1/*
2 *  linux/fs/affs/namei.c
3 *
4 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
5 *
6 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
7 *
8 *  (C) 1991  Linus Torvalds - minix filesystem
9 */
10
11#include "affs.h"
12
13typedef int (*toupper_t)(int);
14
15static int	 affs_toupper(int ch);
16static int	 affs_hash_dentry(const struct dentry *, struct qstr *);
17static int       affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
18		unsigned int len, const char *str, const struct qstr *name);
19static int	 affs_intl_toupper(int ch);
20static int	 affs_intl_hash_dentry(const struct dentry *, struct qstr *);
21static int       affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
22		unsigned int len, const char *str, const struct qstr *name);
23
24const struct dentry_operations affs_dentry_operations = {
25	.d_hash		= affs_hash_dentry,
26	.d_compare	= affs_compare_dentry,
27};
28
29const struct dentry_operations affs_intl_dentry_operations = {
30	.d_hash		= affs_intl_hash_dentry,
31	.d_compare	= affs_intl_compare_dentry,
32};
33
34
35/* Simple toupper() for DOS\1 */
36
37static int
38affs_toupper(int ch)
39{
40	return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
41}
42
43/* International toupper() for DOS\3 ("international") */
44
45static int
46affs_intl_toupper(int ch)
47{
48	return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
49		&& ch <= 0xFE && ch != 0xF7) ?
50		ch - ('a' - 'A') : ch;
51}
52
53static inline toupper_t
54affs_get_toupper(struct super_block *sb)
55{
56	return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ?
57	       affs_intl_toupper : affs_toupper;
58}
59
60/*
61 * Note: the dentry argument is the parent dentry.
62 */
63static inline int
64__affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate)
65{
66	const u8 *name = qstr->name;
67	unsigned long hash;
68	int retval;
69	u32 len;
70
71	retval = affs_check_name(qstr->name, qstr->len, notruncate);
72	if (retval)
73		return retval;
74
75	hash = init_name_hash();
76	len = min(qstr->len, AFFSNAMEMAX);
77	for (; len > 0; name++, len--)
78		hash = partial_name_hash(toupper(*name), hash);
79	qstr->hash = end_name_hash(hash);
80
81	return 0;
82}
83
84static int
85affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
86{
87	return __affs_hash_dentry(qstr, affs_toupper,
88				  affs_nofilenametruncate(dentry));
89
90}
91
92static int
93affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
94{
95	return __affs_hash_dentry(qstr, affs_intl_toupper,
96				  affs_nofilenametruncate(dentry));
97
98}
99
100static inline int __affs_compare_dentry(unsigned int len,
101		const char *str, const struct qstr *name, toupper_t toupper,
102		bool notruncate)
103{
104	const u8 *aname = str;
105	const u8 *bname = name->name;
106
107	/*
108	 * 'str' is the name of an already existing dentry, so the name
109	 * must be valid. 'name' must be validated first.
110	 */
111
112	if (affs_check_name(name->name, name->len, notruncate))
113		return 1;
114
115	/*
116	 * If the names are longer than the allowed 30 chars,
117	 * the excess is ignored, so their length may differ.
118	 */
119	if (len >= AFFSNAMEMAX) {
120		if (name->len < AFFSNAMEMAX)
121			return 1;
122		len = AFFSNAMEMAX;
123	} else if (len != name->len)
124		return 1;
125
126	for (; len > 0; len--)
127		if (toupper(*aname++) != toupper(*bname++))
128			return 1;
129
130	return 0;
131}
132
133static int
134affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
135		unsigned int len, const char *str, const struct qstr *name)
136{
137
138	return __affs_compare_dentry(len, str, name, affs_toupper,
139				     affs_nofilenametruncate(parent));
140}
141
142static int
143affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
144		unsigned int len, const char *str, const struct qstr *name)
145{
146	return __affs_compare_dentry(len, str, name, affs_intl_toupper,
147				     affs_nofilenametruncate(parent));
148
149}
150
151/*
152 * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
153 */
154
155static inline int
156affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
157{
158	const u8 *name = dentry->d_name.name;
159	int len = dentry->d_name.len;
160
161	if (len >= AFFSNAMEMAX) {
162		if (*name2 < AFFSNAMEMAX)
163			return 0;
164		len = AFFSNAMEMAX;
165	} else if (len != *name2)
166		return 0;
167
168	for (name2++; len > 0; len--)
169		if (toupper(*name++) != toupper(*name2++))
170			return 0;
171	return 1;
172}
173
174int
175affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
176{
177	toupper_t toupper = affs_get_toupper(sb);
178	u32 hash;
179
180	hash = len = min(len, AFFSNAMEMAX);
181	for (; len > 0; len--)
182		hash = (hash * 13 + toupper(*name++)) & 0x7ff;
183
184	return hash % AFFS_SB(sb)->s_hashsize;
185}
186
187static struct buffer_head *
188affs_find_entry(struct inode *dir, struct dentry *dentry)
189{
190	struct super_block *sb = dir->i_sb;
191	struct buffer_head *bh;
192	toupper_t toupper = affs_get_toupper(sb);
193	u32 key;
194
195	pr_debug("%s(\"%pd\")\n", __func__, dentry);
196
197	bh = affs_bread(sb, dir->i_ino);
198	if (!bh)
199		return ERR_PTR(-EIO);
200
201	key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
202
203	for (;;) {
204		affs_brelse(bh);
205		if (key == 0)
206			return NULL;
207		bh = affs_bread(sb, key);
208		if (!bh)
209			return ERR_PTR(-EIO);
210		if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
211			return bh;
212		key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
213	}
214}
215
216struct dentry *
217affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
218{
219	struct super_block *sb = dir->i_sb;
220	struct buffer_head *bh;
221	struct inode *inode = NULL;
222
223	pr_debug("%s(\"%pd\")\n", __func__, dentry);
224
225	affs_lock_dir(dir);
226	bh = affs_find_entry(dir, dentry);
227	affs_unlock_dir(dir);
228	if (IS_ERR(bh))
229		return ERR_CAST(bh);
230	if (bh) {
231		u32 ino = bh->b_blocknr;
232
233		/* store the real header ino in d_fsdata for faster lookups */
234		dentry->d_fsdata = (void *)(long)ino;
235		switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
236		//link to dirs disabled
237		//case ST_LINKDIR:
238		case ST_LINKFILE:
239			ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
240		}
241		affs_brelse(bh);
242		inode = affs_iget(sb, ino);
243		if (IS_ERR(inode))
244			return ERR_CAST(inode);
245	}
246	d_add(dentry, inode);
247	return NULL;
248}
249
250int
251affs_unlink(struct inode *dir, struct dentry *dentry)
252{
253	pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
254		 d_inode(dentry)->i_ino, dentry);
255
256	return affs_remove_header(dentry);
257}
258
259int
260affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
261{
262	struct super_block *sb = dir->i_sb;
263	struct inode	*inode;
264	int		 error;
265
266	pr_debug("%s(%lu,\"%pd\",0%ho)\n",
267		 __func__, dir->i_ino, dentry, mode);
268
269	inode = affs_new_inode(dir);
270	if (!inode)
271		return -ENOSPC;
272
273	inode->i_mode = mode;
274	mode_to_prot(inode);
275	mark_inode_dirty(inode);
276
277	inode->i_op = &affs_file_inode_operations;
278	inode->i_fop = &affs_file_operations;
279	inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ?
280				  &affs_aops_ofs : &affs_aops;
281	error = affs_add_entry(dir, inode, dentry, ST_FILE);
282	if (error) {
283		clear_nlink(inode);
284		iput(inode);
285		return error;
286	}
287	return 0;
288}
289
290int
291affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
292{
293	struct inode		*inode;
294	int			 error;
295
296	pr_debug("%s(%lu,\"%pd\",0%ho)\n",
297		 __func__, dir->i_ino, dentry, mode);
298
299	inode = affs_new_inode(dir);
300	if (!inode)
301		return -ENOSPC;
302
303	inode->i_mode = S_IFDIR | mode;
304	mode_to_prot(inode);
305
306	inode->i_op = &affs_dir_inode_operations;
307	inode->i_fop = &affs_dir_operations;
308
309	error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
310	if (error) {
311		clear_nlink(inode);
312		mark_inode_dirty(inode);
313		iput(inode);
314		return error;
315	}
316	return 0;
317}
318
319int
320affs_rmdir(struct inode *dir, struct dentry *dentry)
321{
322	pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
323		 d_inode(dentry)->i_ino, dentry);
324
325	return affs_remove_header(dentry);
326}
327
328int
329affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
330{
331	struct super_block	*sb = dir->i_sb;
332	struct buffer_head	*bh;
333	struct inode		*inode;
334	char			*p;
335	int			 i, maxlen, error;
336	char			 c, lc;
337
338	pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n",
339		 __func__, dir->i_ino, dentry, symname);
340
341	maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
342	inode  = affs_new_inode(dir);
343	if (!inode)
344		return -ENOSPC;
345
346	inode->i_op = &affs_symlink_inode_operations;
347	inode->i_data.a_ops = &affs_symlink_aops;
348	inode->i_mode = S_IFLNK | 0777;
349	mode_to_prot(inode);
350
351	error = -EIO;
352	bh = affs_bread(sb, inode->i_ino);
353	if (!bh)
354		goto err;
355	i  = 0;
356	p  = (char *)AFFS_HEAD(bh)->table;
357	lc = '/';
358	if (*symname == '/') {
359		struct affs_sb_info *sbi = AFFS_SB(sb);
360		while (*symname == '/')
361			symname++;
362		spin_lock(&sbi->symlink_lock);
363		while (sbi->s_volume[i])	/* Cannot overflow */
364			*p++ = sbi->s_volume[i++];
365		spin_unlock(&sbi->symlink_lock);
366	}
367	while (i < maxlen && (c = *symname++)) {
368		if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
369			*p++ = '/';
370			i++;
371			symname += 2;
372			lc = '/';
373		} else if (c == '.' && lc == '/' && *symname == '/') {
374			symname++;
375			lc = '/';
376		} else {
377			*p++ = c;
378			lc   = c;
379			i++;
380		}
381		if (lc == '/')
382			while (*symname == '/')
383				symname++;
384	}
385	*p = 0;
386	mark_buffer_dirty_inode(bh, inode);
387	affs_brelse(bh);
388	mark_inode_dirty(inode);
389
390	error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
391	if (error)
392		goto err;
393
394	return 0;
395
396err:
397	clear_nlink(inode);
398	mark_inode_dirty(inode);
399	iput(inode);
400	return error;
401}
402
403int
404affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
405{
406	struct inode *inode = d_inode(old_dentry);
407
408	pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
409		 dentry);
410
411	return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
412}
413
414int
415affs_rename(struct inode *old_dir, struct dentry *old_dentry,
416	    struct inode *new_dir, struct dentry *new_dentry)
417{
418	struct super_block *sb = old_dir->i_sb;
419	struct buffer_head *bh = NULL;
420	int retval;
421
422	pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__,
423		 old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
424
425	retval = affs_check_name(new_dentry->d_name.name,
426				 new_dentry->d_name.len,
427				 affs_nofilenametruncate(old_dentry));
428
429	if (retval)
430		return retval;
431
432	/* Unlink destination if it already exists */
433	if (d_really_is_positive(new_dentry)) {
434		retval = affs_remove_header(new_dentry);
435		if (retval)
436			return retval;
437	}
438
439	bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
440	if (!bh)
441		return -EIO;
442
443	/* Remove header from its parent directory. */
444	affs_lock_dir(old_dir);
445	retval = affs_remove_hash(old_dir, bh);
446	affs_unlock_dir(old_dir);
447	if (retval)
448		goto done;
449
450	/* And insert it into the new directory with the new name. */
451	affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
452	affs_fix_checksum(sb, bh);
453	affs_lock_dir(new_dir);
454	retval = affs_insert_hash(new_dir, bh);
455	affs_unlock_dir(new_dir);
456	/* TODO: move it back to old_dir, if error? */
457
458done:
459	mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
460	affs_brelse(bh);
461	return retval;
462}
463