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2024-09-20 cf4ce59b3b70238352c7f1729f0f7223214828ad 
 kernel/fs/adfs/dir.c
....@@ -1,208 +1,411 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  *  linux/fs/adfs/dir.c
34  *
45  *  Copyright (C) 1999-2000 Russell King
56  *
6
- * This program is free software; you can redistribute it and/or modify
7
- * it under the terms of the GNU General Public License version 2 as
8
- * published by the Free Software Foundation.
9
- *
107  *  Common directory handling for ADFS
118  */
9
+#include <linux/slab.h>
1210 #include "adfs.h"
1311 
1412 /*
1513  * For future.  This should probably be per-directory.
1614  */
17
-static DEFINE_RWLOCK(adfs_dir_lock);
15
+static DECLARE_RWSEM(adfs_dir_rwsem);
1816 
19
-static int
20
-adfs_readdir(struct file *file, struct dir_context *ctx)
17
+int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
18
+		      size_t len)
19
+{
20
+	struct super_block *sb = dir->sb;
21
+	unsigned int index, remain;
22
+
23
+	index = offset >> sb->s_blocksize_bits;
24
+	offset &= sb->s_blocksize - 1;
25
+	remain = sb->s_blocksize - offset;
26
+	if (index + (remain < len) >= dir->nr_buffers)
27
+		return -EINVAL;
28
+
29
+	if (remain < len) {
30
+		memcpy(dst, dir->bhs[index]->b_data + offset, remain);
31
+		dst += remain;
32
+		len -= remain;
33
+		index += 1;
34
+		offset = 0;
35
+	}
36
+
37
+	memcpy(dst, dir->bhs[index]->b_data + offset, len);
38
+
39
+	return 0;
40
+}
41
+
42
+int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
43
+		    size_t len)
44
+{
45
+	struct super_block *sb = dir->sb;
46
+	unsigned int index, remain;
47
+
48
+	index = offset >> sb->s_blocksize_bits;
49
+	offset &= sb->s_blocksize - 1;
50
+	remain = sb->s_blocksize - offset;
51
+	if (index + (remain < len) >= dir->nr_buffers)
52
+		return -EINVAL;
53
+
54
+	if (remain < len) {
55
+		memcpy(dir->bhs[index]->b_data + offset, src, remain);
56
+		src += remain;
57
+		len -= remain;
58
+		index += 1;
59
+		offset = 0;
60
+	}
61
+
62
+	memcpy(dir->bhs[index]->b_data + offset, src, len);
63
+
64
+	return 0;
65
+}
66
+
67
+static void __adfs_dir_cleanup(struct adfs_dir *dir)
68
+{
69
+	dir->nr_buffers = 0;
70
+
71
+	if (dir->bhs != dir->bh)
72
+		kfree(dir->bhs);
73
+	dir->bhs = NULL;
74
+	dir->sb = NULL;
75
+}
76
+
77
+void adfs_dir_relse(struct adfs_dir *dir)
78
+{
79
+	unsigned int i;
80
+
81
+	for (i = 0; i < dir->nr_buffers; i++)
82
+		brelse(dir->bhs[i]);
83
+
84
+	__adfs_dir_cleanup(dir);
85
+}
86
+
87
+static void adfs_dir_forget(struct adfs_dir *dir)
88
+{
89
+	unsigned int i;
90
+
91
+	for (i = 0; i < dir->nr_buffers; i++)
92
+		bforget(dir->bhs[i]);
93
+
94
+	__adfs_dir_cleanup(dir);
95
+}
96
+
97
+int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
98
+			  unsigned int size, struct adfs_dir *dir)
99
+{
100
+	struct buffer_head **bhs;
101
+	unsigned int i, num;
102
+	int block;
103
+
104
+	num = ALIGN(size, sb->s_blocksize) >> sb->s_blocksize_bits;
105
+	if (num > ARRAY_SIZE(dir->bh)) {
106
+		/* We only allow one extension */
107
+		if (dir->bhs != dir->bh)
108
+			return -EINVAL;
109
+
110
+		bhs = kcalloc(num, sizeof(*bhs), GFP_KERNEL);
111
+		if (!bhs)
112
+			return -ENOMEM;
113
+
114
+		if (dir->nr_buffers)
115
+			memcpy(bhs, dir->bhs, dir->nr_buffers * sizeof(*bhs));
116
+
117
+		dir->bhs = bhs;
118
+	}
119
+
120
+	for (i = dir->nr_buffers; i < num; i++) {
121
+		block = __adfs_block_map(sb, indaddr, i);
122
+		if (!block) {
123
+			adfs_error(sb, "dir %06x has a hole at offset %u",
124
+				   indaddr, i);
125
+			goto error;
126
+		}
127
+
128
+		dir->bhs[i] = sb_bread(sb, block);
129
+		if (!dir->bhs[i]) {
130
+			adfs_error(sb,
131
+				   "dir %06x failed read at offset %u, mapped block 0x%08x",
132
+				   indaddr, i, block);
133
+			goto error;
134
+		}
135
+
136
+		dir->nr_buffers++;
137
+	}
138
+	return 0;
139
+
140
+error:
141
+	adfs_dir_relse(dir);
142
+
143
+	return -EIO;
144
+}
145
+
146
+static int adfs_dir_read(struct super_block *sb, u32 indaddr,
147
+			 unsigned int size, struct adfs_dir *dir)
148
+{
149
+	dir->sb = sb;
150
+	dir->bhs = dir->bh;
151
+	dir->nr_buffers = 0;
152
+
153
+	return ADFS_SB(sb)->s_dir->read(sb, indaddr, size, dir);
154
+}
155
+
156
+static int adfs_dir_read_inode(struct super_block *sb, struct inode *inode,
157
+			       struct adfs_dir *dir)
158
+{
159
+	int ret;
160
+
161
+	ret = adfs_dir_read(sb, ADFS_I(inode)->indaddr, inode->i_size, dir);
162
+	if (ret)
163
+		return ret;
164
+
165
+	if (ADFS_I(inode)->parent_id != dir->parent_id) {
166
+		adfs_error(sb,
167
+			   "parent directory id changed under me! (%06x but got %06x)\n",
168
+			   ADFS_I(inode)->parent_id, dir->parent_id);
169
+		adfs_dir_relse(dir);
170
+		ret = -EIO;
171
+	}
172
+
173
+	return ret;
174
+}
175
+
176
+static void adfs_dir_mark_dirty(struct adfs_dir *dir)
177
+{
178
+	unsigned int i;
179
+
180
+	/* Mark the buffers dirty */
181
+	for (i = 0; i < dir->nr_buffers; i++)
182
+		mark_buffer_dirty(dir->bhs[i]);
183
+}
184
+
185
+static int adfs_dir_sync(struct adfs_dir *dir)
186
+{
187
+	int err = 0;
188
+	int i;
189
+
190
+	for (i = dir->nr_buffers - 1; i >= 0; i--) {
191
+		struct buffer_head *bh = dir->bhs[i];
192
+		sync_dirty_buffer(bh);
193
+		if (buffer_req(bh) && !buffer_uptodate(bh))
194
+			err = -EIO;
195
+	}
196
+
197
+	return err;
198
+}
199
+
200
+void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj)
201
+{
202
+	unsigned int dots, i;
203
+
204
+	/*
205
+	 * RISC OS allows the use of '/' in directory entry names, so we need
206
+	 * to fix these up.  '/' is typically used for FAT compatibility to
207
+	 * represent '.', so do the same conversion here.  In any case, '.'
208
+	 * will never be in a RISC OS name since it is used as the pathname
209
+	 * separator.  Handle the case where we may generate a '.' or '..'
210
+	 * name, replacing the first character with '^' (the RISC OS "parent
211
+	 * directory" character.)
212
+	 */
213
+	for (i = dots = 0; i < obj->name_len; i++)
214
+		if (obj->name[i] == '/') {
215
+			obj->name[i] = '.';
216
+			dots++;
217
+		}
218
+
219
+	if (obj->name_len <= 2 && dots == obj->name_len)
220
+		obj->name[0] = '^';
221
+
222
+	/*
223
+	 * If the object is a file, and the user requested the ,xyz hex
224
+	 * filetype suffix to the name, check the filetype and append.
225
+	 */
226
+	if (!(obj->attr & ADFS_NDA_DIRECTORY) && ADFS_SB(dir->sb)->s_ftsuffix) {
227
+		u16 filetype = adfs_filetype(obj->loadaddr);
228
+
229
+		if (filetype != ADFS_FILETYPE_NONE) {
230
+			obj->name[obj->name_len++] = ',';
231
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 8);
232
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 4);
233
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 0);
234
+		}
235
+	}
236
+}
237
+
238
+static int adfs_iterate(struct file *file, struct dir_context *ctx)
21239 {
22240 	struct inode *inode = file_inode(file);
23241 	struct super_block *sb = inode->i_sb;
24242 	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
25
-	struct object_info obj;
26243 	struct adfs_dir dir;
27
-	int ret = 0;
244
+	int ret;
28245 
29
-	if (ctx->pos >> 32)
30
-		return 0;
31
-
32
-	ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
246
+	down_read(&adfs_dir_rwsem);
247
+	ret = adfs_dir_read_inode(sb, inode, &dir);
33248 	if (ret)
34
-		return ret;
249
+		goto unlock;
35250 
36251 	if (ctx->pos == 0) {
37252 		if (!dir_emit_dot(file, ctx))
38
-			goto free_out;
253
+			goto unlock_relse;
39254 		ctx->pos = 1;
40255 	}
41256 	if (ctx->pos == 1) {
42257 		if (!dir_emit(ctx, "..", 2, dir.parent_id, DT_DIR))
43
-			goto free_out;
258
+			goto unlock_relse;
44259 		ctx->pos = 2;
45260 	}
46261 
47
-	read_lock(&adfs_dir_lock);
262
+	ret = ops->iterate(&dir, ctx);
48263 
49
-	ret = ops->setpos(&dir, ctx->pos - 2);
50
-	if (ret)
51
-		goto unlock_out;
52
-	while (ops->getnext(&dir, &obj) == 0) {
53
-		if (!dir_emit(ctx, obj.name, obj.name_len,
54
-			    obj.file_id, DT_UNKNOWN))
55
-			break;
56
-		ctx->pos++;
57
-	}
264
+unlock_relse:
265
+	up_read(&adfs_dir_rwsem);
266
+	adfs_dir_relse(&dir);
267
+	return ret;
58268 
59
-unlock_out:
60
-	read_unlock(&adfs_dir_lock);
61
-
62
-free_out:
63
-	ops->free(&dir);
269
+unlock:
270
+	up_read(&adfs_dir_rwsem);
64271 	return ret;
65272 }
66273 
67274 int
68275 adfs_dir_update(struct super_block *sb, struct object_info *obj, int wait)
69276 {
70
-	int ret = -EINVAL;
71
-#ifdef CONFIG_ADFS_FS_RW
72
-	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
73
-	struct adfs_dir dir;
74
-
75
-	printk(KERN_INFO "adfs_dir_update: object %06X in dir %06X\n",
76
-		 obj->file_id, obj->parent_id);
77
-
78
-	if (!ops->update) {
79
-		ret = -EINVAL;
80
-		goto out;
81
-	}
82
-
83
-	ret = ops->read(sb, obj->parent_id, 0, &dir);
84
-	if (ret)
85
-		goto out;
86
-
87
-	write_lock(&adfs_dir_lock);
88
-	ret = ops->update(&dir, obj);
89
-	write_unlock(&adfs_dir_lock);
90
-
91
-	if (wait) {
92
-		int err = ops->sync(&dir);
93
-		if (!ret)
94
-			ret = err;
95
-	}
96
-
97
-	ops->free(&dir);
98
-out:
99
-#endif
100
-	return ret;
101
-}
102
-
103
-static int
104
-adfs_match(const struct qstr *name, struct object_info *obj)
105
-{
106
-	int i;
107
-
108
-	if (name->len != obj->name_len)
109
-		return 0;
110
-
111
-	for (i = 0; i < name->len; i++) {
112
-		char c1, c2;
113
-
114
-		c1 = name->name[i];
115
-		c2 = obj->name[i];
116
-
117
-		if (c1 >= 'A' && c1 <= 'Z')
118
-			c1 += 'a' - 'A';
119
-		if (c2 >= 'A' && c2 <= 'Z')
120
-			c2 += 'a' - 'A';
121
-
122
-		if (c1 != c2)
123
-			return 0;
124
-	}
125
-	return 1;
126
-}
127
-
128
-static int
129
-adfs_dir_lookup_byname(struct inode *inode, const struct qstr *name, struct object_info *obj)
130
-{
131
-	struct super_block *sb = inode->i_sb;
132277 	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
133278 	struct adfs_dir dir;
134279 	int ret;
135280 
136
-	ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
281
+	if (!IS_ENABLED(CONFIG_ADFS_FS_RW))
282
+		return -EINVAL;
283
+
284
+	if (!ops->update)
285
+		return -EINVAL;
286
+
287
+	down_write(&adfs_dir_rwsem);
288
+	ret = adfs_dir_read(sb, obj->parent_id, 0, &dir);
137289 	if (ret)
138
-		goto out;
290
+		goto unlock;
139291 
140
-	if (ADFS_I(inode)->parent_id != dir.parent_id) {
141
-		adfs_error(sb, "parent directory changed under me! (%lx but got %x)\n",
142
-			   ADFS_I(inode)->parent_id, dir.parent_id);
143
-		ret = -EIO;
144
-		goto free_out;
145
-	}
292
+	ret = ops->update(&dir, obj);
293
+	if (ret)
294
+		goto forget;
146295 
147
-	obj->parent_id = inode->i_ino;
296
+	ret = ops->commit(&dir);
297
+	if (ret)
298
+		goto forget;
299
+	up_write(&adfs_dir_rwsem);
148300 
149
-	read_lock(&adfs_dir_lock);
301
+	adfs_dir_mark_dirty(&dir);
302
+
303
+	if (wait)
304
+		ret = adfs_dir_sync(&dir);
305
+
306
+	adfs_dir_relse(&dir);
307
+	return ret;
308
+
309
+	/*
310
+	 * If the updated failed because the entry wasn't found, we can
311
+	 * just release the buffers. If it was any other error, forget
312
+	 * the dirtied buffers so they aren't written back to the media.
313
+	 */
314
+forget:
315
+	if (ret == -ENOENT)
316
+		adfs_dir_relse(&dir);
317
+	else
318
+		adfs_dir_forget(&dir);
319
+unlock:
320
+	up_write(&adfs_dir_rwsem);
321
+
322
+	return ret;
323
+}
324
+
325
+static unsigned char adfs_tolower(unsigned char c)
326
+{
327
+	if (c >= 'A' && c <= 'Z')
328
+		c += 'a' - 'A';
329
+	return c;
330
+}
331
+
332
+static int __adfs_compare(const unsigned char *qstr, u32 qlen,
333
+			  const char *str, u32 len)
334
+{
335
+	u32 i;
336
+
337
+	if (qlen != len)
338
+		return 1;
339
+
340
+	for (i = 0; i < qlen; i++)
341
+		if (adfs_tolower(qstr[i]) != adfs_tolower(str[i]))
342
+			return 1;
343
+
344
+	return 0;
345
+}
346
+
347
+static int adfs_dir_lookup_byname(struct inode *inode, const struct qstr *qstr,
348
+				  struct object_info *obj)
349
+{
350
+	struct super_block *sb = inode->i_sb;
351
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
352
+	const unsigned char *name;
353
+	struct adfs_dir dir;
354
+	u32 name_len;
355
+	int ret;
356
+
357
+	down_read(&adfs_dir_rwsem);
358
+	ret = adfs_dir_read_inode(sb, inode, &dir);
359
+	if (ret)
360
+		goto unlock;
150361 
151362 	ret = ops->setpos(&dir, 0);
152363 	if (ret)
153
-		goto unlock_out;
364
+		goto unlock_relse;
154365 
155366 	ret = -ENOENT;
367
+	name = qstr->name;
368
+	name_len = qstr->len;
156369 	while (ops->getnext(&dir, obj) == 0) {
157
-		if (adfs_match(name, obj)) {
370
+		if (!__adfs_compare(name, name_len, obj->name, obj->name_len)) {
158371 			ret = 0;
159372 			break;
160373 		}
161374 	}
375
+	obj->parent_id = ADFS_I(inode)->indaddr;
162376 
163
-unlock_out:
164
-	read_unlock(&adfs_dir_lock);
377
+unlock_relse:
378
+	up_read(&adfs_dir_rwsem);
379
+	adfs_dir_relse(&dir);
380
+	return ret;
165381 
166
-free_out:
167
-	ops->free(&dir);
168
-out:
382
+unlock:
383
+	up_read(&adfs_dir_rwsem);
169384 	return ret;
170385 }
171386 
172387 const struct file_operations adfs_dir_operations = {
173388 	.read		= generic_read_dir,
174389 	.llseek		= generic_file_llseek,
175
-	.iterate	= adfs_readdir,
390
+	.iterate_shared	= adfs_iterate,
176391 	.fsync		= generic_file_fsync,
177392 };
178393 
179394 static int
180395 adfs_hash(const struct dentry *parent, struct qstr *qstr)
181396 {
182
-	const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
183397 	const unsigned char *name;
184398 	unsigned long hash;
185
-	int i;
399
+	u32 len;
186400 
187
-	if (qstr->len < name_len)
188
-		return 0;
401
+	if (qstr->len > ADFS_SB(parent->d_sb)->s_namelen)
402
+		return -ENAMETOOLONG;
189403 
190
-	/*
191
-	 * Truncate the name in place, avoids
192
-	 * having to define a compare function.
193
-	 */
194
-	qstr->len = i = name_len;
404
+	len = qstr->len;
195405 	name = qstr->name;
196406 	hash = init_name_hash(parent);
197
-	while (i--) {
198
-		char c;
199
-
200
-		c = *name++;
201
-		if (c >= 'A' && c <= 'Z')
202
-			c += 'a' - 'A';
203
-
204
-		hash = partial_name_hash(c, hash);
205
-	}
407
+	while (len--)
408
+		hash = partial_name_hash(adfs_tolower(*name++), hash);
206409 	qstr->hash = end_name_hash(hash);
207410 
208411 	return 0;
....@@ -212,30 +415,10 @@
212415  * Compare two names, taking note of the name length
213416  * requirements of the underlying filesystem.
214417  */
215
-static int
216
-adfs_compare(const struct dentry *dentry,
217
-		unsigned int len, const char *str, const struct qstr *name)
418
+static int adfs_compare(const struct dentry *dentry, unsigned int len,
419
+			const char *str, const struct qstr *qstr)
218420 {
219
-	int i;
220
-
221
-	if (len != name->len)
222
-		return 1;
223
-
224
-	for (i = 0; i < name->len; i++) {
225
-		char a, b;
226
-
227
-		a = str[i];
228
-		b = name->name[i];
229
-
230
-		if (a >= 'A' && a <= 'Z')
231
-			a += 'a' - 'A';
232
-		if (b >= 'A' && b <= 'Z')
233
-			b += 'a' - 'A';
234
-
235
-		if (a != b)
236
-			return 1;
237
-	}
238
-	return 0;
421
+	return __adfs_compare(qstr->name, qstr->len, str, len);
239422 }
240423 
241424 const struct dentry_operations adfs_dentry_operations = {