summaryrefslogtreecommitdiffstats
path: root/fs/affs/namei.c
blob: d4c2d636c479dc2aaaa986656a8659424aac56a6 (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
/*
 *  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"

typedef int (*toupper_t)(int);

static int	 affs_toupper(int ch);
static int	 affs_hash_dentry(struct dentry *, struct qstr *);
static int       affs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
static int	 affs_intl_toupper(int ch);
static int	 affs_intl_hash_dentry(struct dentry *, struct qstr *);
static int       affs_intl_compare_dentry(struct dentry *, struct qstr *, struct qstr *);

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

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


/* 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_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(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
{
	const u8 *name = qstr->name;
	unsigned long hash;
	int i;

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

	hash = init_name_hash();
	i = min(qstr->len, 30u);
	for (; i > 0; name++, i--)
		hash = partial_name_hash(toupper(*name), hash);
	qstr->hash = end_name_hash(hash);

	return 0;
}

static int
affs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
{
	return __affs_hash_dentry(dentry, qstr, affs_toupper);
}
static int
affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
{
	return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
}

static inline int
__affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, toupper_t toupper)
{
	const u8 *aname = a->name;
	const u8 *bname = b->name;
	int len;

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

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

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

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

	return 0;
}

static int
affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
{
	return __affs_compare_dentry(dentry, a, b, affs_toupper);
}
static int
affs_intl_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
{
	return __affs_compare_dentry(dentry, a, b, affs_intl_toupper);
}

/*
 * 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 >= 30) {
		if (*name2 < 30)
			return 0;
		len = 30;
	} 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);
	int hash;

	hash = len = min(len, 30u);
	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("AFFS: find_entry(\"%.*s\")\n", (int)dentry->d_name.len, dentry->d_name.name);

	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, struct nameidata *nd)
{
	struct super_block *sb = dir->i_sb;
	struct buffer_head *bh;
	struct inode *inode = NULL;

	pr_debug("AFFS: lookup(\"%.*s\")\n",(int)dentry->d_name.len,dentry->d_name.name);

	affs_lock_dir(dir);
	bh = affs_find_entry(dir, dentry);
	affs_unlock_dir(dir);
	if (IS_ERR(bh)) {
		return ERR_PTR(PTR_ERR(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 = iget(sb, ino);
		if (!inode) {
			return ERR_PTR(-EACCES);
		}
	}
	dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
	d_add(dentry, inode);
	return NULL;
}

int
affs_unlink(struct inode *dir, struct dentry *dentry)
{
	pr_debug("AFFS: unlink(dir=%d, \"%.*s\")\n", (u32)dir->i_ino,
		 (int)dentry->d_name.len, dentry->d_name.name);

	return affs_remove_header(dentry);
}

int
affs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
{
	struct super_block *sb = dir->i_sb;
	struct inode	*inode;
	int		 error;

	pr_debug("AFFS: create(%lu,\"%.*s\",0%o)\n",dir->i_ino,(int)dentry->d_name.len,
		 dentry->d_name.name,mode);

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

	inode->i_mode = mode;
	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_SB(sb)->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
	error = affs_add_entry(dir, inode, dentry, ST_FILE);
	if (error) {
		inode->i_nlink = 0;
		iput(inode);
		return error;
	}
	return 0;
}

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

	pr_debug("AFFS: mkdir(%lu,\"%.*s\",0%o)\n",dir->i_ino,
		 (int)dentry->d_name.len,dentry->d_name.name,mode);

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

	inode->i_mode = S_IFDIR | mode;
	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) {
		inode->i_nlink = 0;
		mark_inode_dirty(inode);
		iput(inode);
		return error;
	}
	return 0;
}

int
affs_rmdir(struct inode *dir, struct dentry *dentry)
{
	pr_debug("AFFS: rmdir(dir=%u, \"%.*s\")\n", (u32)dir->i_ino,
		 (int)dentry->d_name.len, dentry->d_name.name);

	return affs_remove_header(dentry);
}

int
affs_symlink(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("AFFS: symlink(%lu,\"%.*s\" -> \"%s\")\n",dir->i_ino,
		 (int)dentry->d_name.len,dentry->d_name.name,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->i_data.a_ops = &affs_symlink_aops;
	inode->i_mode = S_IFLNK | 0777;
	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 == '/') {
		while (*symname == '/')
			symname++;
		while (AFFS_SB(sb)->s_volume[i])	/* Cannot overflow */
			*p++ = AFFS_SB(sb)->s_volume[i++];
	}
	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;
	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:
	inode->i_nlink = 0;
	mark_inode_dirty(inode);
	iput(inode);
	return error;
}

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

	pr_debug("AFFS: link(%u, %u, \"%.*s\")\n", (u32)inode->i_ino, (u32)dir->i_ino,
		 (int)dentry->d_name.len,dentry->d_name.name);

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

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;

	pr_debug("AFFS: rename(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
		 (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
		 (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);

	retval = affs_check_name(new_dentry->d_name.name,new_dentry->d_name.len);
	if (retval)
		return retval;

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

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

	/* 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;
}
OpenPOWER on IntegriCloud