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)
237 for (i = 0; i < num_blocks; i++, block--)
238 bg->block_bitmap[block / 8] &= ~(1 << (block % 8));
239 bg->free_blocks += num_blocks;
241 for (i = bg->chunk_count; i > 0 ;) {
243 if (bg->chunks[i].len >= num_blocks && bg->chunks[i].block <= block) {
244 if (bg->chunks[i].block == block) {
245 bg->chunks[i].block += num_blocks;
246 bg->chunks[i].len -= num_blocks;
247 } else if (bg->chunks[i].block + bg->chunks[i].len == block + num_blocks) {
248 bg->chunks[i].len -= num_blocks;
255 /* Reduces an existing allocation by len blocks by return the last blocks
256 to the free pool in their block group. Assumes that the blocks being
257 returned were the last ones allocated out of the block group */
258 void reduce_allocation(struct block_allocation *alloc, u32 len)
261 struct region *last_reg = alloc->list.last;
262 struct block_group_info *bg = &aux_info.bgs[last_reg->bg];
264 if (last_reg->len > len) {
265 free_blocks(bg, last_reg->block + last_reg->len - bg->first_block - 1, len);
266 last_reg->len -= len;
269 struct region *reg = alloc->list.last->prev;
270 free_blocks(bg, last_reg->block + last_reg->len - bg->first_block - 1, last_reg->len);
271 len -= last_reg->len;
275 alloc->list.first = NULL;
276 alloc->list.last = NULL;
277 alloc->list.iter = NULL;
278 alloc->list.partial_iter = 0;
285 static void init_bg(struct block_group_info *bg, unsigned int i)
287 int header_blocks = 2 + aux_info.inode_table_blocks;
289 bg->has_superblock = ext4_bg_has_super_block(i);
291 if (bg->has_superblock)
292 header_blocks += 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
294 bg->bitmaps = calloc(info.block_size, 2);
295 bg->block_bitmap = bg->bitmaps;
296 bg->inode_bitmap = bg->bitmaps + info.block_size;
298 bg->header_blocks = header_blocks;
299 bg->first_block = aux_info.first_data_block + i * info.blocks_per_group;
301 u32 block = bg->first_block;
302 if (bg->has_superblock)
303 block += 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
304 sparse_file_add_data(ext4_sparse_file, bg->bitmaps, 2 * info.block_size,
307 bg->data_blocks_used = 0;
308 bg->free_blocks = info.blocks_per_group;
309 bg->free_inodes = info.inodes_per_group;
310 bg->first_free_inode = 1;
311 bg->flags = EXT4_BG_INODE_UNINIT;
314 bg->max_chunk_count = 1;
315 bg->chunks = (struct region*) calloc(bg->max_chunk_count, sizeof(struct region));
317 if (reserve_blocks(bg, i, 0, bg->header_blocks) < 0)
318 error("failed to reserve %u blocks in block group %u\n", bg->header_blocks, i);
319 // Add empty starting delimiter chunk
320 reserve_bg_chunk(i, bg->header_blocks, 0);
322 if (bg->first_block + info.blocks_per_group > aux_info.len_blocks) {
323 u32 overrun = bg->first_block + info.blocks_per_group - aux_info.len_blocks;
324 reserve_blocks(bg, i, info.blocks_per_group - overrun, overrun);
325 // Add empty ending delimiter chunk
326 reserve_bg_chunk(i, info.blocks_per_group - overrun, 0);
328 reserve_bg_chunk(i, info.blocks_per_group - 1, 0);
333 void block_allocator_init()
337 aux_info.bgs = calloc(sizeof(struct block_group_info), aux_info.groups);
338 if (aux_info.bgs == NULL)
339 critical_error_errno("calloc");
341 for (i = 0; i < aux_info.groups; i++)
342 init_bg(&aux_info.bgs[i], i);
345 void block_allocator_free()
349 for (i = 0; i < aux_info.groups; i++) {
350 free(aux_info.bgs[i].bitmaps);
351 free(aux_info.bgs[i].inode_table);
356 /* Allocate a single block and return its block number */
360 struct block_allocation *blk_alloc = allocate_blocks(1);
362 return EXT4_ALLOCATE_FAILED;
364 block = blk_alloc->list.first->block;
365 free_alloc(blk_alloc);
369 static struct region *ext4_allocate_best_fit_partial(u32 len)
373 unsigned int found_bg = 0, found_prev_chunk = 0, found_block = 0;
374 u32 found_allocate_len = 0;
375 bool minimize = false;
376 struct block_group_info *bgs = aux_info.bgs;
379 for (i = 0; i < aux_info.groups; i++) {
380 for (j = 1; j < bgs[i].chunk_count; j++) {
381 u32 hole_start, hole_size;
382 hole_start = bgs[i].chunks[j-1].block + bgs[i].chunks[j-1].len;
383 hole_size = bgs[i].chunks[j].block - hole_start;
384 if (hole_size == len) {
385 // Perfect fit i.e. right between 2 chunks no need to keep searching
387 found_prev_chunk = j - 1;
388 found_block = hole_start;
389 found_allocate_len = hole_size;
391 } else if (hole_size > len && (found_allocate_len == 0 || (found_allocate_len > hole_size))) {
393 found_prev_chunk = j - 1;
394 found_block = hole_start;
395 found_allocate_len = hole_size;
397 } else if (!minimize) {
398 if (found_allocate_len < hole_size) {
400 found_prev_chunk = j - 1;
401 found_block = hole_start;
402 found_allocate_len = hole_size;
408 if (found_allocate_len == 0) {
409 error("failed to allocate %u blocks, out of space?", len);
412 if (found_allocate_len > len) found_allocate_len = len;
414 // reclaim allocated space in chunk
415 bgs[found_bg].chunks[found_prev_chunk].len += found_allocate_len;
416 if (reserve_blocks(&bgs[found_bg],
419 found_allocate_len) < 0) {
420 error("failed to reserve %u blocks in block group %u\n", found_allocate_len, found_bg);
423 bgs[found_bg].data_blocks_used += found_allocate_len;
424 reg = malloc(sizeof(struct region));
425 reg->block = found_block + bgs[found_bg].first_block;
426 reg->len = found_allocate_len;
433 static struct region *ext4_allocate_best_fit(u32 len)
435 struct region *first_reg = NULL;
436 struct region *prev_reg = NULL;
440 reg = ext4_allocate_best_fit_partial(len);
444 if (first_reg == NULL)
448 prev_reg->next = reg;
449 reg->prev = prev_reg;
459 /* Allocate len blocks. The blocks may be spread across multiple block groups,
460 and are returned in a linked list of the blocks in each block group. The
461 allocation algorithm is:
462 1. If the remaining allocation is larger than any available contiguous region,
463 allocate the largest contiguous region and loop
464 2. Otherwise, allocate the smallest contiguous region that it fits in
466 struct block_allocation *allocate_blocks(u32 len)
468 struct region *reg = ext4_allocate_best_fit(len);
473 struct block_allocation *alloc = create_allocation();
474 alloc->list.first = reg;
475 while (reg->next != NULL)
477 alloc->list.last = reg;
478 alloc->list.iter = alloc->list.first;
479 alloc->list.partial_iter = 0;
483 /* Returns the number of discontiguous regions used by an allocation */
484 int block_allocation_num_regions(struct block_allocation *alloc)
487 struct region *reg = alloc->list.first;
489 for (i = 0; reg != NULL; reg = reg->next)
495 int block_allocation_len(struct block_allocation *alloc)
498 struct region *reg = alloc->list.first;
500 for (i = 0; reg != NULL; reg = reg->next)
506 /* Returns the block number of the block'th block in an allocation */
507 u32 get_block(struct block_allocation *alloc, u32 block)
509 struct region *reg = alloc->list.iter;
510 block += alloc->list.partial_iter;
512 for (; reg; reg = reg->next) {
513 if (block < reg->len)
514 return reg->block + block;
517 return EXT4_ALLOCATE_FAILED;
520 u32 get_oob_block(struct block_allocation *alloc, u32 block)
522 struct region *reg = alloc->oob_list.iter;
523 block += alloc->oob_list.partial_iter;
525 for (; reg; reg = reg->next) {
526 if (block < reg->len)
527 return reg->block + block;
530 return EXT4_ALLOCATE_FAILED;
533 /* Gets the starting block and length in blocks of the first region
535 void get_region(struct block_allocation *alloc, u32 *block, u32 *len)
537 *block = alloc->list.iter->block;
538 *len = alloc->list.iter->len - alloc->list.partial_iter;
541 /* Move to the next region in an allocation */
542 void get_next_region(struct block_allocation *alloc)
544 alloc->list.iter = alloc->list.iter->next;
545 alloc->list.partial_iter = 0;
548 /* Returns the number of free blocks in a block group */
549 u32 get_free_blocks(u32 bg)
551 return aux_info.bgs[bg].free_blocks;
554 int last_region(struct block_allocation *alloc)
556 return (alloc->list.iter == NULL);
559 void rewind_alloc(struct block_allocation *alloc)
561 alloc->list.iter = alloc->list.first;
562 alloc->list.partial_iter = 0;
565 static struct region *do_split_allocation(struct block_allocation *alloc, u32 len)
567 struct region *reg = alloc->list.iter;
571 while (reg && len >= reg->len) {
576 if (reg == NULL && len > 0)
580 new = malloc(sizeof(struct region));
583 new->block = reg->block + len;
584 new->len = reg->len - len;
585 new->next = reg->next;
591 tmp = alloc->list.iter;
592 alloc->list.iter = new;
599 /* Splits an allocation into two allocations. The returned allocation will
600 point to the first half, and the original allocation ptr will point to the
602 static struct region *split_allocation(struct block_allocation *alloc, u32 len)
604 /* First make sure there is a split at the current ptr */
605 do_split_allocation(alloc, alloc->list.partial_iter);
607 /* Then split off len blocks */
608 struct region *middle = do_split_allocation(alloc, len);
609 alloc->list.partial_iter = 0;
613 /* Reserve the next blocks for oob data (indirect or extent blocks) */
614 int reserve_oob_blocks(struct block_allocation *alloc, int blocks)
616 struct region *oob = split_allocation(alloc, blocks);
622 while (oob && oob != alloc->list.iter) {
624 region_list_remove(&alloc->list, oob);
625 region_list_append(&alloc->oob_list, oob);
632 static int advance_list_ptr(struct region_list *list, int blocks)
634 struct region *reg = list->iter;
636 while (reg != NULL && blocks > 0) {
637 if (reg->len > list->partial_iter + blocks) {
638 list->partial_iter += blocks;
642 blocks -= (reg->len - list->partial_iter);
643 list->partial_iter = 0;
653 /* Move the allocation pointer forward */
654 int advance_blocks(struct block_allocation *alloc, int blocks)
656 return advance_list_ptr(&alloc->list, blocks);
659 int advance_oob_blocks(struct block_allocation *alloc, int blocks)
661 return advance_list_ptr(&alloc->oob_list, blocks);
664 int append_oob_allocation(struct block_allocation *alloc, u32 len)
666 struct region *reg = ext4_allocate_best_fit(len);
669 error("failed to allocate %d blocks", len);
673 for (; reg; reg = reg->next)
674 region_list_append(&alloc->oob_list, reg);
679 /* Returns an ext4_inode structure for an inode number */
680 struct ext4_inode *get_inode(u32 inode)
683 int bg = inode / info.inodes_per_group;
684 inode %= info.inodes_per_group;
686 allocate_bg_inode_table(&aux_info.bgs[bg]);
687 return (struct ext4_inode *)(aux_info.bgs[bg].inode_table + inode *
691 struct ext4_xattr_header *get_xattr_block_for_inode(struct ext4_inode *inode)
693 struct ext4_xattr_header *block = xattr_list_find(inode);
697 u32 block_num = allocate_block();
698 block = calloc(info.block_size, 1);
700 error("get_xattr: failed to allocate %d", info.block_size);
704 block->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
705 block->h_refcount = cpu_to_le32(1);
706 block->h_blocks = cpu_to_le32(1);
707 inode->i_blocks_lo = cpu_to_le32(le32_to_cpu(inode->i_blocks_lo) + (info.block_size / 512));
708 inode->i_file_acl_lo = cpu_to_le32(block_num);
710 int result = sparse_file_add_data(ext4_sparse_file, block, info.block_size, block_num);
712 error("get_xattr: sparse_file_add_data failure %d", result);
716 xattr_list_insert(inode, block);
720 /* Mark the first len inodes in a block group as used */
721 u32 reserve_inodes(int bg, u32 num)
726 if (get_free_inodes(bg) < num)
727 return EXT4_ALLOCATE_FAILED;
729 for (i = 0; i < num; i++) {
730 inode = aux_info.bgs[bg].first_free_inode + i - 1;
731 aux_info.bgs[bg].inode_bitmap[inode / 8] |= 1 << (inode % 8);
734 inode = aux_info.bgs[bg].first_free_inode;
736 aux_info.bgs[bg].first_free_inode += num;
737 aux_info.bgs[bg].free_inodes -= num;
742 /* Returns the first free inode number
743 TODO: Inodes should be allocated in the block group of the data? */
749 for (bg = 0; bg < aux_info.groups; bg++) {
750 inode = reserve_inodes(bg, 1);
751 if (inode != EXT4_ALLOCATE_FAILED)
752 return bg * info.inodes_per_group + inode;
755 return EXT4_ALLOCATE_FAILED;
758 /* Returns the number of free inodes in a block group */
759 u32 get_free_inodes(u32 bg)
761 return aux_info.bgs[bg].free_inodes;
764 /* Increments the directory count of the block group that contains inode */
765 void add_directory(u32 inode)
767 int bg = (inode - 1) / info.inodes_per_group;
768 aux_info.bgs[bg].used_dirs += 1;
771 /* Returns the number of inodes in a block group that are directories */
772 u16 get_directories(int bg)
774 return aux_info.bgs[bg].used_dirs;
777 /* Returns the flags for a block group */
778 u16 get_bg_flags(int bg)
780 return aux_info.bgs[bg].flags;
783 /* Frees the memory used by a linked list of allocation regions */
784 void free_alloc(struct block_allocation *alloc)
788 reg = alloc->list.first;
790 struct region *next = reg->next;
795 reg = alloc->oob_list.first;
797 struct region *next = reg->next;
805 void reserve_bg_chunk(int bg, u32 start_block, u32 size) {
806 struct block_group_info *bgs = aux_info.bgs;
808 if (bgs[bg].chunk_count == bgs[bg].max_chunk_count) {
809 bgs[bg].max_chunk_count *= 2;
810 bgs[bg].chunks = realloc(bgs[bg].chunks, bgs[bg].max_chunk_count * sizeof(struct region));
812 critical_error("realloc failed");
814 chunk_count = bgs[bg].chunk_count;
815 bgs[bg].chunks[chunk_count].block = start_block;
816 bgs[bg].chunks[chunk_count].len = size;
817 bgs[bg].chunks[chunk_count].bg = bg;
818 bgs[bg].chunk_count++;
821 int reserve_blocks_for_allocation(struct block_allocation *alloc) {
823 struct block_group_info *bgs = aux_info.bgs;
825 if (!alloc) return 0;
826 reg = alloc->list.first;
827 while (reg != NULL) {
828 if (reserve_blocks(&bgs[reg->bg], reg->bg, reg->block - bgs[reg->bg].first_block, reg->len) < 0) {