aboutsummaryrefslogtreecommitdiff
path: root/fs/affs/super.c
blob: beff7d21e6e2f769064e87e92359a133790fedf0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
/*
 *  linux/fs/affs/inode.c
 *
 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
 *
 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
 *
 *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/statfs.h>
#include <linux/parser.h>
#include <linux/magic.h>
#include "affs.h"

extern struct timezone sys_tz;

static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int affs_remount (struct super_block *sb, int *flags, char *data);

static void
affs_put_super(struct super_block *sb)
{
	struct affs_sb_info *sbi = AFFS_SB(sb);
	pr_debug("AFFS: put_super()\n");

	if (!(sb->s_flags & MS_RDONLY)) {
		AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
		secs_to_datestamp(get_seconds(),
				  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
		affs_fix_checksum(sb, sbi->s_root_bh);
		mark_buffer_dirty(sbi->s_root_bh);
	}

	kfree(sbi->s_prefix);
	affs_free_bitmap(sb);
	affs_brelse(sbi->s_root_bh);
	kfree(sbi);
	sb->s_fs_info = NULL;
	return;
}

static void
affs_write_super(struct super_block *sb)
{
	int clean = 2;
	struct affs_sb_info *sbi = AFFS_SB(sb);

	if (!(sb->s_flags & MS_RDONLY)) {
		//	if (sbi->s_bitmap[i].bm_bh) {
		//		if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
		//			clean = 0;
		AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
		secs_to_datestamp(get_seconds(),
				  &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
		affs_fix_checksum(sb, sbi->s_root_bh);
		mark_buffer_dirty(sbi->s_root_bh);
		sb->s_dirt = !clean;	/* redo until bitmap synced */
	} else
		sb->s_dirt = 0;

	pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
}

static struct kmem_cache * affs_inode_cachep;

static struct inode *affs_alloc_inode(struct super_block *sb)
{
	struct affs_inode_info *ei;
	ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	ei->vfs_inode.i_version = 1;
	return &ei->vfs_inode;
}

static void affs_destroy_inode(struct inode *inode)
{
	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
}

static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
{
	struct affs_inode_info *ei = (struct affs_inode_info *) foo;

	if (flags & SLAB_CTOR_CONSTRUCTOR) {
		init_MUTEX(&ei->i_link_lock);
		init_MUTEX(&ei->i_ext_lock);
		inode_init_once(&ei->vfs_inode);
	}
}

static int init_inodecache(void)
{
	affs_inode_cachep = kmem_cache_create("affs_inode_cache",
					     sizeof(struct affs_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once, NULL);
	if (affs_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	kmem_cache_destroy(affs_inode_cachep);
}

static const struct super_operations affs_sops = {
	.alloc_inode	= affs_alloc_inode,
	.destroy_inode	= affs_destroy_inode,
	.read_inode	= affs_read_inode,
	.write_inode	= affs_write_inode,
	.put_inode	= affs_put_inode,
	.drop_inode	= affs_drop_inode,
	.delete_inode	= affs_delete_inode,
	.clear_inode	= affs_clear_inode,
	.put_super	= affs_put_super,
	.write_super	= affs_write_super,
	.statfs		= affs_statfs,
	.remount_fs	= affs_remount,
};

enum {
	Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
	Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
};

static match_table_t tokens = {
	{Opt_bs, "bs=%u"},
	{Opt_mode, "mode=%o"},
	{Opt_mufs, "mufs"},
	{Opt_prefix, "prefix=%s"},
	{Opt_protect, "protect"},
	{Opt_reserved, "reserved=%u"},
	{Opt_root, "root=%u"},
	{Opt_setgid, "setgid=%u"},
	{Opt_setuid, "setuid=%u"},
	{Opt_verbose, "verbose"},
	{Opt_volume, "volume=%s"},
	{Opt_ignore, "grpquota"},
	{Opt_ignore, "noquota"},
	{Opt_ignore, "quota"},
	{Opt_ignore, "usrquota"},
	{Opt_err, NULL},
};

static int
parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
		int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];

	/* Fill in defaults */

	*uid        = current->uid;
	*gid        = current->gid;
	*reserved   = 2;
	*root       = -1;
	*blocksize  = -1;
	volume[0]   = ':';
	volume[1]   = 0;
	*mount_opts = 0;
	if (!options)
		return 1;

	while ((p = strsep(&options, ",")) != NULL) {
		int token, n, option;
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_bs:
			if (match_int(&args[0], &n))
				return -EINVAL;
			if (n != 512 && n != 1024 && n != 2048
			    && n != 4096) {
				printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
				return 0;
			}
			*blocksize = n;
			break;
		case Opt_mode:
			if (match_octal(&args[0], &option))
				return 1;
			*mode = option & 0777;
			*mount_opts |= SF_SETMODE;
			break;
		case Opt_mufs:
			*mount_opts |= SF_MUFS;
			break;
		case Opt_prefix:
			/* Free any previous prefix */
			kfree(*prefix);
			*prefix = NULL;
			*prefix = match_strdup(&args[0]);
			if (!*prefix)
				return 0;
			*mount_opts |= SF_PREFIX;
			break;
		case Opt_protect:
			*mount_opts |= SF_IMMUTABLE;
			break;
		case Opt_reserved:
			if (match_int(&args[0], reserved))
				return 1;
			break;
		case Opt_root:
			if (match_int(&args[0], root))
				return 1;
			break;
		case Opt_setgid:
			if (match_int(&args[0], &option))
				return 1;
			*gid = option;
			*mount_opts |= SF_SETGID;
			break;
		case Opt_setuid:
			if (match_int(&args[0], &option))
				return -EINVAL;
			*uid = option;
			*mount_opts |= SF_SETUID;
			break;
		case Opt_verbose:
			*mount_opts |= SF_VERBOSE;
			break;
		case Opt_volume: {
			char *vol = match_strdup(&args[0]);
			strlcpy(volume, vol, 32);
			kfree(vol);
			break;
		}
		case Opt_ignore:
		 	/* Silently ignore the quota options */
			break;
		default:
			printk("AFFS: Unrecognized mount option \"%s\" "
					"or missing value\n", p);
			return 0;
		}
	}
	return 1;
}

/* This function definitely needs to be split up. Some fine day I'll
 * hopefully have the guts to do so. Until then: sorry for the mess.
 */

static int affs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct affs_sb_info	*sbi;
	struct buffer_head	*root_bh = NULL;
	struct buffer_head	*boot_bh;
	struct inode		*root_inode = NULL;
	s32			 root_block;
	int			 size, blocksize;
	u32			 chksum;
	int			 num_bm;
	int			 i, j;
	s32			 key;
	uid_t			 uid;
	gid_t			 gid;
	int			 reserved;
	unsigned long		 mount_flags;
	int			 tmp_flags;	/* fix remount prototype... */
	u8			 sig[4];

	pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");

	sb->s_magic             = AFFS_SUPER_MAGIC;
	sb->s_op                = &affs_sops;
	sb->s_flags |= MS_NODIRATIME;

	sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;
	sb->s_fs_info = sbi;
	init_MUTEX(&sbi->s_bmlock);

	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
				&blocksize,&sbi->s_prefix,
				sbi->s_volume, &mount_flags)) {
		printk(KERN_ERR "AFFS: Error parsing options\n");
		return -EINVAL;
	}
	/* N.B. after this point s_prefix must be released */

	sbi->s_flags   = mount_flags;
	sbi->s_mode    = i;
	sbi->s_uid     = uid;
	sbi->s_gid     = gid;
	sbi->s_reserved= reserved;

	/* Get the size of the device in 512-byte blocks.
	 * If we later see that the partition uses bigger
	 * blocks, we will have to change it.
	 */

	size = sb->s_bdev->bd_inode->i_size >> 9;
	pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);

	affs_set_blocksize(sb, PAGE_SIZE);
	/* Try to find root block. Its location depends on the block size. */

	i = 512;
	j = 4096;
	if (blocksize > 0) {
		i = j = blocksize;
		size = size / (blocksize / 512);
	}
	for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
		sbi->s_root_block = root_block;
		if (root_block < 0)
			sbi->s_root_block = (reserved + size - 1) / 2;
		pr_debug("AFFS: setting blocksize to %d\n", blocksize);
		affs_set_blocksize(sb, blocksize);
		sbi->s_partition_size = size;

		/* The root block location that was calculated above is not
		 * correct if the partition size is an odd number of 512-
		 * byte blocks, which will be rounded down to a number of
		 * 1024-byte blocks, and if there were an even number of
		 * reserved blocks. Ideally, all partition checkers should
		 * report the real number of blocks of the real blocksize,
		 * but since this just cannot be done, we have to try to
		 * find the root block anyways. In the above case, it is one
		 * block behind the calculated one. So we check this one, too.
		 */
		for (num_bm = 0; num_bm < 2; num_bm++) {
			pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
				"size=%d, reserved=%d\n",
				sb->s_id,
				sbi->s_root_block + num_bm,
				blocksize, size, reserved);
			root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
			if (!root_bh)
				continue;
			if (!affs_checksum_block(sb, root_bh) &&
			    be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
			    be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
				sbi->s_hashsize    = blocksize / 4 - 56;
				sbi->s_root_block += num_bm;
				key                        = 1;
				goto got_root;
			}
			affs_brelse(root_bh);
			root_bh = NULL;
		}
	}
	if (!silent)
		printk(KERN_ERR "AFFS: No valid root block on device %s\n",
			sb->s_id);
	goto out_error;

	/* N.B. after this point bh must be released */
got_root:
	root_block = sbi->s_root_block;

	/* Find out which kind of FS we have */
	boot_bh = sb_bread(sb, 0);
	if (!boot_bh) {
		printk(KERN_ERR "AFFS: Cannot read boot block\n");
		goto out_error;
	}
	memcpy(sig, boot_bh->b_data, 4);
	brelse(boot_bh);
	chksum = be32_to_cpu(*(__be32 *)sig);

	/* Dircache filesystems are compatible with non-dircache ones
	 * when reading. As long as they aren't supported, writing is
	 * not recommended.
	 */
	if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
	     || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
		printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
			sb->s_id);
		sb->s_flags |= MS_RDONLY;
	}
	switch (chksum) {
		case MUFS_FS:
		case MUFS_INTLFFS:
		case MUFS_DCFFS:
			sbi->s_flags |= SF_MUFS;
			/* fall thru */
		case FS_INTLFFS:
		case FS_DCFFS:
			sbi->s_flags |= SF_INTL;
			break;
		case MUFS_FFS:
			sbi->s_flags |= SF_MUFS;
			break;
		case FS_FFS:
			break;
		case MUFS_OFS:
			sbi->s_flags |= SF_MUFS;
			/* fall thru */
		case FS_OFS:
			sbi->s_flags |= SF_OFS;
			sb->s_flags |= MS_NOEXEC;
			break;
		case MUFS_DCOFS:
		case MUFS_INTLOFS:
			sbi->s_flags |= SF_MUFS;
		case FS_DCOFS:
		case FS_INTLOFS:
			sbi->s_flags |= SF_INTL | SF_OFS;
			sb->s_flags |= MS_NOEXEC;
			break;
		default:
			printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
				sb->s_id, chksum);
			goto out_error;
	}

	if (mount_flags & SF_VERBOSE) {
		u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
		printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
			len > 31 ? 31 : len,
			AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
			sig, sig[3] + '0', blocksize);
	}

	sb->s_flags |= MS_NODEV | MS_NOSUID;

	sbi->s_data_blksize = sb->s_blocksize;
	if (sbi->s_flags & SF_OFS)
		sbi->s_data_blksize -= 24;

	/* Keep super block in cache */
	sbi->s_root_bh = root_bh;
	/* N.B. after this point s_root_bh must be released */

	tmp_flags = sb->s_flags;
	if (affs_init_bitmap(sb, &tmp_flags))
		goto out_error;
	sb->s_flags = tmp_flags;

	/* set up enough so that it can read an inode */

	root_inode = iget(sb, root_block);
	sb->s_root = d_alloc_root(root_inode);
	if (!sb->s_root) {
		printk(KERN_ERR "AFFS: Get root inode failed\n");
		goto out_error;
	}
	sb->s_root->d_op = &affs_dentry_operations;

	pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
	return 0;

	/*
	 * Begin the cascaded cleanup ...
	 */
out_error:
	if (root_inode)
		iput(root_inode);
	kfree(sbi->s_bitmap);
	affs_brelse(root_bh);
	kfree(sbi->s_prefix);
	kfree(sbi);
	sb->s_fs_info = NULL;
	return -EINVAL;
}

static int
affs_remount(struct super_block *sb, int *flags, char *data)
{
	struct affs_sb_info	*sbi = AFFS_SB(sb);
	int			 blocksize;
	uid_t			 uid;
	gid_t			 gid;
	int			 mode;
	int			 reserved;
	int			 root_block;
	unsigned long		 mount_flags;
	int			 res = 0;

	pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);

	*flags |= MS_NODIRATIME;

	if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
	    &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
		return -EINVAL;
	sbi->s_flags = mount_flags;
	sbi->s_mode  = mode;
	sbi->s_uid   = uid;
	sbi->s_gid   = gid;

	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
		return 0;
	if (*flags & MS_RDONLY) {
		sb->s_dirt = 1;
		while (sb->s_dirt)
			affs_write_super(sb);
		affs_free_bitmap(sb);
	} else
		res = affs_init_bitmap(sb, flags);

	return res;
}

static int
affs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
	int		 free;

	pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
	     AFFS_SB(sb)->s_reserved);

	free          = affs_count_free_blocks(sb);
	buf->f_type    = AFFS_SUPER_MAGIC;
	buf->f_bsize   = sb->s_blocksize;
	buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
	buf->f_bfree   = free;
	buf->f_bavail  = free;
	return 0;
}

static int affs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
			   mnt);
}

static struct file_system_type affs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "affs",
	.get_sb		= affs_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

static int __init init_affs_fs(void)
{
	int err = init_inodecache();
	if (err)
		goto out1;
	err = register_filesystem(&affs_fs_type);
	if (err)
		goto out;
	return 0;
out:
	destroy_inodecache();
out1:
	return err;
}

static void __exit exit_affs_fs(void)
{
	unregister_filesystem(&affs_fs_type);
	destroy_inodecache();
}

MODULE_DESCRIPTION("Amiga filesystem support for Linux");
MODULE_LICENSE("GPL");

module_init(init_affs_fs)
module_exit(exit_affs_fs)