam_u32oct ("ownmask", Opt_ownmask),
125 fsparam_u32oct ("othmask", Opt_othmask),
126 fsparam_u32 ("ftsuffix", Opt_ftsuffix),
127 {}
128};
129
130static int adfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
131{
132 struct adfs_sb_info *asb = fc->s_fs_info;
133 struct fs_parse_result result;
134 int opt;
135
136 opt = fs_parse(fc, desc: adfs_param_spec, param, result: &result);
137 if (opt < 0)
138 return opt;
139
140 switch (opt) {
141 case Opt_uid:
142 asb->s_uid = result.uid;
143 break;
144 case Opt_gid:
145 asb->s_gid = result.gid;
146 break;
147 case Opt_ownmask:
148 asb->s_owner_mask = result.uint_32;
149 break;
150 case Opt_othmask:
151 asb->s_other_mask = result.uint_32;
152 break;
153 case Opt_ftsuffix:
154 asb->s_ftsuffix = result.uint_32;
155 break;
156 default:
157 return -EINVAL;
158 }
159 return 0;
160}
161
162static int adfs_reconfigure(struct fs_context *fc)
163{
164 struct adfs_sb_info *new_asb = fc->s_fs_info;
165 struct adfs_sb_info *asb = ADFS_SB(sb: fc->root->d_sb);
166
167 sync_filesystem(fc->root->d_sb);
168 fc->sb_flags |= ADFS_SB_FLAGS;
169
170 /* Structure copy newly parsed options */
171 *asb = *new_asb;
172
173 return 0;
174}
175
176static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
177{
178 struct super_block *sb = dentry->d_sb;
179 struct adfs_sb_info *sbi = ADFS_SB(sb);
180 u64 id = huge_encode_dev(dev: sb->s_bdev->bd_dev);
181
182 adfs_map_statfs(sb, buf);
183
184 buf->f_type = ADFS_SUPER_MAGIC;
185 buf->f_namelen = sbi->s_namelen;
186 buf->f_bsize = sb->s_blocksize;
187 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
188 buf->f_fsid = u64_to_fsid(v: id);
189
190 return 0;
191}
192
193static struct kmem_cache *adfs_inode_cachep;
194
195static struct inode *adfs_alloc_inode(struct super_block *sb)
196{
197 struct adfs_inode_info *ei;
198 ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);
199 if (!ei)
200 return NULL;
201 return &ei->vfs_inode;
202}
203
204static void adfs_free_inode(struct inode *inode)
205{
206 kmem_cache_free(s: adfs_inode_cachep, objp: ADFS_I(inode));
207}
208
209static int adfs_drop_inode(struct inode *inode)
210{
211 /* always drop inodes if we are read-only */
212 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);
213}
214
215static void init_once(void *foo)
216{
217 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
218
219 inode_init_once(&ei->vfs_inode);
220}
221
222static int __init init_inodecache(void)
223{
224 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
225 sizeof(struct adfs_inode_info),
226 0, (SLAB_RECLAIM_ACCOUNT|
227 SLAB_ACCOUNT),
228 init_once);
229 if (adfs_inode_cachep == NULL)
230 return -ENOMEM;
231 return 0;
232}
233
234static void destroy_inodecache(void)
235{
236 /*
237 * Make sure all delayed rcu free inodes are flushed before we
238 * destroy cache.
239 */
240 rcu_barrier();
241 kmem_cache_destroy(s: adfs_inode_cachep);
242}
243
244static const struct super_operations adfs_sops = {
245 .alloc_inode = adfs_alloc_inode,
246 .free_inode = adfs_free_inode,
247 .drop_inode = adfs_drop_inode,
248 .write_inode = adfs_write_inode,
249 .put_super = adfs_put_super,
250 .statfs = adfs_statfs,
251 .show_options = adfs_show_options,
252};
253
254static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
255 int (*validate)(struct super_block *sb,
256 struct buffer_head *bh,
257 struct adfs_discrecord **bhp))
258{
259 struct adfs_sb_info *asb = ADFS_SB(sb);
260 struct adfs_discrecord *dr;
261 struct buffer_head *bh;
262 unsigned int blocksize = BLOCK_SIZE;
263 int ret, try;
264
265 for (try = 0; try < 2; try++) {
266 /* try to set the requested block size */
267 if (sb->s_blocksize != blocksize &&
268 !sb_set_blocksize(sb, size: blocksize)) {
269 if (!silent)
270 adfs_msg(sb, KERN_ERR,
271 fmt: "error: unsupported blocksize");
272 return -EINVAL;
273 }
274
275 /* read the buffer */
276 bh = sb_bread(sb, block: offset >> sb->s_blocksize_bits);
277 if (!bh) {
278 adfs_msg(sb, KERN_ERR,
279 fmt: "error: unable to read block %u, try %d",
280 offset >> sb->s_blocksize_bits, try);
281 return -EIO;
282 }
283
284 /* validate it */
285 ret = validate(sb, bh, &dr);
286 if (ret) {
287 brelse(bh);
288 return ret;
289 }
290
291 /* does the block size match the filesystem block size? */
292 blocksize = 1 << dr->log2secsize;
293 if (sb->s_blocksize == blocksize) {
294 asb->s_map = adfs_read_map(sb, dr);
295 brelse(bh);
296 return PTR_ERR_OR_ZERO(ptr: asb->s_map);
297 }
298
299 brelse(bh);
300 }
301
302 return -EIO;
303}
304
305static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
306 struct adfs_discrecord **drp)
307{
308 struct adfs_discrecord *dr;
309 unsigned char *b_data;
310
311 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
312 if (adfs_checkbblk(ptr: b_data))
313 return -EILSEQ;
314
315 /* Do some sanity checks on the ADFS disc record */
316 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
317 if (adfs_checkdiscrecord(dr))
318 return -EILSEQ;
319
320 *drp = dr;
321 return 0;
322}
323
324static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,
325 struct adfs_discrecord **drp)
326{
327 struct adfs_discrecord *dr;
328
329 /* Do some sanity checks on the ADFS disc record */
330 dr = (struct adfs_discrecord *)(bh->b_data + 4);
331 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)
332 return -EILSEQ;
333
334 *drp = dr;
335 return 0;
336}
337
338static int adfs_fill_super(struct super_block *sb, struct fs_context *fc)
339{
340 struct adfs_discrecord *dr;
341 struct object_info root_obj;
342 struct adfs_sb_info *asb = sb->s_fs_info;
343 struct inode *root;
344 int ret = -EINVAL;
345 int silent = fc->sb_flags & SB_SILENT;
346
347 sb->s_flags |= ADFS_SB_FLAGS;
348
349 sb->s_fs_info = asb;
350 sb->s_magic = ADFS_SUPER_MAGIC;
351 sb->s_time_gran = 10000000;
352
353 /* Try to probe the filesystem boot block */
354 ret = adfs_probe(sb, ADFS_DISCRECORD, silent: 1, validate: adfs_validate_bblk);
355 if (ret == -EILSEQ)
356 ret = adfs_probe(sb, offset: 0, silent, validate: adfs_validate_dr0);
357 if (ret == -EILSEQ) {
358 if (!silent)
359 adfs_msg(sb, KERN_ERR,
360 fmt: "error: can't find an ADFS filesystem on dev %s.",
361 sb->s_id);
362 ret = -EINVAL;
363 }
364 if (ret)
365 goto error;
366
367 /* set up enough so that we can read an inode */
368 sb->s_op = &adfs_sops;
369
370 dr = adfs_map_discrecord(dm: asb->s_map);
371
372 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
373 root_obj.name_len = 0;
374 /* Set root object date as 01 Jan 1987 00:00:00 */
375 root_obj.loadaddr = 0xfff0003f;
376 root_obj.execaddr = 0xec22c000;
377 root_obj.size = ADFS_NEWDIR_SIZE;
378 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
379 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
380
381 /*
382 * If this is a F+ disk with variable length directories,
383 * get the root_size from the disc record.
384 */
385 if (dr->format_version) {
386 root_obj.size = le32_to_cpu(dr->root_size);
387 asb->s_dir = &adfs_fplus_dir_ops;
388 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
389 } else {
390 asb->s_dir = &adfs_f_dir_ops;
391 asb->s_namelen = ADFS_F_NAME_LEN;
392 }
393 /*
394 * ,xyz hex filetype suffix may be added by driver
395 * to files that have valid RISC OS filetype
396 */
397 if (asb->s_ftsuffix)
398 asb->s_namelen += 4;
399
400 set_default_d_op(sb, &adfs_dentry_operations);
401 root = adfs_iget(sb, obj: &root_obj);
402 sb->s_root = d_make_root(root);
403 if (!sb->s_root) {
404 adfs_free_map(sb);
405 adfs_error(sb, "get root inode failed\n");
406 ret = -EIO;
407 goto error;
408 }
409 return 0;
410
411error:
412 sb->s_fs_info = NULL;
413 kfree(objp: asb);
414 return ret;
415}
416
417static int adfs_get_tree(struct fs_context *fc)
418{
419 return get_tree_bdev(fc, fill_super: adfs_fill_super);
420}
421
422static void adfs_free_fc(struct fs_context *fc)
423{
424 struct adfs_context *asb = fc->s_fs_info;
425
426 kfree(objp: asb);
427}
428
429static const struct fs_context_operations adfs_context_ops = {
430 .parse_param = adfs_parse_param,
431 .get_tree = adfs_get_tree,
432 .reconfigure = adfs_reconfigure,
433 .free = adfs_free_fc,
434};
435
436static int adfs_init_fs_context(struct fs_context *fc)
437{
438 struct adfs_sb_info *asb;
439
440 asb = kzalloc(sizeof(struct adfs_sb_info), GFP_KERNEL);
441 if (!asb)
442 return -ENOMEM;
443
444 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
445 struct super_block *sb = fc->root->d_sb;
446 struct adfs_sb_info *old_asb = ADFS_SB(sb);
447
448 /* structure copy existing options before parsing */
449 *asb = *old_asb;
450 } else {
451 /* set default options */
452 asb->s_uid = GLOBAL_ROOT_UID;
453 asb->s_gid = GLOBAL_ROOT_GID;
454 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
455 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
456 asb->s_ftsuffix = 0;
457 }
458
459 fc->ops = &adfs_context_ops;
460 fc->s_fs_info = asb;
461
462 return 0;
463}
464
465static struct file_system_type adfs_fs_type = {
466 .owner = THIS_MODULE,
467 .name = "adfs",
468 .kill_sb = kill_block_super,
469 .fs_flags = FS_REQUIRES_DEV,
470 .init_fs_context = adfs_init_fs_context,
471 .parameters = adfs_param_spec,
472};
473MODULE_ALIAS_FS("adfs");
474
475static int __init init_adfs_fs(void)
476{
477 int err = init_inodecache();
478 if (err)
479 goto out1;
480 err = register_filesystem(&adfs_fs_type);
481 if (err)
482 goto out;
483 return 0;
484out:
485 destroy_inodecache();
486out1:
487 return err;
488}
489
490static void __exit exit_adfs_fs(void)
491{
492 unregister_filesystem(&adfs_fs_type);
493 destroy_inodecache();
494}
495
496module_init(init_adfs_fs)
497module_exit(exit_adfs_fs)
498MODULE_DESCRIPTION("Acorn Disc Filing System");
499MODULE_LICENSE("GPL");
500

source code of linux/fs/adfs/super.c