1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/affs/inode.c
4 *
5 * (c) 1996 Hans-Joachim Widmaier - Rewritten
6 *
7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
8 *
9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
10 *
11 * (C) 1991 Linus Torvalds - minix filesystem
12 */
13
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/statfs.h>
17 #include <linux/parser.h>
18 #include <linux/magic.h>
19 #include <linux/sched.h>
20 #include <linux/cred.h>
21 #include <linux/slab.h>
22 #include <linux/writeback.h>
23 #include <linux/blkdev.h>
24 #include <linux/seq_file.h>
25 #include <linux/iversion.h>
26 #include "affs.h"
27
28 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
29 static int affs_show_options(struct seq_file *m, struct dentry *root);
30 static int affs_remount (struct super_block *sb, int *flags, char *data);
31
32 static void
33 affs_commit_super(struct super_block *sb, int wait)
34 {
35 struct affs_sb_info *sbi = AFFS_SB(sb);
36 struct buffer_head *bh = sbi->s_root_bh;
37 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
38
39 lock_buffer(bh);
40 affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change);
41 affs_fix_checksum(sb, bh);
42 unlock_buffer(bh);
43
44 mark_buffer_dirty(bh);
45 if (wait)
46 sync_dirty_buffer(bh);
47 }
48
49 static void
50 affs_put_super(struct super_block *sb)
51 {
52 struct affs_sb_info *sbi = AFFS_SB(sb);
53 pr_debug("%s()\n", __func__);
54
55 cancel_delayed_work_sync(&sbi->sb_work);
56 }
57
58 static int
59 affs_sync_fs(struct super_block *sb, int wait)
60 {
61 affs_commit_super(sb, wait);
62 return 0;
63 }
64
65 static void flush_superblock(struct work_struct *work)
66 {
67 struct affs_sb_info *sbi;
68 struct super_block *sb;
69
70 sbi = container_of(work, struct affs_sb_info, sb_work.work);
71 sb = sbi->sb;
72
73 spin_lock(&sbi->work_lock);
74 sbi->work_queued = 0;
75 spin_unlock(&sbi->work_lock);
76
77 affs_commit_super(sb, 1);
78 }
79
80 void affs_mark_sb_dirty(struct super_block *sb)
81 {
82 struct affs_sb_info *sbi = AFFS_SB(sb);
83 unsigned long delay;
84
85 if (sb_rdonly(sb))
86 return;
87
88 spin_lock(&sbi->work_lock);
89 if (!sbi->work_queued) {
90 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
91 queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
92 sbi->work_queued = 1;
93 }
94 spin_unlock(&sbi->work_lock);
95 }
96
97 static struct kmem_cache * affs_inode_cachep;
98
99 static struct inode *affs_alloc_inode(struct super_block *sb)
100 {
101 struct affs_inode_info *i;
102
103 i = alloc_inode_sb(sb, affs_inode_cachep, GFP_KERNEL);
104 if (!i)
105 return NULL;
106
107 inode_set_iversion(&i->vfs_inode, 1);
108 i->i_lc = NULL;
109 i->i_ext_bh = NULL;
110 i->i_pa_cnt = 0;
111
112 return &i->vfs_inode;
113 }
114
115 static void affs_free_inode(struct inode *inode)
116 {
117 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
118 }
119
120 static void init_once(void *foo)
121 {
122 struct affs_inode_info *ei = (struct affs_inode_info *) foo;
123
124 mutex_init(&ei->i_link_lock);
125 mutex_init(&ei->i_ext_lock);
126 inode_init_once(&ei->vfs_inode);
127 }
128
129 static int __init init_inodecache(void)
130 {
131 affs_inode_cachep = kmem_cache_create("affs_inode_cache",
132 sizeof(struct affs_inode_info),
133 0, (SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT),
134 init_once);
135 if (affs_inode_cachep == NULL)
136 return -ENOMEM;
137 return 0;
138 }
139
140 static void destroy_inodecache(void)
141 {
142 /*
143 * Make sure all delayed rcu free inodes are flushed before we
144 * destroy cache.
145 */
146 rcu_barrier();
147 kmem_cache_destroy(affs_inode_cachep);
148 }
149
150 static const struct super_operations affs_sops = {
151 .alloc_inode = affs_alloc_inode,
152 .free_inode = affs_free_inode,
153 .write_inode = affs_write_inode,
154 .evict_inode = affs_evict_inode,
155 .put_super = affs_put_super,
156 .sync_fs = affs_sync_fs,
157 .statfs = affs_statfs,
158 .remount_fs = affs_remount,
159 .show_options = affs_show_options,
160 };
161
162 enum {
163 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
164 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
165 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
166 };
167
168 static const match_table_t tokens = {
169 {Opt_bs, "bs=%u"},
170 {Opt_mode, "mode=%o"},
171 {Opt_mufs, "mufs"},
172 {Opt_notruncate, "nofilenametruncate"},
173 {Opt_prefix, "prefix=%s"},
174 {Opt_protect, "protect"},
175 {Opt_reserved, "reserved=%u"},
176 {Opt_root, "root=%u"},
177 {Opt_setgid, "setgid=%u"},
178 {Opt_setuid, "setuid=%u"},
179 {Opt_verbose, "verbose"},
180 {Opt_volume, "volume=%s"},
181 {Opt_ignore, "grpquota"},
182 {Opt_ignore, "noquota"},
183 {Opt_ignore, "quota"},
184 {Opt_ignore, "usrquota"},
185 {Opt_err, NULL},
186 };
187
188 static int
189 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
190 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
191 {
192 char *p;
193 substring_t args[MAX_OPT_ARGS];
194
195 /* Fill in defaults */
196
197 *uid = current_uid();
198 *gid = current_gid();
199 *reserved = 2;
200 *root = -1;
201 *blocksize = -1;
202 volume[0] = ':';
203 volume[1] = 0;
204 *mount_opts = 0;
205 if (!options)
206 return 1;
207
208 while ((p = strsep(&options, ",")) != NULL) {
209 int token, n, option;
210 if (!*p)
211 continue;
212
213 token = match_token(p, tokens, args);
214 switch (token) {
215 case Opt_bs:
216 if (match_int(&args[0], &n))
217 return 0;
218 if (n != 512 && n != 1024 && n != 2048
219 && n != 4096) {
220 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
221 return 0;
222 }
223 *blocksize = n;
224 break;
225 case Opt_mode:
226 if (match_octal(&args[0], &option))
227 return 0;
228 *mode = option & 0777;
229 affs_set_opt(*mount_opts, SF_SETMODE);
230 break;
231 case Opt_mufs:
232 affs_set_opt(*mount_opts, SF_MUFS);
233 break;
234 case Opt_notruncate:
235 affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
236 break;
237 case Opt_prefix:
238 kfree(*prefix);
239 *prefix = match_strdup(&args[0]);
240 if (!*prefix)
241 return 0;
242 affs_set_opt(*mount_opts, SF_PREFIX);
243 break;
244 case Opt_protect:
245 affs_set_opt(*mount_opts, SF_IMMUTABLE);
246 break;
247 case Opt_reserved:
248 if (match_int(&args[0], reserved))
249 return 0;
250 break;
251 case Opt_root:
252 if (match_int(&args[0], root))
253 return 0;
254 break;
255 case Opt_setgid:
256 if (match_int(&args[0], &option))
257 return 0;
258 *gid = make_kgid(current_user_ns(), option);
259 if (!gid_valid(*gid))
260 return 0;
261 affs_set_opt(*mount_opts, SF_SETGID);
262 break;
263 case Opt_setuid:
264 if (match_int(&args[0], &option))
265 return 0;
266 *uid = make_kuid(current_user_ns(), option);
267 if (!uid_valid(*uid))
268 return 0;
269 affs_set_opt(*mount_opts, SF_SETUID);
270 break;
271 case Opt_verbose:
272 affs_set_opt(*mount_opts, SF_VERBOSE);
273 break;
274 case Opt_volume: {
275 char *vol = match_strdup(&args[0]);
276 if (!vol)
277 return 0;
278 strscpy(volume, vol, 32);
279 kfree(vol);
280 break;
281 }
282 case Opt_ignore:
283 /* Silently ignore the quota options */
284 break;
285 default:
286 pr_warn("Unrecognized mount option \"%s\" or missing value\n",
287 p);
288 return 0;
289 }
290 }
291 return 1;
292 }
293
294 static int affs_show_options(struct seq_file *m, struct dentry *root)
295 {
296 struct super_block *sb = root->d_sb;
297 struct affs_sb_info *sbi = AFFS_SB(sb);
298
299 if (sb->s_blocksize)
300 seq_printf(m, ",bs=%lu", sb->s_blocksize);
301 if (affs_test_opt(sbi->s_flags, SF_SETMODE))
302 seq_printf(m, ",mode=%o", sbi->s_mode);
303 if (affs_test_opt(sbi->s_flags, SF_MUFS))
304 seq_puts(m, ",mufs");
305 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
306 seq_puts(m, ",nofilenametruncate");
307 if (affs_test_opt(sbi->s_flags, SF_PREFIX))
308 seq_printf(m, ",prefix=%s", sbi->s_prefix);
309 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
310 seq_puts(m, ",protect");
311 if (sbi->s_reserved != 2)
312 seq_printf(m, ",reserved=%u", sbi->s_reserved);
313 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
314 seq_printf(m, ",root=%u", sbi->s_root_block);
315 if (affs_test_opt(sbi->s_flags, SF_SETGID))
316 seq_printf(m, ",setgid=%u",
317 from_kgid_munged(&init_user_ns, sbi->s_gid));
318 if (affs_test_opt(sbi->s_flags, SF_SETUID))
319 seq_printf(m, ",setuid=%u",
320 from_kuid_munged(&init_user_ns, sbi->s_uid));
321 if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
322 seq_puts(m, ",verbose");
323 if (sbi->s_volume[0])
324 seq_printf(m, ",volume=%s", sbi->s_volume);
325 return 0;
326 }
327
328 /* This function definitely needs to be split up. Some fine day I'll
329 * hopefully have the guts to do so. Until then: sorry for the mess.
330 */
331
332 static int affs_fill_super(struct super_block *sb, void *data, int silent)
333 {
334 struct affs_sb_info *sbi;
335 struct buffer_head *root_bh = NULL;
336 struct buffer_head *boot_bh;
337 struct inode *root_inode = NULL;
338 s32 root_block;
339 int size, blocksize;
340 u32 chksum;
341 int num_bm;
342 int i, j;
343 kuid_t uid;
344 kgid_t gid;
345 int reserved;
346 unsigned long mount_flags;
347 int tmp_flags; /* fix remount prototype... */
348 u8 sig[4];
349 int ret;
350
351 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
352
353 sb->s_magic = AFFS_SUPER_MAGIC;
354 sb->s_op = &affs_sops;
355 sb->s_flags |= SB_NODIRATIME;
356
357 sb->s_time_gran = NSEC_PER_SEC;
358 sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;
359 sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min;
360
361 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
362 if (!sbi)
363 return -ENOMEM;
364
365 sb->s_fs_info = sbi;
366 sbi->sb = sb;
367 mutex_init(&sbi->s_bmlock);
368 spin_lock_init(&sbi->symlink_lock);
369 spin_lock_init(&sbi->work_lock);
370 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
371
372 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
373 &blocksize,&sbi->s_prefix,
374 sbi->s_volume, &mount_flags)) {
375 pr_err("Error parsing options\n");
376 return -EINVAL;
377 }
378 /* N.B. after this point s_prefix must be released */
379
380 sbi->s_flags = mount_flags;
381 sbi->s_mode = i;
382 sbi->s_uid = uid;
383 sbi->s_gid = gid;
384 sbi->s_reserved= reserved;
385
386 /* Get the size of the device in 512-byte blocks.
387 * If we later see that the partition uses bigger
388 * blocks, we will have to change it.
389 */
390
391 size = bdev_nr_sectors(sb->s_bdev);
392 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
393
394 affs_set_blocksize(sb, PAGE_SIZE);
395 /* Try to find root block. Its location depends on the block size. */
396
397 i = bdev_logical_block_size(sb->s_bdev);
398 j = PAGE_SIZE;
399 if (blocksize > 0) {
400 i = j = blocksize;
401 size = size / (blocksize / 512);
402 }
403
404 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
405 sbi->s_root_block = root_block;
406 if (root_block < 0)
407 sbi->s_root_block = (reserved + size - 1) / 2;
408 pr_debug("setting blocksize to %d\n", blocksize);
409 affs_set_blocksize(sb, blocksize);
410 sbi->s_partition_size = size;
411
412 /* The root block location that was calculated above is not
413 * correct if the partition size is an odd number of 512-
414 * byte blocks, which will be rounded down to a number of
415 * 1024-byte blocks, and if there were an even number of
416 * reserved blocks. Ideally, all partition checkers should
417 * report the real number of blocks of the real blocksize,
418 * but since this just cannot be done, we have to try to
419 * find the root block anyways. In the above case, it is one
420 * block behind the calculated one. So we check this one, too.
421 */
422 for (num_bm = 0; num_bm < 2; num_bm++) {
423 pr_debug("Dev %s, trying root=%u, bs=%d, "
424 "size=%d, reserved=%d\n",
425 sb->s_id,
426 sbi->s_root_block + num_bm,
427 blocksize, size, reserved);
428 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
429 if (!root_bh)
430 continue;
431 if (!affs_checksum_block(sb, root_bh) &&
432 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
433 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
434 sbi->s_hashsize = blocksize / 4 - 56;
435 sbi->s_root_block += num_bm;
436 goto got_root;
437 }
438 affs_brelse(root_bh);
439 root_bh = NULL;
440 }
441 }
442 if (!silent)
443 pr_err("No valid root block on device %s\n", sb->s_id);
444 return -EINVAL;
445
446 /* N.B. after this point bh must be released */
447 got_root:
448 /* Keep super block in cache */
449 sbi->s_root_bh = root_bh;
450 root_block = sbi->s_root_block;
451
452 /* Find out which kind of FS we have */
453 boot_bh = sb_bread(sb, 0);
454 if (!boot_bh) {
455 pr_err("Cannot read boot block\n");
456 return -EINVAL;
457 }
458 memcpy(sig, boot_bh->b_data, 4);
459 brelse(boot_bh);
460 chksum = be32_to_cpu(*(__be32 *)sig);
461
462 /* Dircache filesystems are compatible with non-dircache ones
463 * when reading. As long as they aren't supported, writing is
464 * not recommended.
465 */
466 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
467 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) {
468 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
469 sb->s_flags |= SB_RDONLY;
470 }
471 switch (chksum) {
472 case MUFS_FS:
473 case MUFS_INTLFFS:
474 case MUFS_DCFFS:
475 affs_set_opt(sbi->s_flags, SF_MUFS);
476 fallthrough;
477 case FS_INTLFFS:
478 case FS_DCFFS:
479 affs_set_opt(sbi->s_flags, SF_INTL);
480 break;
481 case MUFS_FFS:
482 affs_set_opt(sbi->s_flags, SF_MUFS);
483 break;
484 case FS_FFS:
485 break;
486 case MUFS_OFS:
487 affs_set_opt(sbi->s_flags, SF_MUFS);
488 fallthrough;
489 case FS_OFS:
490 affs_set_opt(sbi->s_flags, SF_OFS);
491 sb->s_flags |= SB_NOEXEC;
492 break;
493 case MUFS_DCOFS:
494 case MUFS_INTLOFS:
495 affs_set_opt(sbi->s_flags, SF_MUFS);
496 fallthrough;
497 case FS_DCOFS:
498 case FS_INTLOFS:
499 affs_set_opt(sbi->s_flags, SF_INTL);
500 affs_set_opt(sbi->s_flags, SF_OFS);
501 sb->s_flags |= SB_NOEXEC;
502 break;
503 default:
504 pr_err("Unknown filesystem on device %s: %08X\n",
505 sb->s_id, chksum);
506 return -EINVAL;
507 }
508
509 if (affs_test_opt(mount_flags, SF_VERBOSE)) {
510 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
511 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
512 len > 31 ? 31 : len,
513 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
514 sig, sig[3] + '', blocksize);
515 }
516
517 sb->s_flags |= SB_NODEV | SB_NOSUID;
518
519 sbi->s_data_blksize = sb->s_blocksize;
520 if (affs_test_opt(sbi->s_flags, SF_OFS))
521 sbi->s_data_blksize -= 24;
522
523 tmp_flags = sb->s_flags;
524 ret = affs_init_bitmap(sb, &tmp_flags);
525 if (ret)
526 return ret;
527 sb->s_flags = tmp_flags;
528
529 /* set up enough so that it can read an inode */
530
531 root_inode = affs_iget(sb, root_block);
532 if (IS_ERR(root_inode))
533 return PTR_ERR(root_inode);
534
535 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
536 sb->s_d_op = &affs_intl_dentry_operations;
537 else
538 sb->s_d_op = &affs_dentry_operations;
539
540 sb->s_root = d_make_root(root_inode);
541 if (!sb->s_root) {
542 pr_err("AFFS: Get root inode failed\n");
543 return -ENOMEM;
544 }
545
546 sb->s_export_op = &affs_export_ops;
547 pr_debug("s_flags=%lX\n", sb->s_flags);
548 return 0;
549 }
550
551 static int
552 affs_remount(struct super_block *sb, int *flags, char *data)
553 {
554 struct affs_sb_info *sbi = AFFS_SB(sb);
555 int blocksize;
556 kuid_t uid;
557 kgid_t gid;
558 int mode;
559 int reserved;
560 int root_block;
561 unsigned long mount_flags;
562 int res = 0;
563 char volume[32];
564 char *prefix = NULL;
565
566 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
567
568 sync_filesystem(sb);
569 *flags |= SB_NODIRATIME;
570
571 memcpy(volume, sbi->s_volume, 32);
572 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
573 &blocksize, &prefix, volume,
574 &mount_flags)) {
575 kfree(prefix);
576 return -EINVAL;
577 }
578
579 flush_delayed_work(&sbi->sb_work);
580
581 sbi->s_flags = mount_flags;
582 sbi->s_mode = mode;
583 sbi->s_uid = uid;
584 sbi->s_gid = gid;
585 /* protect against readers */
586 spin_lock(&sbi->symlink_lock);
587 if (prefix) {
588 kfree(sbi->s_prefix);
589 sbi->s_prefix = prefix;
590 }
591 memcpy(sbi->s_volume, volume, 32);
592 spin_unlock(&sbi->symlink_lock);
593
594 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
595 return 0;
596
597 if (*flags & SB_RDONLY)
598 affs_free_bitmap(sb);
599 else
600 res = affs_init_bitmap(sb, flags);
601
602 return res;
603 }
604
605 static int
606 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
607 {
608 struct super_block *sb = dentry->d_sb;
609 int free;
610 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
611
612 pr_debug("%s() partsize=%d, reserved=%d\n",
613 __func__, AFFS_SB(sb)->s_partition_size,
614 AFFS_SB(sb)->s_reserved);
615
616 free = affs_count_free_blocks(sb);
617 buf->f_type = AFFS_SUPER_MAGIC;
618 buf->f_bsize = sb->s_blocksize;
619 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
620 buf->f_bfree = free;
621 buf->f_bavail = free;
622 buf->f_fsid = u64_to_fsid(id);
623 buf->f_namelen = AFFSNAMEMAX;
624 return 0;
625 }
626
627 static struct dentry *affs_mount(struct file_system_type *fs_type,
628 int flags, const char *dev_name, void *data)
629 {
630 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
631 }
632
633 static void affs_kill_sb(struct super_block *sb)
634 {
635 struct affs_sb_info *sbi = AFFS_SB(sb);
636 kill_block_super(sb);
637 if (sbi) {
638 affs_free_bitmap(sb);
639 affs_brelse(sbi->s_root_bh);
640 kfree(sbi->s_prefix);
641 mutex_destroy(&sbi->s_bmlock);
642 kfree_rcu(sbi, rcu);
643 }
644 }
645
646 static struct file_system_type affs_fs_type = {
647 .owner = THIS_MODULE,
648 .name = "affs",
649 .mount = affs_mount,
650 .kill_sb = affs_kill_sb,
651 .fs_flags = FS_REQUIRES_DEV,
652 };
653 MODULE_ALIAS_FS("affs");
654
655 static int __init init_affs_fs(void)
656 {
657 int err = init_inodecache();
658 if (err)
659 goto out1;
660 err = register_filesystem(&affs_fs_type);
661 if (err)
662 goto out;
663 return 0;
664 out:
665 destroy_inodecache();
666 out1:
667 return err;
668 }
669
670 static void __exit exit_affs_fs(void)
671 {
672 unregister_filesystem(&affs_fs_type);
673 destroy_inodecache();
674 }
675
676 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
677 MODULE_LICENSE("GPL");
678
679 module_init(init_affs_fs)
680 module_exit(exit_affs_fs)
681
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