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uio: documentation fixups
[zen-stable.git] / fs / ext3 / xattr.c
blobd565759d82eee0c06b10fa44e77abc51f29827d7
1 /*
2 * linux/fs/ext3/xattr.c
3 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 *
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
7 * Ext3 code with a lot of help from Eric Jarman <ejarman@acm.org>.
8 * Extended attributes for symlinks and special files added per
9 * suggestion of Luka Renko <luka.renko@hermes.si>.
10 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
11 * Red Hat Inc.
12 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
13 * and Andreas Gruenbacher <agruen@suse.de>.
14 */
15
16 /*
17 * Extended attributes are stored directly in inodes (on file systems with
18 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
19 * field contains the block number if an inode uses an additional block. All
20 * attributes must fit in the inode and one additional block. Blocks that
21 * contain the identical set of attributes may be shared among several inodes.
22 * Identical blocks are detected by keeping a cache of blocks that have
23 * recently been accessed.
24 *
25 * The attributes in inodes and on blocks have a different header; the entries
26 * are stored in the same format:
27 *
28 * +------------------+
29 * | header |
30 * | entry 1 | |
31 * | entry 2 | | growing downwards
32 * | entry 3 | v
33 * | four null bytes |
34 * | . . . |
35 * | value 1 | ^
36 * | value 3 | | growing upwards
37 * | value 2 | |
38 * +------------------+
39 *
40 * The header is followed by multiple entry descriptors. In disk blocks, the
41 * entry descriptors are kept sorted. In inodes, they are unsorted. The
42 * attribute values are aligned to the end of the block in no specific order.
43 *
44 * Locking strategy
45 * ----------------
46 * EXT3_I(inode)->i_file_acl is protected by EXT3_I(inode)->xattr_sem.
47 * EA blocks are only changed if they are exclusive to an inode, so
48 * holding xattr_sem also means that nothing but the EA block's reference
49 * count can change. Multiple writers to the same block are synchronized
50 * by the buffer lock.
51 */
52
53 #include <linux/init.h>
54 #include <linux/fs.h>
55 #include <linux/slab.h>
56 #include <linux/ext3_jbd.h>
57 #include <linux/ext3_fs.h>
58 #include <linux/mbcache.h>
59 #include <linux/quotaops.h>
60 #include <linux/rwsem.h>
61 #include "xattr.h"
62 #include "acl.h"
63
64 #define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
65 #define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
66 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
67 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
68
69 #define IHDR(inode, raw_inode) \
70 ((struct ext3_xattr_ibody_header *) \
71 ((void *)raw_inode + \
72 EXT3_GOOD_OLD_INODE_SIZE + \
73 EXT3_I(inode)->i_extra_isize))
74 #define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
75
76 #ifdef EXT3_XATTR_DEBUG
77 # define ea_idebug(inode, f...) do { \
78 printk(KERN_DEBUG "inode %s:%lu: ", \
79 inode->i_sb->s_id, inode->i_ino); \
80 printk(f); \
81 printk("\n"); \
82 } while (0)
83 # define ea_bdebug(bh, f...) do { \
84 char b[BDEVNAME_SIZE]; \
85 printk(KERN_DEBUG "block %s:%lu: ", \
86 bdevname(bh->b_bdev, b), \
87 (unsigned long) bh->b_blocknr); \
88 printk(f); \
89 printk("\n"); \
90 } while (0)
91 #else
92 # define ea_idebug(f...)
93 # define ea_bdebug(f...)
94 #endif
95
96 static void ext3_xattr_cache_insert(struct buffer_head *);
97 static struct buffer_head *ext3_xattr_cache_find(struct inode *,
98 struct ext3_xattr_header *,
99 struct mb_cache_entry **);
100 static void ext3_xattr_rehash(struct ext3_xattr_header *,
101 struct ext3_xattr_entry *);
102 static int ext3_xattr_list(struct dentry *dentry, char *buffer,
103 size_t buffer_size);
104
105 static struct mb_cache *ext3_xattr_cache;
106
107 static const struct xattr_handler *ext3_xattr_handler_map[] = {
108 [EXT3_XATTR_INDEX_USER] = &ext3_xattr_user_handler,
109 #ifdef CONFIG_EXT3_FS_POSIX_ACL
110 [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext3_xattr_acl_access_handler,
111 [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext3_xattr_acl_default_handler,
112 #endif
113 [EXT3_XATTR_INDEX_TRUSTED] = &ext3_xattr_trusted_handler,
114 #ifdef CONFIG_EXT3_FS_SECURITY
115 [EXT3_XATTR_INDEX_SECURITY] = &ext3_xattr_security_handler,
116 #endif
117 };
118
119 const struct xattr_handler *ext3_xattr_handlers[] = {
120 &ext3_xattr_user_handler,
121 &ext3_xattr_trusted_handler,
122 #ifdef CONFIG_EXT3_FS_POSIX_ACL
123 &ext3_xattr_acl_access_handler,
124 &ext3_xattr_acl_default_handler,
125 #endif
126 #ifdef CONFIG_EXT3_FS_SECURITY
127 &ext3_xattr_security_handler,
128 #endif
129 NULL
130 };
131
132 static inline const struct xattr_handler *
133 ext3_xattr_handler(int name_index)
134 {
135 const struct xattr_handler *handler = NULL;
136
137 if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map))
138 handler = ext3_xattr_handler_map[name_index];
139 return handler;
140 }
141
142 /*
143 * Inode operation listxattr()
144 *
145 * dentry->d_inode->i_mutex: don't care
146 */
147 ssize_t
148 ext3_listxattr(struct dentry *dentry, char *buffer, size_t size)
149 {
150 return ext3_xattr_list(dentry, buffer, size);
151 }
152
153 static int
154 ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end)
155 {
156 while (!IS_LAST_ENTRY(entry)) {
157 struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry);
158 if ((void *)next >= end)
159 return -EIO;
160 entry = next;
161 }
162 return 0;
163 }
164
165 static inline int
166 ext3_xattr_check_block(struct buffer_head *bh)
167 {
168 int error;
169
170 if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
171 BHDR(bh)->h_blocks != cpu_to_le32(1))
172 return -EIO;
173 error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
174 return error;
175 }
176
177 static inline int
178 ext3_xattr_check_entry(struct ext3_xattr_entry *entry, size_t size)
179 {
180 size_t value_size = le32_to_cpu(entry->e_value_size);
181
182 if (entry->e_value_block != 0 || value_size > size ||
183 le16_to_cpu(entry->e_value_offs) + value_size > size)
184 return -EIO;
185 return 0;
186 }
187
188 static int
189 ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index,
190 const char *name, size_t size, int sorted)
191 {
192 struct ext3_xattr_entry *entry;
193 size_t name_len;
194 int cmp = 1;
195
196 if (name == NULL)
197 return -EINVAL;
198 name_len = strlen(name);
199 entry = *pentry;
200 for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
201 cmp = name_index - entry->e_name_index;
202 if (!cmp)
203 cmp = name_len - entry->e_name_len;
204 if (!cmp)
205 cmp = memcmp(name, entry->e_name, name_len);
206 if (cmp <= 0 && (sorted || cmp == 0))
207 break;
208 }
209 *pentry = entry;
210 if (!cmp && ext3_xattr_check_entry(entry, size))
211 return -EIO;
212 return cmp ? -ENODATA : 0;
213 }
214
215 static int
216 ext3_xattr_block_get(struct inode *inode, int name_index, const char *name,
217 void *buffer, size_t buffer_size)
218 {
219 struct buffer_head *bh = NULL;
220 struct ext3_xattr_entry *entry;
221 size_t size;
222 int error;
223
224 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
225 name_index, name, buffer, (long)buffer_size);
226
227 error = -ENODATA;
228 if (!EXT3_I(inode)->i_file_acl)
229 goto cleanup;
230 ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
231 bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
232 if (!bh)
233 goto cleanup;
234 ea_bdebug(bh, "b_count=%d, refcount=%d",
235 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
236 if (ext3_xattr_check_block(bh)) {
237 bad_block: ext3_error(inode->i_sb, __func__,
238 "inode %lu: bad block "E3FSBLK, inode->i_ino,
239 EXT3_I(inode)->i_file_acl);
240 error = -EIO;
241 goto cleanup;
242 }
243 ext3_xattr_cache_insert(bh);
244 entry = BFIRST(bh);
245 error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
246 if (error == -EIO)
247 goto bad_block;
248 if (error)
249 goto cleanup;
250 size = le32_to_cpu(entry->e_value_size);
251 if (buffer) {
252 error = -ERANGE;
253 if (size > buffer_size)
254 goto cleanup;
255 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
256 size);
257 }
258 error = size;
259
260 cleanup:
261 brelse(bh);
262 return error;
263 }
264
265 static int
266 ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
267 void *buffer, size_t buffer_size)
268 {
269 struct ext3_xattr_ibody_header *header;
270 struct ext3_xattr_entry *entry;
271 struct ext3_inode *raw_inode;
272 struct ext3_iloc iloc;
273 size_t size;
274 void *end;
275 int error;
276
277 if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
278 return -ENODATA;
279 error = ext3_get_inode_loc(inode, &iloc);
280 if (error)
281 return error;
282 raw_inode = ext3_raw_inode(&iloc);
283 header = IHDR(inode, raw_inode);
284 entry = IFIRST(header);
285 end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
286 error = ext3_xattr_check_names(entry, end);
287 if (error)
288 goto cleanup;
289 error = ext3_xattr_find_entry(&entry, name_index, name,
290 end - (void *)entry, 0);
291 if (error)
292 goto cleanup;
293 size = le32_to_cpu(entry->e_value_size);
294 if (buffer) {
295 error = -ERANGE;
296 if (size > buffer_size)
297 goto cleanup;
298 memcpy(buffer, (void *)IFIRST(header) +
299 le16_to_cpu(entry->e_value_offs), size);
300 }
301 error = size;
302
303 cleanup:
304 brelse(iloc.bh);
305 return error;
306 }
307
308 /*
309 * ext3_xattr_get()
310 *
311 * Copy an extended attribute into the buffer
312 * provided, or compute the buffer size required.
313 * Buffer is NULL to compute the size of the buffer required.
314 *
315 * Returns a negative error number on failure, or the number of bytes
316 * used / required on success.
317 */
318 int
319 ext3_xattr_get(struct inode *inode, int name_index, const char *name,
320 void *buffer, size_t buffer_size)
321 {
322 int error;
323
324 down_read(&EXT3_I(inode)->xattr_sem);
325 error = ext3_xattr_ibody_get(inode, name_index, name, buffer,
326 buffer_size);
327 if (error == -ENODATA)
328 error = ext3_xattr_block_get(inode, name_index, name, buffer,
329 buffer_size);
330 up_read(&EXT3_I(inode)->xattr_sem);
331 return error;
332 }
333
334 static int
335 ext3_xattr_list_entries(struct dentry *dentry, struct ext3_xattr_entry *entry,
336 char *buffer, size_t buffer_size)
337 {
338 size_t rest = buffer_size;
339
340 for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
341 const struct xattr_handler *handler =
342 ext3_xattr_handler(entry->e_name_index);
343
344 if (handler) {
345 size_t size = handler->list(dentry, buffer, rest,
346 entry->e_name,
347 entry->e_name_len,
348 handler->flags);
349 if (buffer) {
350 if (size > rest)
351 return -ERANGE;
352 buffer += size;
353 }
354 rest -= size;
355 }
356 }
357 return buffer_size - rest;
358 }
359
360 static int
361 ext3_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
362 {
363 struct inode *inode = dentry->d_inode;
364 struct buffer_head *bh = NULL;
365 int error;
366
367 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
368 buffer, (long)buffer_size);
369
370 error = 0;
371 if (!EXT3_I(inode)->i_file_acl)
372 goto cleanup;
373 ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
374 bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
375 error = -EIO;
376 if (!bh)
377 goto cleanup;
378 ea_bdebug(bh, "b_count=%d, refcount=%d",
379 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
380 if (ext3_xattr_check_block(bh)) {
381 ext3_error(inode->i_sb, __func__,
382 "inode %lu: bad block "E3FSBLK, inode->i_ino,
383 EXT3_I(inode)->i_file_acl);
384 error = -EIO;
385 goto cleanup;
386 }
387 ext3_xattr_cache_insert(bh);
388 error = ext3_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
389
390 cleanup:
391 brelse(bh);
392
393 return error;
394 }
395
396 static int
397 ext3_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
398 {
399 struct inode *inode = dentry->d_inode;
400 struct ext3_xattr_ibody_header *header;
401 struct ext3_inode *raw_inode;
402 struct ext3_iloc iloc;
403 void *end;
404 int error;
405
406 if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
407 return 0;
408 error = ext3_get_inode_loc(inode, &iloc);
409 if (error)
410 return error;
411 raw_inode = ext3_raw_inode(&iloc);
412 header = IHDR(inode, raw_inode);
413 end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
414 error = ext3_xattr_check_names(IFIRST(header), end);
415 if (error)
416 goto cleanup;
417 error = ext3_xattr_list_entries(dentry, IFIRST(header),
418 buffer, buffer_size);
419
420 cleanup:
421 brelse(iloc.bh);
422 return error;
423 }
424
425 /*
426 * ext3_xattr_list()
427 *
428 * Copy a list of attribute names into the buffer
429 * provided, or compute the buffer size required.
430 * Buffer is NULL to compute the size of the buffer required.
431 *
432 * Returns a negative error number on failure, or the number of bytes
433 * used / required on success.
434 */
435 static int
436 ext3_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
437 {
438 int i_error, b_error;
439
440 down_read(&EXT3_I(dentry->d_inode)->xattr_sem);
441 i_error = ext3_xattr_ibody_list(dentry, buffer, buffer_size);
442 if (i_error < 0) {
443 b_error = 0;
444 } else {
445 if (buffer) {
446 buffer += i_error;
447 buffer_size -= i_error;
448 }
449 b_error = ext3_xattr_block_list(dentry, buffer, buffer_size);
450 if (b_error < 0)
451 i_error = 0;
452 }
453 up_read(&EXT3_I(dentry->d_inode)->xattr_sem);
454 return i_error + b_error;
455 }
456
457 /*
458 * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
459 * not set, set it.
460 */
461 static void ext3_xattr_update_super_block(handle_t *handle,
462 struct super_block *sb)
463 {
464 if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR))
465 return;
466
467 if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) {
468 EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR);
469 ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
470 }
471 }
472
473 /*
474 * Release the xattr block BH: If the reference count is > 1, decrement
475 * it; otherwise free the block.
476 */
477 static void
478 ext3_xattr_release_block(handle_t *handle, struct inode *inode,
479 struct buffer_head *bh)
480 {
481 struct mb_cache_entry *ce = NULL;
482 int error = 0;
483
484 ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
485 error = ext3_journal_get_write_access(handle, bh);
486 if (error)
487 goto out;
488
489 lock_buffer(bh);
490
491 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
492 ea_bdebug(bh, "refcount now=0; freeing");
493 if (ce)
494 mb_cache_entry_free(ce);
495 ext3_free_blocks(handle, inode, bh->b_blocknr, 1);
496 get_bh(bh);
497 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
498 } else {
499 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
500 error = ext3_journal_dirty_metadata(handle, bh);
501 if (IS_SYNC(inode))
502 handle->h_sync = 1;
503 dquot_free_block(inode, 1);
504 ea_bdebug(bh, "refcount now=%d; releasing",
505 le32_to_cpu(BHDR(bh)->h_refcount));
506 if (ce)
507 mb_cache_entry_release(ce);
508 }
509 unlock_buffer(bh);
510 out:
511 ext3_std_error(inode->i_sb, error);
512 return;
513 }
514
515 struct ext3_xattr_info {
516 int name_index;
517 const char *name;
518 const void *value;
519 size_t value_len;
520 };
521
522 struct ext3_xattr_search {
523 struct ext3_xattr_entry *first;
524 void *base;
525 void *end;
526 struct ext3_xattr_entry *here;
527 int not_found;
528 };
529
530 static int
531 ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s)
532 {
533 struct ext3_xattr_entry *last;
534 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
535
536 /* Compute min_offs and last. */
537 last = s->first;
538 for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) {
539 if (!last->e_value_block && last->e_value_size) {
540 size_t offs = le16_to_cpu(last->e_value_offs);
541 if (offs < min_offs)
542 min_offs = offs;
543 }
544 }
545 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
546 if (!s->not_found) {
547 if (!s->here->e_value_block && s->here->e_value_size) {
548 size_t size = le32_to_cpu(s->here->e_value_size);
549 free += EXT3_XATTR_SIZE(size);
550 }
551 free += EXT3_XATTR_LEN(name_len);
552 }
553 if (i->value) {
554 if (free < EXT3_XATTR_SIZE(i->value_len) ||
555 free < EXT3_XATTR_LEN(name_len) +
556 EXT3_XATTR_SIZE(i->value_len))
557 return -ENOSPC;
558 }
559
560 if (i->value && s->not_found) {
561 /* Insert the new name. */
562 size_t size = EXT3_XATTR_LEN(name_len);
563 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
564 memmove((void *)s->here + size, s->here, rest);
565 memset(s->here, 0, size);
566 s->here->e_name_index = i->name_index;
567 s->here->e_name_len = name_len;
568 memcpy(s->here->e_name, i->name, name_len);
569 } else {
570 if (!s->here->e_value_block && s->here->e_value_size) {
571 void *first_val = s->base + min_offs;
572 size_t offs = le16_to_cpu(s->here->e_value_offs);
573 void *val = s->base + offs;
574 size_t size = EXT3_XATTR_SIZE(
575 le32_to_cpu(s->here->e_value_size));
576
577 if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) {
578 /* The old and the new value have the same
579 size. Just replace. */
580 s->here->e_value_size =
581 cpu_to_le32(i->value_len);
582 memset(val + size - EXT3_XATTR_PAD, 0,
583 EXT3_XATTR_PAD); /* Clear pad bytes. */
584 memcpy(val, i->value, i->value_len);
585 return 0;
586 }
587
588 /* Remove the old value. */
589 memmove(first_val + size, first_val, val - first_val);
590 memset(first_val, 0, size);
591 s->here->e_value_size = 0;
592 s->here->e_value_offs = 0;
593 min_offs += size;
594
595 /* Adjust all value offsets. */
596 last = s->first;
597 while (!IS_LAST_ENTRY(last)) {
598 size_t o = le16_to_cpu(last->e_value_offs);
599 if (!last->e_value_block &&
600 last->e_value_size && o < offs)
601 last->e_value_offs =
602 cpu_to_le16(o + size);
603 last = EXT3_XATTR_NEXT(last);
604 }
605 }
606 if (!i->value) {
607 /* Remove the old name. */
608 size_t size = EXT3_XATTR_LEN(name_len);
609 last = ENTRY((void *)last - size);
610 memmove(s->here, (void *)s->here + size,
611 (void *)last - (void *)s->here + sizeof(__u32));
612 memset(last, 0, size);
613 }
614 }
615
616 if (i->value) {
617 /* Insert the new value. */
618 s->here->e_value_size = cpu_to_le32(i->value_len);
619 if (i->value_len) {
620 size_t size = EXT3_XATTR_SIZE(i->value_len);
621 void *val = s->base + min_offs - size;
622 s->here->e_value_offs = cpu_to_le16(min_offs - size);
623 memset(val + size - EXT3_XATTR_PAD, 0,
624 EXT3_XATTR_PAD); /* Clear the pad bytes. */
625 memcpy(val, i->value, i->value_len);
626 }
627 }
628 return 0;
629 }
630
631 struct ext3_xattr_block_find {
632 struct ext3_xattr_search s;
633 struct buffer_head *bh;
634 };
635
636 static int
637 ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i,
638 struct ext3_xattr_block_find *bs)
639 {
640 struct super_block *sb = inode->i_sb;
641 int error;
642
643 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
644 i->name_index, i->name, i->value, (long)i->value_len);
645
646 if (EXT3_I(inode)->i_file_acl) {
647 /* The inode already has an extended attribute block. */
648 bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl);
649 error = -EIO;
650 if (!bs->bh)
651 goto cleanup;
652 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
653 atomic_read(&(bs->bh->b_count)),
654 le32_to_cpu(BHDR(bs->bh)->h_refcount));
655 if (ext3_xattr_check_block(bs->bh)) {
656 ext3_error(sb, __func__,
657 "inode %lu: bad block "E3FSBLK, inode->i_ino,
658 EXT3_I(inode)->i_file_acl);
659 error = -EIO;
660 goto cleanup;
661 }
662 /* Find the named attribute. */
663 bs->s.base = BHDR(bs->bh);
664 bs->s.first = BFIRST(bs->bh);
665 bs->s.end = bs->bh->b_data + bs->bh->b_size;
666 bs->s.here = bs->s.first;
667 error = ext3_xattr_find_entry(&bs->s.here, i->name_index,
668 i->name, bs->bh->b_size, 1);
669 if (error && error != -ENODATA)
670 goto cleanup;
671 bs->s.not_found = error;
672 }
673 error = 0;
674
675 cleanup:
676 return error;
677 }
678
679 static int
680 ext3_xattr_block_set(handle_t *handle, struct inode *inode,
681 struct ext3_xattr_info *i,
682 struct ext3_xattr_block_find *bs)
683 {
684 struct super_block *sb = inode->i_sb;
685 struct buffer_head *new_bh = NULL;
686 struct ext3_xattr_search *s = &bs->s;
687 struct mb_cache_entry *ce = NULL;
688 int error = 0;
689
690 #define header(x) ((struct ext3_xattr_header *)(x))
691
692 if (i->value && i->value_len > sb->s_blocksize)
693 return -ENOSPC;
694 if (s->base) {
695 ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
696 bs->bh->b_blocknr);
697 error = ext3_journal_get_write_access(handle, bs->bh);
698 if (error)
699 goto cleanup;
700 lock_buffer(bs->bh);
701
702 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
703 if (ce) {
704 mb_cache_entry_free(ce);
705 ce = NULL;
706 }
707 ea_bdebug(bs->bh, "modifying in-place");
708 error = ext3_xattr_set_entry(i, s);
709 if (!error) {
710 if (!IS_LAST_ENTRY(s->first))
711 ext3_xattr_rehash(header(s->base),
712 s->here);
713 ext3_xattr_cache_insert(bs->bh);
714 }
715 unlock_buffer(bs->bh);
716 if (error == -EIO)
717 goto bad_block;
718 if (!error)
719 error = ext3_journal_dirty_metadata(handle,
720 bs->bh);
721 if (error)
722 goto cleanup;
723 goto inserted;
724 } else {
725 int offset = (char *)s->here - bs->bh->b_data;
726
727 unlock_buffer(bs->bh);
728 journal_release_buffer(handle, bs->bh);
729
730 if (ce) {
731 mb_cache_entry_release(ce);
732 ce = NULL;
733 }
734 ea_bdebug(bs->bh, "cloning");
735 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
736 error = -ENOMEM;
737 if (s->base == NULL)
738 goto cleanup;
739 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
740 s->first = ENTRY(header(s->base)+1);
741 header(s->base)->h_refcount = cpu_to_le32(1);
742 s->here = ENTRY(s->base + offset);
743 s->end = s->base + bs->bh->b_size;
744 }
745 } else {
746 /* Allocate a buffer where we construct the new block. */
747 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
748 /* assert(header == s->base) */
749 error = -ENOMEM;
750 if (s->base == NULL)
751 goto cleanup;
752 header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
753 header(s->base)->h_blocks = cpu_to_le32(1);
754 header(s->base)->h_refcount = cpu_to_le32(1);
755 s->first = ENTRY(header(s->base)+1);
756 s->here = ENTRY(header(s->base)+1);
757 s->end = s->base + sb->s_blocksize;
758 }
759
760 error = ext3_xattr_set_entry(i, s);
761 if (error == -EIO)
762 goto bad_block;
763 if (error)
764 goto cleanup;
765 if (!IS_LAST_ENTRY(s->first))
766 ext3_xattr_rehash(header(s->base), s->here);
767
768 inserted:
769 if (!IS_LAST_ENTRY(s->first)) {
770 new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce);
771 if (new_bh) {
772 /* We found an identical block in the cache. */
773 if (new_bh == bs->bh)
774 ea_bdebug(new_bh, "keeping");
775 else {
776 /* The old block is released after updating
777 the inode. */
778 error = dquot_alloc_block(inode, 1);
779 if (error)
780 goto cleanup;
781 error = ext3_journal_get_write_access(handle,
782 new_bh);
783 if (error)
784 goto cleanup_dquot;
785 lock_buffer(new_bh);
786 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
787 ea_bdebug(new_bh, "reusing; refcount now=%d",
788 le32_to_cpu(BHDR(new_bh)->h_refcount));
789 unlock_buffer(new_bh);
790 error = ext3_journal_dirty_metadata(handle,
791 new_bh);
792 if (error)
793 goto cleanup_dquot;
794 }
795 mb_cache_entry_release(ce);
796 ce = NULL;
797 } else if (bs->bh && s->base == bs->bh->b_data) {
798 /* We were modifying this block in-place. */
799 ea_bdebug(bs->bh, "keeping this block");
800 new_bh = bs->bh;
801 get_bh(new_bh);
802 } else {
803 /* We need to allocate a new block */
804 ext3_fsblk_t goal = ext3_group_first_block_no(sb,
805 EXT3_I(inode)->i_block_group);
806 ext3_fsblk_t block;
807
808 /*
809 * Protect us agaist concurrent allocations to the
810 * same inode from ext3_..._writepage(). Reservation
811 * code does not expect racing allocations.
812 */
813 mutex_lock(&EXT3_I(inode)->truncate_mutex);
814 block = ext3_new_block(handle, inode, goal, &error);
815 mutex_unlock(&EXT3_I(inode)->truncate_mutex);
816 if (error)
817 goto cleanup;
818 ea_idebug(inode, "creating block %d", block);
819
820 new_bh = sb_getblk(sb, block);
821 if (!new_bh) {
822 getblk_failed:
823 ext3_free_blocks(handle, inode, block, 1);
824 error = -EIO;
825 goto cleanup;
826 }
827 lock_buffer(new_bh);
828 error = ext3_journal_get_create_access(handle, new_bh);
829 if (error) {
830 unlock_buffer(new_bh);
831 goto getblk_failed;
832 }
833 memcpy(new_bh->b_data, s->base, new_bh->b_size);
834 set_buffer_uptodate(new_bh);
835 unlock_buffer(new_bh);
836 ext3_xattr_cache_insert(new_bh);
837 error = ext3_journal_dirty_metadata(handle, new_bh);
838 if (error)
839 goto cleanup;
840 }
841 }
842
843 /* Update the inode. */
844 EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
845
846 /* Drop the previous xattr block. */
847 if (bs->bh && bs->bh != new_bh)
848 ext3_xattr_release_block(handle, inode, bs->bh);
849 error = 0;
850
851 cleanup:
852 if (ce)
853 mb_cache_entry_release(ce);
854 brelse(new_bh);
855 if (!(bs->bh && s->base == bs->bh->b_data))
856 kfree(s->base);
857
858 return error;
859
860 cleanup_dquot:
861 dquot_free_block(inode, 1);
862 goto cleanup;
863
864 bad_block:
865 ext3_error(inode->i_sb, __func__,
866 "inode %lu: bad block "E3FSBLK, inode->i_ino,
867 EXT3_I(inode)->i_file_acl);
868 goto cleanup;
869
870 #undef header
871 }
872
873 struct ext3_xattr_ibody_find {
874 struct ext3_xattr_search s;
875 struct ext3_iloc iloc;
876 };
877
878 static int
879 ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i,
880 struct ext3_xattr_ibody_find *is)
881 {
882 struct ext3_xattr_ibody_header *header;
883 struct ext3_inode *raw_inode;
884 int error;
885
886 if (EXT3_I(inode)->i_extra_isize == 0)
887 return 0;
888 raw_inode = ext3_raw_inode(&is->iloc);
889 header = IHDR(inode, raw_inode);
890 is->s.base = is->s.first = IFIRST(header);
891 is->s.here = is->s.first;
892 is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
893 if (ext3_test_inode_state(inode, EXT3_STATE_XATTR)) {
894 error = ext3_xattr_check_names(IFIRST(header), is->s.end);
895 if (error)
896 return error;
897 /* Find the named attribute. */
898 error = ext3_xattr_find_entry(&is->s.here, i->name_index,
899 i->name, is->s.end -
900 (void *)is->s.base, 0);
901 if (error && error != -ENODATA)
902 return error;
903 is->s.not_found = error;
904 }
905 return 0;
906 }
907
908 static int
909 ext3_xattr_ibody_set(handle_t *handle, struct inode *inode,
910 struct ext3_xattr_info *i,
911 struct ext3_xattr_ibody_find *is)
912 {
913 struct ext3_xattr_ibody_header *header;
914 struct ext3_xattr_search *s = &is->s;
915 int error;
916
917 if (EXT3_I(inode)->i_extra_isize == 0)
918 return -ENOSPC;
919 error = ext3_xattr_set_entry(i, s);
920 if (error)
921 return error;
922 header = IHDR(inode, ext3_raw_inode(&is->iloc));
923 if (!IS_LAST_ENTRY(s->first)) {
924 header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
925 ext3_set_inode_state(inode, EXT3_STATE_XATTR);
926 } else {
927 header->h_magic = cpu_to_le32(0);
928 ext3_clear_inode_state(inode, EXT3_STATE_XATTR);
929 }
930 return 0;
931 }
932
933 /*
934 * ext3_xattr_set_handle()
935 *
936 * Create, replace or remove an extended attribute for this inode. Value
937 * is NULL to remove an existing extended attribute, and non-NULL to
938 * either replace an existing extended attribute, or create a new extended
939 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
940 * specify that an extended attribute must exist and must not exist
941 * previous to the call, respectively.
942 *
943 * Returns 0, or a negative error number on failure.
944 */
945 int
946 ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
947 const char *name, const void *value, size_t value_len,
948 int flags)
949 {
950 struct ext3_xattr_info i = {
951 .name_index = name_index,
952 .name = name,
953 .value = value,
954 .value_len = value_len,
955
956 };
957 struct ext3_xattr_ibody_find is = {
958 .s = { .not_found = -ENODATA, },
959 };
960 struct ext3_xattr_block_find bs = {
961 .s = { .not_found = -ENODATA, },
962 };
963 int error;
964
965 if (!name)
966 return -EINVAL;
967 if (strlen(name) > 255)
968 return -ERANGE;
969 down_write(&EXT3_I(inode)->xattr_sem);
970 error = ext3_get_inode_loc(inode, &is.iloc);
971 if (error)
972 goto cleanup;
973
974 error = ext3_journal_get_write_access(handle, is.iloc.bh);
975 if (error)
976 goto cleanup;
977
978 if (ext3_test_inode_state(inode, EXT3_STATE_NEW)) {
979 struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc);
980 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
981 ext3_clear_inode_state(inode, EXT3_STATE_NEW);
982 }
983
984 error = ext3_xattr_ibody_find(inode, &i, &is);
985 if (error)
986 goto cleanup;
987 if (is.s.not_found)
988 error = ext3_xattr_block_find(inode, &i, &bs);
989 if (error)
990 goto cleanup;
991 if (is.s.not_found && bs.s.not_found) {
992 error = -ENODATA;
993 if (flags & XATTR_REPLACE)
994 goto cleanup;
995 error = 0;
996 if (!value)
997 goto cleanup;
998 } else {
999 error = -EEXIST;
1000 if (flags & XATTR_CREATE)
1001 goto cleanup;
1002 }
1003 if (!value) {
1004 if (!is.s.not_found)
1005 error = ext3_xattr_ibody_set(handle, inode, &i, &is);
1006 else if (!bs.s.not_found)
1007 error = ext3_xattr_block_set(handle, inode, &i, &bs);
1008 } else {
1009 error = ext3_xattr_ibody_set(handle, inode, &i, &is);
1010 if (!error && !bs.s.not_found) {
1011 i.value = NULL;
1012 error = ext3_xattr_block_set(handle, inode, &i, &bs);
1013 } else if (error == -ENOSPC) {
1014 if (EXT3_I(inode)->i_file_acl && !bs.s.base) {
1015 error = ext3_xattr_block_find(inode, &i, &bs);
1016 if (error)
1017 goto cleanup;
1018 }
1019 error = ext3_xattr_block_set(handle, inode, &i, &bs);
1020 if (error)
1021 goto cleanup;
1022 if (!is.s.not_found) {
1023 i.value = NULL;
1024 error = ext3_xattr_ibody_set(handle, inode, &i,
1025 &is);
1026 }
1027 }
1028 }
1029 if (!error) {
1030 ext3_xattr_update_super_block(handle, inode->i_sb);
1031 inode->i_ctime = CURRENT_TIME_SEC;
1032 error = ext3_mark_iloc_dirty(handle, inode, &is.iloc);
1033 /*
1034 * The bh is consumed by ext3_mark_iloc_dirty, even with
1035 * error != 0.
1036 */
1037 is.iloc.bh = NULL;
1038 if (IS_SYNC(inode))
1039 handle->h_sync = 1;
1040 }
1041
1042 cleanup:
1043 brelse(is.iloc.bh);
1044 brelse(bs.bh);
1045 up_write(&EXT3_I(inode)->xattr_sem);
1046 return error;
1047 }
1048
1049 /*
1050 * ext3_xattr_set()
1051 *
1052 * Like ext3_xattr_set_handle, but start from an inode. This extended
1053 * attribute modification is a filesystem transaction by itself.
1054 *
1055 * Returns 0, or a negative error number on failure.
1056 */
1057 int
1058 ext3_xattr_set(struct inode *inode, int name_index, const char *name,
1059 const void *value, size_t value_len, int flags)
1060 {
1061 handle_t *handle;
1062 int error, retries = 0;
1063
1064 retry:
1065 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
1066 if (IS_ERR(handle)) {
1067 error = PTR_ERR(handle);
1068 } else {
1069 int error2;
1070
1071 error = ext3_xattr_set_handle(handle, inode, name_index, name,
1072 value, value_len, flags);
1073 error2 = ext3_journal_stop(handle);
1074 if (error == -ENOSPC &&
1075 ext3_should_retry_alloc(inode->i_sb, &retries))
1076 goto retry;
1077 if (error == 0)
1078 error = error2;
1079 }
1080
1081 return error;
1082 }
1083
1084 /*
1085 * ext3_xattr_delete_inode()
1086 *
1087 * Free extended attribute resources associated with this inode. This
1088 * is called immediately before an inode is freed. We have exclusive
1089 * access to the inode.
1090 */
1091 void
1092 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
1093 {
1094 struct buffer_head *bh = NULL;
1095
1096 if (!EXT3_I(inode)->i_file_acl)
1097 goto cleanup;
1098 bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
1099 if (!bh) {
1100 ext3_error(inode->i_sb, __func__,
1101 "inode %lu: block "E3FSBLK" read error", inode->i_ino,
1102 EXT3_I(inode)->i_file_acl);
1103 goto cleanup;
1104 }
1105 if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
1106 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
1107 ext3_error(inode->i_sb, __func__,
1108 "inode %lu: bad block "E3FSBLK, inode->i_ino,
1109 EXT3_I(inode)->i_file_acl);
1110 goto cleanup;
1111 }
1112 ext3_xattr_release_block(handle, inode, bh);
1113 EXT3_I(inode)->i_file_acl = 0;
1114
1115 cleanup:
1116 brelse(bh);
1117 }
1118
1119 /*
1120 * ext3_xattr_put_super()
1121 *
1122 * This is called when a file system is unmounted.
1123 */
1124 void
1125 ext3_xattr_put_super(struct super_block *sb)
1126 {
1127 mb_cache_shrink(sb->s_bdev);
1128 }
1129
1130 /*
1131 * ext3_xattr_cache_insert()
1132 *
1133 * Create a new entry in the extended attribute cache, and insert
1134 * it unless such an entry is already in the cache.
1135 *
1136 * Returns 0, or a negative error number on failure.
1137 */
1138 static void
1139 ext3_xattr_cache_insert(struct buffer_head *bh)
1140 {
1141 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1142 struct mb_cache_entry *ce;
1143 int error;
1144
1145 ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS);
1146 if (!ce) {
1147 ea_bdebug(bh, "out of memory");
1148 return;
1149 }
1150 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
1151 if (error) {
1152 mb_cache_entry_free(ce);
1153 if (error == -EBUSY) {
1154 ea_bdebug(bh, "already in cache");
1155 error = 0;
1156 }
1157 } else {
1158 ea_bdebug(bh, "inserting [%x]", (int)hash);
1159 mb_cache_entry_release(ce);
1160 }
1161 }
1162
1163 /*
1164 * ext3_xattr_cmp()
1165 *
1166 * Compare two extended attribute blocks for equality.
1167 *
1168 * Returns 0 if the blocks are equal, 1 if they differ, and
1169 * a negative error number on errors.
1170 */
1171 static int
1172 ext3_xattr_cmp(struct ext3_xattr_header *header1,
1173 struct ext3_xattr_header *header2)
1174 {
1175 struct ext3_xattr_entry *entry1, *entry2;
1176
1177 entry1 = ENTRY(header1+1);
1178 entry2 = ENTRY(header2+1);
1179 while (!IS_LAST_ENTRY(entry1)) {
1180 if (IS_LAST_ENTRY(entry2))
1181 return 1;
1182 if (entry1->e_hash != entry2->e_hash ||
1183 entry1->e_name_index != entry2->e_name_index ||
1184 entry1->e_name_len != entry2->e_name_len ||
1185 entry1->e_value_size != entry2->e_value_size ||
1186 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1187 return 1;
1188 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1189 return -EIO;
1190 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1191 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1192 le32_to_cpu(entry1->e_value_size)))
1193 return 1;
1194
1195 entry1 = EXT3_XATTR_NEXT(entry1);
1196 entry2 = EXT3_XATTR_NEXT(entry2);
1197 }
1198 if (!IS_LAST_ENTRY(entry2))
1199 return 1;
1200 return 0;
1201 }
1202
1203 /*
1204 * ext3_xattr_cache_find()
1205 *
1206 * Find an identical extended attribute block.
1207 *
1208 * Returns a pointer to the block found, or NULL if such a block was
1209 * not found or an error occurred.
1210 */
1211 static struct buffer_head *
1212 ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header,
1213 struct mb_cache_entry **pce)
1214 {
1215 __u32 hash = le32_to_cpu(header->h_hash);
1216 struct mb_cache_entry *ce;
1217
1218 if (!header->h_hash)
1219 return NULL; /* never share */
1220 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1221 again:
1222 ce = mb_cache_entry_find_first(ext3_xattr_cache, inode->i_sb->s_bdev,
1223 hash);
1224 while (ce) {
1225 struct buffer_head *bh;
1226
1227 if (IS_ERR(ce)) {
1228 if (PTR_ERR(ce) == -EAGAIN)
1229 goto again;
1230 break;
1231 }
1232 bh = sb_bread(inode->i_sb, ce->e_block);
1233 if (!bh) {
1234 ext3_error(inode->i_sb, __func__,
1235 "inode %lu: block %lu read error",
1236 inode->i_ino, (unsigned long) ce->e_block);
1237 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
1238 EXT3_XATTR_REFCOUNT_MAX) {
1239 ea_idebug(inode, "block %lu refcount %d>=%d",
1240 (unsigned long) ce->e_block,
1241 le32_to_cpu(BHDR(bh)->h_refcount),
1242 EXT3_XATTR_REFCOUNT_MAX);
1243 } else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) {
1244 *pce = ce;
1245 return bh;
1246 }
1247 brelse(bh);
1248 ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
1249 }
1250 return NULL;
1251 }
1252
1253 #define NAME_HASH_SHIFT 5
1254 #define VALUE_HASH_SHIFT 16
1255
1256 /*
1257 * ext3_xattr_hash_entry()
1258 *
1259 * Compute the hash of an extended attribute.
1260 */
1261 static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header,
1262 struct ext3_xattr_entry *entry)
1263 {
1264 __u32 hash = 0;
1265 char *name = entry->e_name;
1266 int n;
1267
1268 for (n=0; n < entry->e_name_len; n++) {
1269 hash = (hash << NAME_HASH_SHIFT) ^
1270 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1271 *name++;
1272 }
1273
1274 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1275 __le32 *value = (__le32 *)((char *)header +
1276 le16_to_cpu(entry->e_value_offs));
1277 for (n = (le32_to_cpu(entry->e_value_size) +
1278 EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) {
1279 hash = (hash << VALUE_HASH_SHIFT) ^
1280 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1281 le32_to_cpu(*value++);
1282 }
1283 }
1284 entry->e_hash = cpu_to_le32(hash);
1285 }
1286
1287 #undef NAME_HASH_SHIFT
1288 #undef VALUE_HASH_SHIFT
1289
1290 #define BLOCK_HASH_SHIFT 16
1291
1292 /*
1293 * ext3_xattr_rehash()
1294 *
1295 * Re-compute the extended attribute hash value after an entry has changed.
1296 */
1297 static void ext3_xattr_rehash(struct ext3_xattr_header *header,
1298 struct ext3_xattr_entry *entry)
1299 {
1300 struct ext3_xattr_entry *here;
1301 __u32 hash = 0;
1302
1303 ext3_xattr_hash_entry(header, entry);
1304 here = ENTRY(header+1);
1305 while (!IS_LAST_ENTRY(here)) {
1306 if (!here->e_hash) {
1307 /* Block is not shared if an entry's hash value == 0 */
1308 hash = 0;
1309 break;
1310 }
1311 hash = (hash << BLOCK_HASH_SHIFT) ^
1312 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1313 le32_to_cpu(here->e_hash);
1314 here = EXT3_XATTR_NEXT(here);
1315 }
1316 header->h_hash = cpu_to_le32(hash);
1317 }
1318
1319 #undef BLOCK_HASH_SHIFT
1320
1321 int __init
1322 init_ext3_xattr(void)
1323 {
1324 ext3_xattr_cache = mb_cache_create("ext3_xattr", 6);
1325 if (!ext3_xattr_cache)
1326 return -ENOMEM;
1327 return 0;
1328 }
1329
1330 void
1331 exit_ext3_xattr(void)
1332 {
1333 if (ext3_xattr_cache)
1334 mb_cache_destroy(ext3_xattr_cache);
1335 ext3_xattr_cache = NULL;
1336 }