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67cf5b09 TM |
1 | /* |
2 | * Copyright (c) 2012 Taobao. | |
3 | * Written by Tao Ma <boyu.mt@taobao.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of version 2.1 of the GNU Lesser General Public License | |
7 | * as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | #include "ext4_jbd2.h" | |
15 | #include "ext4.h" | |
16 | #include "xattr.h" | |
17 | ||
18 | #define EXT4_XATTR_SYSTEM_DATA "data" | |
19 | #define EXT4_MIN_INLINE_DATA_SIZE ((sizeof(__le32) * EXT4_N_BLOCKS)) | |
20 | ||
21 | int ext4_get_inline_size(struct inode *inode) | |
22 | { | |
23 | if (EXT4_I(inode)->i_inline_off) | |
24 | return EXT4_I(inode)->i_inline_size; | |
25 | ||
26 | return 0; | |
27 | } | |
28 | ||
29 | static int get_max_inline_xattr_value_size(struct inode *inode, | |
30 | struct ext4_iloc *iloc) | |
31 | { | |
32 | struct ext4_xattr_ibody_header *header; | |
33 | struct ext4_xattr_entry *entry; | |
34 | struct ext4_inode *raw_inode; | |
35 | int free, min_offs; | |
36 | ||
37 | min_offs = EXT4_SB(inode->i_sb)->s_inode_size - | |
38 | EXT4_GOOD_OLD_INODE_SIZE - | |
39 | EXT4_I(inode)->i_extra_isize - | |
40 | sizeof(struct ext4_xattr_ibody_header); | |
41 | ||
42 | /* | |
43 | * We need to subtract another sizeof(__u32) since an in-inode xattr | |
44 | * needs an empty 4 bytes to indicate the gap between the xattr entry | |
45 | * and the name/value pair. | |
46 | */ | |
47 | if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) | |
48 | return EXT4_XATTR_SIZE(min_offs - | |
49 | EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA)) - | |
50 | EXT4_XATTR_ROUND - sizeof(__u32)); | |
51 | ||
52 | raw_inode = ext4_raw_inode(iloc); | |
53 | header = IHDR(inode, raw_inode); | |
54 | entry = IFIRST(header); | |
55 | ||
56 | /* Compute min_offs. */ | |
57 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { | |
58 | if (!entry->e_value_block && entry->e_value_size) { | |
59 | size_t offs = le16_to_cpu(entry->e_value_offs); | |
60 | if (offs < min_offs) | |
61 | min_offs = offs; | |
62 | } | |
63 | } | |
64 | free = min_offs - | |
65 | ((void *)entry - (void *)IFIRST(header)) - sizeof(__u32); | |
66 | ||
67 | if (EXT4_I(inode)->i_inline_off) { | |
68 | entry = (struct ext4_xattr_entry *) | |
69 | ((void *)raw_inode + EXT4_I(inode)->i_inline_off); | |
70 | ||
71 | free += le32_to_cpu(entry->e_value_size); | |
72 | goto out; | |
73 | } | |
74 | ||
75 | free -= EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA)); | |
76 | ||
77 | if (free > EXT4_XATTR_ROUND) | |
78 | free = EXT4_XATTR_SIZE(free - EXT4_XATTR_ROUND); | |
79 | else | |
80 | free = 0; | |
81 | ||
82 | out: | |
83 | return free; | |
84 | } | |
85 | ||
86 | /* | |
87 | * Get the maximum size we now can store in an inode. | |
88 | * If we can't find the space for a xattr entry, don't use the space | |
89 | * of the extents since we have no space to indicate the inline data. | |
90 | */ | |
91 | int ext4_get_max_inline_size(struct inode *inode) | |
92 | { | |
93 | int error, max_inline_size; | |
94 | struct ext4_iloc iloc; | |
95 | ||
96 | if (EXT4_I(inode)->i_extra_isize == 0) | |
97 | return 0; | |
98 | ||
99 | error = ext4_get_inode_loc(inode, &iloc); | |
100 | if (error) { | |
101 | ext4_error_inode(inode, __func__, __LINE__, 0, | |
102 | "can't get inode location %lu", | |
103 | inode->i_ino); | |
104 | return 0; | |
105 | } | |
106 | ||
107 | down_read(&EXT4_I(inode)->xattr_sem); | |
108 | max_inline_size = get_max_inline_xattr_value_size(inode, &iloc); | |
109 | up_read(&EXT4_I(inode)->xattr_sem); | |
110 | ||
111 | brelse(iloc.bh); | |
112 | ||
113 | if (!max_inline_size) | |
114 | return 0; | |
115 | ||
116 | return max_inline_size + EXT4_MIN_INLINE_DATA_SIZE; | |
117 | } | |
118 | ||
119 | int ext4_has_inline_data(struct inode *inode) | |
120 | { | |
121 | return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) && | |
122 | EXT4_I(inode)->i_inline_off; | |
123 | } | |
124 | ||
125 | /* | |
126 | * this function does not take xattr_sem, which is OK because it is | |
127 | * currently only used in a code path coming form ext4_iget, before | |
128 | * the new inode has been unlocked | |
129 | */ | |
130 | int ext4_find_inline_data_nolock(struct inode *inode) | |
131 | { | |
132 | struct ext4_xattr_ibody_find is = { | |
133 | .s = { .not_found = -ENODATA, }, | |
134 | }; | |
135 | struct ext4_xattr_info i = { | |
136 | .name_index = EXT4_XATTR_INDEX_SYSTEM, | |
137 | .name = EXT4_XATTR_SYSTEM_DATA, | |
138 | }; | |
139 | int error; | |
140 | ||
141 | if (EXT4_I(inode)->i_extra_isize == 0) | |
142 | return 0; | |
143 | ||
144 | error = ext4_get_inode_loc(inode, &is.iloc); | |
145 | if (error) | |
146 | return error; | |
147 | ||
148 | error = ext4_xattr_ibody_find(inode, &i, &is); | |
149 | if (error) | |
150 | goto out; | |
151 | ||
152 | if (!is.s.not_found) { | |
153 | EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here - | |
154 | (void *)ext4_raw_inode(&is.iloc)); | |
155 | EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE + | |
156 | le32_to_cpu(is.s.here->e_value_size); | |
157 | ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); | |
158 | } | |
159 | out: | |
160 | brelse(is.iloc.bh); | |
161 | return error; | |
162 | } | |
163 | ||
164 | static int ext4_read_inline_data(struct inode *inode, void *buffer, | |
165 | unsigned int len, | |
166 | struct ext4_iloc *iloc) | |
167 | { | |
168 | struct ext4_xattr_entry *entry; | |
169 | struct ext4_xattr_ibody_header *header; | |
170 | int cp_len = 0; | |
171 | struct ext4_inode *raw_inode; | |
172 | ||
173 | if (!len) | |
174 | return 0; | |
175 | ||
176 | BUG_ON(len > EXT4_I(inode)->i_inline_size); | |
177 | ||
178 | cp_len = len < EXT4_MIN_INLINE_DATA_SIZE ? | |
179 | len : EXT4_MIN_INLINE_DATA_SIZE; | |
180 | ||
181 | raw_inode = ext4_raw_inode(iloc); | |
182 | memcpy(buffer, (void *)(raw_inode->i_block), cp_len); | |
183 | ||
184 | len -= cp_len; | |
185 | buffer += cp_len; | |
186 | ||
187 | if (!len) | |
188 | goto out; | |
189 | ||
190 | header = IHDR(inode, raw_inode); | |
191 | entry = (struct ext4_xattr_entry *)((void *)raw_inode + | |
192 | EXT4_I(inode)->i_inline_off); | |
193 | len = min_t(unsigned int, len, | |
194 | (unsigned int)le32_to_cpu(entry->e_value_size)); | |
195 | ||
196 | memcpy(buffer, | |
197 | (void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs), len); | |
198 | cp_len += len; | |
199 | ||
200 | out: | |
201 | return cp_len; | |
202 | } | |
203 | ||
204 | /* | |
205 | * write the buffer to the inline inode. | |
206 | * If 'create' is set, we don't need to do the extra copy in the xattr | |
207 | * value since it is already handled by ext4_xattr_ibody_set. That saves | |
208 | * us one memcpy. | |
209 | */ | |
210 | void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc, | |
211 | void *buffer, loff_t pos, unsigned int len) | |
212 | { | |
213 | struct ext4_xattr_entry *entry; | |
214 | struct ext4_xattr_ibody_header *header; | |
215 | struct ext4_inode *raw_inode; | |
216 | int cp_len = 0; | |
217 | ||
218 | BUG_ON(!EXT4_I(inode)->i_inline_off); | |
219 | BUG_ON(pos + len > EXT4_I(inode)->i_inline_size); | |
220 | ||
221 | raw_inode = ext4_raw_inode(iloc); | |
222 | buffer += pos; | |
223 | ||
224 | if (pos < EXT4_MIN_INLINE_DATA_SIZE) { | |
225 | cp_len = pos + len > EXT4_MIN_INLINE_DATA_SIZE ? | |
226 | EXT4_MIN_INLINE_DATA_SIZE - pos : len; | |
227 | memcpy((void *)raw_inode->i_block + pos, buffer, cp_len); | |
228 | ||
229 | len -= cp_len; | |
230 | buffer += cp_len; | |
231 | pos += cp_len; | |
232 | } | |
233 | ||
234 | if (!len) | |
235 | return; | |
236 | ||
237 | pos -= EXT4_MIN_INLINE_DATA_SIZE; | |
238 | header = IHDR(inode, raw_inode); | |
239 | entry = (struct ext4_xattr_entry *)((void *)raw_inode + | |
240 | EXT4_I(inode)->i_inline_off); | |
241 | ||
242 | memcpy((void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs) + pos, | |
243 | buffer, len); | |
244 | } | |
245 | ||
246 | static int ext4_create_inline_data(handle_t *handle, | |
247 | struct inode *inode, unsigned len) | |
248 | { | |
249 | int error; | |
250 | void *value = NULL; | |
251 | struct ext4_xattr_ibody_find is = { | |
252 | .s = { .not_found = -ENODATA, }, | |
253 | }; | |
254 | struct ext4_xattr_info i = { | |
255 | .name_index = EXT4_XATTR_INDEX_SYSTEM, | |
256 | .name = EXT4_XATTR_SYSTEM_DATA, | |
257 | }; | |
258 | ||
259 | error = ext4_get_inode_loc(inode, &is.iloc); | |
260 | if (error) | |
261 | return error; | |
262 | ||
263 | error = ext4_journal_get_write_access(handle, is.iloc.bh); | |
264 | if (error) | |
265 | goto out; | |
266 | ||
267 | if (len > EXT4_MIN_INLINE_DATA_SIZE) { | |
268 | value = (void *)empty_zero_page; | |
269 | len -= EXT4_MIN_INLINE_DATA_SIZE; | |
270 | } else { | |
271 | value = ""; | |
272 | len = 0; | |
273 | } | |
274 | ||
275 | /* Insert the the xttr entry. */ | |
276 | i.value = value; | |
277 | i.value_len = len; | |
278 | ||
279 | error = ext4_xattr_ibody_find(inode, &i, &is); | |
280 | if (error) | |
281 | goto out; | |
282 | ||
283 | BUG_ON(!is.s.not_found); | |
284 | ||
285 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); | |
286 | if (error) { | |
287 | if (error == -ENOSPC) | |
288 | ext4_clear_inode_state(inode, | |
289 | EXT4_STATE_MAY_INLINE_DATA); | |
290 | goto out; | |
291 | } | |
292 | ||
293 | memset((void *)ext4_raw_inode(&is.iloc)->i_block, | |
294 | 0, EXT4_MIN_INLINE_DATA_SIZE); | |
295 | ||
296 | EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here - | |
297 | (void *)ext4_raw_inode(&is.iloc)); | |
298 | EXT4_I(inode)->i_inline_size = len + EXT4_MIN_INLINE_DATA_SIZE; | |
299 | ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); | |
300 | ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA); | |
301 | get_bh(is.iloc.bh); | |
302 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); | |
303 | ||
304 | out: | |
305 | brelse(is.iloc.bh); | |
306 | return error; | |
307 | } | |
308 | ||
309 | static int ext4_update_inline_data(handle_t *handle, struct inode *inode, | |
310 | unsigned int len) | |
311 | { | |
312 | int error; | |
313 | void *value = NULL; | |
314 | struct ext4_xattr_ibody_find is = { | |
315 | .s = { .not_found = -ENODATA, }, | |
316 | }; | |
317 | struct ext4_xattr_info i = { | |
318 | .name_index = EXT4_XATTR_INDEX_SYSTEM, | |
319 | .name = EXT4_XATTR_SYSTEM_DATA, | |
320 | }; | |
321 | ||
322 | /* If the old space is ok, write the data directly. */ | |
323 | if (len <= EXT4_I(inode)->i_inline_size) | |
324 | return 0; | |
325 | ||
326 | error = ext4_get_inode_loc(inode, &is.iloc); | |
327 | if (error) | |
328 | return error; | |
329 | ||
330 | error = ext4_xattr_ibody_find(inode, &i, &is); | |
331 | if (error) | |
332 | goto out; | |
333 | ||
334 | BUG_ON(is.s.not_found); | |
335 | ||
336 | len -= EXT4_MIN_INLINE_DATA_SIZE; | |
337 | value = kzalloc(len, GFP_NOFS); | |
338 | if (!value) | |
339 | goto out; | |
340 | ||
341 | error = ext4_xattr_ibody_get(inode, i.name_index, i.name, | |
342 | value, len); | |
343 | if (error == -ENODATA) | |
344 | goto out; | |
345 | ||
346 | error = ext4_journal_get_write_access(handle, is.iloc.bh); | |
347 | if (error) | |
348 | goto out; | |
349 | ||
350 | /* Update the xttr entry. */ | |
351 | i.value = value; | |
352 | i.value_len = len; | |
353 | ||
354 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); | |
355 | if (error) | |
356 | goto out; | |
357 | ||
358 | EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here - | |
359 | (void *)ext4_raw_inode(&is.iloc)); | |
360 | EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE + | |
361 | le32_to_cpu(is.s.here->e_value_size); | |
362 | ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); | |
363 | get_bh(is.iloc.bh); | |
364 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); | |
365 | ||
366 | out: | |
367 | kfree(value); | |
368 | brelse(is.iloc.bh); | |
369 | return error; | |
370 | } | |
371 | ||
372 | int ext4_prepare_inline_data(handle_t *handle, struct inode *inode, | |
373 | unsigned int len) | |
374 | { | |
375 | int ret, size; | |
376 | struct ext4_inode_info *ei = EXT4_I(inode); | |
377 | ||
378 | if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) | |
379 | return -ENOSPC; | |
380 | ||
381 | size = ext4_get_max_inline_size(inode); | |
382 | if (size < len) | |
383 | return -ENOSPC; | |
384 | ||
385 | down_write(&EXT4_I(inode)->xattr_sem); | |
386 | ||
387 | if (ei->i_inline_off) | |
388 | ret = ext4_update_inline_data(handle, inode, len); | |
389 | else | |
390 | ret = ext4_create_inline_data(handle, inode, len); | |
391 | ||
392 | up_write(&EXT4_I(inode)->xattr_sem); | |
393 | ||
394 | return ret; | |
395 | } | |
396 | ||
397 | static int ext4_destroy_inline_data_nolock(handle_t *handle, | |
398 | struct inode *inode) | |
399 | { | |
400 | struct ext4_inode_info *ei = EXT4_I(inode); | |
401 | struct ext4_xattr_ibody_find is = { | |
402 | .s = { .not_found = 0, }, | |
403 | }; | |
404 | struct ext4_xattr_info i = { | |
405 | .name_index = EXT4_XATTR_INDEX_SYSTEM, | |
406 | .name = EXT4_XATTR_SYSTEM_DATA, | |
407 | .value = NULL, | |
408 | .value_len = 0, | |
409 | }; | |
410 | int error; | |
411 | ||
412 | if (!ei->i_inline_off) | |
413 | return 0; | |
414 | ||
415 | error = ext4_get_inode_loc(inode, &is.iloc); | |
416 | if (error) | |
417 | return error; | |
418 | ||
419 | error = ext4_xattr_ibody_find(inode, &i, &is); | |
420 | if (error) | |
421 | goto out; | |
422 | ||
423 | error = ext4_journal_get_write_access(handle, is.iloc.bh); | |
424 | if (error) | |
425 | goto out; | |
426 | ||
427 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); | |
428 | if (error) | |
429 | goto out; | |
430 | ||
431 | memset((void *)ext4_raw_inode(&is.iloc)->i_block, | |
432 | 0, EXT4_MIN_INLINE_DATA_SIZE); | |
433 | ||
434 | if (EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb, | |
435 | EXT4_FEATURE_INCOMPAT_EXTENTS)) { | |
436 | if (S_ISDIR(inode->i_mode) || | |
437 | S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode)) { | |
438 | ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS); | |
439 | ext4_ext_tree_init(handle, inode); | |
440 | } | |
441 | } | |
442 | ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA); | |
443 | ||
444 | get_bh(is.iloc.bh); | |
445 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); | |
446 | ||
447 | EXT4_I(inode)->i_inline_off = 0; | |
448 | EXT4_I(inode)->i_inline_size = 0; | |
449 | ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); | |
450 | out: | |
451 | brelse(is.iloc.bh); | |
452 | if (error == -ENODATA) | |
453 | error = 0; | |
454 | return error; | |
455 | } | |
456 | ||
457 | int ext4_destroy_inline_data(handle_t *handle, struct inode *inode) | |
458 | { | |
459 | int ret; | |
460 | ||
461 | down_write(&EXT4_I(inode)->xattr_sem); | |
462 | ret = ext4_destroy_inline_data_nolock(handle, inode); | |
463 | up_write(&EXT4_I(inode)->xattr_sem); | |
464 | ||
465 | return ret; | |
466 | } |