2 * Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
3 * Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com)
7 * Copyright (c) 2012 Martin Sucha
8 * Copyright (c) 2012 Frantisek Princ
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
15 * - Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * - Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * - The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 /** @addtogroup lwext4
40 * @brief Extended Attribute manipulation.
43 #include "ext4_config.h"
44 #include "ext4_types.h"
46 #include "ext4_errno.h"
47 #include "ext4_blockdev.h"
48 #include "ext4_super.h"
49 #include "ext4_debug.h"
50 #include "ext4_block_group.h"
51 #include "ext4_balloc.h"
52 #include "ext4_inode.h"
53 #include "ext4_extent.h"
60 * @brief Extended Attribute Manipulation
63 #define NAME_HASH_SHIFT 5
64 #define VALUE_HASH_SHIFT 16
67 ext4_xattr_compute_hash(struct ext4_xattr_header *header,
68 struct ext4_xattr_entry *entry)
71 char *name = EXT4_XATTR_NAME(entry);
74 for (n = 0; n < entry->e_name_len; n++) {
75 hash = (hash << NAME_HASH_SHIFT) ^
76 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
80 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
81 uint32_t *value = (uint32_t *)((char *)header +
82 to_le16(entry->e_value_offs));
83 for (n = (to_le32(entry->e_value_size) +
84 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
85 hash = (hash << VALUE_HASH_SHIFT) ^
86 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
90 entry->e_hash = to_le32(hash);
93 #define BLOCK_HASH_SHIFT 16
98 * Re-compute the extended attribute hash value after an entry has changed.
100 static void ext4_xattr_rehash(struct ext4_xattr_header *header,
101 struct ext4_xattr_entry *entry)
103 struct ext4_xattr_entry *here;
106 ext4_xattr_compute_hash(header, entry);
107 here = EXT4_XATTR_ENTRY(header+1);
108 while (!EXT4_XATTR_IS_LAST_ENTRY(here)) {
110 /* Block is not shared if an entry's hash value == 0 */
114 hash = (hash << BLOCK_HASH_SHIFT) ^
115 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
116 to_le32(here->e_hash);
117 here = EXT4_XATTR_NEXT(here);
119 header->h_hash = to_le32(hash);
122 static int ext4_xattr_item_cmp(struct ext4_xattr_item *a,
123 struct ext4_xattr_item *b)
126 result = a->name_index - b->name_index;
130 result = a->name_len - b->name_len;
134 return memcmp(a->name, b->name, a->name_len);
137 RB_GENERATE_INTERNAL(ext4_xattr_tree,
143 static struct ext4_xattr_item *
144 ext4_xattr_item_alloc(uint8_t name_index,
148 struct ext4_xattr_item *item;
149 item = malloc(sizeof(struct ext4_xattr_item) +
154 item->name_index = name_index;
155 item->name = (char *)(item + 1);
156 item->name_len = name_len;
160 memset(&item->node, 0, sizeof(item->node));
161 memcpy(item->name, name, name_len);
167 ext4_xattr_item_alloc_data(struct ext4_xattr_item *item,
172 ext4_assert(!item->data);
173 data = malloc(data_size);
178 memcpy(data, orig_data, data_size);
181 item->data_size = data_size;
186 ext4_xattr_item_free_data(struct ext4_xattr_item *item)
188 ext4_assert(item->data);
195 ext4_xattr_item_resize_data(struct ext4_xattr_item *item,
196 size_t new_data_size)
198 if (new_data_size != item->data_size) {
200 new_data = realloc(item->data, new_data_size);
204 item->data = new_data;
205 item->data_size = new_data_size;
211 ext4_xattr_item_free(struct ext4_xattr_item *item)
214 ext4_xattr_item_free_data(item);
220 static void *ext4_xattr_entry_data(struct ext4_xattr_ref *xattr_ref,
221 struct ext4_xattr_entry *entry,
226 struct ext4_xattr_ibody_header *header;
227 struct ext4_xattr_entry *first_entry;
228 uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
230 header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
231 first_entry = EXT4_XATTR_IFIRST(header);
233 ret = (void *)((char *)first_entry + to_le16(entry->e_value_offs));
234 if ((char *)ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size))
235 - (char *)xattr_ref->inode_ref->inode >
240 uint32_t block_size =
241 ext4_sb_get_block_size(&xattr_ref->fs->sb);
242 ret = (void *)((char *)xattr_ref->block.data +
243 to_le16(entry->e_value_offs));
244 if ((char *)ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size))
245 - (char *)xattr_ref->block.data >
252 static int ext4_xattr_block_fetch(struct ext4_xattr_ref *xattr_ref)
257 struct ext4_xattr_entry *entry = NULL;
259 ext4_assert(xattr_ref->block.data);
260 entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
262 size_rem = ext4_sb_get_block_size(&xattr_ref->fs->sb);
263 for(;size_rem > 0 && !EXT4_XATTR_IS_LAST_ENTRY(entry);
264 entry = EXT4_XATTR_NEXT(entry),
265 size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
266 struct ext4_xattr_item *item;
267 char *e_name = EXT4_XATTR_NAME(entry);
269 data = ext4_xattr_entry_data(xattr_ref, entry,
276 item = ext4_xattr_item_alloc(entry->e_name_index,
278 (size_t)entry->e_name_len);
283 if (ext4_xattr_item_alloc_data(item,
285 to_le32(entry->e_value_size))
287 ext4_xattr_item_free(item);
291 RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
292 xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
293 EXT4_XATTR_LEN(item->name_len);
300 static int ext4_xattr_inode_fetch(struct ext4_xattr_ref *xattr_ref)
305 struct ext4_xattr_ibody_header *header = NULL;
306 struct ext4_xattr_entry *entry = NULL;
307 uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
310 header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
311 entry = EXT4_XATTR_IFIRST(header);
313 size_rem = inode_size -
314 EXT4_GOOD_OLD_INODE_SIZE -
315 xattr_ref->inode_ref->inode->extra_isize;
316 for(;size_rem > 0 && !EXT4_XATTR_IS_LAST_ENTRY(entry);
317 entry = EXT4_XATTR_NEXT(entry),
318 size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
319 struct ext4_xattr_item *item;
320 char *e_name = EXT4_XATTR_NAME(entry);
322 data = ext4_xattr_entry_data(xattr_ref, entry,
329 item = ext4_xattr_item_alloc(entry->e_name_index,
331 (size_t)entry->e_name_len);
336 if (ext4_xattr_item_alloc_data(item,
338 to_le32(entry->e_value_size))
340 ext4_xattr_item_free(item);
344 RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
345 xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
346 EXT4_XATTR_LEN(item->name_len);
355 ext4_xattr_inode_space(struct ext4_xattr_ref *xattr_ref)
357 uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
359 uint16_t size_rem = inode_size -
360 EXT4_GOOD_OLD_INODE_SIZE -
361 xattr_ref->inode_ref->inode->extra_isize;
366 ext4_xattr_block_space(struct ext4_xattr_ref *xattr_ref)
368 return ext4_sb_get_block_size(&xattr_ref->fs->sb);
371 static int ext4_xattr_fetch(struct ext4_xattr_ref *xattr_ref)
374 uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
376 if (inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
377 ret = ext4_xattr_inode_fetch(xattr_ref);
383 if (xattr_ref->block_loaded)
384 ret = ext4_xattr_block_fetch(xattr_ref);
386 xattr_ref->dirty = false;
390 static struct ext4_xattr_item *
391 ext4_xattr_lookup_item(struct ext4_xattr_ref *xattr_ref,
396 struct ext4_xattr_item tmp, *ret;
397 tmp.name_index = name_index;
399 tmp.name_len = name_len;
400 ret = RB_FIND(ext4_xattr_tree, &xattr_ref->root,
405 static struct ext4_xattr_item *
406 ext4_xattr_insert_item(struct ext4_xattr_ref *xattr_ref,
413 struct ext4_xattr_item *item;
414 item = ext4_xattr_item_alloc(name_index,
420 if (xattr_ref->ea_size + EXT4_XATTR_SIZE(item->data_size) +
421 EXT4_XATTR_LEN(item->name_len) >
422 ext4_xattr_inode_space(xattr_ref) +
423 ext4_xattr_block_space(xattr_ref)) {
424 ext4_xattr_item_free(item);
427 if (ext4_xattr_item_alloc_data(item,
430 ext4_xattr_item_free(item);
433 RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
434 xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
435 EXT4_XATTR_LEN(item->name_len);
436 xattr_ref->dirty = true;
441 ext4_xattr_remove_item(struct ext4_xattr_ref *xattr_ref,
447 struct ext4_xattr_item *item =
448 ext4_xattr_lookup_item(xattr_ref,
453 RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
454 ext4_xattr_item_free(item);
455 xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
456 EXT4_XATTR_LEN(item->name_len);
457 xattr_ref->dirty = true;
464 ext4_xattr_resize_item(struct ext4_xattr_ref *xattr_ref,
465 struct ext4_xattr_item *item,
466 size_t new_data_size)
469 if (xattr_ref->ea_size - EXT4_XATTR_SIZE(item->data_size) +
470 EXT4_XATTR_SIZE(new_data_size) >
471 ext4_xattr_inode_space(xattr_ref) +
472 ext4_xattr_block_space(xattr_ref)) {
476 ret = ext4_xattr_item_resize_data(item,
481 xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
482 EXT4_XATTR_SIZE(new_data_size);
483 xattr_ref->dirty = true;
488 ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref)
490 struct ext4_xattr_item *item, *save_item;
491 RB_FOREACH_SAFE(item,
495 RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
496 ext4_xattr_item_free(item);
498 xattr_ref->ea_size = sizeof(struct ext4_xattr_header) +
499 sizeof(struct ext4_xattr_ibody_header);
504 ext4_xattr_try_alloc_block(struct ext4_xattr_ref *xattr_ref)
508 uint64_t xattr_block;
509 xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
512 ret = ext4_balloc_alloc_block(xattr_ref->inode_ref,
513 (uint32_t *)&xattr_block);
517 ret = ext4_block_get(xattr_ref->fs->bdev,
521 ext4_balloc_free_block(xattr_ref->inode_ref,
526 ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
529 xattr_ref->inode_ref->dirty = true;
530 xattr_ref->block_loaded = true;
531 xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
539 ext4_xattr_try_free_block(struct ext4_xattr_ref *xattr_ref)
541 uint64_t xattr_block;
543 ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
545 ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
548 ext4_block_set(xattr_ref->fs->bdev,
550 ext4_balloc_free_block(xattr_ref->inode_ref,
552 xattr_ref->inode_ref->dirty = true;
553 xattr_ref->block_loaded = false;
554 xattr_ref->ea_size -= sizeof(struct ext4_xattr_header);
559 ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
562 bool block_modified = false;
563 void *ibody_data, *block_data;
564 struct ext4_xattr_item *item, *save_item;
565 size_t inode_size_rem, block_size_rem;
566 struct ext4_xattr_header *header = NULL;
567 struct ext4_xattr_ibody_header *ibody_header = NULL;
568 struct ext4_xattr_entry *entry = NULL;
569 struct ext4_xattr_entry *block_entry = NULL;
571 inode_size_rem = ext4_xattr_inode_space(xattr_ref);
572 block_size_rem = ext4_xattr_block_space(xattr_ref);
573 if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
574 ibody_header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
575 entry = EXT4_XATTR_IFIRST(ibody_header);
578 if (xattr_ref->dirty) {
579 /* If there are enough spaces in the ibody EA table.*/
580 if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
581 memset(ibody_header, 0, inode_size_rem);
582 ibody_header->h_magic = EXT4_XATTR_MAGIC;
583 xattr_ref->inode_ref->dirty = true;
584 ibody_data = (char *)ibody_header + inode_size_rem;
585 inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
587 /* If we need an extra block to hold the EA entries*/
588 if (xattr_ref->ea_size > inode_size_rem) {
589 if (!xattr_ref->block_loaded) {
590 ret = ext4_xattr_try_alloc_block(xattr_ref);
595 header = EXT4_XATTR_BHDR(&xattr_ref->block);
596 block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
597 memset(header, 0, sizeof(struct ext4_xattr_header));
598 header->h_magic = EXT4_XATTR_MAGIC;
599 header->h_refcount = to_le32(1);
600 header->h_blocks = to_le32(1);
601 block_data = (char *)header + block_size_rem;
602 block_size_rem -= sizeof(struct ext4_xattr_header);
603 xattr_ref->block.dirty = true;
605 /* We don't need an extra block.*/
606 if (xattr_ref->block_loaded) {
607 header = EXT4_XATTR_BHDR(&xattr_ref->block);
609 to_le32(to_le32(header->h_refcount) - 1);
610 if (!header->h_refcount) {
611 ext4_xattr_try_free_block(xattr_ref);
614 xattr_ref->block.dirty = true;
615 block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
616 block_data = (char *)header + block_size_rem;
617 block_size_rem -= sizeof(struct ext4_xattr_header);
621 RB_FOREACH_SAFE(item,
625 if (EXT4_XATTR_SIZE(item->data_size) +
626 EXT4_XATTR_LEN(item->name_len) <=
628 ibody_data = (char *)ibody_data - EXT4_XATTR_SIZE(item->data_size);
629 entry->e_name_len = to_le32(item->name_len);
630 entry->e_name_index = item->name_index;
631 entry->e_value_offs =
633 (char *)EXT4_XATTR_IFIRST(ibody_header);
634 entry->e_value_block = 0;
635 entry->e_value_size = item->data_size;
636 memcpy(EXT4_XATTR_NAME(entry), item->name, item->name_len);
637 memcpy(ibody_data, item->data, item->data_size);
638 entry = EXT4_XATTR_NEXT(entry);
640 EXT4_XATTR_SIZE(item->data_size) +
641 EXT4_XATTR_LEN(item->name_len);
644 if (EXT4_XATTR_SIZE(item->data_size) +
645 EXT4_XATTR_LEN(item->name_len) > block_size_rem) {
649 block_data = (char *)block_data - EXT4_XATTR_SIZE(item->data_size);
650 block_entry->e_name_len = to_le32(item->name_len);
651 block_entry->e_name_index = item->name_index;
652 block_entry->e_value_offs =
653 (char *)block_data - (char *)header;
654 block_entry->e_value_block = 0;
655 block_entry->e_value_size = item->data_size;
656 memcpy(EXT4_XATTR_NAME(block_entry), item->name, item->name_len);
657 memcpy(block_data, item->data, item->data_size);
658 block_entry = EXT4_XATTR_NEXT(block_entry);
660 EXT4_XATTR_SIZE(item->data_size) +
661 EXT4_XATTR_LEN(item->name_len);
662 block_modified = true;
664 xattr_ref->dirty = false;
665 if (block_modified) {
666 ext4_xattr_rehash(header,
667 EXT4_XATTR_BFIRST(&xattr_ref->block));
676 int ext4_fs_set_xattr(struct ext4_xattr_ref *ref,
685 struct ext4_xattr_item *item =
686 ext4_xattr_lookup_item(ref,
695 if (item->data_size != data_size)
696 ret = ext4_xattr_resize_item(ref,
703 memcpy(item->data, data, data_size);
709 item = ext4_xattr_insert_item(ref,
723 int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref,
728 return ext4_xattr_remove_item(ref,
734 int ext4_fs_get_xattr(struct ext4_xattr_ref *ref,
743 size_t item_size = 0;
744 struct ext4_xattr_item *item =
745 ext4_xattr_lookup_item(ref,
754 item_size = item->data_size;
755 if (buf_size > item_size)
756 buf_size = item_size;
759 memcpy(buf, item->data, buf_size);
763 *size_got = buf_size;
768 int ext4_fs_get_xattr_ref(struct ext4_fs *fs,
769 struct ext4_inode_ref *inode_ref,
770 struct ext4_xattr_ref *ref)
773 uint64_t xattr_block;
774 xattr_block = ext4_inode_get_file_acl(inode_ref->inode,
779 rc = ext4_block_get(fs->bdev,
780 &inode_ref->block, xattr_block);
784 ref->ea_size += sizeof(struct ext4_xattr_header);
785 ref->block_loaded = true;
787 ref->block_loaded = false;
789 ref->inode_ref = inode_ref;
792 if (ext4_xattr_inode_space(ref) >
793 sizeof(struct ext4_xattr_ibody_header))
794 ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
796 rc = ext4_xattr_fetch(ref);
798 ext4_xattr_purge_items(ref);
800 ext4_block_set(fs->bdev, &inode_ref->block);
802 ref->block_loaded = false;
808 void ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref)
810 if (ref->block_loaded) {
811 ext4_block_set(ref->fs->bdev, &ref->block);
812 ref->block_loaded = false;
814 ext4_xattr_write_to_disk(ref);
815 ext4_xattr_purge_items(ref);
816 ref->inode_ref = NULL;