inline.c 11.1 KB
Newer Older
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
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
/*
 * Copyright (c) 2012 Taobao.
 * Written by Tao Ma <boyu.mt@taobao.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2.1 of the GNU Lesser General Public License
 * 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.
 */
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"

#define EXT4_XATTR_SYSTEM_DATA	"data"
#define EXT4_MIN_INLINE_DATA_SIZE	((sizeof(__le32) * EXT4_N_BLOCKS))

int ext4_get_inline_size(struct inode *inode)
{
	if (EXT4_I(inode)->i_inline_off)
		return EXT4_I(inode)->i_inline_size;

	return 0;
}

static int get_max_inline_xattr_value_size(struct inode *inode,
					   struct ext4_iloc *iloc)
{
	struct ext4_xattr_ibody_header *header;
	struct ext4_xattr_entry *entry;
	struct ext4_inode *raw_inode;
	int free, min_offs;

	min_offs = EXT4_SB(inode->i_sb)->s_inode_size -
			EXT4_GOOD_OLD_INODE_SIZE -
			EXT4_I(inode)->i_extra_isize -
			sizeof(struct ext4_xattr_ibody_header);

	/*
	 * We need to subtract another sizeof(__u32) since an in-inode xattr
	 * needs an empty 4 bytes to indicate the gap between the xattr entry
	 * and the name/value pair.
	 */
	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
		return EXT4_XATTR_SIZE(min_offs -
			EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA)) -
			EXT4_XATTR_ROUND - sizeof(__u32));

	raw_inode = ext4_raw_inode(iloc);
	header = IHDR(inode, raw_inode);
	entry = IFIRST(header);

	/* Compute min_offs. */
	for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
		if (!entry->e_value_block && entry->e_value_size) {
			size_t offs = le16_to_cpu(entry->e_value_offs);
			if (offs < min_offs)
				min_offs = offs;
		}
	}
	free = min_offs -
		((void *)entry - (void *)IFIRST(header)) - sizeof(__u32);

	if (EXT4_I(inode)->i_inline_off) {
		entry = (struct ext4_xattr_entry *)
			((void *)raw_inode + EXT4_I(inode)->i_inline_off);

		free += le32_to_cpu(entry->e_value_size);
		goto out;
	}

	free -= EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA));

	if (free > EXT4_XATTR_ROUND)
		free = EXT4_XATTR_SIZE(free - EXT4_XATTR_ROUND);
	else
		free = 0;

out:
	return free;
}

/*
 * Get the maximum size we now can store in an inode.
 * If we can't find the space for a xattr entry, don't use the space
 * of the extents since we have no space to indicate the inline data.
 */
int ext4_get_max_inline_size(struct inode *inode)
{
	int error, max_inline_size;
	struct ext4_iloc iloc;

	if (EXT4_I(inode)->i_extra_isize == 0)
		return 0;

	error = ext4_get_inode_loc(inode, &iloc);
	if (error) {
		ext4_error_inode(inode, __func__, __LINE__, 0,
				 "can't get inode location %lu",
				 inode->i_ino);
		return 0;
	}

	down_read(&EXT4_I(inode)->xattr_sem);
	max_inline_size = get_max_inline_xattr_value_size(inode, &iloc);
	up_read(&EXT4_I(inode)->xattr_sem);

	brelse(iloc.bh);

	if (!max_inline_size)
		return 0;

	return max_inline_size + EXT4_MIN_INLINE_DATA_SIZE;
}

int ext4_has_inline_data(struct inode *inode)
{
	return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
	       EXT4_I(inode)->i_inline_off;
}

/*
 * this function does not take xattr_sem, which is OK because it is
 * currently only used in a code path coming form ext4_iget, before
 * the new inode has been unlocked
 */
int ext4_find_inline_data_nolock(struct inode *inode)
{
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = -ENODATA, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM,
		.name = EXT4_XATTR_SYSTEM_DATA,
	};
	int error;

	if (EXT4_I(inode)->i_extra_isize == 0)
		return 0;

	error = ext4_get_inode_loc(inode, &is.iloc);
	if (error)
		return error;

	error = ext4_xattr_ibody_find(inode, &i, &is);
	if (error)
		goto out;

	if (!is.s.not_found) {
		EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here -
					(void *)ext4_raw_inode(&is.iloc));
		EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE +
				le32_to_cpu(is.s.here->e_value_size);
		ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
	}
out:
	brelse(is.iloc.bh);
	return error;
}

static int ext4_read_inline_data(struct inode *inode, void *buffer,
				 unsigned int len,
				 struct ext4_iloc *iloc)
{
	struct ext4_xattr_entry *entry;
	struct ext4_xattr_ibody_header *header;
	int cp_len = 0;
	struct ext4_inode *raw_inode;

	if (!len)
		return 0;

	BUG_ON(len > EXT4_I(inode)->i_inline_size);

	cp_len = len < EXT4_MIN_INLINE_DATA_SIZE ?
			len : EXT4_MIN_INLINE_DATA_SIZE;

	raw_inode = ext4_raw_inode(iloc);
	memcpy(buffer, (void *)(raw_inode->i_block), cp_len);

	len -= cp_len;
	buffer += cp_len;

	if (!len)
		goto out;

	header = IHDR(inode, raw_inode);
	entry = (struct ext4_xattr_entry *)((void *)raw_inode +
					    EXT4_I(inode)->i_inline_off);
	len = min_t(unsigned int, len,
		    (unsigned int)le32_to_cpu(entry->e_value_size));

	memcpy(buffer,
	       (void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs), len);
	cp_len += len;

out:
	return cp_len;
}

/*
 * write the buffer to the inline inode.
 * If 'create' is set, we don't need to do the extra copy in the xattr
 * value since it is already handled by ext4_xattr_ibody_set. That saves
 * us one memcpy.
 */
void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc,
			    void *buffer, loff_t pos, unsigned int len)
{
	struct ext4_xattr_entry *entry;
	struct ext4_xattr_ibody_header *header;
	struct ext4_inode *raw_inode;
	int cp_len = 0;

	BUG_ON(!EXT4_I(inode)->i_inline_off);
	BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);

	raw_inode = ext4_raw_inode(iloc);
	buffer += pos;

	if (pos < EXT4_MIN_INLINE_DATA_SIZE) {
		cp_len = pos + len > EXT4_MIN_INLINE_DATA_SIZE ?
			 EXT4_MIN_INLINE_DATA_SIZE - pos : len;
		memcpy((void *)raw_inode->i_block + pos, buffer, cp_len);

		len -= cp_len;
		buffer += cp_len;
		pos += cp_len;
	}

	if (!len)
		return;

	pos -= EXT4_MIN_INLINE_DATA_SIZE;
	header = IHDR(inode, raw_inode);
	entry = (struct ext4_xattr_entry *)((void *)raw_inode +
					    EXT4_I(inode)->i_inline_off);

	memcpy((void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs) + pos,
	       buffer, len);
}

static int ext4_create_inline_data(handle_t *handle,
				   struct inode *inode, unsigned len)
{
	int error;
	void *value = NULL;
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = -ENODATA, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM,
		.name = EXT4_XATTR_SYSTEM_DATA,
	};

	error = ext4_get_inode_loc(inode, &is.iloc);
	if (error)
		return error;

	error = ext4_journal_get_write_access(handle, is.iloc.bh);
	if (error)
		goto out;

	if (len > EXT4_MIN_INLINE_DATA_SIZE) {
		value = (void *)empty_zero_page;
		len -= EXT4_MIN_INLINE_DATA_SIZE;
	} else {
		value = "";
		len = 0;
	}

	/* Insert the the xttr entry. */
	i.value = value;
	i.value_len = len;

	error = ext4_xattr_ibody_find(inode, &i, &is);
	if (error)
		goto out;

	BUG_ON(!is.s.not_found);

	error = ext4_xattr_ibody_set(handle, inode, &i, &is);
	if (error) {
		if (error == -ENOSPC)
			ext4_clear_inode_state(inode,
					       EXT4_STATE_MAY_INLINE_DATA);
		goto out;
	}

	memset((void *)ext4_raw_inode(&is.iloc)->i_block,
		0, EXT4_MIN_INLINE_DATA_SIZE);

	EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here -
				      (void *)ext4_raw_inode(&is.iloc));
	EXT4_I(inode)->i_inline_size = len + EXT4_MIN_INLINE_DATA_SIZE;
	ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
	ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA);
	get_bh(is.iloc.bh);
	error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);

out:
	brelse(is.iloc.bh);
	return error;
}

static int ext4_update_inline_data(handle_t *handle, struct inode *inode,
				   unsigned int len)
{
	int error;
	void *value = NULL;
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = -ENODATA, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM,
		.name = EXT4_XATTR_SYSTEM_DATA,
	};

	/* If the old space is ok, write the data directly. */
	if (len <= EXT4_I(inode)->i_inline_size)
		return 0;

	error = ext4_get_inode_loc(inode, &is.iloc);
	if (error)
		return error;

	error = ext4_xattr_ibody_find(inode, &i, &is);
	if (error)
		goto out;

	BUG_ON(is.s.not_found);

	len -= EXT4_MIN_INLINE_DATA_SIZE;
	value = kzalloc(len, GFP_NOFS);
	if (!value)
		goto out;

	error = ext4_xattr_ibody_get(inode, i.name_index, i.name,
				     value, len);
	if (error == -ENODATA)
		goto out;

	error = ext4_journal_get_write_access(handle, is.iloc.bh);
	if (error)
		goto out;

	/* Update the xttr entry. */
	i.value = value;
	i.value_len = len;

	error = ext4_xattr_ibody_set(handle, inode, &i, &is);
	if (error)
		goto out;

	EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here -
				      (void *)ext4_raw_inode(&is.iloc));
	EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE +
				le32_to_cpu(is.s.here->e_value_size);
	ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
	get_bh(is.iloc.bh);
	error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);

out:
	kfree(value);
	brelse(is.iloc.bh);
	return error;
}

int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
			     unsigned int len)
{
	int ret, size;
	struct ext4_inode_info *ei = EXT4_I(inode);

	if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
		return -ENOSPC;

	size = ext4_get_max_inline_size(inode);
	if (size < len)
		return -ENOSPC;

	down_write(&EXT4_I(inode)->xattr_sem);

	if (ei->i_inline_off)
		ret = ext4_update_inline_data(handle, inode, len);
	else
		ret = ext4_create_inline_data(handle, inode, len);

	up_write(&EXT4_I(inode)->xattr_sem);

	return ret;
}

static int ext4_destroy_inline_data_nolock(handle_t *handle,
					   struct inode *inode)
{
	struct ext4_inode_info *ei = EXT4_I(inode);
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = 0, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM,
		.name = EXT4_XATTR_SYSTEM_DATA,
		.value = NULL,
		.value_len = 0,
	};
	int error;

	if (!ei->i_inline_off)
		return 0;

	error = ext4_get_inode_loc(inode, &is.iloc);
	if (error)
		return error;

	error = ext4_xattr_ibody_find(inode, &i, &is);
	if (error)
		goto out;

	error = ext4_journal_get_write_access(handle, is.iloc.bh);
	if (error)
		goto out;

	error = ext4_xattr_ibody_set(handle, inode, &i, &is);
	if (error)
		goto out;

	memset((void *)ext4_raw_inode(&is.iloc)->i_block,
		0, EXT4_MIN_INLINE_DATA_SIZE);

	if (EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
				      EXT4_FEATURE_INCOMPAT_EXTENTS)) {
		if (S_ISDIR(inode->i_mode) ||
		    S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode)) {
			ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
			ext4_ext_tree_init(handle, inode);
		}
	}
	ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA);

	get_bh(is.iloc.bh);
	error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);

	EXT4_I(inode)->i_inline_off = 0;
	EXT4_I(inode)->i_inline_size = 0;
	ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
out:
	brelse(is.iloc.bh);
	if (error == -ENODATA)
		error = 0;
	return error;
}

int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
{
	int ret;

	down_write(&EXT4_I(inode)->xattr_sem);
	ret = ext4_destroy_inline_data_nolock(handle, inode);
	up_write(&EXT4_I(inode)->xattr_sem);

	return ret;
}