2 * Copyright (C) 2010 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
22 #include <sparse/sparse.h>
24 #include "ext4_utils/ext4_utils.h"
26 struct xattr_list_element {
27 struct ext4_inode *inode;
28 struct ext4_xattr_header *header;
29 struct xattr_list_element *next;
32 struct block_allocation *create_allocation()
34 struct block_allocation *alloc = malloc(sizeof(struct block_allocation));
35 alloc->list.first = NULL;
36 alloc->list.last = NULL;
37 alloc->oob_list.first = NULL;
38 alloc->oob_list.last = NULL;
39 alloc->list.iter = NULL;
40 alloc->list.partial_iter = 0;
41 alloc->oob_list.iter = NULL;
42 alloc->oob_list.partial_iter = 0;
43 alloc->filename = NULL;
48 static struct ext4_xattr_header *xattr_list_find(struct ext4_inode *inode)
50 struct xattr_list_element *element;
51 for (element = aux_info.xattrs; element != NULL; element = element->next) {
52 if (element->inode == inode)
53 return element->header;
58 static void xattr_list_insert(struct ext4_inode *inode, struct ext4_xattr_header *header)
60 struct xattr_list_element *element = malloc(sizeof(struct xattr_list_element));
61 element->inode = inode;
62 element->header = header;
63 element->next = aux_info.xattrs;
64 aux_info.xattrs = element;
67 static void region_list_remove(struct region_list *list, struct region *reg)
70 reg->prev->next = reg->next;
73 reg->next->prev = reg->prev;
75 if (list->first == reg)
76 list->first = reg->next;
78 if (list->last == reg)
79 list->last = reg->prev;
85 void region_list_append(struct region_list *list, struct region *reg)
87 if (list->first == NULL) {
91 list->partial_iter = 0;
94 list->last->next = reg;
95 reg->prev = list->last;
101 void region_list_merge(struct region_list *list1, struct region_list *list2)
103 if (list1->first == NULL) {
104 list1->first = list2->first;
105 list1->last = list2->last;
106 list1->iter = list2->first;
107 list1->partial_iter = 0;
108 list1->first->prev = NULL;
110 list1->last->next = list2->first;
111 list2->first->prev = list1->last;
112 list1->last = list2->last;
116 static void dump_starting_from(struct region *reg)
118 for (; reg; reg = reg->next) {
119 printf("%p: Blocks %d-%d (%d)\n", reg,
120 reg->block, reg->block + reg->len - 1, reg->len)
124 static void dump_region_lists(struct block_allocation *alloc) {
126 printf("Main list:\n");
127 dump_starting_from(alloc->list.first);
129 printf("OOB list:\n");
130 dump_starting_from(alloc->oob_list.first);
134 void print_blocks(FILE* f, struct block_allocation *alloc, char separator)
138 for (reg = alloc->list.first; reg; reg = reg->next) {
140 fprintf(f, "%d", reg->block);
142 fprintf(f, "%d-%d", reg->block, reg->block + reg->len - 1);
149 void append_region(struct block_allocation *alloc,
150 u32 block, u32 len, int bg_num)
153 reg = malloc(sizeof(struct region));
159 region_list_append(&alloc->list, reg);
162 static void allocate_bg_inode_table(struct block_group_info *bg)
164 if (bg->inode_table != NULL)
167 u32 block = bg->first_block + 2;
169 if (bg->has_superblock)
170 block += aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks + 1;
172 bg->inode_table = calloc(aux_info.inode_table_blocks, info.block_size);
173 if (bg->inode_table == NULL)
174 critical_error_errno("calloc");
176 sparse_file_add_data(ext4_sparse_file, bg->inode_table,
177 aux_info.inode_table_blocks * info.block_size, block);
179 bg->flags &= ~EXT4_BG_INODE_UNINIT;
182 static int bitmap_set_bit(u8 *bitmap, u32 bit)
184 if (bitmap[bit / 8] & 1 << (bit % 8))
187 bitmap[bit / 8] |= 1 << (bit % 8);
191 static int bitmap_set_8_bits(u8 *bitmap, u32 bit)
193 int ret = bitmap[bit / 8];
194 bitmap[bit / 8] = 0xFF;
198 /* Marks a the first num_blocks blocks in a block group as used, and accounts
199 for them in the block group free block info. */
200 static int reserve_blocks(struct block_group_info *bg, u32 bg_num, u32 start, u32 num)
205 for (i = 0; i < num && block % 8 != 0; i++, block++) {
206 if (bitmap_set_bit(bg->block_bitmap, block)) {
207 error("attempted to reserve already reserved block %d in block group %d", block, bg_num);
212 for (; i + 8 <= (num & ~7); i += 8, block += 8) {
213 if (bitmap_set_8_bits(bg->block_bitmap, block)) {
214 error("attempted to reserve already reserved block %d in block group %d", block, bg_num);
219 for (; i < num; i++, block++) {
220 if (bitmap_set_bit(bg->block_bitmap, block)) {
221 error("attempted to reserve already reserved block %d in block group %d", block, bg_num);
226 bg->free_blocks -= num;
231 static void free_blocks(struct block_group_info *bg, u32 block, u32 num_blocks)
234 for (i = 0; i < num_blocks; i++, block--)
235 bg->block_bitmap[block / 8] &= ~(1 << (block % 8));
236 bg->free_blocks += num_blocks;
239 /* Reduces an existing allocation by len blocks by return the last blocks
240 to the free pool in their block group. Assumes that the blocks being
241 returned were the last ones allocated out of the block group */
242 void reduce_allocation(struct block_allocation *alloc, u32 len)
245 struct region *last_reg = alloc->list.last;
246 struct block_group_info *bg = &aux_info.bgs[last_reg->bg];
248 if (last_reg->len > len) {
249 free_blocks(bg, last_reg->block + last_reg->len - bg->first_block - 1, len);
250 last_reg->len -= len;
253 struct region *reg = alloc->list.last->prev;
254 free_blocks(bg, last_reg->block + last_reg->len - bg->first_block - 1, last_reg->len);
255 len -= last_reg->len;
259 alloc->list.first = NULL;
260 alloc->list.last = NULL;
261 alloc->list.iter = NULL;
262 alloc->list.partial_iter = 0;
269 static void init_bg(struct block_group_info *bg, unsigned int i)
271 int header_blocks = 2 + aux_info.inode_table_blocks;
273 bg->has_superblock = ext4_bg_has_super_block(i);
275 if (bg->has_superblock)
276 header_blocks += 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
278 bg->bitmaps = calloc(info.block_size, 2);
279 bg->block_bitmap = bg->bitmaps;
280 bg->inode_bitmap = bg->bitmaps + info.block_size;
282 bg->header_blocks = header_blocks;
283 bg->first_block = aux_info.first_data_block + i * info.blocks_per_group;
285 u32 block = bg->first_block;
286 if (bg->has_superblock)
287 block += 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
288 sparse_file_add_data(ext4_sparse_file, bg->bitmaps, 2 * info.block_size,
291 bg->data_blocks_used = 0;
292 bg->free_blocks = info.blocks_per_group;
293 bg->free_inodes = info.inodes_per_group;
294 bg->first_free_inode = 1;
295 bg->flags = EXT4_BG_INODE_UNINIT;
298 bg->max_chunk_count = 1;
299 bg->chunks = (struct region*) calloc(bg->max_chunk_count, sizeof(struct region));
301 if (reserve_blocks(bg, i, 0, bg->header_blocks) < 0)
302 error("failed to reserve %u blocks in block group %u\n", bg->header_blocks, i);
303 // Add empty starting delimiter chunk
304 reserve_bg_chunk(i, bg->header_blocks, 0);
306 if (bg->first_block + info.blocks_per_group > aux_info.len_blocks) {
307 u32 overrun = bg->first_block + info.blocks_per_group - aux_info.len_blocks;
308 reserve_blocks(bg, i, info.blocks_per_group - overrun, overrun);
309 // Add empty ending delimiter chunk
310 reserve_bg_chunk(i, info.blocks_per_group - overrun, 0);
312 reserve_bg_chunk(i, info.blocks_per_group - 1, 0);
317 void block_allocator_init()
321 aux_info.bgs = calloc(sizeof(struct block_group_info), aux_info.groups);
322 if (aux_info.bgs == NULL)
323 critical_error_errno("calloc");
325 for (i = 0; i < aux_info.groups; i++)
326 init_bg(&aux_info.bgs[i], i);
329 void block_allocator_free()
333 for (i = 0; i < aux_info.groups; i++) {
334 free(aux_info.bgs[i].bitmaps);
335 free(aux_info.bgs[i].inode_table);
340 /* Allocate a single block and return its block number */
344 struct block_allocation *blk_alloc = allocate_blocks(1);
346 return EXT4_ALLOCATE_FAILED;
348 block = blk_alloc->list.first->block;
349 free_alloc(blk_alloc);
353 static struct region *ext4_allocate_best_fit_partial(u32 len)
357 unsigned int found_bg = 0, found_prev_chunk = 0, found_block = 0;
358 u32 found_allocate_len = 0;
359 bool minimize = false;
360 struct block_group_info *bgs = aux_info.bgs;
363 for (i = 0; i < aux_info.groups; i++) {
364 for (j = 1; j < bgs[i].chunk_count; j++) {
365 u32 hole_start, hole_size;
366 hole_start = bgs[i].chunks[j-1].block + bgs[i].chunks[j-1].len;
367 hole_size = bgs[i].chunks[j].block - hole_start;
368 if (hole_size == len) {
369 // Perfect fit i.e. right between 2 chunks no need to keep searching
371 found_prev_chunk = j - 1;
372 found_block = hole_start;
373 found_allocate_len = hole_size;
375 } else if (hole_size > len && (found_allocate_len == 0 || (found_allocate_len > hole_size))) {
377 found_prev_chunk = j - 1;
378 found_block = hole_start;
379 found_allocate_len = hole_size;
381 } else if (!minimize) {
382 if (found_allocate_len < hole_size) {
384 found_prev_chunk = j - 1;
385 found_block = hole_start;
386 found_allocate_len = hole_size;
392 if (found_allocate_len == 0) {
393 error("failed to allocate %u blocks, out of space?", len);
396 if (found_allocate_len > len) found_allocate_len = len;
398 // reclaim allocated space in chunk
399 bgs[found_bg].chunks[found_prev_chunk].len += found_allocate_len;
400 if (reserve_blocks(&bgs[found_bg],
403 found_allocate_len) < 0) {
404 error("failed to reserve %u blocks in block group %u\n", found_allocate_len, found_bg);
407 bgs[found_bg].data_blocks_used += found_allocate_len;
408 reg = malloc(sizeof(struct region));
409 reg->block = found_block + bgs[found_bg].first_block;
410 reg->len = found_allocate_len;
417 static struct region *ext4_allocate_best_fit(u32 len)
419 struct region *first_reg = NULL;
420 struct region *prev_reg = NULL;
424 reg = ext4_allocate_best_fit_partial(len);
428 if (first_reg == NULL)
432 prev_reg->next = reg;
433 reg->prev = prev_reg;
443 /* Allocate len blocks. The blocks may be spread across multiple block groups,
444 and are returned in a linked list of the blocks in each block group. The
445 allocation algorithm is:
446 1. If the remaining allocation is larger than any available contiguous region,
447 allocate the largest contiguous region and loop
448 2. Otherwise, allocate the smallest contiguous region that it fits in
450 struct block_allocation *allocate_blocks(u32 len)
452 struct region *reg = ext4_allocate_best_fit(len);
457 struct block_allocation *alloc = create_allocation();
458 alloc->list.first = reg;
459 while (reg->next != NULL)
461 alloc->list.last = reg;
462 alloc->list.iter = alloc->list.first;
463 alloc->list.partial_iter = 0;
467 /* Returns the number of discontiguous regions used by an allocation */
468 int block_allocation_num_regions(struct block_allocation *alloc)
471 struct region *reg = alloc->list.first;
473 for (i = 0; reg != NULL; reg = reg->next)
479 int block_allocation_len(struct block_allocation *alloc)
482 struct region *reg = alloc->list.first;
484 for (i = 0; reg != NULL; reg = reg->next)
490 /* Returns the block number of the block'th block in an allocation */
491 u32 get_block(struct block_allocation *alloc, u32 block)
493 struct region *reg = alloc->list.iter;
494 block += alloc->list.partial_iter;
496 for (; reg; reg = reg->next) {
497 if (block < reg->len)
498 return reg->block + block;
501 return EXT4_ALLOCATE_FAILED;
504 u32 get_oob_block(struct block_allocation *alloc, u32 block)
506 struct region *reg = alloc->oob_list.iter;
507 block += alloc->oob_list.partial_iter;
509 for (; reg; reg = reg->next) {
510 if (block < reg->len)
511 return reg->block + block;
514 return EXT4_ALLOCATE_FAILED;
517 /* Gets the starting block and length in blocks of the first region
519 void get_region(struct block_allocation *alloc, u32 *block, u32 *len)
521 *block = alloc->list.iter->block;
522 *len = alloc->list.iter->len - alloc->list.partial_iter;
525 /* Move to the next region in an allocation */
526 void get_next_region(struct block_allocation *alloc)
528 alloc->list.iter = alloc->list.iter->next;
529 alloc->list.partial_iter = 0;
532 /* Returns the number of free blocks in a block group */
533 u32 get_free_blocks(u32 bg)
535 return aux_info.bgs[bg].free_blocks;
538 int last_region(struct block_allocation *alloc)
540 return (alloc->list.iter == NULL);
543 void rewind_alloc(struct block_allocation *alloc)
545 alloc->list.iter = alloc->list.first;
546 alloc->list.partial_iter = 0;
549 static struct region *do_split_allocation(struct block_allocation *alloc, u32 len)
551 struct region *reg = alloc->list.iter;
555 while (reg && len >= reg->len) {
560 if (reg == NULL && len > 0)
564 new = malloc(sizeof(struct region));
567 new->block = reg->block + len;
568 new->len = reg->len - len;
569 new->next = reg->next;
575 tmp = alloc->list.iter;
576 alloc->list.iter = new;
583 /* Splits an allocation into two allocations. The returned allocation will
584 point to the first half, and the original allocation ptr will point to the
586 static struct region *split_allocation(struct block_allocation *alloc, u32 len)
588 /* First make sure there is a split at the current ptr */
589 do_split_allocation(alloc, alloc->list.partial_iter);
591 /* Then split off len blocks */
592 struct region *middle = do_split_allocation(alloc, len);
593 alloc->list.partial_iter = 0;
597 /* Reserve the next blocks for oob data (indirect or extent blocks) */
598 int reserve_oob_blocks(struct block_allocation *alloc, int blocks)
600 struct region *oob = split_allocation(alloc, blocks);
606 while (oob && oob != alloc->list.iter) {
608 region_list_remove(&alloc->list, oob);
609 region_list_append(&alloc->oob_list, oob);
616 static int advance_list_ptr(struct region_list *list, int blocks)
618 struct region *reg = list->iter;
620 while (reg != NULL && blocks > 0) {
621 if (reg->len > list->partial_iter + blocks) {
622 list->partial_iter += blocks;
626 blocks -= (reg->len - list->partial_iter);
627 list->partial_iter = 0;
637 /* Move the allocation pointer forward */
638 int advance_blocks(struct block_allocation *alloc, int blocks)
640 return advance_list_ptr(&alloc->list, blocks);
643 int advance_oob_blocks(struct block_allocation *alloc, int blocks)
645 return advance_list_ptr(&alloc->oob_list, blocks);
648 int append_oob_allocation(struct block_allocation *alloc, u32 len)
650 struct region *reg = ext4_allocate_best_fit(len);
653 error("failed to allocate %d blocks", len);
657 for (; reg; reg = reg->next)
658 region_list_append(&alloc->oob_list, reg);
663 /* Returns an ext4_inode structure for an inode number */
664 struct ext4_inode *get_inode(u32 inode)
667 int bg = inode / info.inodes_per_group;
668 inode %= info.inodes_per_group;
670 allocate_bg_inode_table(&aux_info.bgs[bg]);
671 return (struct ext4_inode *)(aux_info.bgs[bg].inode_table + inode *
675 struct ext4_xattr_header *get_xattr_block_for_inode(struct ext4_inode *inode)
677 struct ext4_xattr_header *block = xattr_list_find(inode);
681 u32 block_num = allocate_block();
682 block = calloc(info.block_size, 1);
684 error("get_xattr: failed to allocate %d", info.block_size);
688 block->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
689 block->h_refcount = cpu_to_le32(1);
690 block->h_blocks = cpu_to_le32(1);
691 inode->i_blocks_lo = cpu_to_le32(le32_to_cpu(inode->i_blocks_lo) + (info.block_size / 512));
692 inode->i_file_acl_lo = cpu_to_le32(block_num);
694 int result = sparse_file_add_data(ext4_sparse_file, block, info.block_size, block_num);
696 error("get_xattr: sparse_file_add_data failure %d", result);
700 xattr_list_insert(inode, block);
704 /* Mark the first len inodes in a block group as used */
705 u32 reserve_inodes(int bg, u32 num)
710 if (get_free_inodes(bg) < num)
711 return EXT4_ALLOCATE_FAILED;
713 for (i = 0; i < num; i++) {
714 inode = aux_info.bgs[bg].first_free_inode + i - 1;
715 aux_info.bgs[bg].inode_bitmap[inode / 8] |= 1 << (inode % 8);
718 inode = aux_info.bgs[bg].first_free_inode;
720 aux_info.bgs[bg].first_free_inode += num;
721 aux_info.bgs[bg].free_inodes -= num;
726 /* Returns the first free inode number
727 TODO: Inodes should be allocated in the block group of the data? */
733 for (bg = 0; bg < aux_info.groups; bg++) {
734 inode = reserve_inodes(bg, 1);
735 if (inode != EXT4_ALLOCATE_FAILED)
736 return bg * info.inodes_per_group + inode;
739 return EXT4_ALLOCATE_FAILED;
742 /* Returns the number of free inodes in a block group */
743 u32 get_free_inodes(u32 bg)
745 return aux_info.bgs[bg].free_inodes;
748 /* Increments the directory count of the block group that contains inode */
749 void add_directory(u32 inode)
751 int bg = (inode - 1) / info.inodes_per_group;
752 aux_info.bgs[bg].used_dirs += 1;
755 /* Returns the number of inodes in a block group that are directories */
756 u16 get_directories(int bg)
758 return aux_info.bgs[bg].used_dirs;
761 /* Returns the flags for a block group */
762 u16 get_bg_flags(int bg)
764 return aux_info.bgs[bg].flags;
767 /* Frees the memory used by a linked list of allocation regions */
768 void free_alloc(struct block_allocation *alloc)
772 reg = alloc->list.first;
774 struct region *next = reg->next;
779 reg = alloc->oob_list.first;
781 struct region *next = reg->next;
789 void reserve_bg_chunk(int bg, u32 start_block, u32 size) {
790 struct block_group_info *bgs = aux_info.bgs;
792 if (bgs[bg].chunk_count == bgs[bg].max_chunk_count) {
793 bgs[bg].max_chunk_count *= 2;
794 bgs[bg].chunks = realloc(bgs[bg].chunks, bgs[bg].max_chunk_count * sizeof(struct region));
796 critical_error("realloc failed");
798 chunk_count = bgs[bg].chunk_count;
799 bgs[bg].chunks[chunk_count].block = start_block;
800 bgs[bg].chunks[chunk_count].len = size;
801 bgs[bg].chunks[chunk_count].bg = bg;
802 bgs[bg].chunk_count++;
805 int reserve_blocks_for_allocation(struct block_allocation *alloc) {
807 struct block_group_info *bgs = aux_info.bgs;
809 if (!alloc) return 0;
810 reg = alloc->list.first;
811 while (reg != NULL) {
812 if (reserve_blocks(&bgs[reg->bg], reg->bg, reg->block - bgs[reg->bg].first_block, reg->len) < 0) {