summaryrefslogtreecommitdiffstats
path: root/fs/adfs/dir.c
blob: 16a2639d3ca5f7f192e3731fbede52cf6b1c805f (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/fs/adfs/dir.c
 *
 *  Copyright (C) 1999-2000 Russell King
 *
 *  Common directory handling for ADFS
 */
#include <linux/slab.h>
#include "adfs.h"

/*
 * For future.  This should probably be per-directory.
 */
static DEFINE_RWLOCK(adfs_dir_lock);

void adfs_dir_relse(struct adfs_dir *dir)
{
	unsigned int i;

	for (i = 0; i < dir->nr_buffers; i++)
		brelse(dir->bhs[i]);
	dir->nr_buffers = 0;

	if (dir->bhs != dir->bh)
		kfree(dir->bhs);
	dir->bhs = NULL;
	dir->sb = NULL;
}

static int adfs_dir_read(struct super_block *sb, u32 indaddr,
			 unsigned int size, struct adfs_dir *dir)
{
	dir->sb = sb;
	dir->bhs = dir->bh;
	dir->nr_buffers = 0;

	return ADFS_SB(sb)->s_dir->read(sb, indaddr, size, dir);
}

static int adfs_dir_sync(struct adfs_dir *dir)
{
	int err = 0;
	int i;

	for (i = dir->nr_buffers - 1; i >= 0; i--) {
		struct buffer_head *bh = dir->bhs[i];
		sync_dirty_buffer(bh);
		if (buffer_req(bh) && !buffer_uptodate(bh))
			err = -EIO;
	}

	return err;
}

void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj)
{
	unsigned int dots, i;

	/*
	 * RISC OS allows the use of '/' in directory entry names, so we need
	 * to fix these up.  '/' is typically used for FAT compatibility to
	 * represent '.', so do the same conversion here.  In any case, '.'
	 * will never be in a RISC OS name since it is used as the pathname
	 * separator.  Handle the case where we may generate a '.' or '..'
	 * name, replacing the first character with '^' (the RISC OS "parent
	 * directory" character.)
	 */
	for (i = dots = 0; i < obj->name_len; i++)
		if (obj->name[i] == '/') {
			obj->name[i] = '.';
			dots++;
		}

	if (obj->name_len <= 2 && dots == obj->name_len)
		obj->name[0] = '^';

	/*
	 * If the object is a file, and the user requested the ,xyz hex
	 * filetype suffix to the name, check the filetype and append.
	 */
	if (!(obj->attr & ADFS_NDA_DIRECTORY) && ADFS_SB(dir->sb)->s_ftsuffix) {
		u16 filetype = adfs_filetype(obj->loadaddr);

		if (filetype != ADFS_FILETYPE_NONE) {
			obj->name[obj->name_len++] = ',';
			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 8);
			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 4);
			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 0);
		}
	}
}

static int
adfs_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	struct super_block *sb = inode->i_sb;
	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
	struct object_info obj;
	struct adfs_dir dir;
	int ret = 0;

	if (ctx->pos >> 32)
		return 0;

	ret = adfs_dir_read(sb, inode->i_ino, inode->i_size, &dir);
	if (ret)
		return ret;

	if (ctx->pos == 0) {
		if (!dir_emit_dot(file, ctx))
			goto free_out;
		ctx->pos = 1;
	}
	if (ctx->pos == 1) {
		if (!dir_emit(ctx, "..", 2, dir.parent_id, DT_DIR))
			goto free_out;
		ctx->pos = 2;
	}

	read_lock(&adfs_dir_lock);

	ret = ops->setpos(&dir, ctx->pos - 2);
	if (ret)
		goto unlock_out;
	while (ops->getnext(&dir, &obj) == 0) {
		if (!dir_emit(ctx, obj.name, obj.name_len,
			      obj.indaddr, DT_UNKNOWN))
			break;
		ctx->pos++;
	}

unlock_out:
	read_unlock(&adfs_dir_lock);

free_out:
	adfs_dir_relse(&dir);
	return ret;
}

int
adfs_dir_update(struct super_block *sb, struct object_info *obj, int wait)
{
	int ret = -EINVAL;
#ifdef CONFIG_ADFS_FS_RW
	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
	struct adfs_dir dir;

	printk(KERN_INFO "adfs_dir_update: object %06x in dir %06x\n",
		 obj->indaddr, obj->parent_id);

	if (!ops->update)
		return -EINVAL;

	ret = adfs_dir_read(sb, obj->parent_id, 0, &dir);
	if (ret)
		goto out;

	write_lock(&adfs_dir_lock);
	ret = ops->update(&dir, obj);
	write_unlock(&adfs_dir_lock);

	if (wait) {
		int err = adfs_dir_sync(&dir);
		if (!ret)
			ret = err;
	}

	adfs_dir_relse(&dir);
out:
#endif
	return ret;
}

static unsigned char adfs_tolower(unsigned char c)
{
	if (c >= 'A' && c <= 'Z')
		c += 'a' - 'A';
	return c;
}

static int __adfs_compare(const unsigned char *qstr, u32 qlen,
			  const char *str, u32 len)
{
	u32 i;

	if (qlen != len)
		return 1;

	for (i = 0; i < qlen; i++)
		if (adfs_tolower(qstr[i]) != adfs_tolower(str[i]))
			return 1;

	return 0;
}

static int adfs_dir_lookup_byname(struct inode *inode, const struct qstr *qstr,
				  struct object_info *obj)
{
	struct super_block *sb = inode->i_sb;
	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
	const unsigned char *name;
	struct adfs_dir dir;
	u32 name_len;
	int ret;

	ret = adfs_dir_read(sb, inode->i_ino, inode->i_size, &dir);
	if (ret)
		goto out;

	if (ADFS_I(inode)->parent_id != dir.parent_id) {
		adfs_error(sb,
			   "parent directory changed under me! (%06x but got %06x)\n",
			   ADFS_I(inode)->parent_id, dir.parent_id);
		ret = -EIO;
		goto free_out;
	}

	obj->parent_id = inode->i_ino;

	read_lock(&adfs_dir_lock);

	ret = ops->setpos(&dir, 0);
	if (ret)
		goto unlock_out;

	ret = -ENOENT;
	name = qstr->name;
	name_len = qstr->len;
	while (ops->getnext(&dir, obj) == 0) {
		if (!__adfs_compare(name, name_len, obj->name, obj->name_len)) {
			ret = 0;
			break;
		}
	}

unlock_out:
	read_unlock(&adfs_dir_lock);

free_out:
	adfs_dir_relse(&dir);
out:
	return ret;
}

const struct file_operations adfs_dir_operations = {
	.read		= generic_read_dir,
	.llseek		= generic_file_llseek,
	.iterate	= adfs_readdir,
	.fsync		= generic_file_fsync,
};

static int
adfs_hash(const struct dentry *parent, struct qstr *qstr)
{
	const unsigned char *name;
	unsigned long hash;
	u32 len;

	if (qstr->len > ADFS_SB(parent->d_sb)->s_namelen)
		return -ENAMETOOLONG;

	len = qstr->len;
	name = qstr->name;
	hash = init_name_hash(parent);
	while (len--)
		hash = partial_name_hash(adfs_tolower(*name++), hash);
	qstr->hash = end_name_hash(hash);

	return 0;
}

/*
 * Compare two names, taking note of the name length
 * requirements of the underlying filesystem.
 */
static int adfs_compare(const struct dentry *dentry, unsigned int len,
			const char *str, const struct qstr *qstr)
{
	return __adfs_compare(qstr->name, qstr->len, str, len);
}

const struct dentry_operations adfs_dentry_operations = {
	.d_hash		= adfs_hash,
	.d_compare	= adfs_compare,
};

static struct dentry *
adfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	struct inode *inode = NULL;
	struct object_info obj;
	int error;

	error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
	if (error == 0) {
		/*
		 * This only returns NULL if get_empty_inode
		 * fails.
		 */
		inode = adfs_iget(dir->i_sb, &obj);
		if (!inode)
			inode = ERR_PTR(-EACCES);
	} else if (error != -ENOENT) {
		inode = ERR_PTR(error);
	}
	return d_splice_alias(inode, dentry);
}

/*
 * directories can handle most operations...
 */
const struct inode_operations adfs_dir_inode_operations = {
	.lookup		= adfs_lookup,
	.setattr	= adfs_notify_change,
};