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)
356 unsigned int found_bg = 0, found_prev_chunk = 0, found_block = 0;
357 u32 found_allocate_len = 0;
358 bool minimize = false;
359 struct block_group_info *bgs = aux_info.bgs;
362 for (i = 0; i < aux_info.groups; i++) {
363 for (j = 1; j < bgs[i].chunk_count; j++) {
364 u32 hole_start, hole_size;
365 hole_start = bgs[i].chunks[j-1].block + bgs[i].chunks[j-1].len;
366 hole_size = bgs[i].chunks[j].block - hole_start;
367 if (hole_size == len) {
368 // Perfect fit i.e. right between 2 chunks no need to keep searching
370 found_prev_chunk = j - 1;
371 found_block = hole_start;
372 found_allocate_len = hole_size;
374 } else if (hole_size > len && (found_allocate_len == 0 || (found_allocate_len > hole_size))) {
376 found_prev_chunk = j - 1;
377 found_block = hole_start;
378 found_allocate_len = hole_size;
380 } else if (!minimize) {
381 if (found_allocate_len < hole_size) {
383 found_prev_chunk = j - 1;
384 found_block = hole_start;
385 found_allocate_len = hole_size;
391 if (found_allocate_len == 0) {
392 error("failed to allocate %u blocks, out of space?", len);
395 if (found_allocate_len > len) found_allocate_len = len;
397 // reclaim allocated space in chunk
398 bgs[found_bg].chunks[found_prev_chunk].len += found_allocate_len;
399 if (reserve_blocks(&bgs[found_bg],
402 found_allocate_len) < 0) {
403 error("failed to reserve %u blocks in block group %u\n", found_allocate_len, found_bg);
406 bgs[found_bg].data_blocks_used += found_allocate_len;
407 reg = malloc(sizeof(struct region));
408 reg->block = found_block + bgs[found_bg].first_block;
409 reg->len = found_allocate_len;
416 static struct region *ext4_allocate_best_fit(u32 len)
418 struct region *first_reg = NULL;
419 struct region *prev_reg = NULL;
423 reg = ext4_allocate_best_fit_partial(len);
427 if (first_reg == NULL)
431 prev_reg->next = reg;
432 reg->prev = prev_reg;
442 /* Allocate len blocks. The blocks may be spread across multiple block groups,
443 and are returned in a linked list of the blocks in each block group. The
444 allocation algorithm is:
445 1. If the remaining allocation is larger than any available contiguous region,
446 allocate the largest contiguous region and loop
447 2. Otherwise, allocate the smallest contiguous region that it fits in
449 struct block_allocation *allocate_blocks(u32 len)
451 struct region *reg = ext4_allocate_best_fit(len);
456 struct block_allocation *alloc = create_allocation();
457 alloc->list.first = reg;
458 while (reg->next != NULL)
460 alloc->list.last = reg;
461 alloc->list.iter = alloc->list.first;
462 alloc->list.partial_iter = 0;
466 /* Returns the number of discontiguous regions used by an allocation */
467 int block_allocation_num_regions(struct block_allocation *alloc)
470 struct region *reg = alloc->list.first;
472 for (i = 0; reg != NULL; reg = reg->next)
478 int block_allocation_len(struct block_allocation *alloc)
481 struct region *reg = alloc->list.first;
483 for (i = 0; reg != NULL; reg = reg->next)
489 /* Returns the block number of the block'th block in an allocation */
490 u32 get_block(struct block_allocation *alloc, u32 block)
492 struct region *reg = alloc->list.iter;
493 block += alloc->list.partial_iter;
495 for (; reg; reg = reg->next) {
496 if (block < reg->len)
497 return reg->block + block;
500 return EXT4_ALLOCATE_FAILED;
503 u32 get_oob_block(struct block_allocation *alloc, u32 block)
505 struct region *reg = alloc->oob_list.iter;
506 block += alloc->oob_list.partial_iter;
508 for (; reg; reg = reg->next) {
509 if (block < reg->len)
510 return reg->block + block;
513 return EXT4_ALLOCATE_FAILED;
516 /* Gets the starting block and length in blocks of the first region
518 void get_region(struct block_allocation *alloc, u32 *block, u32 *len)
520 *block = alloc->list.iter->block;
521 *len = alloc->list.iter->len - alloc->list.partial_iter;
524 /* Move to the next region in an allocation */
525 void get_next_region(struct block_allocation *alloc)
527 alloc->list.iter = alloc->list.iter->next;
528 alloc->list.partial_iter = 0;
531 /* Returns the number of free blocks in a block group */
532 u32 get_free_blocks(u32 bg)
534 return aux_info.bgs[bg].free_blocks;
537 int last_region(struct block_allocation *alloc)
539 return (alloc->list.iter == NULL);
542 void rewind_alloc(struct block_allocation *alloc)
544 alloc->list.iter = alloc->list.first;
545 alloc->list.partial_iter = 0;
548 static struct region *do_split_allocation(struct block_allocation *alloc, u32 len)
550 struct region *reg = alloc->list.iter;
554 while (reg && len >= reg->len) {
559 if (reg == NULL && len > 0)
563 new = malloc(sizeof(struct region));
566 new->block = reg->block + len;
567 new->len = reg->len - len;
568 new->next = reg->next;
574 tmp = alloc->list.iter;
575 alloc->list.iter = new;
582 /* Splits an allocation into two allocations. The returned allocation will
583 point to the first half, and the original allocation ptr will point to the
585 static struct region *split_allocation(struct block_allocation *alloc, u32 len)
587 /* First make sure there is a split at the current ptr */
588 do_split_allocation(alloc, alloc->list.partial_iter);
590 /* Then split off len blocks */
591 struct region *middle = do_split_allocation(alloc, len);
592 alloc->list.partial_iter = 0;
596 /* Reserve the next blocks for oob data (indirect or extent blocks) */
597 int reserve_oob_blocks(struct block_allocation *alloc, int blocks)
599 struct region *oob = split_allocation(alloc, blocks);
605 while (oob && oob != alloc->list.iter) {
607 region_list_remove(&alloc->list, oob);
608 region_list_append(&alloc->oob_list, oob);
615 static int advance_list_ptr(struct region_list *list, int blocks)
617 struct region *reg = list->iter;
619 while (reg != NULL && blocks > 0) {
620 if (reg->len > list->partial_iter + blocks) {
621 list->partial_iter += blocks;
625 blocks -= (reg->len - list->partial_iter);
626 list->partial_iter = 0;
636 /* Move the allocation pointer forward */
637 int advance_blocks(struct block_allocation *alloc, int blocks)
639 return advance_list_ptr(&alloc->list, blocks);
642 int advance_oob_blocks(struct block_allocation *alloc, int blocks)
644 return advance_list_ptr(&alloc->oob_list, blocks);
647 int append_oob_allocation(struct block_allocation *alloc, u32 len)
649 struct region *reg = ext4_allocate_best_fit(len);
652 error("failed to allocate %d blocks", len);
656 for (; reg; reg = reg->next)
657 region_list_append(&alloc->oob_list, reg);
662 /* Returns an ext4_inode structure for an inode number */
663 struct ext4_inode *get_inode(u32 inode)
666 int bg = inode / info.inodes_per_group;
667 inode %= info.inodes_per_group;
669 allocate_bg_inode_table(&aux_info.bgs[bg]);
670 return (struct ext4_inode *)(aux_info.bgs[bg].inode_table + inode *
674 struct ext4_xattr_header *get_xattr_block_for_inode(struct ext4_inode *inode)
676 struct ext4_xattr_header *block = xattr_list_find(inode);
680 u32 block_num = allocate_block();
681 block = calloc(info.block_size, 1);
683 error("get_xattr: failed to allocate %d", info.block_size);
687 block->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
688 block->h_refcount = cpu_to_le32(1);
689 block->h_blocks = cpu_to_le32(1);
690 inode->i_blocks_lo = cpu_to_le32(le32_to_cpu(inode->i_blocks_lo) + (info.block_size / 512));
691 inode->i_file_acl_lo = cpu_to_le32(block_num);
693 int result = sparse_file_add_data(ext4_sparse_file, block, info.block_size, block_num);
695 error("get_xattr: sparse_file_add_data failure %d", result);
699 xattr_list_insert(inode, block);
703 /* Mark the first len inodes in a block group as used */
704 u32 reserve_inodes(int bg, u32 num)
709 if (get_free_inodes(bg) < num)
710 return EXT4_ALLOCATE_FAILED;
712 for (i = 0; i < num; i++) {
713 inode = aux_info.bgs[bg].first_free_inode + i - 1;
714 aux_info.bgs[bg].inode_bitmap[inode / 8] |= 1 << (inode % 8);
717 inode = aux_info.bgs[bg].first_free_inode;
719 aux_info.bgs[bg].first_free_inode += num;
720 aux_info.bgs[bg].free_inodes -= num;
725 /* Returns the first free inode number
726 TODO: Inodes should be allocated in the block group of the data? */
732 for (bg = 0; bg < aux_info.groups; bg++) {
733 inode = reserve_inodes(bg, 1);
734 if (inode != EXT4_ALLOCATE_FAILED)
735 return bg * info.inodes_per_group + inode;
738 return EXT4_ALLOCATE_FAILED;
741 /* Returns the number of free inodes in a block group */
742 u32 get_free_inodes(u32 bg)
744 return aux_info.bgs[bg].free_inodes;
747 /* Increments the directory count of the block group that contains inode */
748 void add_directory(u32 inode)
750 int bg = (inode - 1) / info.inodes_per_group;
751 aux_info.bgs[bg].used_dirs += 1;
754 /* Returns the number of inodes in a block group that are directories */
755 u16 get_directories(int bg)
757 return aux_info.bgs[bg].used_dirs;
760 /* Returns the flags for a block group */
761 u16 get_bg_flags(int bg)
763 return aux_info.bgs[bg].flags;
766 /* Frees the memory used by a linked list of allocation regions */
767 void free_alloc(struct block_allocation *alloc)
771 reg = alloc->list.first;
773 struct region *next = reg->next;
778 reg = alloc->oob_list.first;
780 struct region *next = reg->next;
788 void reserve_bg_chunk(int bg, u32 start_block, u32 size) {
789 struct block_group_info *bgs = aux_info.bgs;
791 if (bgs[bg].chunk_count == bgs[bg].max_chunk_count) {
792 bgs[bg].max_chunk_count *= 2;
793 bgs[bg].chunks = realloc(bgs[bg].chunks, bgs[bg].max_chunk_count * sizeof(struct region));
795 critical_error("realloc failed");
797 chunk_count = bgs[bg].chunk_count;
798 bgs[bg].chunks[chunk_count].block = start_block;
799 bgs[bg].chunks[chunk_count].len = size;
800 bgs[bg].chunks[chunk_count].bg = bg;
801 bgs[bg].chunk_count++;
804 int reserve_blocks_for_allocation(struct block_allocation *alloc) {
806 struct block_group_info *bgs = aux_info.bgs;
808 if (!alloc) return 0;
809 reg = alloc->list.first;
810 while (reg != NULL) {
811 if (reserve_blocks(&bgs[reg->bg], reg->bg, reg->block - bgs[reg->bg].first_block, reg->len) < 0) {