Loading...
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/fs_parser.h>
18#include <linux/fs_context.h>
19#include <linux/magic.h>
20#include <linux/sched.h>
21#include <linux/cred.h>
22#include <linux/slab.h>
23#include <linux/writeback.h>
24#include <linux/blkdev.h>
25#include <linux/seq_file.h>
26#include <linux/iversion.h>
27#include "affs.h"
28
29static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
30static int affs_show_options(struct seq_file *m, struct dentry *root);
31
32static void
33affs_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
49static void
50affs_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
58static int
59affs_sync_fs(struct super_block *sb, int wait)
60{
61 affs_commit_super(sb, wait);
62 return 0;
63}
64
65static 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
80void 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
97static struct kmem_cache * affs_inode_cachep;
98
99static 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
115static void affs_free_inode(struct inode *inode)
116{
117 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
118}
119
120static 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
129static 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
140static 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
150static 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 .show_options = affs_show_options,
159};
160
161enum {
162 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
163 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
164 Opt_verbose, Opt_volume, Opt_ignore,
165};
166
167struct affs_context {
168 kuid_t uid; /* uid to override */
169 kgid_t gid; /* gid to override */
170 unsigned int mode; /* mode to override */
171 unsigned int reserved; /* Number of reserved blocks */
172 int root_block; /* FFS root block number */
173 int blocksize; /* Initial device blksize */
174 char *prefix; /* Prefix for volumes and assigns */
175 char volume[32]; /* Vol. prefix for absolute symlinks */
176 unsigned long mount_flags; /* Options */
177};
178
179static const struct fs_parameter_spec affs_param_spec[] = {
180 fsparam_u32 ("bs", Opt_bs),
181 fsparam_u32oct ("mode", Opt_mode),
182 fsparam_flag ("mufs", Opt_mufs),
183 fsparam_flag ("nofilenametruncate", Opt_notruncate),
184 fsparam_string ("prefix", Opt_prefix),
185 fsparam_flag ("protect", Opt_protect),
186 fsparam_u32 ("reserved", Opt_reserved),
187 fsparam_u32 ("root", Opt_root),
188 fsparam_gid ("setgid", Opt_setgid),
189 fsparam_uid ("setuid", Opt_setuid),
190 fsparam_flag ("verbose", Opt_verbose),
191 fsparam_string ("volume", Opt_volume),
192 fsparam_flag ("grpquota", Opt_ignore),
193 fsparam_flag ("noquota", Opt_ignore),
194 fsparam_flag ("quota", Opt_ignore),
195 fsparam_flag ("usrquota", Opt_ignore),
196 {},
197};
198
199static int affs_parse_param(struct fs_context *fc, struct fs_parameter *param)
200{
201 struct affs_context *ctx = fc->fs_private;
202 struct fs_parse_result result;
203 int n;
204 int opt;
205
206 opt = fs_parse(fc, affs_param_spec, param, &result);
207 if (opt < 0)
208 return opt;
209
210 switch (opt) {
211 case Opt_bs:
212 n = result.uint_32;
213 if (n != 512 && n != 1024 && n != 2048
214 && n != 4096) {
215 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
216 return -EINVAL;
217 }
218 ctx->blocksize = n;
219 break;
220 case Opt_mode:
221 ctx->mode = result.uint_32 & 0777;
222 affs_set_opt(ctx->mount_flags, SF_SETMODE);
223 break;
224 case Opt_mufs:
225 affs_set_opt(ctx->mount_flags, SF_MUFS);
226 break;
227 case Opt_notruncate:
228 affs_set_opt(ctx->mount_flags, SF_NO_TRUNCATE);
229 break;
230 case Opt_prefix:
231 kfree(ctx->prefix);
232 ctx->prefix = param->string;
233 param->string = NULL;
234 affs_set_opt(ctx->mount_flags, SF_PREFIX);
235 break;
236 case Opt_protect:
237 affs_set_opt(ctx->mount_flags, SF_IMMUTABLE);
238 break;
239 case Opt_reserved:
240 ctx->reserved = result.uint_32;
241 break;
242 case Opt_root:
243 ctx->root_block = result.uint_32;
244 break;
245 case Opt_setgid:
246 ctx->gid = result.gid;
247 affs_set_opt(ctx->mount_flags, SF_SETGID);
248 break;
249 case Opt_setuid:
250 ctx->uid = result.uid;
251 affs_set_opt(ctx->mount_flags, SF_SETUID);
252 break;
253 case Opt_verbose:
254 affs_set_opt(ctx->mount_flags, SF_VERBOSE);
255 break;
256 case Opt_volume:
257 strscpy(ctx->volume, param->string, 32);
258 break;
259 case Opt_ignore:
260 /* Silently ignore the quota options */
261 break;
262 default:
263 return -EINVAL;
264 }
265 return 0;
266}
267
268static int affs_show_options(struct seq_file *m, struct dentry *root)
269{
270 struct super_block *sb = root->d_sb;
271 struct affs_sb_info *sbi = AFFS_SB(sb);
272
273 if (sb->s_blocksize)
274 seq_printf(m, ",bs=%lu", sb->s_blocksize);
275 if (affs_test_opt(sbi->s_flags, SF_SETMODE))
276 seq_printf(m, ",mode=%o", sbi->s_mode);
277 if (affs_test_opt(sbi->s_flags, SF_MUFS))
278 seq_puts(m, ",mufs");
279 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
280 seq_puts(m, ",nofilenametruncate");
281 if (affs_test_opt(sbi->s_flags, SF_PREFIX))
282 seq_printf(m, ",prefix=%s", sbi->s_prefix);
283 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
284 seq_puts(m, ",protect");
285 if (sbi->s_reserved != 2)
286 seq_printf(m, ",reserved=%u", sbi->s_reserved);
287 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
288 seq_printf(m, ",root=%u", sbi->s_root_block);
289 if (affs_test_opt(sbi->s_flags, SF_SETGID))
290 seq_printf(m, ",setgid=%u",
291 from_kgid_munged(&init_user_ns, sbi->s_gid));
292 if (affs_test_opt(sbi->s_flags, SF_SETUID))
293 seq_printf(m, ",setuid=%u",
294 from_kuid_munged(&init_user_ns, sbi->s_uid));
295 if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
296 seq_puts(m, ",verbose");
297 if (sbi->s_volume[0])
298 seq_printf(m, ",volume=%s", sbi->s_volume);
299 return 0;
300}
301
302/* This function definitely needs to be split up. Some fine day I'll
303 * hopefully have the guts to do so. Until then: sorry for the mess.
304 */
305
306static int affs_fill_super(struct super_block *sb, struct fs_context *fc)
307{
308 struct affs_sb_info *sbi;
309 struct affs_context *ctx = fc->fs_private;
310 struct buffer_head *root_bh = NULL;
311 struct buffer_head *boot_bh;
312 struct inode *root_inode = NULL;
313 int silent = fc->sb_flags & SB_SILENT;
314 int size, blocksize;
315 u32 chksum;
316 int num_bm;
317 int i, j;
318 int tmp_flags; /* fix remount prototype... */
319 u8 sig[4];
320 int ret;
321
322 sb->s_magic = AFFS_SUPER_MAGIC;
323 sb->s_op = &affs_sops;
324 sb->s_flags |= SB_NODIRATIME;
325
326 sb->s_time_gran = NSEC_PER_SEC;
327 sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;
328 sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min;
329
330 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
331 if (!sbi)
332 return -ENOMEM;
333
334 sb->s_fs_info = sbi;
335 sbi->sb = sb;
336 mutex_init(&sbi->s_bmlock);
337 spin_lock_init(&sbi->symlink_lock);
338 spin_lock_init(&sbi->work_lock);
339 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
340
341 sbi->s_flags = ctx->mount_flags;
342 sbi->s_mode = ctx->mode;
343 sbi->s_uid = ctx->uid;
344 sbi->s_gid = ctx->gid;
345 sbi->s_reserved = ctx->reserved;
346 sbi->s_prefix = ctx->prefix;
347 ctx->prefix = NULL;
348 memcpy(sbi->s_volume, ctx->volume, 32);
349
350 /* N.B. after this point s_prefix must be released */
351
352 /* Get the size of the device in 512-byte blocks.
353 * If we later see that the partition uses bigger
354 * blocks, we will have to change it.
355 */
356
357 size = bdev_nr_sectors(sb->s_bdev);
358 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
359
360 affs_set_blocksize(sb, PAGE_SIZE);
361 /* Try to find root block. Its location depends on the block size. */
362
363 i = bdev_logical_block_size(sb->s_bdev);
364 j = PAGE_SIZE;
365 blocksize = ctx->blocksize;
366 if (blocksize > 0) {
367 i = j = blocksize;
368 size = size / (blocksize / 512);
369 }
370
371 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
372 sbi->s_root_block = ctx->root_block;
373 if (ctx->root_block < 0)
374 sbi->s_root_block = (ctx->reserved + size - 1) / 2;
375 pr_debug("setting blocksize to %d\n", blocksize);
376 affs_set_blocksize(sb, blocksize);
377 sbi->s_partition_size = size;
378
379 /* The root block location that was calculated above is not
380 * correct if the partition size is an odd number of 512-
381 * byte blocks, which will be rounded down to a number of
382 * 1024-byte blocks, and if there were an even number of
383 * reserved blocks. Ideally, all partition checkers should
384 * report the real number of blocks of the real blocksize,
385 * but since this just cannot be done, we have to try to
386 * find the root block anyways. In the above case, it is one
387 * block behind the calculated one. So we check this one, too.
388 */
389 for (num_bm = 0; num_bm < 2; num_bm++) {
390 pr_debug("Dev %s, trying root=%u, bs=%d, "
391 "size=%d, reserved=%d\n",
392 sb->s_id,
393 sbi->s_root_block + num_bm,
394 ctx->blocksize, size, ctx->reserved);
395 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
396 if (!root_bh)
397 continue;
398 if (!affs_checksum_block(sb, root_bh) &&
399 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
400 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
401 sbi->s_hashsize = blocksize / 4 - 56;
402 sbi->s_root_block += num_bm;
403 goto got_root;
404 }
405 affs_brelse(root_bh);
406 root_bh = NULL;
407 }
408 }
409 if (!silent)
410 pr_err("No valid root block on device %s\n", sb->s_id);
411 return -EINVAL;
412
413 /* N.B. after this point bh must be released */
414got_root:
415 /* Keep super block in cache */
416 sbi->s_root_bh = root_bh;
417 ctx->root_block = sbi->s_root_block;
418
419 /* Find out which kind of FS we have */
420 boot_bh = sb_bread(sb, 0);
421 if (!boot_bh) {
422 pr_err("Cannot read boot block\n");
423 return -EINVAL;
424 }
425 memcpy(sig, boot_bh->b_data, 4);
426 brelse(boot_bh);
427 chksum = be32_to_cpu(*(__be32 *)sig);
428
429 /* Dircache filesystems are compatible with non-dircache ones
430 * when reading. As long as they aren't supported, writing is
431 * not recommended.
432 */
433 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
434 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) {
435 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
436 sb->s_flags |= SB_RDONLY;
437 }
438 switch (chksum) {
439 case MUFS_FS:
440 case MUFS_INTLFFS:
441 case MUFS_DCFFS:
442 affs_set_opt(sbi->s_flags, SF_MUFS);
443 fallthrough;
444 case FS_INTLFFS:
445 case FS_DCFFS:
446 affs_set_opt(sbi->s_flags, SF_INTL);
447 break;
448 case MUFS_FFS:
449 affs_set_opt(sbi->s_flags, SF_MUFS);
450 break;
451 case FS_FFS:
452 break;
453 case MUFS_OFS:
454 affs_set_opt(sbi->s_flags, SF_MUFS);
455 fallthrough;
456 case FS_OFS:
457 affs_set_opt(sbi->s_flags, SF_OFS);
458 sb->s_flags |= SB_NOEXEC;
459 break;
460 case MUFS_DCOFS:
461 case MUFS_INTLOFS:
462 affs_set_opt(sbi->s_flags, SF_MUFS);
463 fallthrough;
464 case FS_DCOFS:
465 case FS_INTLOFS:
466 affs_set_opt(sbi->s_flags, SF_INTL);
467 affs_set_opt(sbi->s_flags, SF_OFS);
468 sb->s_flags |= SB_NOEXEC;
469 break;
470 default:
471 pr_err("Unknown filesystem on device %s: %08X\n",
472 sb->s_id, chksum);
473 return -EINVAL;
474 }
475
476 if (affs_test_opt(ctx->mount_flags, SF_VERBOSE)) {
477 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
478 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
479 len > 31 ? 31 : len,
480 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
481 sig, sig[3] + '0', blocksize);
482 }
483
484 sb->s_flags |= SB_NODEV | SB_NOSUID;
485
486 sbi->s_data_blksize = sb->s_blocksize;
487 if (affs_test_opt(sbi->s_flags, SF_OFS))
488 sbi->s_data_blksize -= 24;
489
490 tmp_flags = sb->s_flags;
491 ret = affs_init_bitmap(sb, &tmp_flags);
492 if (ret)
493 return ret;
494 sb->s_flags = tmp_flags;
495
496 /* set up enough so that it can read an inode */
497
498 root_inode = affs_iget(sb, ctx->root_block);
499 if (IS_ERR(root_inode))
500 return PTR_ERR(root_inode);
501
502 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
503 sb->s_d_op = &affs_intl_dentry_operations;
504 else
505 sb->s_d_op = &affs_dentry_operations;
506
507 sb->s_root = d_make_root(root_inode);
508 if (!sb->s_root) {
509 pr_err("AFFS: Get root inode failed\n");
510 return -ENOMEM;
511 }
512
513 sb->s_export_op = &affs_export_ops;
514 pr_debug("s_flags=%lX\n", sb->s_flags);
515 return 0;
516}
517
518static int affs_reconfigure(struct fs_context *fc)
519{
520 struct super_block *sb = fc->root->d_sb;
521 struct affs_context *ctx = fc->fs_private;
522 struct affs_sb_info *sbi = AFFS_SB(sb);
523 int res = 0;
524
525 sync_filesystem(sb);
526 fc->sb_flags |= SB_NODIRATIME;
527
528 flush_delayed_work(&sbi->sb_work);
529
530 /*
531 * NB: Historically, only mount_flags, mode, uid, gic, prefix,
532 * and volume are accepted during remount.
533 */
534 sbi->s_flags = ctx->mount_flags;
535 sbi->s_mode = ctx->mode;
536 sbi->s_uid = ctx->uid;
537 sbi->s_gid = ctx->gid;
538 /* protect against readers */
539 spin_lock(&sbi->symlink_lock);
540 if (ctx->prefix) {
541 kfree(sbi->s_prefix);
542 sbi->s_prefix = ctx->prefix;
543 ctx->prefix = NULL;
544 }
545 memcpy(sbi->s_volume, ctx->volume, 32);
546 spin_unlock(&sbi->symlink_lock);
547
548 if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
549 return 0;
550
551 if (fc->sb_flags & SB_RDONLY)
552 affs_free_bitmap(sb);
553 else
554 res = affs_init_bitmap(sb, &fc->sb_flags);
555
556 return res;
557}
558
559static int
560affs_statfs(struct dentry *dentry, struct kstatfs *buf)
561{
562 struct super_block *sb = dentry->d_sb;
563 int free;
564 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
565
566 pr_debug("%s() partsize=%d, reserved=%d\n",
567 __func__, AFFS_SB(sb)->s_partition_size,
568 AFFS_SB(sb)->s_reserved);
569
570 free = affs_count_free_blocks(sb);
571 buf->f_type = AFFS_SUPER_MAGIC;
572 buf->f_bsize = sb->s_blocksize;
573 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
574 buf->f_bfree = free;
575 buf->f_bavail = free;
576 buf->f_fsid = u64_to_fsid(id);
577 buf->f_namelen = AFFSNAMEMAX;
578 return 0;
579}
580
581static int affs_get_tree(struct fs_context *fc)
582{
583 return get_tree_bdev(fc, affs_fill_super);
584}
585
586static void affs_kill_sb(struct super_block *sb)
587{
588 struct affs_sb_info *sbi = AFFS_SB(sb);
589 kill_block_super(sb);
590 if (sbi) {
591 affs_free_bitmap(sb);
592 affs_brelse(sbi->s_root_bh);
593 kfree(sbi->s_prefix);
594 mutex_destroy(&sbi->s_bmlock);
595 kfree_rcu(sbi, rcu);
596 }
597}
598
599static void affs_free_fc(struct fs_context *fc)
600{
601 struct affs_context *ctx = fc->fs_private;
602
603 kfree(ctx->prefix);
604 kfree(ctx);
605}
606
607static const struct fs_context_operations affs_context_ops = {
608 .parse_param = affs_parse_param,
609 .get_tree = affs_get_tree,
610 .reconfigure = affs_reconfigure,
611 .free = affs_free_fc,
612};
613
614static int affs_init_fs_context(struct fs_context *fc)
615{
616 struct affs_context *ctx;
617
618 ctx = kzalloc(sizeof(struct affs_context), GFP_KERNEL);
619 if (!ctx)
620 return -ENOMEM;
621
622 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
623 struct super_block *sb = fc->root->d_sb;
624 struct affs_sb_info *sbi = AFFS_SB(sb);
625
626 /*
627 * NB: historically, no options other than volume were
628 * preserved across a remount unless they were explicitly
629 * passed in.
630 */
631 memcpy(ctx->volume, sbi->s_volume, 32);
632 } else {
633 ctx->uid = current_uid();
634 ctx->gid = current_gid();
635 ctx->reserved = 2;
636 ctx->root_block = -1;
637 ctx->blocksize = -1;
638 ctx->volume[0] = ':';
639 }
640
641 fc->ops = &affs_context_ops;
642 fc->fs_private = ctx;
643
644 return 0;
645}
646
647static struct file_system_type affs_fs_type = {
648 .owner = THIS_MODULE,
649 .name = "affs",
650 .kill_sb = affs_kill_sb,
651 .fs_flags = FS_REQUIRES_DEV,
652 .init_fs_context = affs_init_fs_context,
653 .parameters = affs_param_spec,
654};
655MODULE_ALIAS_FS("affs");
656
657static int __init init_affs_fs(void)
658{
659 int err = init_inodecache();
660 if (err)
661 goto out1;
662 err = register_filesystem(&affs_fs_type);
663 if (err)
664 goto out;
665 return 0;
666out:
667 destroy_inodecache();
668out1:
669 return err;
670}
671
672static void __exit exit_affs_fs(void)
673{
674 unregister_filesystem(&affs_fs_type);
675 destroy_inodecache();
676}
677
678MODULE_DESCRIPTION("Amiga filesystem support for Linux");
679MODULE_LICENSE("GPL");
680
681module_init(init_affs_fs)
682module_exit(exit_affs_fs)
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
28static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
29static int affs_show_options(struct seq_file *m, struct dentry *root);
30static int affs_remount (struct super_block *sb, int *flags, char *data);
31
32static void
33affs_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
49static void
50affs_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
58static int
59affs_sync_fs(struct super_block *sb, int wait)
60{
61 affs_commit_super(sb, wait);
62 return 0;
63}
64
65static 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
80void 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
97static struct kmem_cache * affs_inode_cachep;
98
99static 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
115static void affs_free_inode(struct inode *inode)
116{
117 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
118}
119
120static 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
129static 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|
134 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
135 init_once);
136 if (affs_inode_cachep == NULL)
137 return -ENOMEM;
138 return 0;
139}
140
141static void destroy_inodecache(void)
142{
143 /*
144 * Make sure all delayed rcu free inodes are flushed before we
145 * destroy cache.
146 */
147 rcu_barrier();
148 kmem_cache_destroy(affs_inode_cachep);
149}
150
151static const struct super_operations affs_sops = {
152 .alloc_inode = affs_alloc_inode,
153 .free_inode = affs_free_inode,
154 .write_inode = affs_write_inode,
155 .evict_inode = affs_evict_inode,
156 .put_super = affs_put_super,
157 .sync_fs = affs_sync_fs,
158 .statfs = affs_statfs,
159 .remount_fs = affs_remount,
160 .show_options = affs_show_options,
161};
162
163enum {
164 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
165 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
166 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
167};
168
169static const match_table_t tokens = {
170 {Opt_bs, "bs=%u"},
171 {Opt_mode, "mode=%o"},
172 {Opt_mufs, "mufs"},
173 {Opt_notruncate, "nofilenametruncate"},
174 {Opt_prefix, "prefix=%s"},
175 {Opt_protect, "protect"},
176 {Opt_reserved, "reserved=%u"},
177 {Opt_root, "root=%u"},
178 {Opt_setgid, "setgid=%u"},
179 {Opt_setuid, "setuid=%u"},
180 {Opt_verbose, "verbose"},
181 {Opt_volume, "volume=%s"},
182 {Opt_ignore, "grpquota"},
183 {Opt_ignore, "noquota"},
184 {Opt_ignore, "quota"},
185 {Opt_ignore, "usrquota"},
186 {Opt_err, NULL},
187};
188
189static int
190parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
191 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
192{
193 char *p;
194 substring_t args[MAX_OPT_ARGS];
195
196 /* Fill in defaults */
197
198 *uid = current_uid();
199 *gid = current_gid();
200 *reserved = 2;
201 *root = -1;
202 *blocksize = -1;
203 volume[0] = ':';
204 volume[1] = 0;
205 *mount_opts = 0;
206 if (!options)
207 return 1;
208
209 while ((p = strsep(&options, ",")) != NULL) {
210 int token, n, option;
211 if (!*p)
212 continue;
213
214 token = match_token(p, tokens, args);
215 switch (token) {
216 case Opt_bs:
217 if (match_int(&args[0], &n))
218 return 0;
219 if (n != 512 && n != 1024 && n != 2048
220 && n != 4096) {
221 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
222 return 0;
223 }
224 *blocksize = n;
225 break;
226 case Opt_mode:
227 if (match_octal(&args[0], &option))
228 return 0;
229 *mode = option & 0777;
230 affs_set_opt(*mount_opts, SF_SETMODE);
231 break;
232 case Opt_mufs:
233 affs_set_opt(*mount_opts, SF_MUFS);
234 break;
235 case Opt_notruncate:
236 affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
237 break;
238 case Opt_prefix:
239 kfree(*prefix);
240 *prefix = match_strdup(&args[0]);
241 if (!*prefix)
242 return 0;
243 affs_set_opt(*mount_opts, SF_PREFIX);
244 break;
245 case Opt_protect:
246 affs_set_opt(*mount_opts, SF_IMMUTABLE);
247 break;
248 case Opt_reserved:
249 if (match_int(&args[0], reserved))
250 return 0;
251 break;
252 case Opt_root:
253 if (match_int(&args[0], root))
254 return 0;
255 break;
256 case Opt_setgid:
257 if (match_int(&args[0], &option))
258 return 0;
259 *gid = make_kgid(current_user_ns(), option);
260 if (!gid_valid(*gid))
261 return 0;
262 affs_set_opt(*mount_opts, SF_SETGID);
263 break;
264 case Opt_setuid:
265 if (match_int(&args[0], &option))
266 return 0;
267 *uid = make_kuid(current_user_ns(), option);
268 if (!uid_valid(*uid))
269 return 0;
270 affs_set_opt(*mount_opts, SF_SETUID);
271 break;
272 case Opt_verbose:
273 affs_set_opt(*mount_opts, SF_VERBOSE);
274 break;
275 case Opt_volume: {
276 char *vol = match_strdup(&args[0]);
277 if (!vol)
278 return 0;
279 strscpy(volume, vol, 32);
280 kfree(vol);
281 break;
282 }
283 case Opt_ignore:
284 /* Silently ignore the quota options */
285 break;
286 default:
287 pr_warn("Unrecognized mount option \"%s\" or missing value\n",
288 p);
289 return 0;
290 }
291 }
292 return 1;
293}
294
295static int affs_show_options(struct seq_file *m, struct dentry *root)
296{
297 struct super_block *sb = root->d_sb;
298 struct affs_sb_info *sbi = AFFS_SB(sb);
299
300 if (sb->s_blocksize)
301 seq_printf(m, ",bs=%lu", sb->s_blocksize);
302 if (affs_test_opt(sbi->s_flags, SF_SETMODE))
303 seq_printf(m, ",mode=%o", sbi->s_mode);
304 if (affs_test_opt(sbi->s_flags, SF_MUFS))
305 seq_puts(m, ",mufs");
306 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
307 seq_puts(m, ",nofilenametruncate");
308 if (affs_test_opt(sbi->s_flags, SF_PREFIX))
309 seq_printf(m, ",prefix=%s", sbi->s_prefix);
310 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
311 seq_puts(m, ",protect");
312 if (sbi->s_reserved != 2)
313 seq_printf(m, ",reserved=%u", sbi->s_reserved);
314 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
315 seq_printf(m, ",root=%u", sbi->s_root_block);
316 if (affs_test_opt(sbi->s_flags, SF_SETGID))
317 seq_printf(m, ",setgid=%u",
318 from_kgid_munged(&init_user_ns, sbi->s_gid));
319 if (affs_test_opt(sbi->s_flags, SF_SETUID))
320 seq_printf(m, ",setuid=%u",
321 from_kuid_munged(&init_user_ns, sbi->s_uid));
322 if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
323 seq_puts(m, ",verbose");
324 if (sbi->s_volume[0])
325 seq_printf(m, ",volume=%s", sbi->s_volume);
326 return 0;
327}
328
329/* This function definitely needs to be split up. Some fine day I'll
330 * hopefully have the guts to do so. Until then: sorry for the mess.
331 */
332
333static int affs_fill_super(struct super_block *sb, void *data, int silent)
334{
335 struct affs_sb_info *sbi;
336 struct buffer_head *root_bh = NULL;
337 struct buffer_head *boot_bh;
338 struct inode *root_inode = NULL;
339 s32 root_block;
340 int size, blocksize;
341 u32 chksum;
342 int num_bm;
343 int i, j;
344 kuid_t uid;
345 kgid_t gid;
346 int reserved;
347 unsigned long mount_flags;
348 int tmp_flags; /* fix remount prototype... */
349 u8 sig[4];
350 int ret;
351
352 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
353
354 sb->s_magic = AFFS_SUPER_MAGIC;
355 sb->s_op = &affs_sops;
356 sb->s_flags |= SB_NODIRATIME;
357
358 sb->s_time_gran = NSEC_PER_SEC;
359 sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;
360 sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min;
361
362 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
363 if (!sbi)
364 return -ENOMEM;
365
366 sb->s_fs_info = sbi;
367 sbi->sb = sb;
368 mutex_init(&sbi->s_bmlock);
369 spin_lock_init(&sbi->symlink_lock);
370 spin_lock_init(&sbi->work_lock);
371 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
372
373 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
374 &blocksize,&sbi->s_prefix,
375 sbi->s_volume, &mount_flags)) {
376 pr_err("Error parsing options\n");
377 return -EINVAL;
378 }
379 /* N.B. after this point s_prefix must be released */
380
381 sbi->s_flags = mount_flags;
382 sbi->s_mode = i;
383 sbi->s_uid = uid;
384 sbi->s_gid = gid;
385 sbi->s_reserved= reserved;
386
387 /* Get the size of the device in 512-byte blocks.
388 * If we later see that the partition uses bigger
389 * blocks, we will have to change it.
390 */
391
392 size = bdev_nr_sectors(sb->s_bdev);
393 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
394
395 affs_set_blocksize(sb, PAGE_SIZE);
396 /* Try to find root block. Its location depends on the block size. */
397
398 i = bdev_logical_block_size(sb->s_bdev);
399 j = PAGE_SIZE;
400 if (blocksize > 0) {
401 i = j = blocksize;
402 size = size / (blocksize / 512);
403 }
404
405 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
406 sbi->s_root_block = root_block;
407 if (root_block < 0)
408 sbi->s_root_block = (reserved + size - 1) / 2;
409 pr_debug("setting blocksize to %d\n", blocksize);
410 affs_set_blocksize(sb, blocksize);
411 sbi->s_partition_size = size;
412
413 /* The root block location that was calculated above is not
414 * correct if the partition size is an odd number of 512-
415 * byte blocks, which will be rounded down to a number of
416 * 1024-byte blocks, and if there were an even number of
417 * reserved blocks. Ideally, all partition checkers should
418 * report the real number of blocks of the real blocksize,
419 * but since this just cannot be done, we have to try to
420 * find the root block anyways. In the above case, it is one
421 * block behind the calculated one. So we check this one, too.
422 */
423 for (num_bm = 0; num_bm < 2; num_bm++) {
424 pr_debug("Dev %s, trying root=%u, bs=%d, "
425 "size=%d, reserved=%d\n",
426 sb->s_id,
427 sbi->s_root_block + num_bm,
428 blocksize, size, reserved);
429 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
430 if (!root_bh)
431 continue;
432 if (!affs_checksum_block(sb, root_bh) &&
433 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
434 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
435 sbi->s_hashsize = blocksize / 4 - 56;
436 sbi->s_root_block += num_bm;
437 goto got_root;
438 }
439 affs_brelse(root_bh);
440 root_bh = NULL;
441 }
442 }
443 if (!silent)
444 pr_err("No valid root block on device %s\n", sb->s_id);
445 return -EINVAL;
446
447 /* N.B. after this point bh must be released */
448got_root:
449 /* Keep super block in cache */
450 sbi->s_root_bh = root_bh;
451 root_block = sbi->s_root_block;
452
453 /* Find out which kind of FS we have */
454 boot_bh = sb_bread(sb, 0);
455 if (!boot_bh) {
456 pr_err("Cannot read boot block\n");
457 return -EINVAL;
458 }
459 memcpy(sig, boot_bh->b_data, 4);
460 brelse(boot_bh);
461 chksum = be32_to_cpu(*(__be32 *)sig);
462
463 /* Dircache filesystems are compatible with non-dircache ones
464 * when reading. As long as they aren't supported, writing is
465 * not recommended.
466 */
467 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
468 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) {
469 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
470 sb->s_flags |= SB_RDONLY;
471 }
472 switch (chksum) {
473 case MUFS_FS:
474 case MUFS_INTLFFS:
475 case MUFS_DCFFS:
476 affs_set_opt(sbi->s_flags, SF_MUFS);
477 fallthrough;
478 case FS_INTLFFS:
479 case FS_DCFFS:
480 affs_set_opt(sbi->s_flags, SF_INTL);
481 break;
482 case MUFS_FFS:
483 affs_set_opt(sbi->s_flags, SF_MUFS);
484 break;
485 case FS_FFS:
486 break;
487 case MUFS_OFS:
488 affs_set_opt(sbi->s_flags, SF_MUFS);
489 fallthrough;
490 case FS_OFS:
491 affs_set_opt(sbi->s_flags, SF_OFS);
492 sb->s_flags |= SB_NOEXEC;
493 break;
494 case MUFS_DCOFS:
495 case MUFS_INTLOFS:
496 affs_set_opt(sbi->s_flags, SF_MUFS);
497 fallthrough;
498 case FS_DCOFS:
499 case FS_INTLOFS:
500 affs_set_opt(sbi->s_flags, SF_INTL);
501 affs_set_opt(sbi->s_flags, SF_OFS);
502 sb->s_flags |= SB_NOEXEC;
503 break;
504 default:
505 pr_err("Unknown filesystem on device %s: %08X\n",
506 sb->s_id, chksum);
507 return -EINVAL;
508 }
509
510 if (affs_test_opt(mount_flags, SF_VERBOSE)) {
511 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
512 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
513 len > 31 ? 31 : len,
514 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
515 sig, sig[3] + '0', blocksize);
516 }
517
518 sb->s_flags |= SB_NODEV | SB_NOSUID;
519
520 sbi->s_data_blksize = sb->s_blocksize;
521 if (affs_test_opt(sbi->s_flags, SF_OFS))
522 sbi->s_data_blksize -= 24;
523
524 tmp_flags = sb->s_flags;
525 ret = affs_init_bitmap(sb, &tmp_flags);
526 if (ret)
527 return ret;
528 sb->s_flags = tmp_flags;
529
530 /* set up enough so that it can read an inode */
531
532 root_inode = affs_iget(sb, root_block);
533 if (IS_ERR(root_inode))
534 return PTR_ERR(root_inode);
535
536 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
537 sb->s_d_op = &affs_intl_dentry_operations;
538 else
539 sb->s_d_op = &affs_dentry_operations;
540
541 sb->s_root = d_make_root(root_inode);
542 if (!sb->s_root) {
543 pr_err("AFFS: Get root inode failed\n");
544 return -ENOMEM;
545 }
546
547 sb->s_export_op = &affs_export_ops;
548 pr_debug("s_flags=%lX\n", sb->s_flags);
549 return 0;
550}
551
552static int
553affs_remount(struct super_block *sb, int *flags, char *data)
554{
555 struct affs_sb_info *sbi = AFFS_SB(sb);
556 int blocksize;
557 kuid_t uid;
558 kgid_t gid;
559 int mode;
560 int reserved;
561 int root_block;
562 unsigned long mount_flags;
563 int res = 0;
564 char volume[32];
565 char *prefix = NULL;
566
567 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
568
569 sync_filesystem(sb);
570 *flags |= SB_NODIRATIME;
571
572 memcpy(volume, sbi->s_volume, 32);
573 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
574 &blocksize, &prefix, volume,
575 &mount_flags)) {
576 kfree(prefix);
577 return -EINVAL;
578 }
579
580 flush_delayed_work(&sbi->sb_work);
581
582 sbi->s_flags = mount_flags;
583 sbi->s_mode = mode;
584 sbi->s_uid = uid;
585 sbi->s_gid = gid;
586 /* protect against readers */
587 spin_lock(&sbi->symlink_lock);
588 if (prefix) {
589 kfree(sbi->s_prefix);
590 sbi->s_prefix = prefix;
591 }
592 memcpy(sbi->s_volume, volume, 32);
593 spin_unlock(&sbi->symlink_lock);
594
595 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
596 return 0;
597
598 if (*flags & SB_RDONLY)
599 affs_free_bitmap(sb);
600 else
601 res = affs_init_bitmap(sb, flags);
602
603 return res;
604}
605
606static int
607affs_statfs(struct dentry *dentry, struct kstatfs *buf)
608{
609 struct super_block *sb = dentry->d_sb;
610 int free;
611 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
612
613 pr_debug("%s() partsize=%d, reserved=%d\n",
614 __func__, AFFS_SB(sb)->s_partition_size,
615 AFFS_SB(sb)->s_reserved);
616
617 free = affs_count_free_blocks(sb);
618 buf->f_type = AFFS_SUPER_MAGIC;
619 buf->f_bsize = sb->s_blocksize;
620 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
621 buf->f_bfree = free;
622 buf->f_bavail = free;
623 buf->f_fsid = u64_to_fsid(id);
624 buf->f_namelen = AFFSNAMEMAX;
625 return 0;
626}
627
628static struct dentry *affs_mount(struct file_system_type *fs_type,
629 int flags, const char *dev_name, void *data)
630{
631 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
632}
633
634static void affs_kill_sb(struct super_block *sb)
635{
636 struct affs_sb_info *sbi = AFFS_SB(sb);
637 kill_block_super(sb);
638 if (sbi) {
639 affs_free_bitmap(sb);
640 affs_brelse(sbi->s_root_bh);
641 kfree(sbi->s_prefix);
642 mutex_destroy(&sbi->s_bmlock);
643 kfree(sbi);
644 }
645}
646
647static struct file_system_type affs_fs_type = {
648 .owner = THIS_MODULE,
649 .name = "affs",
650 .mount = affs_mount,
651 .kill_sb = affs_kill_sb,
652 .fs_flags = FS_REQUIRES_DEV,
653};
654MODULE_ALIAS_FS("affs");
655
656static int __init init_affs_fs(void)
657{
658 int err = init_inodecache();
659 if (err)
660 goto out1;
661 err = register_filesystem(&affs_fs_type);
662 if (err)
663 goto out;
664 return 0;
665out:
666 destroy_inodecache();
667out1:
668 return err;
669}
670
671static void __exit exit_affs_fs(void)
672{
673 unregister_filesystem(&affs_fs_type);
674 destroy_inodecache();
675}
676
677MODULE_DESCRIPTION("Amiga filesystem support for Linux");
678MODULE_LICENSE("GPL");
679
680module_init(init_affs_fs)
681module_exit(exit_affs_fs)