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#include <linux/buffer_head.h>
57#include <linux/init.h>
58#include <linux/slab.h>
59#include <linux/mbcache.h>
60#include <linux/quotaops.h>
61#include <linux/rwsem.h>
62#include <linux/security.h>
63#include "ext2.h"
64#include "xattr.h"
65#include "acl.h"
66
67#define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data))
68#define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr))
69#define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
70#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
71
72#ifdef EXT2_XATTR_DEBUG
73# define ea_idebug(inode, f...) do { \
74 printk(KERN_DEBUG "inode %s:%ld: ", \
75 inode->i_sb->s_id, inode->i_ino); \
76 printk(f); \
77 printk("\n"); \
78 } while (0)
79# define ea_bdebug(bh, f...) do { \
80 printk(KERN_DEBUG "block %pg:%lu: ", \
81 bh->b_bdev, (unsigned long) bh->b_blocknr); \
82 printk(f); \
83 printk("\n"); \
84 } while (0)
85#else
86# define ea_idebug(f...)
87# define ea_bdebug(f...)
88#endif
89
90static int ext2_xattr_set2(struct inode *, struct buffer_head *,
91 struct ext2_xattr_header *);
92
93static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
94static struct buffer_head *ext2_xattr_cache_find(struct inode *,
95 struct ext2_xattr_header *);
96static void ext2_xattr_rehash(struct ext2_xattr_header *,
97 struct ext2_xattr_entry *);
98
99static const struct xattr_handler *ext2_xattr_handler_map[] = {
100 [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
101#ifdef CONFIG_EXT2_FS_POSIX_ACL
102 [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
103 [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
104#endif
105 [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler,
106#ifdef CONFIG_EXT2_FS_SECURITY
107 [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler,
108#endif
109};
110
111const struct xattr_handler *ext2_xattr_handlers[] = {
112 &ext2_xattr_user_handler,
113 &ext2_xattr_trusted_handler,
114#ifdef CONFIG_EXT2_FS_POSIX_ACL
115 &posix_acl_access_xattr_handler,
116 &posix_acl_default_xattr_handler,
117#endif
118#ifdef CONFIG_EXT2_FS_SECURITY
119 &ext2_xattr_security_handler,
120#endif
121 NULL
122};
123
124#define EA_BLOCK_CACHE(inode) (EXT2_SB(inode->i_sb)->s_ea_block_cache)
125
126static inline const struct xattr_handler *
127ext2_xattr_handler(int name_index)
128{
129 const struct xattr_handler *handler = NULL;
130
131 if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
132 handler = ext2_xattr_handler_map[name_index];
133 return handler;
134}
135
136
137
138
139
140
141
142
143
144
145
146int
147ext2_xattr_get(struct inode *inode, int name_index, const char *name,
148 void *buffer, size_t buffer_size)
149{
150 struct buffer_head *bh = NULL;
151 struct ext2_xattr_entry *entry;
152 size_t name_len, size;
153 char *end;
154 int error;
155 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
156
157 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
158 name_index, name, buffer, (long)buffer_size);
159
160 if (name == NULL)
161 return -EINVAL;
162 name_len = strlen(name);
163 if (name_len > 255)
164 return -ERANGE;
165
166 down_read(&EXT2_I(inode)->xattr_sem);
167 error = -ENODATA;
168 if (!EXT2_I(inode)->i_file_acl)
169 goto cleanup;
170 ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
171 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
172 error = -EIO;
173 if (!bh)
174 goto cleanup;
175 ea_bdebug(bh, "b_count=%d, refcount=%d",
176 atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
177 end = bh->b_data + bh->b_size;
178 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
179 HDR(bh)->h_blocks != cpu_to_le32(1)) {
180bad_block: ext2_error(inode->i_sb, "ext2_xattr_get",
181 "inode %ld: bad block %d", inode->i_ino,
182 EXT2_I(inode)->i_file_acl);
183 error = -EIO;
184 goto cleanup;
185 }
186
187
188 entry = FIRST_ENTRY(bh);
189 while (!IS_LAST_ENTRY(entry)) {
190 struct ext2_xattr_entry *next =
191 EXT2_XATTR_NEXT(entry);
192 if ((char *)next >= end)
193 goto bad_block;
194 if (name_index == entry->e_name_index &&
195 name_len == entry->e_name_len &&
196 memcmp(name, entry->e_name, name_len) == 0)
197 goto found;
198 entry = next;
199 }
200 if (ext2_xattr_cache_insert(ea_block_cache, bh))
201 ea_idebug(inode, "cache insert failed");
202 error = -ENODATA;
203 goto cleanup;
204found:
205
206 if (entry->e_value_block != 0)
207 goto bad_block;
208 size = le32_to_cpu(entry->e_value_size);
209 if (size > inode->i_sb->s_blocksize ||
210 le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
211 goto bad_block;
212
213 if (ext2_xattr_cache_insert(ea_block_cache, bh))
214 ea_idebug(inode, "cache insert failed");
215 if (buffer) {
216 error = -ERANGE;
217 if (size > buffer_size)
218 goto cleanup;
219
220 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
221 size);
222 }
223 error = size;
224
225cleanup:
226 brelse(bh);
227 up_read(&EXT2_I(inode)->xattr_sem);
228
229 return error;
230}
231
232
233
234
235
236
237
238
239
240
241
242static int
243ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
244{
245 struct inode *inode = d_inode(dentry);
246 struct buffer_head *bh = NULL;
247 struct ext2_xattr_entry *entry;
248 char *end;
249 size_t rest = buffer_size;
250 int error;
251 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
252
253 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
254 buffer, (long)buffer_size);
255
256 down_read(&EXT2_I(inode)->xattr_sem);
257 error = 0;
258 if (!EXT2_I(inode)->i_file_acl)
259 goto cleanup;
260 ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
261 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
262 error = -EIO;
263 if (!bh)
264 goto cleanup;
265 ea_bdebug(bh, "b_count=%d, refcount=%d",
266 atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
267 end = bh->b_data + bh->b_size;
268 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
269 HDR(bh)->h_blocks != cpu_to_le32(1)) {
270bad_block: ext2_error(inode->i_sb, "ext2_xattr_list",
271 "inode %ld: bad block %d", inode->i_ino,
272 EXT2_I(inode)->i_file_acl);
273 error = -EIO;
274 goto cleanup;
275 }
276
277
278 entry = FIRST_ENTRY(bh);
279 while (!IS_LAST_ENTRY(entry)) {
280 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry);
281
282 if ((char *)next >= end)
283 goto bad_block;
284 entry = next;
285 }
286 if (ext2_xattr_cache_insert(ea_block_cache, bh))
287 ea_idebug(inode, "cache insert failed");
288
289
290 for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
291 entry = EXT2_XATTR_NEXT(entry)) {
292 const struct xattr_handler *handler =
293 ext2_xattr_handler(entry->e_name_index);
294
295 if (handler && (!handler->list || handler->list(dentry))) {
296 const char *prefix = handler->prefix ?: handler->name;
297 size_t prefix_len = strlen(prefix);
298 size_t size = prefix_len + entry->e_name_len + 1;
299
300 if (buffer) {
301 if (size > rest) {
302 error = -ERANGE;
303 goto cleanup;
304 }
305 memcpy(buffer, prefix, prefix_len);
306 buffer += prefix_len;
307 memcpy(buffer, entry->e_name, entry->e_name_len);
308 buffer += entry->e_name_len;
309 *buffer++ = 0;
310 }
311 rest -= size;
312 }
313 }
314 error = buffer_size - rest;
315
316cleanup:
317 brelse(bh);
318 up_read(&EXT2_I(inode)->xattr_sem);
319
320 return error;
321}
322
323
324
325
326
327
328ssize_t
329ext2_listxattr(struct dentry *dentry, char *buffer, size_t size)
330{
331 return ext2_xattr_list(dentry, buffer, size);
332}
333
334
335
336
337
338static void ext2_xattr_update_super_block(struct super_block *sb)
339{
340 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR))
341 return;
342
343 spin_lock(&EXT2_SB(sb)->s_lock);
344 EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR);
345 spin_unlock(&EXT2_SB(sb)->s_lock);
346 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
347}
348
349
350
351
352
353
354
355
356
357
358
359
360
361int
362ext2_xattr_set(struct inode *inode, int name_index, const char *name,
363 const void *value, size_t value_len, int flags)
364{
365 struct super_block *sb = inode->i_sb;
366 struct buffer_head *bh = NULL;
367 struct ext2_xattr_header *header = NULL;
368 struct ext2_xattr_entry *here, *last;
369 size_t name_len, free, min_offs = sb->s_blocksize;
370 int not_found = 1, error;
371 char *end;
372
373
374
375
376
377
378
379
380
381
382
383
384
385 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
386 name_index, name, value, (long)value_len);
387
388 if (value == NULL)
389 value_len = 0;
390 if (name == NULL)
391 return -EINVAL;
392 name_len = strlen(name);
393 if (name_len > 255 || value_len > sb->s_blocksize)
394 return -ERANGE;
395 down_write(&EXT2_I(inode)->xattr_sem);
396 if (EXT2_I(inode)->i_file_acl) {
397
398 bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
399 error = -EIO;
400 if (!bh)
401 goto cleanup;
402 ea_bdebug(bh, "b_count=%d, refcount=%d",
403 atomic_read(&(bh->b_count)),
404 le32_to_cpu(HDR(bh)->h_refcount));
405 header = HDR(bh);
406 end = bh->b_data + bh->b_size;
407 if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
408 header->h_blocks != cpu_to_le32(1)) {
409bad_block: ext2_error(sb, "ext2_xattr_set",
410 "inode %ld: bad block %d", inode->i_ino,
411 EXT2_I(inode)->i_file_acl);
412 error = -EIO;
413 goto cleanup;
414 }
415
416 here = FIRST_ENTRY(bh);
417 while (!IS_LAST_ENTRY(here)) {
418 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here);
419 if ((char *)next >= end)
420 goto bad_block;
421 if (!here->e_value_block && here->e_value_size) {
422 size_t offs = le16_to_cpu(here->e_value_offs);
423 if (offs < min_offs)
424 min_offs = offs;
425 }
426 not_found = name_index - here->e_name_index;
427 if (!not_found)
428 not_found = name_len - here->e_name_len;
429 if (!not_found)
430 not_found = memcmp(name, here->e_name,name_len);
431 if (not_found <= 0)
432 break;
433 here = next;
434 }
435 last = here;
436
437 while (!IS_LAST_ENTRY(last)) {
438 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last);
439 if ((char *)next >= end)
440 goto bad_block;
441 if (!last->e_value_block && last->e_value_size) {
442 size_t offs = le16_to_cpu(last->e_value_offs);
443 if (offs < min_offs)
444 min_offs = offs;
445 }
446 last = next;
447 }
448
449
450 free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
451 } else {
452
453 free = sb->s_blocksize -
454 sizeof(struct ext2_xattr_header) - sizeof(__u32);
455 here = last = NULL;
456 }
457
458 if (not_found) {
459
460 error = -ENODATA;
461 if (flags & XATTR_REPLACE)
462 goto cleanup;
463 error = 0;
464 if (value == NULL)
465 goto cleanup;
466 } else {
467
468 error = -EEXIST;
469 if (flags & XATTR_CREATE)
470 goto cleanup;
471 if (!here->e_value_block && here->e_value_size) {
472 size_t size = le32_to_cpu(here->e_value_size);
473
474 if (le16_to_cpu(here->e_value_offs) + size >
475 sb->s_blocksize || size > sb->s_blocksize)
476 goto bad_block;
477 free += EXT2_XATTR_SIZE(size);
478 }
479 free += EXT2_XATTR_LEN(name_len);
480 }
481 error = -ENOSPC;
482 if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len))
483 goto cleanup;
484
485
486
487 if (header) {
488
489 lock_buffer(bh);
490 if (header->h_refcount == cpu_to_le32(1)) {
491 __u32 hash = le32_to_cpu(header->h_hash);
492
493 ea_bdebug(bh, "modifying in-place");
494
495
496
497
498 mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
499 bh->b_blocknr);
500
501
502 } else {
503 int offset;
504
505 unlock_buffer(bh);
506 ea_bdebug(bh, "cloning");
507 header = kmalloc(bh->b_size, GFP_KERNEL);
508 error = -ENOMEM;
509 if (header == NULL)
510 goto cleanup;
511 memcpy(header, HDR(bh), bh->b_size);
512 header->h_refcount = cpu_to_le32(1);
513
514 offset = (char *)here - bh->b_data;
515 here = ENTRY((char *)header + offset);
516 offset = (char *)last - bh->b_data;
517 last = ENTRY((char *)header + offset);
518 }
519 } else {
520
521 header = kzalloc(sb->s_blocksize, GFP_KERNEL);
522 error = -ENOMEM;
523 if (header == NULL)
524 goto cleanup;
525 end = (char *)header + sb->s_blocksize;
526 header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC);
527 header->h_blocks = header->h_refcount = cpu_to_le32(1);
528 last = here = ENTRY(header+1);
529 }
530
531
532
533 if (not_found) {
534
535 size_t size = EXT2_XATTR_LEN(name_len);
536 size_t rest = (char *)last - (char *)here;
537 memmove((char *)here + size, here, rest);
538 memset(here, 0, size);
539 here->e_name_index = name_index;
540 here->e_name_len = name_len;
541 memcpy(here->e_name, name, name_len);
542 } else {
543 if (!here->e_value_block && here->e_value_size) {
544 char *first_val = (char *)header + min_offs;
545 size_t offs = le16_to_cpu(here->e_value_offs);
546 char *val = (char *)header + offs;
547 size_t size = EXT2_XATTR_SIZE(
548 le32_to_cpu(here->e_value_size));
549
550 if (size == EXT2_XATTR_SIZE(value_len)) {
551
552
553 here->e_value_size = cpu_to_le32(value_len);
554 memset(val + size - EXT2_XATTR_PAD, 0,
555 EXT2_XATTR_PAD);
556 memcpy(val, value, value_len);
557 goto skip_replace;
558 }
559
560
561 memmove(first_val + size, first_val, val - first_val);
562 memset(first_val, 0, size);
563 here->e_value_offs = 0;
564 min_offs += size;
565
566
567 last = ENTRY(header+1);
568 while (!IS_LAST_ENTRY(last)) {
569 size_t o = le16_to_cpu(last->e_value_offs);
570 if (!last->e_value_block && o < offs)
571 last->e_value_offs =
572 cpu_to_le16(o + size);
573 last = EXT2_XATTR_NEXT(last);
574 }
575 }
576 if (value == NULL) {
577
578 size_t size = EXT2_XATTR_LEN(name_len);
579 last = ENTRY((char *)last - size);
580 memmove(here, (char*)here + size,
581 (char*)last - (char*)here);
582 memset(last, 0, size);
583 }
584 }
585
586 if (value != NULL) {
587
588 here->e_value_size = cpu_to_le32(value_len);
589 if (value_len) {
590 size_t size = EXT2_XATTR_SIZE(value_len);
591 char *val = (char *)header + min_offs - size;
592 here->e_value_offs =
593 cpu_to_le16((char *)val - (char *)header);
594 memset(val + size - EXT2_XATTR_PAD, 0,
595 EXT2_XATTR_PAD);
596 memcpy(val, value, value_len);
597 }
598 }
599
600skip_replace:
601 if (IS_LAST_ENTRY(ENTRY(header+1))) {
602
603 if (bh && header == HDR(bh))
604 unlock_buffer(bh);
605 error = ext2_xattr_set2(inode, bh, NULL);
606 } else {
607 ext2_xattr_rehash(header, here);
608 if (bh && header == HDR(bh))
609 unlock_buffer(bh);
610 error = ext2_xattr_set2(inode, bh, header);
611 }
612
613cleanup:
614 brelse(bh);
615 if (!(bh && header == HDR(bh)))
616 kfree(header);
617 up_write(&EXT2_I(inode)->xattr_sem);
618
619 return error;
620}
621
622
623
624
625static int
626ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
627 struct ext2_xattr_header *header)
628{
629 struct super_block *sb = inode->i_sb;
630 struct buffer_head *new_bh = NULL;
631 int error;
632 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
633
634 if (header) {
635 new_bh = ext2_xattr_cache_find(inode, header);
636 if (new_bh) {
637
638 if (new_bh == old_bh) {
639 ea_bdebug(new_bh, "keeping this block");
640 } else {
641
642
643 ea_bdebug(new_bh, "reusing block");
644
645 error = dquot_alloc_block(inode, 1);
646 if (error) {
647 unlock_buffer(new_bh);
648 goto cleanup;
649 }
650 le32_add_cpu(&HDR(new_bh)->h_refcount, 1);
651 ea_bdebug(new_bh, "refcount now=%d",
652 le32_to_cpu(HDR(new_bh)->h_refcount));
653 }
654 unlock_buffer(new_bh);
655 } else if (old_bh && header == HDR(old_bh)) {
656
657
658 new_bh = old_bh;
659 get_bh(new_bh);
660 ext2_xattr_cache_insert(ea_block_cache, new_bh);
661 } else {
662
663 ext2_fsblk_t goal = ext2_group_first_block_no(sb,
664 EXT2_I(inode)->i_block_group);
665 int block = ext2_new_block(inode, goal, &error);
666 if (error)
667 goto cleanup;
668 ea_idebug(inode, "creating block %d", block);
669
670 new_bh = sb_getblk(sb, block);
671 if (unlikely(!new_bh)) {
672 ext2_free_blocks(inode, block, 1);
673 mark_inode_dirty(inode);
674 error = -ENOMEM;
675 goto cleanup;
676 }
677 lock_buffer(new_bh);
678 memcpy(new_bh->b_data, header, new_bh->b_size);
679 set_buffer_uptodate(new_bh);
680 unlock_buffer(new_bh);
681 ext2_xattr_cache_insert(ea_block_cache, new_bh);
682
683 ext2_xattr_update_super_block(sb);
684 }
685 mark_buffer_dirty(new_bh);
686 if (IS_SYNC(inode)) {
687 sync_dirty_buffer(new_bh);
688 error = -EIO;
689 if (buffer_req(new_bh) && !buffer_uptodate(new_bh))
690 goto cleanup;
691 }
692 }
693
694
695 EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
696 inode->i_ctime = current_time(inode);
697 if (IS_SYNC(inode)) {
698 error = sync_inode_metadata(inode, 1);
699
700
701
702 if (error && error != -ENOSPC) {
703 if (new_bh && new_bh != old_bh) {
704 dquot_free_block_nodirty(inode, 1);
705 mark_inode_dirty(inode);
706 }
707 goto cleanup;
708 }
709 } else
710 mark_inode_dirty(inode);
711
712 error = 0;
713 if (old_bh && old_bh != new_bh) {
714
715
716
717
718 lock_buffer(old_bh);
719 if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
720 __u32 hash = le32_to_cpu(HDR(old_bh)->h_hash);
721
722
723
724
725
726 mb_cache_entry_delete(ea_block_cache, hash,
727 old_bh->b_blocknr);
728
729 ea_bdebug(old_bh, "freeing");
730 ext2_free_blocks(inode, old_bh->b_blocknr, 1);
731 mark_inode_dirty(inode);
732
733
734 get_bh(old_bh);
735 bforget(old_bh);
736 } else {
737
738 le32_add_cpu(&HDR(old_bh)->h_refcount, -1);
739 dquot_free_block_nodirty(inode, 1);
740 mark_inode_dirty(inode);
741 mark_buffer_dirty(old_bh);
742 ea_bdebug(old_bh, "refcount now=%d",
743 le32_to_cpu(HDR(old_bh)->h_refcount));
744 }
745 unlock_buffer(old_bh);
746 }
747
748cleanup:
749 brelse(new_bh);
750
751 return error;
752}
753
754
755
756
757
758
759
760void
761ext2_xattr_delete_inode(struct inode *inode)
762{
763 struct buffer_head *bh = NULL;
764 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
765
766 down_write(&EXT2_I(inode)->xattr_sem);
767 if (!EXT2_I(inode)->i_file_acl)
768 goto cleanup;
769
770 if (!ext2_data_block_valid(sbi, EXT2_I(inode)->i_file_acl, 0)) {
771 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
772 "inode %ld: xattr block %d is out of data blocks range",
773 inode->i_ino, EXT2_I(inode)->i_file_acl);
774 goto cleanup;
775 }
776
777 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
778 if (!bh) {
779 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
780 "inode %ld: block %d read error", inode->i_ino,
781 EXT2_I(inode)->i_file_acl);
782 goto cleanup;
783 }
784 ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
785 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
786 HDR(bh)->h_blocks != cpu_to_le32(1)) {
787 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
788 "inode %ld: bad block %d", inode->i_ino,
789 EXT2_I(inode)->i_file_acl);
790 goto cleanup;
791 }
792 lock_buffer(bh);
793 if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
794 __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
795
796
797
798
799
800 mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
801 bh->b_blocknr);
802 ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1);
803 get_bh(bh);
804 bforget(bh);
805 unlock_buffer(bh);
806 } else {
807 le32_add_cpu(&HDR(bh)->h_refcount, -1);
808 ea_bdebug(bh, "refcount now=%d",
809 le32_to_cpu(HDR(bh)->h_refcount));
810 unlock_buffer(bh);
811 mark_buffer_dirty(bh);
812 if (IS_SYNC(inode))
813 sync_dirty_buffer(bh);
814 dquot_free_block_nodirty(inode, 1);
815 }
816 EXT2_I(inode)->i_file_acl = 0;
817
818cleanup:
819 brelse(bh);
820 up_write(&EXT2_I(inode)->xattr_sem);
821}
822
823
824
825
826
827
828
829
830
831static int
832ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
833{
834 __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
835 int error;
836
837 error = mb_cache_entry_create(cache, GFP_NOFS, hash, bh->b_blocknr, 1);
838 if (error) {
839 if (error == -EBUSY) {
840 ea_bdebug(bh, "already in cache (%d cache entries)",
841 atomic_read(&ext2_xattr_cache->c_entry_count));
842 error = 0;
843 }
844 } else
845 ea_bdebug(bh, "inserting [%x]", (int)hash);
846 return error;
847}
848
849
850
851
852
853
854
855
856
857static int
858ext2_xattr_cmp(struct ext2_xattr_header *header1,
859 struct ext2_xattr_header *header2)
860{
861 struct ext2_xattr_entry *entry1, *entry2;
862
863 entry1 = ENTRY(header1+1);
864 entry2 = ENTRY(header2+1);
865 while (!IS_LAST_ENTRY(entry1)) {
866 if (IS_LAST_ENTRY(entry2))
867 return 1;
868 if (entry1->e_hash != entry2->e_hash ||
869 entry1->e_name_index != entry2->e_name_index ||
870 entry1->e_name_len != entry2->e_name_len ||
871 entry1->e_value_size != entry2->e_value_size ||
872 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
873 return 1;
874 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
875 return -EIO;
876 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
877 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
878 le32_to_cpu(entry1->e_value_size)))
879 return 1;
880
881 entry1 = EXT2_XATTR_NEXT(entry1);
882 entry2 = EXT2_XATTR_NEXT(entry2);
883 }
884 if (!IS_LAST_ENTRY(entry2))
885 return 1;
886 return 0;
887}
888
889
890
891
892
893
894
895
896
897static struct buffer_head *
898ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
899{
900 __u32 hash = le32_to_cpu(header->h_hash);
901 struct mb_cache_entry *ce;
902 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
903
904 if (!header->h_hash)
905 return NULL;
906 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
907again:
908 ce = mb_cache_entry_find_first(ea_block_cache, hash);
909 while (ce) {
910 struct buffer_head *bh;
911
912 bh = sb_bread(inode->i_sb, ce->e_value);
913 if (!bh) {
914 ext2_error(inode->i_sb, "ext2_xattr_cache_find",
915 "inode %ld: block %ld read error",
916 inode->i_ino, (unsigned long) ce->e_value);
917 } else {
918 lock_buffer(bh);
919
920
921
922
923
924
925
926
927
928 if (hlist_bl_unhashed(&ce->e_hash_list)) {
929 mb_cache_entry_put(ea_block_cache, ce);
930 unlock_buffer(bh);
931 brelse(bh);
932 goto again;
933 } else if (le32_to_cpu(HDR(bh)->h_refcount) >
934 EXT2_XATTR_REFCOUNT_MAX) {
935 ea_idebug(inode, "block %ld refcount %d>%d",
936 (unsigned long) ce->e_value,
937 le32_to_cpu(HDR(bh)->h_refcount),
938 EXT2_XATTR_REFCOUNT_MAX);
939 } else if (!ext2_xattr_cmp(header, HDR(bh))) {
940 ea_bdebug(bh, "b_count=%d",
941 atomic_read(&(bh->b_count)));
942 mb_cache_entry_touch(ea_block_cache, ce);
943 mb_cache_entry_put(ea_block_cache, ce);
944 return bh;
945 }
946 unlock_buffer(bh);
947 brelse(bh);
948 }
949 ce = mb_cache_entry_find_next(ea_block_cache, ce);
950 }
951 return NULL;
952}
953
954#define NAME_HASH_SHIFT 5
955#define VALUE_HASH_SHIFT 16
956
957
958
959
960
961
962static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header,
963 struct ext2_xattr_entry *entry)
964{
965 __u32 hash = 0;
966 char *name = entry->e_name;
967 int n;
968
969 for (n=0; n < entry->e_name_len; n++) {
970 hash = (hash << NAME_HASH_SHIFT) ^
971 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
972 *name++;
973 }
974
975 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
976 __le32 *value = (__le32 *)((char *)header +
977 le16_to_cpu(entry->e_value_offs));
978 for (n = (le32_to_cpu(entry->e_value_size) +
979 EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) {
980 hash = (hash << VALUE_HASH_SHIFT) ^
981 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
982 le32_to_cpu(*value++);
983 }
984 }
985 entry->e_hash = cpu_to_le32(hash);
986}
987
988#undef NAME_HASH_SHIFT
989#undef VALUE_HASH_SHIFT
990
991#define BLOCK_HASH_SHIFT 16
992
993
994
995
996
997
998static void ext2_xattr_rehash(struct ext2_xattr_header *header,
999 struct ext2_xattr_entry *entry)
1000{
1001 struct ext2_xattr_entry *here;
1002 __u32 hash = 0;
1003
1004 ext2_xattr_hash_entry(header, entry);
1005 here = ENTRY(header+1);
1006 while (!IS_LAST_ENTRY(here)) {
1007 if (!here->e_hash) {
1008
1009 hash = 0;
1010 break;
1011 }
1012 hash = (hash << BLOCK_HASH_SHIFT) ^
1013 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1014 le32_to_cpu(here->e_hash);
1015 here = EXT2_XATTR_NEXT(here);
1016 }
1017 header->h_hash = cpu_to_le32(hash);
1018}
1019
1020#undef BLOCK_HASH_SHIFT
1021
1022#define HASH_BUCKET_BITS 10
1023
1024struct mb_cache *ext2_xattr_create_cache(void)
1025{
1026 return mb_cache_create(HASH_BUCKET_BITS);
1027}
1028
1029void ext2_xattr_destroy_cache(struct mb_cache *cache)
1030{
1031 if (cache)
1032 mb_cache_destroy(cache);
1033}
1034