aboutsummaryrefslogtreecommitdiff
path: root/fs/btrfs/dir-item.c
blob: e4f30090d640bf74b4ec99a1bdd7148a890d2883 (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
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include "ctree.h"
#include "disk-io.h"
#include "hash.h"
#include "transaction.h"

static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
						   *trans,
						   struct btrfs_root *root,
						   struct btrfs_path *path,
						   struct btrfs_key *cpu_key,
						   u32 data_size,
						   const char *name,
						   int name_len)
{
	int ret;
	char *ptr;
	struct btrfs_item *item;
	struct extent_buffer *leaf;

	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
	if (ret == -EEXIST) {
		struct btrfs_dir_item *di;
		di = btrfs_match_dir_item_name(root, path, name, name_len);
		if (di)
			return ERR_PTR(-EEXIST);
		ret = btrfs_extend_item(trans, root, path, data_size);
		WARN_ON(ret > 0);
	}
	if (ret < 0)
		return ERR_PTR(ret);
	WARN_ON(ret > 0);
	leaf = path->nodes[0];
	item = btrfs_item_nr(leaf, path->slots[0]);
	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
	BUG_ON(data_size > btrfs_item_size(leaf, item));
	ptr += btrfs_item_size(leaf, item) - data_size;
	return (struct btrfs_dir_item *)ptr;
}

int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root, const char *name,
			    u16 name_len, const void *data, u16 data_len,
			    u64 dir)
{
	int ret = 0;
	struct btrfs_path *path;
	struct btrfs_dir_item *dir_item;
	unsigned long name_ptr, data_ptr;
	struct btrfs_key key, location;
	struct btrfs_disk_key disk_key;
	struct extent_buffer *leaf;
	u32 data_size;

	key.objectid = dir;
	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
	key.offset = btrfs_name_hash(name, name_len);
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	if (name_len + data_len + sizeof(struct btrfs_dir_item) >
	    BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
		return -ENOSPC;

	data_size = sizeof(*dir_item) + name_len + data_len;
	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
					name, name_len);
	/*
	 * FIXME: at some point we should handle xattr's that are larger than
	 * what we can fit in our leaf.  We set location to NULL b/c we arent
	 * pointing at anything else, that will change if we store the xattr
	 * data in a separate inode.
	 */
	BUG_ON(IS_ERR(dir_item));
	memset(&location, 0, sizeof(location));

	leaf = path->nodes[0];
	btrfs_cpu_key_to_disk(&disk_key, &location);
	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
	btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
	btrfs_set_dir_name_len(leaf, dir_item, name_len);
	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
	btrfs_set_dir_data_len(leaf, dir_item, data_len);
	name_ptr = (unsigned long)(dir_item + 1);
	data_ptr = (unsigned long)((char *)name_ptr + name_len);

	write_extent_buffer(leaf, name, name_ptr, name_len);
	write_extent_buffer(leaf, data, data_ptr, data_len);
	btrfs_mark_buffer_dirty(path->nodes[0]);

	btrfs_free_path(path);
	return ret;
}

int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
			  *root, const char *name, int name_len, u64 dir,
			  struct btrfs_key *location, u8 type, u64 index)
{
	int ret = 0;
	int ret2 = 0;
	struct btrfs_path *path;
	struct btrfs_dir_item *dir_item;
	struct extent_buffer *leaf;
	unsigned long name_ptr;
	struct btrfs_key key;
	struct btrfs_disk_key disk_key;
	u32 data_size;

	key.objectid = dir;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
	key.offset = btrfs_name_hash(name, name_len);
	path = btrfs_alloc_path();
	data_size = sizeof(*dir_item) + name_len;
	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
					name, name_len);
	if (IS_ERR(dir_item)) {
		ret = PTR_ERR(dir_item);
		if (ret == -EEXIST)
			goto second_insert;
		goto out;
	}

	leaf = path->nodes[0];
	btrfs_cpu_key_to_disk(&disk_key, location);
	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
	btrfs_set_dir_type(leaf, dir_item, type);
	btrfs_set_dir_data_len(leaf, dir_item, 0);
	btrfs_set_dir_name_len(leaf, dir_item, name_len);
	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
	name_ptr = (unsigned long)(dir_item + 1);

	write_extent_buffer(leaf, name, name_ptr, name_len);
	btrfs_mark_buffer_dirty(leaf);

second_insert:
	/* FIXME, use some real flag for selecting the extra index */
	if (root == root->fs_info->tree_root) {
		ret = 0;
		goto out;
	}
	btrfs_release_path(root, path);

	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
	key.offset = index;
	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
					name, name_len);
	if (IS_ERR(dir_item)) {
		ret2 = PTR_ERR(dir_item);
		goto out;
	}
	leaf = path->nodes[0];
	btrfs_cpu_key_to_disk(&disk_key, location);
	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
	btrfs_set_dir_type(leaf, dir_item, type);
	btrfs_set_dir_data_len(leaf, dir_item, 0);
	btrfs_set_dir_name_len(leaf, dir_item, name_len);
	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
	name_ptr = (unsigned long)(dir_item + 1);
	write_extent_buffer(leaf, name, name_ptr, name_len);
	btrfs_mark_buffer_dirty(leaf);
out:
	btrfs_free_path(path);
	if (ret)
		return ret;
	if (ret2)
		return ret2;
	return 0;
}

struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
					     struct btrfs_root *root,
					     struct btrfs_path *path, u64 dir,
					     const char *name, int name_len,
					     int mod)
{
	int ret;
	struct btrfs_key key;
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;
	struct btrfs_key found_key;
	struct extent_buffer *leaf;

	key.objectid = dir;
	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);

	key.offset = btrfs_name_hash(name, name_len);

	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	if (ret < 0)
		return ERR_PTR(ret);
	if (ret > 0) {
		if (path->slots[0] == 0)
			return NULL;
		path->slots[0]--;
	}

	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

	if (found_key.objectid != dir ||
	    btrfs_key_type(&found_key) != BTRFS_DIR_ITEM_KEY ||
	    found_key.offset != key.offset)
		return NULL;

	return btrfs_match_dir_item_name(root, path, name, name_len);
}

struct btrfs_dir_item *
btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root,
			    struct btrfs_path *path, u64 dir,
			    u64 objectid, const char *name, int name_len,
			    int mod)
{
	int ret;
	struct btrfs_key key;
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;

	key.objectid = dir;
	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
	key.offset = objectid;

	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	if (ret < 0)
		return ERR_PTR(ret);
	if (ret > 0)
		return ERR_PTR(-ENOENT);
	return btrfs_match_dir_item_name(root, path, name, name_len);
}

struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
					  struct btrfs_root *root,
					  struct btrfs_path *path, u64 dir,
					  const char *name, u16 name_len,
					  int mod)
{
	int ret;
	struct btrfs_key key;
	int ins_len = mod < 0 ? -1 : 0;
	int cow = mod != 0;
	struct btrfs_key found_key;
	struct extent_buffer *leaf;

	key.objectid = dir;
	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
	key.offset = btrfs_name_hash(name, name_len);
	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
	if (ret < 0)
		return ERR_PTR(ret);
	if (ret > 0) {
		if (path->slots[0] == 0)
			return NULL;
		path->slots[0]--;
	}

	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

	if (found_key.objectid != dir ||
	    btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
	    found_key.offset != key.offset)
		return NULL;

	return btrfs_match_dir_item_name(root, path, name, name_len);
}

struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
			      struct btrfs_path *path,
			      const char *name, int name_len)
{
	struct btrfs_dir_item *dir_item;
	unsigned long name_ptr;
	u32 total_len;
	u32 cur = 0;
	u32 this_len;
	struct extent_buffer *leaf;

	leaf = path->nodes[0];
	dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
	total_len = btrfs_item_size_nr(leaf, path->slots[0]);
	while(cur < total_len) {
		this_len = sizeof(*dir_item) +
			btrfs_dir_name_len(leaf, dir_item) +
			btrfs_dir_data_len(leaf, dir_item);
		name_ptr = (unsigned long)(dir_item + 1);

		if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
		    memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
			return dir_item;

		cur += this_len;
		dir_item = (struct btrfs_dir_item *)((char *)dir_item +
						     this_len);
	}
	return NULL;
}

int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root,
			      struct btrfs_path *path,
			      struct btrfs_dir_item *di)
{

	struct extent_buffer *leaf;
	u32 sub_item_len;
	u32 item_len;
	int ret = 0;

	leaf = path->nodes[0];
	sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
		btrfs_dir_data_len(leaf, di);
	item_len = btrfs_item_size_nr(leaf, path->slots[0]);
	if (sub_item_len == item_len) {
		ret = btrfs_del_item(trans, root, path);
	} else {
		/* MARKER */
		unsigned long ptr = (unsigned long)di;
		unsigned long start;

		start = btrfs_item_ptr_offset(leaf, path->slots[0]);
		memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
			item_len - (ptr + sub_item_len - start));
		ret = btrfs_truncate_item(trans, root, path,
					  item_len - sub_item_len, 1);
	}
	return 0;
}