summaryrefslogtreecommitdiff
path: root/fs/affs/namei.c
blob: 9ad22befce28888389b2723be48c4337253a150a (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
570
571
572
573
574
575
576
577
578
579
580
581
582
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/affs/namei.c
 *
 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
 *
 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 */

#include "affs.h"
#include <linux/exportfs.h>

typedef int (*toupper_t)(int);

/* Simple toupper() for DOS\1 */

static int
affs_toupper(int ch)
{
	return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
}

/* International toupper() for DOS\3 ("international") */

static int
affs_intl_toupper(int ch)
{
	return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
		&& ch <= 0xFE && ch != 0xF7) ?
		ch - ('a' - 'A') : ch;
}

static inline toupper_t
affs_get_toupper(struct super_block *sb)
{
	return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ?
	       affs_intl_toupper : affs_toupper;
}

/*
 * Note: the dentry argument is the parent dentry.
 */
static inline int
__affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t toupper, bool notruncate)
{
	const u8 *name = qstr->name;
	unsigned long hash;
	int retval;
	u32 len;

	retval = affs_check_name(qstr->name, qstr->len, notruncate);
	if (retval)
		return retval;

	hash = init_name_hash(dentry);
	len = min(qstr->len, AFFSNAMEMAX);
	for (; len > 0; name++, len--)
		hash = partial_name_hash(toupper(*name), hash);
	qstr->hash = end_name_hash(hash);

	return 0;
}

static int
affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
{
	return __affs_hash_dentry(dentry, qstr, affs_toupper,
				  affs_nofilenametruncate(dentry));

}

static int
affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
{
	return __affs_hash_dentry(dentry, qstr, affs_intl_toupper,
				  affs_nofilenametruncate(dentry));

}

static inline int __affs_compare_dentry(unsigned int len,
		const char *str, const struct qstr *name, toupper_t toupper,
		bool notruncate)
{
	const u8 *aname = str;
	const u8 *bname = name->name;

	/*
	 * 'str' is the name of an already existing dentry, so the name
	 * must be valid. 'name' must be validated first.
	 */

	if (affs_check_name(name->name, name->len, notruncate))
		return 1;

	/*
	 * If the names are longer than the allowed 30 chars,
	 * the excess is ignored, so their length may differ.
	 */
	if (len >= AFFSNAMEMAX) {
		if (name->len < AFFSNAMEMAX)
			return 1;
		len = AFFSNAMEMAX;
	} else if (len != name->len)
		return 1;

	for (; len > 0; len--)
		if (toupper(*aname++) != toupper(*bname++))
			return 1;

	return 0;
}

static int
affs_compare_dentry(const struct dentry *dentry,
		unsigned int len, const char *str, const struct qstr *name)
{

	return __affs_compare_dentry(len, str, name, affs_toupper,
				     affs_nofilenametruncate(dentry));
}

static int
affs_intl_compare_dentry(const struct dentry *dentry,
		unsigned int len, const char *str, const struct qstr *name)
{
	return __affs_compare_dentry(len, str, name, affs_intl_toupper,
				     affs_nofilenametruncate(dentry));

}

/*
 * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
 */

static inline int
affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
{
	const u8 *name = dentry->d_name.name;
	int len = dentry->d_name.len;

	if (len >= AFFSNAMEMAX) {
		if (*name2 < AFFSNAMEMAX)
			return 0;
		len = AFFSNAMEMAX;
	} else if (len != *name2)
		return 0;

	for (name2++; len > 0; len--)
		if (toupper(*name++) != toupper(*name2++))
			return 0;
	return 1;
}

int
affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
{
	toupper_t toupper = affs_get_toupper(sb);
	u32 hash;

	hash = len = min(len, AFFSNAMEMAX);
	for (; len > 0; len--)
		hash = (hash * 13 + toupper(*name++)) & 0x7ff;

	return hash % AFFS_SB(sb)->s_hashsize;
}

static struct buffer_head *
affs_find_entry(struct inode *dir, struct dentry *dentry)
{
	struct super_block *sb = dir->i_sb;
	struct buffer_head *bh;
	toupper_t toupper = affs_get_toupper(sb);
	u32 key;

	pr_debug("%s(\"%pd\")\n", __func__, dentry);

	bh = affs_bread(sb, dir->i_ino);
	if (!bh)
		return ERR_PTR(-EIO);

	key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);

	for (;;) {
		affs_brelse(bh);
		if (key == 0)
			return NULL;
		bh = affs_bread(sb, key);
		if (!bh)
			return ERR_PTR(-EIO);
		if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
			return bh;
		key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
	}
}

struct dentry *
affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	struct super_block *sb = dir->i_sb;
	struct buffer_head *bh;
	struct inode *inode = NULL;
	struct dentry *res;

	pr_debug("%s(\"%pd\")\n", __func__, dentry);

	affs_lock_dir(dir);
	bh = affs_find_entry(dir, dentry);
	if (IS_ERR(bh)) {
		affs_unlock_dir(dir);
		return ERR_CAST(bh);
	}
	if (bh) {
		u32 ino = bh->b_blocknr;

		/* store the real header ino in d_fsdata for faster lookups */
		dentry->d_fsdata = (void *)(long)ino;
		switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
		//link to dirs disabled
		//case ST_LINKDIR:
		case ST_LINKFILE:
			ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
		}
		affs_brelse(bh);
		inode = affs_iget(sb, ino);
	}
	res = d_splice_alias(inode, dentry);
	if (!IS_ERR_OR_NULL(res))
		res->d_fsdata = dentry->d_fsdata;
	affs_unlock_dir(dir);
	return res;
}

int
affs_unlink(struct inode *dir, struct dentry *dentry)
{
	pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
		 d_inode(dentry)->i_ino, dentry);

	return affs_remove_header(dentry);
}

int
affs_create(struct user_namespace *mnt_userns, struct inode *dir,
	    struct dentry *dentry, umode_t mode, bool excl)
{
	struct super_block *sb = dir->i_sb;
	struct inode	*inode;
	int		 error;

	pr_debug("%s(%lu,\"%pd\",0%ho)\n",
		 __func__, dir->i_ino, dentry, mode);

	inode = affs_new_inode(dir);
	if (!inode)
		return -ENOSPC;

	inode->i_mode = mode;
	affs_mode_to_prot(inode);
	mark_inode_dirty(inode);

	inode->i_op = &affs_file_inode_operations;
	inode->i_fop = &affs_file_operations;
	inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ?
				  &affs_aops_ofs : &affs_aops;
	error = affs_add_entry(dir, inode, dentry, ST_FILE);
	if (error) {
		clear_nlink(inode);
		iput(inode);
		return error;
	}
	return 0;
}

int
affs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
	   struct dentry *dentry, umode_t mode)
{
	struct inode		*inode;
	int			 error;

	pr_debug("%s(%lu,\"%pd\",0%ho)\n",
		 __func__, dir->i_ino, dentry, mode);

	inode = affs_new_inode(dir);
	if (!inode)
		return -ENOSPC;

	inode->i_mode = S_IFDIR | mode;
	affs_mode_to_prot(inode);

	inode->i_op = &affs_dir_inode_operations;
	inode->i_fop = &affs_dir_operations;

	error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
	if (error) {
		clear_nlink(inode);
		mark_inode_dirty(inode);
		iput(inode);
		return error;
	}
	return 0;
}

int
affs_rmdir(struct inode *dir, struct dentry *dentry)
{
	pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
		 d_inode(dentry)->i_ino, dentry);

	return affs_remove_header(dentry);
}

int
affs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
	     struct dentry *dentry, const char *symname)
{
	struct super_block	*sb = dir->i_sb;
	struct buffer_head	*bh;
	struct inode		*inode;
	char			*p;
	int			 i, maxlen, error;
	char			 c, lc;

	pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n",
		 __func__, dir->i_ino, dentry, symname);

	maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
	inode  = affs_new_inode(dir);
	if (!inode)
		return -ENOSPC;

	inode->i_op = &affs_symlink_inode_operations;
	inode_nohighmem(inode);
	inode->i_data.a_ops = &affs_symlink_aops;
	inode->i_mode = S_IFLNK | 0777;
	affs_mode_to_prot(inode);

	error = -EIO;
	bh = affs_bread(sb, inode->i_ino);
	if (!bh)
		goto err;
	i  = 0;
	p  = (char *)AFFS_HEAD(bh)->table;
	lc = '/';
	if (*symname == '/') {
		struct affs_sb_info *sbi = AFFS_SB(sb);
		while (*symname == '/')
			symname++;
		spin_lock(&sbi->symlink_lock);
		while (sbi->s_volume[i])	/* Cannot overflow */
			*p++ = sbi->s_volume[i++];
		spin_unlock(&sbi->symlink_lock);
	}
	while (i < maxlen && (c = *symname++)) {
		if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
			*p++ = '/';
			i++;
			symname += 2;
			lc = '/';
		} else if (c == '.' && lc == '/' && *symname == '/') {
			symname++;
			lc = '/';
		} else {
			*p++ = c;
			lc   = c;
			i++;
		}
		if (lc == '/')
			while (*symname == '/')
				symname++;
	}
	*p = 0;
	inode->i_size = i + 1;
	mark_buffer_dirty_inode(bh, inode);
	affs_brelse(bh);
	mark_inode_dirty(inode);

	error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
	if (error)
		goto err;

	return 0;

err:
	clear_nlink(inode);
	mark_inode_dirty(inode);
	iput(inode);
	return error;
}

int
affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = d_inode(old_dentry);

	pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
		 dentry);

	return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
}

static int
affs_rename(struct inode *old_dir, struct dentry *old_dentry,
	    struct inode *new_dir, struct dentry *new_dentry)
{
	struct super_block *sb = old_dir->i_sb;
	struct buffer_head *bh = NULL;
	int retval;

	retval = affs_check_name(new_dentry->d_name.name,
				 new_dentry->d_name.len,
				 affs_nofilenametruncate(old_dentry));

	if (retval)
		return retval;

	/* Unlink destination if it already exists */
	if (d_really_is_positive(new_dentry)) {
		retval = affs_remove_header(new_dentry);
		if (retval)
			return retval;
	}

	bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
	if (!bh)
		return -EIO;

	/* Remove header from its parent directory. */
	affs_lock_dir(old_dir);
	retval = affs_remove_hash(old_dir, bh);
	affs_unlock_dir(old_dir);
	if (retval)
		goto done;

	/* And insert it into the new directory with the new name. */
	affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
	affs_fix_checksum(sb, bh);
	affs_lock_dir(new_dir);
	retval = affs_insert_hash(new_dir, bh);
	affs_unlock_dir(new_dir);
	/* TODO: move it back to old_dir, if error? */

done:
	mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
	affs_brelse(bh);
	return retval;
}

static int
affs_xrename(struct inode *old_dir, struct dentry *old_dentry,
	     struct inode *new_dir, struct dentry *new_dentry)
{

	struct super_block *sb = old_dir->i_sb;
	struct buffer_head *bh_old = NULL;
	struct buffer_head *bh_new = NULL;
	int retval;

	bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino);
	if (!bh_old)
		return -EIO;

	bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
	if (!bh_new)
		return -EIO;

	/* Remove old header from its parent directory. */
	affs_lock_dir(old_dir);
	retval = affs_remove_hash(old_dir, bh_old);
	affs_unlock_dir(old_dir);
	if (retval)
		goto done;

	/* Remove new header from its parent directory. */
	affs_lock_dir(new_dir);
	retval = affs_remove_hash(new_dir, bh_new);
	affs_unlock_dir(new_dir);
	if (retval)
		goto done;

	/* Insert old into the new directory with the new name. */
	affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry);
	affs_fix_checksum(sb, bh_old);
	affs_lock_dir(new_dir);
	retval = affs_insert_hash(new_dir, bh_old);
	affs_unlock_dir(new_dir);

	/* Insert new into the old directory with the old name. */
	affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry);
	affs_fix_checksum(sb, bh_new);
	affs_lock_dir(old_dir);
	retval = affs_insert_hash(old_dir, bh_new);
	affs_unlock_dir(old_dir);
done:
	mark_buffer_dirty_inode(bh_old, new_dir);
	mark_buffer_dirty_inode(bh_new, old_dir);
	affs_brelse(bh_old);
	affs_brelse(bh_new);
	return retval;
}

int affs_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
		 struct dentry *old_dentry, struct inode *new_dir,
		 struct dentry *new_dentry, unsigned int flags)
{

	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
		return -EINVAL;

	pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__,
		 old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);

	if (flags & RENAME_EXCHANGE)
		return affs_xrename(old_dir, old_dentry, new_dir, new_dentry);

	return affs_rename(old_dir, old_dentry, new_dir, new_dentry);
}

static struct dentry *affs_get_parent(struct dentry *child)
{
	struct inode *parent;
	struct buffer_head *bh;

	bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
	if (!bh)
		return ERR_PTR(-EIO);

	parent = affs_iget(child->d_sb,
			   be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
	brelse(bh);
	if (IS_ERR(parent))
		return ERR_CAST(parent);

	return d_obtain_alias(parent);
}

static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
					u32 generation)
{
	struct inode *inode;

	if (!affs_validblock(sb, ino))
		return ERR_PTR(-ESTALE);

	inode = affs_iget(sb, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	return inode;
}

static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
					int fh_len, int fh_type)
{
	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
				    affs_nfs_get_inode);
}

static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
					int fh_len, int fh_type)
{
	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
				    affs_nfs_get_inode);
}

const struct export_operations affs_export_ops = {
	.fh_to_dentry = affs_fh_to_dentry,
	.fh_to_parent = affs_fh_to_parent,
	.get_parent = affs_get_parent,
};

const struct dentry_operations affs_dentry_operations = {
	.d_hash		= affs_hash_dentry,
	.d_compare	= affs_compare_dentry,
};

const struct dentry_operations affs_intl_dentry_operations = {
	.d_hash		= affs_intl_hash_dentry,
	.d_compare	= affs_intl_compare_dentry,
};