2 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
6 * Copyright (c) 2012 Martin Sucha
7 * Copyright (c) 2012 Frantisek Princ
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * - Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * - Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * - The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 /** @addtogroup lwext4
39 * @brief Physical block allocator.
42 #include <ext4_config.h>
43 #include <ext4_balloc.h>
44 #include <ext4_super.h>
45 #include <ext4_block_group.h>
47 #include <ext4_bitmap.h>
48 #include <ext4_inode.h>
51 /**@brief Compute number of block group from block address.
52 * @param sb Superblock pointer.
53 * @param baddr Absolute address of block.
54 * @return Block group index
56 static uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
59 if(ext4_get32(s, first_data_block))
62 return baddr / ext4_get32(s, blocks_per_group);
66 uint32_t ext4_balloc_get_first_data_block_in_group(struct ext4_sblock *s,
67 struct ext4_block_group_ref * bg_ref)
69 uint32_t block_group_count = ext4_block_group_cnt(s);
70 uint32_t inode_table_first_block =
71 ext4_bg_get_inode_table_first_block(bg_ref->block_group, s);
72 uint32_t block_size = ext4_sb_get_block_size(s);
74 uint16_t inode_size = ext4_get16(s, inode_size);
75 uint32_t inodes_per_group = ext4_get32(s, inodes_per_group);
77 uint32_t inode_table_bytes;
80 if (bg_ref->index < block_group_count - 1) {
81 inode_table_bytes = inodes_per_group * inode_size;
83 /* Last block group could be smaller */
84 uint32_t inodes_count_total = ext4_get32(s, inodes_count);
86 (inodes_count_total - ((block_group_count - 1) *
87 inodes_per_group)) * inode_size;
90 uint32_t inode_table_blocks = inode_table_bytes / block_size;
92 if (inode_table_bytes % block_size)
95 return inode_table_first_block + inode_table_blocks;
98 int ext4_balloc_free_block(struct ext4_inode_ref *inode_ref, uint32_t baddr)
100 struct ext4_fs *fs = inode_ref->fs;
101 struct ext4_sblock *sb = &fs->sb;
104 uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
105 uint32_t index_in_group = ext4_fs_baddr2_index_in_group(sb, baddr);
107 /* Load block group reference */
108 struct ext4_block_group_ref bg_ref;
109 int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
113 /* Load block with bitmap */
114 uint32_t bitmap_block_addr =
115 ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
117 struct ext4_block bitmap_block;
119 rc = ext4_block_get(fs->bdev, &bitmap_block, bitmap_block_addr);
124 ext4_bmap_bit_clr(bitmap_block.data, index_in_group);
125 bitmap_block.dirty = true;
127 /* Release block with bitmap */
128 rc = ext4_block_set(fs->bdev, &bitmap_block);
130 /* Error in saving bitmap */
131 ext4_fs_put_block_group_ref(&bg_ref);
135 uint32_t block_size = ext4_sb_get_block_size(sb);
137 /* Update superblock free blocks count */
138 uint64_t sb_free_blocks =
139 ext4_sb_get_free_blocks_cnt(sb);
141 ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
143 /* Update inode blocks count */
144 uint64_t ino_blocks =
145 ext4_inode_get_blocks_count(sb, inode_ref->inode);
146 ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
147 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
148 inode_ref->dirty = true;
150 /* Update block group free blocks count */
151 uint32_t free_blocks =
152 ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
154 ext4_bg_set_free_blocks_count(bg_ref.block_group,
159 /* Release block group reference */
160 rc = ext4_fs_put_block_group_ref(&bg_ref);
167 int ext4_balloc_free_blocks(struct ext4_inode_ref *inode_ref, uint32_t first,
170 struct ext4_fs *fs = inode_ref->fs;
171 struct ext4_sblock *sb = &fs->sb;
173 /* Compute indexes */
174 uint32_t block_group_first =
175 ext4_balloc_get_bgid_of_block(sb, first);
176 uint32_t block_group_last =
177 ext4_balloc_get_bgid_of_block(sb, first + count - 1);
179 ext4_assert(block_group_first == block_group_last);
181 /* Load block group reference */
182 struct ext4_block_group_ref bg_ref;
183 int rc = ext4_fs_get_block_group_ref(fs, block_group_first, &bg_ref);
187 uint32_t index_in_group_first =
188 ext4_fs_baddr2_index_in_group(sb, first);
190 /* Load block with bitmap */
191 uint32_t bitmap_block_addr =
192 ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
194 struct ext4_block bitmap_block;
196 rc = ext4_block_get(fs->bdev, &bitmap_block, bitmap_block_addr);
201 ext4_bmap_bits_free(bitmap_block.data, index_in_group_first, count);
202 bitmap_block.dirty = true;
204 /* Release block with bitmap */
205 rc = ext4_block_set(fs->bdev, &bitmap_block);
207 ext4_fs_put_block_group_ref(&bg_ref);
211 uint32_t block_size = ext4_sb_get_block_size(sb);
213 /* Update superblock free blocks count */
214 uint64_t sb_free_blocks =
215 ext4_sb_get_free_blocks_cnt(sb);
216 sb_free_blocks += count;
217 ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
219 /* Update inode blocks count */
220 uint64_t ino_blocks =
221 ext4_inode_get_blocks_count(sb, inode_ref->inode);
222 ino_blocks -= count * (block_size / EXT4_INODE_BLOCK_SIZE);
223 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
224 inode_ref->dirty = true;
226 /* Update block group free blocks count */
227 uint32_t free_blocks =
228 ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
229 free_blocks += count;
230 ext4_bg_set_free_blocks_count(bg_ref.block_group,
234 /* Release block group reference */
235 rc = ext4_fs_put_block_group_ref(&bg_ref);
243 /**@brief Compute 'goal' for allocation algorithm.
244 * @param inode_ref Reference to inode, to allocate block for
245 * @return Goal block number
247 static uint32_t ext4_balloc_find_goal(struct ext4_inode_ref *inode_ref)
251 struct ext4_sblock *sb = &inode_ref->fs->sb;
253 uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
254 uint32_t block_size = ext4_sb_get_block_size(sb);
255 uint32_t inode_block_count = inode_size / block_size;
257 if (inode_size % block_size != 0)
260 /* If inode has some blocks, get last block address + 1 */
261 if (inode_block_count > 0) {
262 int rc = ext4_fs_get_inode_data_block_index(inode_ref,
263 inode_block_count - 1, &goal);
272 /* If goal == 0, sparse file -> continue */
275 /* Identify block group of inode */
277 uint32_t inodes_per_group = ext4_get32(sb, inodes_per_group);
278 uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
279 block_size = ext4_sb_get_block_size(sb);
281 /* Load block group reference */
282 struct ext4_block_group_ref bg_ref;
283 int rc = ext4_fs_get_block_group_ref(inode_ref->fs,
284 block_group, &bg_ref);
288 /* Compute indexes */
289 uint32_t block_group_count = ext4_block_group_cnt(sb);
290 uint32_t inode_table_first_block =
291 ext4_bg_get_inode_table_first_block(bg_ref.block_group, sb);
292 uint16_t inode_table_item_size = ext4_get16(sb, inode_size);
293 uint32_t inode_table_bytes;
295 /* Check for last block group */
296 if (block_group < block_group_count - 1) {
297 inode_table_bytes = inodes_per_group * inode_table_item_size;
299 /* Last block group could be smaller */
300 uint32_t inodes_count_total = ext4_get32(sb, inodes_count);
303 (inodes_count_total - ((block_group_count - 1) *
304 inodes_per_group)) * inode_table_item_size;
307 uint32_t inode_table_blocks = inode_table_bytes / block_size;
309 if (inode_table_bytes % block_size)
310 inode_table_blocks++;
312 goal = inode_table_first_block + inode_table_blocks;
314 ext4_fs_put_block_group_ref(&bg_ref);
320 int ext4_balloc_alloc_block(struct ext4_inode_ref *inode_ref,
323 uint32_t allocated_block = 0;
324 uint32_t bitmap_block_addr;
325 uint32_t rel_block_idx = 0;
327 struct ext4_block bitmap_block;
330 uint32_t goal = ext4_balloc_find_goal(inode_ref);
332 /* no goal found => partition is full */
336 struct ext4_sblock *sb = &inode_ref->fs->sb;
338 /* Load block group number for goal and relative index */
339 uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, goal);
340 uint32_t index_in_group =
341 ext4_fs_baddr2_index_in_group(sb, goal);
343 /* Load block group reference */
344 struct ext4_block_group_ref bg_ref;
345 int rc = ext4_fs_get_block_group_ref(inode_ref->fs,
346 block_group, &bg_ref);
350 /* Compute indexes */
351 uint32_t first_in_group =
352 ext4_balloc_get_first_data_block_in_group(sb, &bg_ref);
354 uint32_t first_in_group_index =
355 ext4_fs_baddr2_index_in_group(sb, first_in_group);
357 if (index_in_group < first_in_group_index)
358 index_in_group = first_in_group_index;
360 /* Load block with bitmap */
362 ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
364 rc = ext4_block_get(inode_ref->fs->bdev, &bitmap_block,
367 ext4_fs_put_block_group_ref(&bg_ref);
371 /* Check if goal is free */
372 if (ext4_bmap_is_bit_clr(bitmap_block.data, index_in_group)) {
373 ext4_bmap_bit_set(bitmap_block.data, index_in_group);
374 bitmap_block.dirty = true;
375 rc = ext4_block_set(inode_ref->fs->bdev, &bitmap_block);
377 ext4_fs_put_block_group_ref(&bg_ref);
382 ext4_fs_index_in_group2_baddr(sb, index_in_group,
388 uint32_t blocks_in_group =
389 ext4_blocks_in_group_cnt(sb, block_group);
391 uint32_t end_idx = (index_in_group + 63) & ~63;
392 if (end_idx > blocks_in_group)
393 end_idx = blocks_in_group;
395 /* Try to find free block near to goal */
397 for (tmp_idx = index_in_group + 1; tmp_idx < end_idx;
399 if (ext4_bmap_is_bit_clr(bitmap_block.data, tmp_idx)) {
400 ext4_bmap_bit_set(bitmap_block.data, tmp_idx);
402 bitmap_block.dirty = true;
403 rc = ext4_block_set(inode_ref->fs->bdev, &bitmap_block);
408 ext4_fs_index_in_group2_baddr(sb, tmp_idx,
417 /* Find free bit in bitmap */
418 rc = ext4_bmap_bit_find_clr(bitmap_block.data,
419 index_in_group, blocks_in_group, &rel_block_idx);
421 ext4_bmap_bit_set(bitmap_block.data, rel_block_idx);
422 bitmap_block.dirty = true;
423 rc = ext4_block_set(inode_ref->fs->bdev, &bitmap_block);
428 ext4_fs_index_in_group2_baddr(sb, rel_block_idx,
434 /* No free block found yet */
435 ext4_block_set(inode_ref->fs->bdev, &bitmap_block);
436 ext4_fs_put_block_group_ref(&bg_ref);
438 /* Try other block groups */
439 uint32_t block_group_count = ext4_block_group_cnt(sb);
441 uint32_t bgid = (block_group + 1) % block_group_count;
442 uint32_t count = block_group_count;
445 rc = ext4_fs_get_block_group_ref(inode_ref->fs, bgid,
450 /* Load block with bitmap */
452 ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
454 rc = ext4_block_get(inode_ref->fs->bdev, &bitmap_block,
458 ext4_fs_put_block_group_ref(&bg_ref);
462 /* Compute indexes */
464 ext4_balloc_get_first_data_block_in_group(sb, &bg_ref);
466 ext4_fs_baddr2_index_in_group(sb, first_in_group);
467 blocks_in_group = ext4_blocks_in_group_cnt(sb, bgid);
469 first_in_group_index =
470 ext4_fs_baddr2_index_in_group(sb, first_in_group);
472 if (index_in_group < first_in_group_index)
473 index_in_group = first_in_group_index;
476 rc = ext4_bmap_bit_find_clr(bitmap_block.data,
477 index_in_group, blocks_in_group, &rel_block_idx);
481 ext4_bmap_bit_set(bitmap_block.data, rel_block_idx);
483 bitmap_block.dirty = true;
484 rc = ext4_block_set(inode_ref->fs->bdev, &bitmap_block);
489 ext4_fs_index_in_group2_baddr(sb, rel_block_idx,
495 ext4_block_set(inode_ref->fs->bdev, &bitmap_block);
496 ext4_fs_put_block_group_ref(&bg_ref);
498 /* Goto next group */
499 bgid = (bgid + 1) % block_group_count;
506 /* Empty command - because of syntax */
509 uint32_t block_size = ext4_sb_get_block_size(sb);
511 /* Update superblock free blocks count */
512 uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
514 ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
516 /* Update inode blocks (different block size!) count */
517 uint64_t ino_blocks =
518 ext4_inode_get_blocks_count(sb, inode_ref->inode);
519 ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
520 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
521 inode_ref->dirty = true;
523 /* Update block group free blocks count */
524 uint32_t bg_free_blocks =
525 ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
527 ext4_bg_set_free_blocks_count(bg_ref.block_group, sb,
532 ext4_fs_put_block_group_ref(&bg_ref);
534 *fblock = allocated_block;
538 int ext4_balloc_try_alloc_block(struct ext4_inode_ref *inode_ref,
539 uint32_t baddr, bool *free)
543 struct ext4_fs *fs = inode_ref->fs;
544 struct ext4_sblock *sb = &fs->sb;
546 /* Compute indexes */
547 uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
548 uint32_t index_in_group =
549 ext4_fs_baddr2_index_in_group(sb, baddr);
551 /* Load block group reference */
552 struct ext4_block_group_ref bg_ref;
553 rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
557 /* Load block with bitmap */
558 uint32_t bitmap_block_addr =
559 ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
562 struct ext4_block bitmap_block;
564 rc = ext4_block_get(fs->bdev, &bitmap_block, bitmap_block_addr);
568 /* Check if block is free */
569 *free = ext4_bmap_is_bit_clr(bitmap_block.data, index_in_group);
571 /* Allocate block if possible */
573 ext4_bmap_bit_set(bitmap_block.data, index_in_group);
574 bitmap_block.dirty = true;
577 /* Release block with bitmap */
578 rc = ext4_block_set(fs->bdev, &bitmap_block);
580 /* Error in saving bitmap */
581 ext4_fs_put_block_group_ref(&bg_ref);
585 /* If block is not free, return */
589 uint32_t block_size = ext4_sb_get_block_size(sb);
591 /* Update superblock free blocks count */
592 uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
594 ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
596 /* Update inode blocks count */
597 uint64_t ino_blocks =
598 ext4_inode_get_blocks_count(sb, inode_ref->inode);
599 ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
600 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
601 inode_ref->dirty = true;
603 /* Update block group free blocks count */
604 uint32_t free_blocks =
605 ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
607 ext4_bg_set_free_blocks_count(bg_ref.block_group,
613 return ext4_fs_put_block_group_ref(&bg_ref);