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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 char b[BDEVNAME_SIZE]; \
81 printk(KERN_DEBUG "block %s:%lu: ", \
82 bdevname(bh->b_bdev, b), \
83 (unsigned long) bh->b_blocknr); \
84 printk(f); \
85 printk("\n"); \
86 } while (0)
87#else
88# define ea_idebug(f...)
89# define ea_bdebug(f...)
90#endif
91
92static int ext2_xattr_set2(struct inode *, struct buffer_head *,
93 struct ext2_xattr_header *);
94
95static int ext2_xattr_cache_insert(struct buffer_head *);
96static struct buffer_head *ext2_xattr_cache_find(struct inode *,
97 struct ext2_xattr_header *);
98static void ext2_xattr_rehash(struct ext2_xattr_header *,
99 struct ext2_xattr_entry *);
100
101static struct mb_cache *ext2_xattr_cache;
102
103static const struct xattr_handler *ext2_xattr_handler_map[] = {
104 [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
105#ifdef CONFIG_EXT2_FS_POSIX_ACL
106 [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext2_xattr_acl_access_handler,
107 [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext2_xattr_acl_default_handler,
108#endif
109 [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler,
110#ifdef CONFIG_EXT2_FS_SECURITY
111 [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler,
112#endif
113};
114
115const struct xattr_handler *ext2_xattr_handlers[] = {
116 &ext2_xattr_user_handler,
117 &ext2_xattr_trusted_handler,
118#ifdef CONFIG_EXT2_FS_POSIX_ACL
119 &ext2_xattr_acl_access_handler,
120 &ext2_xattr_acl_default_handler,
121#endif
122#ifdef CONFIG_EXT2_FS_SECURITY
123 &ext2_xattr_security_handler,
124#endif
125 NULL
126};
127
128static inline const struct xattr_handler *
129ext2_xattr_handler(int name_index)
130{
131 const struct xattr_handler *handler = NULL;
132
133 if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
134 handler = ext2_xattr_handler_map[name_index];
135 return handler;
136}
137
138
139
140
141
142
143
144
145
146
147
148int
149ext2_xattr_get(struct inode *inode, int name_index, const char *name,
150 void *buffer, size_t buffer_size)
151{
152 struct buffer_head *bh = NULL;
153 struct ext2_xattr_entry *entry;
154 size_t name_len, size;
155 char *end;
156 int error;
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(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(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 = dentry->d_inode;
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
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(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) {
296 size_t size = handler->list(dentry, buffer, rest,
297 entry->e_name,
298 entry->e_name_len,
299 handler->flags);
300 if (buffer) {
301 if (size > rest) {
302 error = -ERANGE;
303 goto cleanup;
304 }
305 buffer += size;
306 }
307 rest -= size;
308 }
309 }
310 error = buffer_size - rest;
311
312cleanup:
313 brelse(bh);
314 up_read(&EXT2_I(inode)->xattr_sem);
315
316 return error;
317}
318
319
320
321
322
323
324ssize_t
325ext2_listxattr(struct dentry *dentry, char *buffer, size_t size)
326{
327 return ext2_xattr_list(dentry, buffer, size);
328}
329
330
331
332
333
334static void ext2_xattr_update_super_block(struct super_block *sb)
335{
336 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR))
337 return;
338
339 spin_lock(&EXT2_SB(sb)->s_lock);
340 EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR);
341 spin_unlock(&EXT2_SB(sb)->s_lock);
342 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
343}
344
345
346
347
348
349
350
351
352
353
354
355
356
357int
358ext2_xattr_set(struct inode *inode, int name_index, const char *name,
359 const void *value, size_t value_len, int flags)
360{
361 struct super_block *sb = inode->i_sb;
362 struct buffer_head *bh = NULL;
363 struct ext2_xattr_header *header = NULL;
364 struct ext2_xattr_entry *here, *last;
365 size_t name_len, free, min_offs = sb->s_blocksize;
366 int not_found = 1, error;
367 char *end;
368
369
370
371
372
373
374
375
376
377
378
379
380
381 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
382 name_index, name, value, (long)value_len);
383
384 if (value == NULL)
385 value_len = 0;
386 if (name == NULL)
387 return -EINVAL;
388 name_len = strlen(name);
389 if (name_len > 255 || value_len > sb->s_blocksize)
390 return -ERANGE;
391 down_write(&EXT2_I(inode)->xattr_sem);
392 if (EXT2_I(inode)->i_file_acl) {
393
394 bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
395 error = -EIO;
396 if (!bh)
397 goto cleanup;
398 ea_bdebug(bh, "b_count=%d, refcount=%d",
399 atomic_read(&(bh->b_count)),
400 le32_to_cpu(HDR(bh)->h_refcount));
401 header = HDR(bh);
402 end = bh->b_data + bh->b_size;
403 if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
404 header->h_blocks != cpu_to_le32(1)) {
405bad_block: ext2_error(sb, "ext2_xattr_set",
406 "inode %ld: bad block %d", inode->i_ino,
407 EXT2_I(inode)->i_file_acl);
408 error = -EIO;
409 goto cleanup;
410 }
411
412 here = FIRST_ENTRY(bh);
413 while (!IS_LAST_ENTRY(here)) {
414 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here);
415 if ((char *)next >= end)
416 goto bad_block;
417 if (!here->e_value_block && here->e_value_size) {
418 size_t offs = le16_to_cpu(here->e_value_offs);
419 if (offs < min_offs)
420 min_offs = offs;
421 }
422 not_found = name_index - here->e_name_index;
423 if (!not_found)
424 not_found = name_len - here->e_name_len;
425 if (!not_found)
426 not_found = memcmp(name, here->e_name,name_len);
427 if (not_found <= 0)
428 break;
429 here = next;
430 }
431 last = here;
432
433 while (!IS_LAST_ENTRY(last)) {
434 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last);
435 if ((char *)next >= end)
436 goto bad_block;
437 if (!last->e_value_block && last->e_value_size) {
438 size_t offs = le16_to_cpu(last->e_value_offs);
439 if (offs < min_offs)
440 min_offs = offs;
441 }
442 last = next;
443 }
444
445
446 free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
447 } else {
448
449 free = sb->s_blocksize -
450 sizeof(struct ext2_xattr_header) - sizeof(__u32);
451 here = last = NULL;
452 }
453
454 if (not_found) {
455
456 error = -ENODATA;
457 if (flags & XATTR_REPLACE)
458 goto cleanup;
459 error = 0;
460 if (value == NULL)
461 goto cleanup;
462 } else {
463
464 error = -EEXIST;
465 if (flags & XATTR_CREATE)
466 goto cleanup;
467 if (!here->e_value_block && here->e_value_size) {
468 size_t size = le32_to_cpu(here->e_value_size);
469
470 if (le16_to_cpu(here->e_value_offs) + size >
471 sb->s_blocksize || size > sb->s_blocksize)
472 goto bad_block;
473 free += EXT2_XATTR_SIZE(size);
474 }
475 free += EXT2_XATTR_LEN(name_len);
476 }
477 error = -ENOSPC;
478 if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len))
479 goto cleanup;
480
481
482
483 if (header) {
484 struct mb_cache_entry *ce;
485
486
487 ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev,
488 bh->b_blocknr);
489 lock_buffer(bh);
490 if (header->h_refcount == cpu_to_le32(1)) {
491 ea_bdebug(bh, "modifying in-place");
492 if (ce)
493 mb_cache_entry_free(ce);
494
495 } else {
496 int offset;
497
498 if (ce)
499 mb_cache_entry_release(ce);
500 unlock_buffer(bh);
501 ea_bdebug(bh, "cloning");
502 header = kmalloc(bh->b_size, GFP_KERNEL);
503 error = -ENOMEM;
504 if (header == NULL)
505 goto cleanup;
506 memcpy(header, HDR(bh), bh->b_size);
507 header->h_refcount = cpu_to_le32(1);
508
509 offset = (char *)here - bh->b_data;
510 here = ENTRY((char *)header + offset);
511 offset = (char *)last - bh->b_data;
512 last = ENTRY((char *)header + offset);
513 }
514 } else {
515
516 header = kzalloc(sb->s_blocksize, GFP_KERNEL);
517 error = -ENOMEM;
518 if (header == NULL)
519 goto cleanup;
520 end = (char *)header + sb->s_blocksize;
521 header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC);
522 header->h_blocks = header->h_refcount = cpu_to_le32(1);
523 last = here = ENTRY(header+1);
524 }
525
526
527
528 if (not_found) {
529
530 size_t size = EXT2_XATTR_LEN(name_len);
531 size_t rest = (char *)last - (char *)here;
532 memmove((char *)here + size, here, rest);
533 memset(here, 0, size);
534 here->e_name_index = name_index;
535 here->e_name_len = name_len;
536 memcpy(here->e_name, name, name_len);
537 } else {
538 if (!here->e_value_block && here->e_value_size) {
539 char *first_val = (char *)header + min_offs;
540 size_t offs = le16_to_cpu(here->e_value_offs);
541 char *val = (char *)header + offs;
542 size_t size = EXT2_XATTR_SIZE(
543 le32_to_cpu(here->e_value_size));
544
545 if (size == EXT2_XATTR_SIZE(value_len)) {
546
547
548 here->e_value_size = cpu_to_le32(value_len);
549 memset(val + size - EXT2_XATTR_PAD, 0,
550 EXT2_XATTR_PAD);
551 memcpy(val, value, value_len);
552 goto skip_replace;
553 }
554
555
556 memmove(first_val + size, first_val, val - first_val);
557 memset(first_val, 0, size);
558 here->e_value_offs = 0;
559 min_offs += size;
560
561
562 last = ENTRY(header+1);
563 while (!IS_LAST_ENTRY(last)) {
564 size_t o = le16_to_cpu(last->e_value_offs);
565 if (!last->e_value_block && o < offs)
566 last->e_value_offs =
567 cpu_to_le16(o + size);
568 last = EXT2_XATTR_NEXT(last);
569 }
570 }
571 if (value == NULL) {
572
573 size_t size = EXT2_XATTR_LEN(name_len);
574 last = ENTRY((char *)last - size);
575 memmove(here, (char*)here + size,
576 (char*)last - (char*)here);
577 memset(last, 0, size);
578 }
579 }
580
581 if (value != NULL) {
582
583 here->e_value_size = cpu_to_le32(value_len);
584 if (value_len) {
585 size_t size = EXT2_XATTR_SIZE(value_len);
586 char *val = (char *)header + min_offs - size;
587 here->e_value_offs =
588 cpu_to_le16((char *)val - (char *)header);
589 memset(val + size - EXT2_XATTR_PAD, 0,
590 EXT2_XATTR_PAD);
591 memcpy(val, value, value_len);
592 }
593 }
594
595skip_replace:
596 if (IS_LAST_ENTRY(ENTRY(header+1))) {
597
598 if (bh && header == HDR(bh))
599 unlock_buffer(bh);
600 error = ext2_xattr_set2(inode, bh, NULL);
601 } else {
602 ext2_xattr_rehash(header, here);
603 if (bh && header == HDR(bh))
604 unlock_buffer(bh);
605 error = ext2_xattr_set2(inode, bh, header);
606 }
607
608cleanup:
609 brelse(bh);
610 if (!(bh && header == HDR(bh)))
611 kfree(header);
612 up_write(&EXT2_I(inode)->xattr_sem);
613
614 return error;
615}
616
617
618
619
620static int
621ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
622 struct ext2_xattr_header *header)
623{
624 struct super_block *sb = inode->i_sb;
625 struct buffer_head *new_bh = NULL;
626 int error;
627
628 if (header) {
629 new_bh = ext2_xattr_cache_find(inode, header);
630 if (new_bh) {
631
632 if (new_bh == old_bh) {
633 ea_bdebug(new_bh, "keeping this block");
634 } else {
635
636
637 ea_bdebug(new_bh, "reusing block");
638
639 error = dquot_alloc_block(inode, 1);
640 if (error) {
641 unlock_buffer(new_bh);
642 goto cleanup;
643 }
644 le32_add_cpu(&HDR(new_bh)->h_refcount, 1);
645 ea_bdebug(new_bh, "refcount now=%d",
646 le32_to_cpu(HDR(new_bh)->h_refcount));
647 }
648 unlock_buffer(new_bh);
649 } else if (old_bh && header == HDR(old_bh)) {
650
651
652 new_bh = old_bh;
653 get_bh(new_bh);
654 ext2_xattr_cache_insert(new_bh);
655 } else {
656
657 ext2_fsblk_t goal = ext2_group_first_block_no(sb,
658 EXT2_I(inode)->i_block_group);
659 int block = ext2_new_block(inode, goal, &error);
660 if (error)
661 goto cleanup;
662 ea_idebug(inode, "creating block %d", block);
663
664 new_bh = sb_getblk(sb, block);
665 if (unlikely(!new_bh)) {
666 ext2_free_blocks(inode, block, 1);
667 mark_inode_dirty(inode);
668 error = -ENOMEM;
669 goto cleanup;
670 }
671 lock_buffer(new_bh);
672 memcpy(new_bh->b_data, header, new_bh->b_size);
673 set_buffer_uptodate(new_bh);
674 unlock_buffer(new_bh);
675 ext2_xattr_cache_insert(new_bh);
676
677 ext2_xattr_update_super_block(sb);
678 }
679 mark_buffer_dirty(new_bh);
680 if (IS_SYNC(inode)) {
681 sync_dirty_buffer(new_bh);
682 error = -EIO;
683 if (buffer_req(new_bh) && !buffer_uptodate(new_bh))
684 goto cleanup;
685 }
686 }
687
688
689 EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
690 inode->i_ctime = CURRENT_TIME_SEC;
691 if (IS_SYNC(inode)) {
692 error = sync_inode_metadata(inode, 1);
693
694
695
696 if (error && error != -ENOSPC) {
697 if (new_bh && new_bh != old_bh) {
698 dquot_free_block_nodirty(inode, 1);
699 mark_inode_dirty(inode);
700 }
701 goto cleanup;
702 }
703 } else
704 mark_inode_dirty(inode);
705
706 error = 0;
707 if (old_bh && old_bh != new_bh) {
708 struct mb_cache_entry *ce;
709
710
711
712
713
714 ce = mb_cache_entry_get(ext2_xattr_cache, old_bh->b_bdev,
715 old_bh->b_blocknr);
716 lock_buffer(old_bh);
717 if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
718
719 if (ce)
720 mb_cache_entry_free(ce);
721 ea_bdebug(old_bh, "freeing");
722 ext2_free_blocks(inode, old_bh->b_blocknr, 1);
723 mark_inode_dirty(inode);
724
725
726 get_bh(old_bh);
727 bforget(old_bh);
728 } else {
729
730 le32_add_cpu(&HDR(old_bh)->h_refcount, -1);
731 if (ce)
732 mb_cache_entry_release(ce);
733 dquot_free_block_nodirty(inode, 1);
734 mark_inode_dirty(inode);
735 mark_buffer_dirty(old_bh);
736 ea_bdebug(old_bh, "refcount now=%d",
737 le32_to_cpu(HDR(old_bh)->h_refcount));
738 }
739 unlock_buffer(old_bh);
740 }
741
742cleanup:
743 brelse(new_bh);
744
745 return error;
746}
747
748
749
750
751
752
753
754void
755ext2_xattr_delete_inode(struct inode *inode)
756{
757 struct buffer_head *bh = NULL;
758 struct mb_cache_entry *ce;
759
760 down_write(&EXT2_I(inode)->xattr_sem);
761 if (!EXT2_I(inode)->i_file_acl)
762 goto cleanup;
763 bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
764 if (!bh) {
765 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
766 "inode %ld: block %d read error", inode->i_ino,
767 EXT2_I(inode)->i_file_acl);
768 goto cleanup;
769 }
770 ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
771 if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
772 HDR(bh)->h_blocks != cpu_to_le32(1)) {
773 ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
774 "inode %ld: bad block %d", inode->i_ino,
775 EXT2_I(inode)->i_file_acl);
776 goto cleanup;
777 }
778 ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev, bh->b_blocknr);
779 lock_buffer(bh);
780 if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
781 if (ce)
782 mb_cache_entry_free(ce);
783 ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1);
784 get_bh(bh);
785 bforget(bh);
786 unlock_buffer(bh);
787 } else {
788 le32_add_cpu(&HDR(bh)->h_refcount, -1);
789 if (ce)
790 mb_cache_entry_release(ce);
791 ea_bdebug(bh, "refcount now=%d",
792 le32_to_cpu(HDR(bh)->h_refcount));
793 unlock_buffer(bh);
794 mark_buffer_dirty(bh);
795 if (IS_SYNC(inode))
796 sync_dirty_buffer(bh);
797 dquot_free_block_nodirty(inode, 1);
798 }
799 EXT2_I(inode)->i_file_acl = 0;
800
801cleanup:
802 brelse(bh);
803 up_write(&EXT2_I(inode)->xattr_sem);
804}
805
806
807
808
809
810
811void
812ext2_xattr_put_super(struct super_block *sb)
813{
814 mb_cache_shrink(sb->s_bdev);
815}
816
817
818
819
820
821
822
823
824
825
826static int
827ext2_xattr_cache_insert(struct buffer_head *bh)
828{
829 __u32 hash = le32_to_cpu(HDR(bh)->h_hash);
830 struct mb_cache_entry *ce;
831 int error;
832
833 ce = mb_cache_entry_alloc(ext2_xattr_cache, GFP_NOFS);
834 if (!ce)
835 return -ENOMEM;
836 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
837 if (error) {
838 mb_cache_entry_free(ce);
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] (%d cache entries)", (int)hash,
846 atomic_read(&ext2_xattr_cache->c_entry_count));
847 mb_cache_entry_release(ce);
848 }
849 return error;
850}
851
852
853
854
855
856
857
858
859
860static int
861ext2_xattr_cmp(struct ext2_xattr_header *header1,
862 struct ext2_xattr_header *header2)
863{
864 struct ext2_xattr_entry *entry1, *entry2;
865
866 entry1 = ENTRY(header1+1);
867 entry2 = ENTRY(header2+1);
868 while (!IS_LAST_ENTRY(entry1)) {
869 if (IS_LAST_ENTRY(entry2))
870 return 1;
871 if (entry1->e_hash != entry2->e_hash ||
872 entry1->e_name_index != entry2->e_name_index ||
873 entry1->e_name_len != entry2->e_name_len ||
874 entry1->e_value_size != entry2->e_value_size ||
875 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
876 return 1;
877 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
878 return -EIO;
879 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
880 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
881 le32_to_cpu(entry1->e_value_size)))
882 return 1;
883
884 entry1 = EXT2_XATTR_NEXT(entry1);
885 entry2 = EXT2_XATTR_NEXT(entry2);
886 }
887 if (!IS_LAST_ENTRY(entry2))
888 return 1;
889 return 0;
890}
891
892
893
894
895
896
897
898
899
900static struct buffer_head *
901ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
902{
903 __u32 hash = le32_to_cpu(header->h_hash);
904 struct mb_cache_entry *ce;
905
906 if (!header->h_hash)
907 return NULL;
908 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
909again:
910 ce = mb_cache_entry_find_first(ext2_xattr_cache, inode->i_sb->s_bdev,
911 hash);
912 while (ce) {
913 struct buffer_head *bh;
914
915 if (IS_ERR(ce)) {
916 if (PTR_ERR(ce) == -EAGAIN)
917 goto again;
918 break;
919 }
920
921 bh = sb_bread(inode->i_sb, ce->e_block);
922 if (!bh) {
923 ext2_error(inode->i_sb, "ext2_xattr_cache_find",
924 "inode %ld: block %ld read error",
925 inode->i_ino, (unsigned long) ce->e_block);
926 } else {
927 lock_buffer(bh);
928 if (le32_to_cpu(HDR(bh)->h_refcount) >
929 EXT2_XATTR_REFCOUNT_MAX) {
930 ea_idebug(inode, "block %ld refcount %d>%d",
931 (unsigned long) ce->e_block,
932 le32_to_cpu(HDR(bh)->h_refcount),
933 EXT2_XATTR_REFCOUNT_MAX);
934 } else if (!ext2_xattr_cmp(header, HDR(bh))) {
935 ea_bdebug(bh, "b_count=%d",
936 atomic_read(&(bh->b_count)));
937 mb_cache_entry_release(ce);
938 return bh;
939 }
940 unlock_buffer(bh);
941 brelse(bh);
942 }
943 ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
944 }
945 return NULL;
946}
947
948#define NAME_HASH_SHIFT 5
949#define VALUE_HASH_SHIFT 16
950
951
952
953
954
955
956static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header,
957 struct ext2_xattr_entry *entry)
958{
959 __u32 hash = 0;
960 char *name = entry->e_name;
961 int n;
962
963 for (n=0; n < entry->e_name_len; n++) {
964 hash = (hash << NAME_HASH_SHIFT) ^
965 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
966 *name++;
967 }
968
969 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
970 __le32 *value = (__le32 *)((char *)header +
971 le16_to_cpu(entry->e_value_offs));
972 for (n = (le32_to_cpu(entry->e_value_size) +
973 EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) {
974 hash = (hash << VALUE_HASH_SHIFT) ^
975 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
976 le32_to_cpu(*value++);
977 }
978 }
979 entry->e_hash = cpu_to_le32(hash);
980}
981
982#undef NAME_HASH_SHIFT
983#undef VALUE_HASH_SHIFT
984
985#define BLOCK_HASH_SHIFT 16
986
987
988
989
990
991
992static void ext2_xattr_rehash(struct ext2_xattr_header *header,
993 struct ext2_xattr_entry *entry)
994{
995 struct ext2_xattr_entry *here;
996 __u32 hash = 0;
997
998 ext2_xattr_hash_entry(header, entry);
999 here = ENTRY(header+1);
1000 while (!IS_LAST_ENTRY(here)) {
1001 if (!here->e_hash) {
1002
1003 hash = 0;
1004 break;
1005 }
1006 hash = (hash << BLOCK_HASH_SHIFT) ^
1007 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1008 le32_to_cpu(here->e_hash);
1009 here = EXT2_XATTR_NEXT(here);
1010 }
1011 header->h_hash = cpu_to_le32(hash);
1012}
1013
1014#undef BLOCK_HASH_SHIFT
1015
1016int __init
1017init_ext2_xattr(void)
1018{
1019 ext2_xattr_cache = mb_cache_create("ext2_xattr", 6);
1020 if (!ext2_xattr_cache)
1021 return -ENOMEM;
1022 return 0;
1023}
1024
1025void
1026exit_ext2_xattr(void)
1027{
1028 mb_cache_destroy(ext2_xattr_cache);
1029}
1030