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57#include <linux/buffer_head.h>
58#include <linux/init.h>
59#include <linux/slab.h>
60#include <linux/mbcache.h>
61#include <linux/quotaops.h>
62#include <linux/rwsem.h>
63#include <linux/security.h>
64#include "ext2.h"
65#include "xattr.h"
66#include "acl.h"
67
68#define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data))
69#define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr))
70#define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
71#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
72
73#ifdef EXT2_XATTR_DEBUG
74# define ea_idebug(inode, f...) do { \
75 printk(KERN_DEBUG "inode %s:%ld: ", \
76 inode->i_sb->s_id, inode->i_ino); \
77 printk(f); \
78 printk("\n"); \
79 } while (0)
80# define ea_bdebug(bh, f...) do { \
81 printk(KERN_DEBUG "block %pg:%lu: ", \
82 bh->b_bdev, (unsigned long) bh->b_blocknr); \
83 printk(f); \
84 printk("\n"); \
85 } while (0)
86#else
87# define ea_idebug(f...)
88# define ea_bdebug(f...)
89#endif
90
91static int ext2_xattr_set2(struct inode *, struct buffer_head *,
92 struct ext2_xattr_header *);
93
94static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
95static struct buffer_head *ext2_xattr_cache_find(struct inode *,
96 struct ext2_xattr_header *);
97static void ext2_xattr_rehash(struct ext2_xattr_header *,
98 struct ext2_xattr_entry *);
99
100static const struct xattr_handler *ext2_xattr_handler_map[] = {
101 [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
102#ifdef CONFIG_EXT2_FS_POSIX_ACL
103 [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
104 [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
105#endif
106 [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler,
107#ifdef CONFIG_EXT2_FS_SECURITY
108 [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler,
109#endif
110};
111
112const struct xattr_handler *ext2_xattr_handlers[] = {
113 &ext2_xattr_user_handler,
114 &ext2_xattr_trusted_handler,
115#ifdef CONFIG_EXT2_FS_POSIX_ACL
116 &posix_acl_access_xattr_handler,
117 &posix_acl_default_xattr_handler,
118#endif
119#ifdef CONFIG_EXT2_FS_SECURITY
120 &ext2_xattr_security_handler,
121#endif
122 NULL
123};
124
125#define EA_BLOCK_CACHE(inode) (EXT2_SB(inode->i_sb)->s_ea_block_cache)
126
127static inline const struct xattr_handler *
128ext2_xattr_handler(int name_index)
129{
130 const struct xattr_handler *handler = NULL;
131
132 if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
133 handler = ext2_xattr_handler_map[name_index];
134 return handler;
135}
136
137
138
139
140
141
142
143
144
145
146
147int
148ext2_xattr_get(struct inode *inode, int name_index, const char *name,
149 void *buffer, size_t buffer_size)
150{
151 struct buffer_head *bh = NULL;
152 struct ext2_xattr_entry *entry;
153 size_t name_len, size;
154 char *end;
155 int error;
156 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
157
158 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
159 name_index, name, buffer, (long)buffer_size);
160
161 if (name == NULL)
162 return -EINVAL;
163 name_len = strlen(name);
164 if (name_len > 255)
165 return -ERANGE;
166
167 down_read(&EXT2_I(inode)->xattr_sem);
168 error = -ENODATA;
169 if (!EXT2_I(inode)->i_file_acl)
170 goto cleanup;
171 ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
172 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
173 error = -EIO;
174 if (!bh)
175 goto cleanup;
176 ea_bdebug(bh, "b_count=%d, refcount=%d",
177 atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
178 end = bh->b_data + bh->b_size;
179 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
180 HDR(bh)->h_blocks != cpu_to_le32(1)) {
181bad_block: ext2_error(inode->i_sb, "ext2_xattr_get",
182 "inode %ld: bad block %d", inode->i_ino,
183 EXT2_I(inode)->i_file_acl);
184 error = -EIO;
185 goto cleanup;
186 }
187
188
189 entry = FIRST_ENTRY(bh);
190 while (!IS_LAST_ENTRY(entry)) {
191 struct ext2_xattr_entry *next =
192 EXT2_XATTR_NEXT(entry);
193 if ((char *)next >= end)
194 goto bad_block;
195 if (name_index == entry->e_name_index &&
196 name_len == entry->e_name_len &&
197 memcmp(name, entry->e_name, name_len) == 0)
198 goto found;
199 entry = next;
200 }
201 if (ext2_xattr_cache_insert(ea_block_cache, bh))
202 ea_idebug(inode, "cache insert failed");
203 error = -ENODATA;
204 goto cleanup;
205found:
206
207 if (entry->e_value_block != 0)
208 goto bad_block;
209 size = le32_to_cpu(entry->e_value_size);
210 if (size > inode->i_sb->s_blocksize ||
211 le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
212 goto bad_block;
213
214 if (ext2_xattr_cache_insert(ea_block_cache, bh))
215 ea_idebug(inode, "cache insert failed");
216 if (buffer) {
217 error = -ERANGE;
218 if (size > buffer_size)
219 goto cleanup;
220
221 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
222 size);
223 }
224 error = size;
225
226cleanup:
227 brelse(bh);
228 up_read(&EXT2_I(inode)->xattr_sem);
229
230 return error;
231}
232
233
234
235
236
237
238
239
240
241
242
243static int
244ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
245{
246 struct inode *inode = d_inode(dentry);
247 struct buffer_head *bh = NULL;
248 struct ext2_xattr_entry *entry;
249 char *end;
250 size_t rest = buffer_size;
251 int error;
252 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
253
254 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
255 buffer, (long)buffer_size);
256
257 down_read(&EXT2_I(inode)->xattr_sem);
258 error = 0;
259 if (!EXT2_I(inode)->i_file_acl)
260 goto cleanup;
261 ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
262 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
263 error = -EIO;
264 if (!bh)
265 goto cleanup;
266 ea_bdebug(bh, "b_count=%d, refcount=%d",
267 atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
268 end = bh->b_data + bh->b_size;
269 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
270 HDR(bh)->h_blocks != cpu_to_le32(1)) {
271bad_block: ext2_error(inode->i_sb, "ext2_xattr_list",
272 "inode %ld: bad block %d", inode->i_ino,
273 EXT2_I(inode)->i_file_acl);
274 error = -EIO;
275 goto cleanup;
276 }
277
278
279 entry = FIRST_ENTRY(bh);
280 while (!IS_LAST_ENTRY(entry)) {
281 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry);
282
283 if ((char *)next >= end)
284 goto bad_block;
285 entry = next;
286 }
287 if (ext2_xattr_cache_insert(ea_block_cache, bh))
288 ea_idebug(inode, "cache insert failed");
289
290
291 for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
292 entry = EXT2_XATTR_NEXT(entry)) {
293 const struct xattr_handler *handler =
294 ext2_xattr_handler(entry->e_name_index);
295
296 if (handler && (!handler->list || handler->list(dentry))) {
297 const char *prefix = handler->prefix ?: handler->name;
298 size_t prefix_len = strlen(prefix);
299 size_t size = prefix_len + entry->e_name_len + 1;
300
301 if (buffer) {
302 if (size > rest) {
303 error = -ERANGE;
304 goto cleanup;
305 }
306 memcpy(buffer, prefix, prefix_len);
307 buffer += prefix_len;
308 memcpy(buffer, entry->e_name, entry->e_name_len);
309 buffer += entry->e_name_len;
310 *buffer++ = 0;
311 }
312 rest -= size;
313 }
314 }
315 error = buffer_size - rest;
316
317cleanup:
318 brelse(bh);
319 up_read(&EXT2_I(inode)->xattr_sem);
320
321 return error;
322}
323
324
325
326
327
328
329ssize_t
330ext2_listxattr(struct dentry *dentry, char *buffer, size_t size)
331{
332 return ext2_xattr_list(dentry, buffer, size);
333}
334
335
336
337
338
339static void ext2_xattr_update_super_block(struct super_block *sb)
340{
341 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR))
342 return;
343
344 spin_lock(&EXT2_SB(sb)->s_lock);
345 EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR);
346 spin_unlock(&EXT2_SB(sb)->s_lock);
347 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
348}
349
350
351
352
353
354
355
356
357
358
359
360
361
362int
363ext2_xattr_set(struct inode *inode, int name_index, const char *name,
364 const void *value, size_t value_len, int flags)
365{
366 struct super_block *sb = inode->i_sb;
367 struct buffer_head *bh = NULL;
368 struct ext2_xattr_header *header = NULL;
369 struct ext2_xattr_entry *here, *last;
370 size_t name_len, free, min_offs = sb->s_blocksize;
371 int not_found = 1, error;
372 char *end;
373
374
375
376
377
378
379
380
381
382
383
384
385
386 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
387 name_index, name, value, (long)value_len);
388
389 if (value == NULL)
390 value_len = 0;
391 if (name == NULL)
392 return -EINVAL;
393 name_len = strlen(name);
394 if (name_len > 255 || value_len > sb->s_blocksize)
395 return -ERANGE;
396 down_write(&EXT2_I(inode)->xattr_sem);
397 if (EXT2_I(inode)->i_file_acl) {
398
399 bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
400 error = -EIO;
401 if (!bh)
402 goto cleanup;
403 ea_bdebug(bh, "b_count=%d, refcount=%d",
404 atomic_read(&(bh->b_count)),
405 le32_to_cpu(HDR(bh)->h_refcount));
406 header = HDR(bh);
407 end = bh->b_data + bh->b_size;
408 if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
409 header->h_blocks != cpu_to_le32(1)) {
410bad_block: ext2_error(sb, "ext2_xattr_set",
411 "inode %ld: bad block %d", inode->i_ino,
412 EXT2_I(inode)->i_file_acl);
413 error = -EIO;
414 goto cleanup;
415 }
416
417 here = FIRST_ENTRY(bh);
418 while (!IS_LAST_ENTRY(here)) {
419 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here);
420 if ((char *)next >= end)
421 goto bad_block;
422 if (!here->e_value_block && here->e_value_size) {
423 size_t offs = le16_to_cpu(here->e_value_offs);
424 if (offs < min_offs)
425 min_offs = offs;
426 }
427 not_found = name_index - here->e_name_index;
428 if (!not_found)
429 not_found = name_len - here->e_name_len;
430 if (!not_found)
431 not_found = memcmp(name, here->e_name,name_len);
432 if (not_found <= 0)
433 break;
434 here = next;
435 }
436 last = here;
437
438 while (!IS_LAST_ENTRY(last)) {
439 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last);
440 if ((char *)next >= end)
441 goto bad_block;
442 if (!last->e_value_block && last->e_value_size) {
443 size_t offs = le16_to_cpu(last->e_value_offs);
444 if (offs < min_offs)
445 min_offs = offs;
446 }
447 last = next;
448 }
449
450
451 free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
452 } else {
453
454 free = sb->s_blocksize -
455 sizeof(struct ext2_xattr_header) - sizeof(__u32);
456 here = last = NULL;
457 }
458
459 if (not_found) {
460
461 error = -ENODATA;
462 if (flags & XATTR_REPLACE)
463 goto cleanup;
464 error = 0;
465 if (value == NULL)
466 goto cleanup;
467 } else {
468
469 error = -EEXIST;
470 if (flags & XATTR_CREATE)
471 goto cleanup;
472 if (!here->e_value_block && here->e_value_size) {
473 size_t size = le32_to_cpu(here->e_value_size);
474
475 if (le16_to_cpu(here->e_value_offs) + size >
476 sb->s_blocksize || size > sb->s_blocksize)
477 goto bad_block;
478 free += EXT2_XATTR_SIZE(size);
479 }
480 free += EXT2_XATTR_LEN(name_len);
481 }
482 error = -ENOSPC;
483 if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len))
484 goto cleanup;
485
486
487
488 if (header) {
489
490 lock_buffer(bh);
491 if (header->h_refcount == cpu_to_le32(1)) {
492 __u32 hash = le32_to_cpu(header->h_hash);
493
494 ea_bdebug(bh, "modifying in-place");
495
496
497
498
499 mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
500 bh->b_blocknr);
501
502
503 } else {
504 int offset;
505
506 unlock_buffer(bh);
507 ea_bdebug(bh, "cloning");
508 header = kmalloc(bh->b_size, GFP_KERNEL);
509 error = -ENOMEM;
510 if (header == NULL)
511 goto cleanup;
512 memcpy(header, HDR(bh), bh->b_size);
513 header->h_refcount = cpu_to_le32(1);
514
515 offset = (char *)here - bh->b_data;
516 here = ENTRY((char *)header + offset);
517 offset = (char *)last - bh->b_data;
518 last = ENTRY((char *)header + offset);
519 }
520 } else {
521
522 header = kzalloc(sb->s_blocksize, GFP_KERNEL);
523 error = -ENOMEM;
524 if (header == NULL)
525 goto cleanup;
526 end = (char *)header + sb->s_blocksize;
527 header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC);
528 header->h_blocks = header->h_refcount = cpu_to_le32(1);
529 last = here = ENTRY(header+1);
530 }
531
532
533
534 if (not_found) {
535
536 size_t size = EXT2_XATTR_LEN(name_len);
537 size_t rest = (char *)last - (char *)here;
538 memmove((char *)here + size, here, rest);
539 memset(here, 0, size);
540 here->e_name_index = name_index;
541 here->e_name_len = name_len;
542 memcpy(here->e_name, name, name_len);
543 } else {
544 if (!here->e_value_block && here->e_value_size) {
545 char *first_val = (char *)header + min_offs;
546 size_t offs = le16_to_cpu(here->e_value_offs);
547 char *val = (char *)header + offs;
548 size_t size = EXT2_XATTR_SIZE(
549 le32_to_cpu(here->e_value_size));
550
551 if (size == EXT2_XATTR_SIZE(value_len)) {
552
553
554 here->e_value_size = cpu_to_le32(value_len);
555 memset(val + size - EXT2_XATTR_PAD, 0,
556 EXT2_XATTR_PAD);
557 memcpy(val, value, value_len);
558 goto skip_replace;
559 }
560
561
562 memmove(first_val + size, first_val, val - first_val);
563 memset(first_val, 0, size);
564 here->e_value_offs = 0;
565 min_offs += size;
566
567
568 last = ENTRY(header+1);
569 while (!IS_LAST_ENTRY(last)) {
570 size_t o = le16_to_cpu(last->e_value_offs);
571 if (!last->e_value_block && o < offs)
572 last->e_value_offs =
573 cpu_to_le16(o + size);
574 last = EXT2_XATTR_NEXT(last);
575 }
576 }
577 if (value == NULL) {
578
579 size_t size = EXT2_XATTR_LEN(name_len);
580 last = ENTRY((char *)last - size);
581 memmove(here, (char*)here + size,
582 (char*)last - (char*)here);
583 memset(last, 0, size);
584 }
585 }
586
587 if (value != NULL) {
588
589 here->e_value_size = cpu_to_le32(value_len);
590 if (value_len) {
591 size_t size = EXT2_XATTR_SIZE(value_len);
592 char *val = (char *)header + min_offs - size;
593 here->e_value_offs =
594 cpu_to_le16((char *)val - (char *)header);
595 memset(val + size - EXT2_XATTR_PAD, 0,
596 EXT2_XATTR_PAD);
597 memcpy(val, value, value_len);
598 }
599 }
600
601skip_replace:
602 if (IS_LAST_ENTRY(ENTRY(header+1))) {
603
604 if (bh && header == HDR(bh))
605 unlock_buffer(bh);
606 error = ext2_xattr_set2(inode, bh, NULL);
607 } else {
608 ext2_xattr_rehash(header, here);
609 if (bh && header == HDR(bh))
610 unlock_buffer(bh);
611 error = ext2_xattr_set2(inode, bh, header);
612 }
613
614cleanup:
615 brelse(bh);
616 if (!(bh && header == HDR(bh)))
617 kfree(header);
618 up_write(&EXT2_I(inode)->xattr_sem);
619
620 return error;
621}
622
623
624
625
626static int
627ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
628 struct ext2_xattr_header *header)
629{
630 struct super_block *sb = inode->i_sb;
631 struct buffer_head *new_bh = NULL;
632 int error;
633 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
634
635 if (header) {
636 new_bh = ext2_xattr_cache_find(inode, header);
637 if (new_bh) {
638
639 if (new_bh == old_bh) {
640 ea_bdebug(new_bh, "keeping this block");
641 } else {
642
643
644 ea_bdebug(new_bh, "reusing block");
645
646 error = dquot_alloc_block(inode, 1);
647 if (error) {
648 unlock_buffer(new_bh);
649 goto cleanup;
650 }
651 le32_add_cpu(&HDR(new_bh)->h_refcount, 1);
652 ea_bdebug(new_bh, "refcount now=%d",
653 le32_to_cpu(HDR(new_bh)->h_refcount));
654 }
655 unlock_buffer(new_bh);
656 } else if (old_bh && header == HDR(old_bh)) {
657
658
659 new_bh = old_bh;
660 get_bh(new_bh);
661 ext2_xattr_cache_insert(ea_block_cache, new_bh);
662 } else {
663
664 ext2_fsblk_t goal = ext2_group_first_block_no(sb,
665 EXT2_I(inode)->i_block_group);
666 int block = ext2_new_block(inode, goal, &error);
667 if (error)
668 goto cleanup;
669 ea_idebug(inode, "creating block %d", block);
670
671 new_bh = sb_getblk(sb, block);
672 if (unlikely(!new_bh)) {
673 ext2_free_blocks(inode, block, 1);
674 mark_inode_dirty(inode);
675 error = -ENOMEM;
676 goto cleanup;
677 }
678 lock_buffer(new_bh);
679 memcpy(new_bh->b_data, header, new_bh->b_size);
680 set_buffer_uptodate(new_bh);
681 unlock_buffer(new_bh);
682 ext2_xattr_cache_insert(ea_block_cache, new_bh);
683
684 ext2_xattr_update_super_block(sb);
685 }
686 mark_buffer_dirty(new_bh);
687 if (IS_SYNC(inode)) {
688 sync_dirty_buffer(new_bh);
689 error = -EIO;
690 if (buffer_req(new_bh) && !buffer_uptodate(new_bh))
691 goto cleanup;
692 }
693 }
694
695
696 EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
697 inode->i_ctime = current_time(inode);
698 if (IS_SYNC(inode)) {
699 error = sync_inode_metadata(inode, 1);
700
701
702
703 if (error && error != -ENOSPC) {
704 if (new_bh && new_bh != old_bh) {
705 dquot_free_block_nodirty(inode, 1);
706 mark_inode_dirty(inode);
707 }
708 goto cleanup;
709 }
710 } else
711 mark_inode_dirty(inode);
712
713 error = 0;
714 if (old_bh && old_bh != new_bh) {
715
716
717
718
719 lock_buffer(old_bh);
720 if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
721 __u32 hash = le32_to_cpu(HDR(old_bh)->h_hash);
722
723
724
725
726
727 mb_cache_entry_delete(ea_block_cache, hash,
728 old_bh->b_blocknr);
729
730 ea_bdebug(old_bh, "freeing");
731 ext2_free_blocks(inode, old_bh->b_blocknr, 1);
732 mark_inode_dirty(inode);
733
734
735 get_bh(old_bh);
736 bforget(old_bh);
737 } else {
738
739 le32_add_cpu(&HDR(old_bh)->h_refcount, -1);
740 dquot_free_block_nodirty(inode, 1);
741 mark_inode_dirty(inode);
742 mark_buffer_dirty(old_bh);
743 ea_bdebug(old_bh, "refcount now=%d",
744 le32_to_cpu(HDR(old_bh)->h_refcount));
745 }
746 unlock_buffer(old_bh);
747 }
748
749cleanup:
750 brelse(new_bh);
751
752 return error;
753}
754
755
756
757
758
759
760
761void
762ext2_xattr_delete_inode(struct inode *inode)
763{
764 struct buffer_head *bh = NULL;
765 struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
766
767 down_write(&EXT2_I(inode)->xattr_sem);
768 if (!EXT2_I(inode)->i_file_acl)
769 goto cleanup;
770
771 if (!ext2_data_block_valid(sbi, EXT2_I(inode)->i_file_acl, 0)) {
772 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
773 "inode %ld: xattr block %d is out of data blocks range",
774 inode->i_ino, EXT2_I(inode)->i_file_acl);
775 goto cleanup;
776 }
777
778 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
779 if (!bh) {
780 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
781 "inode %ld: block %d read error", inode->i_ino,
782 EXT2_I(inode)->i_file_acl);
783 goto cleanup;
784 }
785 ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
786 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
787 HDR(bh)->h_blocks != cpu_to_le32(1)) {
788 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
789 "inode %ld: bad block %d", inode->i_ino,
790 EXT2_I(inode)->i_file_acl);
791 goto cleanup;
792 }
793 lock_buffer(bh);
794 if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
795 __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
796
797
798
799
800
801 mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
802 bh->b_blocknr);
803 ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1);
804 get_bh(bh);
805 bforget(bh);
806 unlock_buffer(bh);
807 } else {
808 le32_add_cpu(&HDR(bh)->h_refcount, -1);
809 ea_bdebug(bh, "refcount now=%d",
810 le32_to_cpu(HDR(bh)->h_refcount));
811 unlock_buffer(bh);
812 mark_buffer_dirty(bh);
813 if (IS_SYNC(inode))
814 sync_dirty_buffer(bh);
815 dquot_free_block_nodirty(inode, 1);
816 }
817 EXT2_I(inode)->i_file_acl = 0;
818
819cleanup:
820 brelse(bh);
821 up_write(&EXT2_I(inode)->xattr_sem);
822}
823
824
825
826
827
828
829
830
831
832static int
833ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
834{
835 __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
836 int error;
837
838 error = mb_cache_entry_create(cache, GFP_NOFS, hash, bh->b_blocknr, 1);
839 if (error) {
840 if (error == -EBUSY) {
841 ea_bdebug(bh, "already in cache (%d cache entries)",
842 atomic_read(&ext2_xattr_cache->c_entry_count));
843 error = 0;
844 }
845 } else
846 ea_bdebug(bh, "inserting [%x]", (int)hash);
847 return error;
848}
849
850
851
852
853
854
855
856
857
858static int
859ext2_xattr_cmp(struct ext2_xattr_header *header1,
860 struct ext2_xattr_header *header2)
861{
862 struct ext2_xattr_entry *entry1, *entry2;
863
864 entry1 = ENTRY(header1+1);
865 entry2 = ENTRY(header2+1);
866 while (!IS_LAST_ENTRY(entry1)) {
867 if (IS_LAST_ENTRY(entry2))
868 return 1;
869 if (entry1->e_hash != entry2->e_hash ||
870 entry1->e_name_index != entry2->e_name_index ||
871 entry1->e_name_len != entry2->e_name_len ||
872 entry1->e_value_size != entry2->e_value_size ||
873 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
874 return 1;
875 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
876 return -EIO;
877 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
878 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
879 le32_to_cpu(entry1->e_value_size)))
880 return 1;
881
882 entry1 = EXT2_XATTR_NEXT(entry1);
883 entry2 = EXT2_XATTR_NEXT(entry2);
884 }
885 if (!IS_LAST_ENTRY(entry2))
886 return 1;
887 return 0;
888}
889
890
891
892
893
894
895
896
897
898static struct buffer_head *
899ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
900{
901 __u32 hash = le32_to_cpu(header->h_hash);
902 struct mb_cache_entry *ce;
903 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
904
905 if (!header->h_hash)
906 return NULL;
907 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
908again:
909 ce = mb_cache_entry_find_first(ea_block_cache, hash);
910 while (ce) {
911 struct buffer_head *bh;
912
913 bh = sb_bread(inode->i_sb, ce->e_value);
914 if (!bh) {
915 ext2_error(inode->i_sb, "ext2_xattr_cache_find",
916 "inode %ld: block %ld read error",
917 inode->i_ino, (unsigned long) ce->e_value);
918 } else {
919 lock_buffer(bh);
920
921
922
923
924
925
926
927
928
929 if (hlist_bl_unhashed(&ce->e_hash_list)) {
930 mb_cache_entry_put(ea_block_cache, ce);
931 unlock_buffer(bh);
932 brelse(bh);
933 goto again;
934 } else if (le32_to_cpu(HDR(bh)->h_refcount) >
935 EXT2_XATTR_REFCOUNT_MAX) {
936 ea_idebug(inode, "block %ld refcount %d>%d",
937 (unsigned long) ce->e_value,
938 le32_to_cpu(HDR(bh)->h_refcount),
939 EXT2_XATTR_REFCOUNT_MAX);
940 } else if (!ext2_xattr_cmp(header, HDR(bh))) {
941 ea_bdebug(bh, "b_count=%d",
942 atomic_read(&(bh->b_count)));
943 mb_cache_entry_touch(ea_block_cache, ce);
944 mb_cache_entry_put(ea_block_cache, ce);
945 return bh;
946 }
947 unlock_buffer(bh);
948 brelse(bh);
949 }
950 ce = mb_cache_entry_find_next(ea_block_cache, ce);
951 }
952 return NULL;
953}
954
955#define NAME_HASH_SHIFT 5
956#define VALUE_HASH_SHIFT 16
957
958
959
960
961
962
963static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header,
964 struct ext2_xattr_entry *entry)
965{
966 __u32 hash = 0;
967 char *name = entry->e_name;
968 int n;
969
970 for (n=0; n < entry->e_name_len; n++) {
971 hash = (hash << NAME_HASH_SHIFT) ^
972 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
973 *name++;
974 }
975
976 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
977 __le32 *value = (__le32 *)((char *)header +
978 le16_to_cpu(entry->e_value_offs));
979 for (n = (le32_to_cpu(entry->e_value_size) +
980 EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) {
981 hash = (hash << VALUE_HASH_SHIFT) ^
982 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
983 le32_to_cpu(*value++);
984 }
985 }
986 entry->e_hash = cpu_to_le32(hash);
987}
988
989#undef NAME_HASH_SHIFT
990#undef VALUE_HASH_SHIFT
991
992#define BLOCK_HASH_SHIFT 16
993
994
995
996
997
998
999static void ext2_xattr_rehash(struct ext2_xattr_header *header,
1000 struct ext2_xattr_entry *entry)
1001{
1002 struct ext2_xattr_entry *here;
1003 __u32 hash = 0;
1004
1005 ext2_xattr_hash_entry(header, entry);
1006 here = ENTRY(header+1);
1007 while (!IS_LAST_ENTRY(here)) {
1008 if (!here->e_hash) {
1009
1010 hash = 0;
1011 break;
1012 }
1013 hash = (hash << BLOCK_HASH_SHIFT) ^
1014 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1015 le32_to_cpu(here->e_hash);
1016 here = EXT2_XATTR_NEXT(here);
1017 }
1018 header->h_hash = cpu_to_le32(hash);
1019}
1020
1021#undef BLOCK_HASH_SHIFT
1022
1023#define HASH_BUCKET_BITS 10
1024
1025struct mb_cache *ext2_xattr_create_cache(void)
1026{
1027 return mb_cache_create(HASH_BUCKET_BITS);
1028}
1029
1030void ext2_xattr_destroy_cache(struct mb_cache *cache)
1031{
1032 if (cache)
1033 mb_cache_destroy(cache);
1034}
1035