source: mainline/uspace/lib/ext4/libext4_balloc.c@ 4358513

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 4358513 was 4358513, checked in by Frantisek Princ <frantisek.princ@…>, 13 years ago

comments for block allocator

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[2674db6]1/*
2 * Copyright (c) 2011 Frantisek Princ
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libext4
30 * @{
31 */
32
[b12ca16]33/**
34 * @file libext4_balloc.c
[e63ce679]35 * @brief Physical block allocator.
[b12ca16]36 */
37
[2674db6]38#include <errno.h>
39#include <sys/types.h>
40#include "libext4.h"
41
[4358513]42/** Convert block address to relative index in block group.
43 *
44 * @param sb superblock pointer
45 * @param block_addr block number to convert
46 * @return relative number of block
47 */
[b12ca16]48static uint32_t ext4_balloc_blockaddr2_index_in_group(ext4_superblock_t *sb,
49 uint32_t block_addr)
[2674db6]50{
[b12ca16]51 uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
52 uint32_t first_block = ext4_superblock_get_first_data_block(sb);
[2674db6]53
[b12ca16]54 // First block == 0 or 1
55 if (first_block == 0) {
56 return block_addr % blocks_per_group;
57 } else {
58 return (block_addr - 1) % blocks_per_group;
59 }
60}
61
[4358513]62/** Convert relative block number to absolute.
63 *
64 * @param sb superblock pointer
65 * @param index relative index of block in group
66 * @param bgid index of block group
67 * @return absolute number of block
68 */
[b12ca16]69static uint32_t ext4_balloc_index_in_group2blockaddr(ext4_superblock_t *sb,
70 uint32_t index, uint32_t bgid)
71{
72 uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
73
74 if (ext4_superblock_get_first_data_block(sb) == 0) {
75 return bgid * blocks_per_group + index;
76 } else {
77 return bgid * blocks_per_group + index + 1;
78 }
79
80}
81
[4358513]82/** Compute number of block group from block address.
83 *
84 * @param sb superblock pointer
85 * @param block_addr absolute address of block
86 * @return block group index
87 */
[b12ca16]88static uint32_t ext4_balloc_get_bgid_of_block(ext4_superblock_t *sb,
89 uint32_t block_addr)
90{
91 uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
92 uint32_t first_block = ext4_superblock_get_first_data_block(sb);
[2674db6]93
94 // First block == 0 or 1
95 if (first_block == 0) {
[b12ca16]96 return block_addr / blocks_per_group;
[2674db6]97 } else {
[b12ca16]98 return (block_addr - 1) / blocks_per_group;
[2674db6]99 }
[b12ca16]100}
101
102
[4358513]103/** Free block.
104 *
105 * @param inode_ref inode, where the block is allocated
106 * @param block_addr absolute block address to free
107 * @return error code
108 */
[1ac1ab4]109int ext4_balloc_free_block(ext4_inode_ref_t *inode_ref, uint32_t block_addr)
[b12ca16]110{
111 int rc;
[2674db6]112
[1ac1ab4]113 ext4_filesystem_t *fs = inode_ref->fs;
114 ext4_superblock_t *sb = fs->superblock;
115
[4358513]116 // Compute indexes
[1ac1ab4]117 uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, block_addr);
118 uint32_t index_in_group = ext4_balloc_blockaddr2_index_in_group(sb, block_addr);
[b12ca16]119
[4358513]120 // Load block group reference
[b12ca16]121 ext4_block_group_ref_t *bg_ref;
[2674db6]122 rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
123 if (rc != EOK) {
[b12ca16]124 EXT4FS_DBG("error in loading bg_ref \%d", rc);
[2674db6]125 return rc;
126 }
127
[4358513]128 // Load block with bitmap
[fe27eb4]129 uint32_t bitmap_block_addr = ext4_block_group_get_block_bitmap(
[1ac1ab4]130 bg_ref->block_group, sb);
[b12ca16]131 block_t *bitmap_block;
132 rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
[2674db6]133 if (rc != EOK) {
[b12ca16]134 EXT4FS_DBG("error in loading bitmap \%d", rc);
[2674db6]135 return rc;
136 }
137
[4358513]138 // Modify bitmap
[b12ca16]139 ext4_bitmap_free_bit(bitmap_block->data, index_in_group);
140 bitmap_block->dirty = true;
[2674db6]141
[4358513]142
143 // Release block with bitmap
[b12ca16]144 rc = block_put(bitmap_block);
[2674db6]145 if (rc != EOK) {
[b12ca16]146 // Error in saving bitmap
147 ext4_filesystem_put_block_group_ref(bg_ref);
148 EXT4FS_DBG("error in saving bitmap \%d", rc);
[2674db6]149 return rc;
150 }
151
[1ac1ab4]152 uint32_t block_size = ext4_superblock_get_block_size(sb);
[b12ca16]153
[ae3d4f8]154 // Update superblock free blocks count
[1ac1ab4]155 uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
[662bd71]156 sb_free_blocks++;
[1ac1ab4]157 ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
[ae3d4f8]158
159 // Update inode blocks count
[1ac1ab4]160 uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
[2674db6]161 ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
[1ac1ab4]162 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
[2674db6]163 inode_ref->dirty = true;
164
[ae3d4f8]165 // Update block group free blocks count
[fe27eb4]166 uint32_t free_blocks = ext4_block_group_get_free_blocks_count(
[1ac1ab4]167 bg_ref->block_group, sb);
[2674db6]168 free_blocks++;
[fe27eb4]169 ext4_block_group_set_free_blocks_count(bg_ref->block_group,
[1ac1ab4]170 sb, free_blocks);
[2674db6]171 bg_ref->dirty = true;
172
[4358513]173 // Release block group reference
[2674db6]174 rc = ext4_filesystem_put_block_group_ref(bg_ref);
175 if (rc != EOK) {
176 EXT4FS_DBG("error in saving bg_ref \%d", rc);
177 return rc;
178 }
179
180 return EOK;
181}
182
[4358513]183
184/** Free continuous set of blocks.
185 *
186 * @param inode_ref inode, where the blocks are allocated
187 * @param first first block to release
188 * @param count number of blocks to release
189 */
[662bd71]190int ext4_balloc_free_blocks(ext4_inode_ref_t *inode_ref,
191 uint32_t first, uint32_t count)
192{
193 int rc;
194
195 ext4_filesystem_t *fs = inode_ref->fs;
196 ext4_superblock_t *sb = fs->superblock;
197
[4358513]198 // Compute indexes
[662bd71]199 uint32_t block_group_first =
200 ext4_balloc_get_bgid_of_block(sb, first);
201 uint32_t block_group_last =
[3e2952b]202 ext4_balloc_get_bgid_of_block(sb, first + count - 1);
[662bd71]203
[3e2952b]204 assert(block_group_first == block_group_last);
[662bd71]205
[4358513]206 // Load block group reference
[c6a44a3]207 ext4_block_group_ref_t *bg_ref;
[662bd71]208 rc = ext4_filesystem_get_block_group_ref(fs, block_group_first, &bg_ref);
209 if (rc != EOK) {
210 EXT4FS_DBG("error in loading bg_ref \%d", rc);
211 return rc;
212 }
213
214 uint32_t index_in_group_first =
215 ext4_balloc_blockaddr2_index_in_group(sb, first);
216
[4358513]217
218 // Load block with bitmap
[662bd71]219 uint32_t bitmap_block_addr = ext4_block_group_get_block_bitmap(
220 bg_ref->block_group, sb);
221
222 block_t *bitmap_block;
223 rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
224 if (rc != EOK) {
225 EXT4FS_DBG("error in loading bitmap \%d", rc);
226 return rc;
227 }
228
[4358513]229 // Modify bitmap
[662bd71]230 ext4_bitmap_free_bits(bitmap_block->data, index_in_group_first, count);
231 bitmap_block->dirty = true;
232
[4358513]233 // Release block with bitmap
[662bd71]234 rc = block_put(bitmap_block);
235 if (rc != EOK) {
236 // Error in saving bitmap
237 ext4_filesystem_put_block_group_ref(bg_ref);
238 EXT4FS_DBG("error in saving bitmap \%d", rc);
239 return rc;
240 }
241
242 uint32_t block_size = ext4_superblock_get_block_size(sb);
243
244 // Update superblock free blocks count
245 uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
246 sb_free_blocks += count;
247 ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
248
249 // Update inode blocks count
250 uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
251 ino_blocks -= count * (block_size / EXT4_INODE_BLOCK_SIZE);
252 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
253 inode_ref->dirty = true;
254
255 // Update block group free blocks count
256 uint32_t free_blocks = ext4_block_group_get_free_blocks_count(
257 bg_ref->block_group, sb);
258 free_blocks += count;
259 ext4_block_group_set_free_blocks_count(bg_ref->block_group,
260 sb, free_blocks);
261 bg_ref->dirty = true;
262
[4358513]263 // Release block group reference
[662bd71]264 rc = ext4_filesystem_put_block_group_ref(bg_ref);
265 if (rc != EOK) {
266 EXT4FS_DBG("error in saving bg_ref \%d", rc);
267 return rc;
268 }
269
270 return EOK;
271}
272
[4358513]273/** Compute first block for data in block group.
274 *
275 * @param sb pointer to superblock
276 * @param bg pointer to block group
277 * @param bgid index of block group
278 * @return absolute block index of first block
279 */
[b12ca16]280static uint32_t ext4_balloc_get_first_data_block_in_group(
281 ext4_superblock_t *sb, ext4_block_group_t *bg, uint32_t bgid)
282{
283 uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
[fe27eb4]284 uint32_t inode_table_first_block = ext4_block_group_get_inode_table_first_block(
285 bg, sb);
[b12ca16]286 uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
287 uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
288 uint32_t block_size = ext4_superblock_get_block_size(sb);
289 uint32_t inode_table_bytes;
290
291 if (bgid < block_group_count - 1) {
292 inode_table_bytes = inodes_per_group * inode_table_item_size;
293 } else {
294 // last block group could be smaller
295 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
296 inode_table_bytes =
297 (inodes_count_total - ((block_group_count - 1) * inodes_per_group))
298 * inode_table_item_size;
299 }
300
301 uint32_t inode_table_blocks = inode_table_bytes / block_size;
302
303 if (inode_table_bytes % block_size) {
304 inode_table_blocks++;
305 }
306
307 return inode_table_first_block + inode_table_blocks;
308}
309
[4358513]310/** Compute 'goal' for allocation algorithm.
311 *
312 * @param inode_ref reference to inode, to allocate block for
313 * @return goal block number
314 */
[1ac1ab4]315static uint32_t ext4_balloc_find_goal(ext4_inode_ref_t *inode_ref)
[2674db6]316{
[b12ca16]317 int rc;
[2674db6]318 uint32_t goal = 0;
319
[1ac1ab4]320 ext4_superblock_t *sb = inode_ref->fs->superblock;
321
322 uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
323 uint32_t block_size = ext4_superblock_get_block_size(sb);
[2674db6]324 uint32_t inode_block_count = inode_size / block_size;
325
326 if (inode_size % block_size != 0) {
327 inode_block_count++;
328 }
329
[4358513]330 // If inode has some blocks, get last block address + 1
[2674db6]331 if (inode_block_count > 0) {
332
[95947d24]333 rc = ext4_filesystem_get_inode_data_block_index(inode_ref, inode_block_count - 1, &goal);
334 if (rc != EOK) {
335 return 0;
336 }
337
338 if (goal != 0) {
339 goal++;
340 return goal;
341 }
[b12ca16]342
[95947d24]343 // if goal == 0, sparse file -> continue
[2674db6]344 }
345
346 // Identify block group of inode
[1ac1ab4]347 uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
[2674db6]348 uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
[1ac1ab4]349 block_size = ext4_superblock_get_block_size(sb);
[2674db6]350
[4358513]351 // Load block group reference
[2674db6]352 ext4_block_group_ref_t *bg_ref;
[1ac1ab4]353 rc = ext4_filesystem_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
[2674db6]354 if (rc != EOK) {
355 return 0;
356 }
357
[4358513]358 // Compute indexes
[1ac1ab4]359 uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
[fe27eb4]360 uint32_t inode_table_first_block = ext4_block_group_get_inode_table_first_block(
[1ac1ab4]361 bg_ref->block_group, sb);
362 uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
[b12ca16]363 uint32_t inode_table_bytes;
364
[4358513]365 // Check for last block group
[b12ca16]366 if (block_group < block_group_count - 1) {
367 inode_table_bytes = inodes_per_group * inode_table_item_size;
368 } else {
369 // last block group could be smaller
[1ac1ab4]370 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
[b12ca16]371 inode_table_bytes =
372 (inodes_count_total - ((block_group_count - 1) * inodes_per_group))
373 * inode_table_item_size;
374 }
375
[2674db6]376 uint32_t inode_table_blocks = inode_table_bytes / block_size;
377
378 if (inode_table_bytes % block_size) {
379 inode_table_blocks++;
380 }
381
382 goal = inode_table_first_block + inode_table_blocks;
383
384 ext4_filesystem_put_block_group_ref(bg_ref);
385
386 return goal;
387}
388
[4358513]389/** Data block allocation algorithm.
390 *
391 * @param inode_ref inode to allocate block for
392 * @param fblock allocated block address
393 * @return error code
394 */
[1ac1ab4]395int ext4_balloc_alloc_block(
[412f813]396 ext4_inode_ref_t *inode_ref, uint32_t *fblock)
[2674db6]397{
398 int rc;
[b12ca16]399 uint32_t allocated_block = 0;
400
[528e5b3]401 uint32_t bitmap_block_addr;
402 block_t *bitmap_block;
[2674db6]403 uint32_t rel_block_idx = 0;
404
[b12ca16]405 // Find GOAL
[1ac1ab4]406 uint32_t goal = ext4_balloc_find_goal(inode_ref);
[2674db6]407 if (goal == 0) {
[95947d24]408 // no goal found => partition is full
[2674db6]409 EXT4FS_DBG("ERRORR (goal == 0)");
[b12ca16]410 return ENOSPC;
[2674db6]411 }
412
[1ac1ab4]413 ext4_superblock_t *sb = inode_ref->fs->superblock;
414
[b12ca16]415 // Load block group number for goal and relative index
[1ac1ab4]416 uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, goal);
417 uint32_t index_in_group = ext4_balloc_blockaddr2_index_in_group(sb, goal);
[2674db6]418
419
[4358513]420 // Load block group reference
[b12ca16]421 ext4_block_group_ref_t *bg_ref;
[1ac1ab4]422 rc = ext4_filesystem_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
[2674db6]423 if (rc != EOK) {
[b12ca16]424 EXT4FS_DBG("initial BG ref not loaded");
[2674db6]425 return rc;
426 }
427
[4358513]428 // Compute indexes
[b12ca16]429 uint32_t first_in_group =
[1ac1ab4]430 ext4_balloc_get_first_data_block_in_group(sb,
[b12ca16]431 bg_ref->block_group, block_group);
432
[528e5b3]433 uint32_t first_in_group_index = ext4_balloc_blockaddr2_index_in_group(
[1ac1ab4]434 sb, first_in_group);
[528e5b3]435
436 if (index_in_group < first_in_group_index) {
437 index_in_group = first_in_group_index;
[b12ca16]438 }
439
[4358513]440 // Load block with bitmap
[fe27eb4]441 bitmap_block_addr = ext4_block_group_get_block_bitmap(bg_ref->block_group,
[1ac1ab4]442 sb);
[2674db6]443
[1ac1ab4]444 rc = block_get(&bitmap_block, inode_ref->fs->device, bitmap_block_addr, 0);
[2674db6]445 if (rc != EOK) {
446 ext4_filesystem_put_block_group_ref(bg_ref);
[b12ca16]447 EXT4FS_DBG("initial bitmap not loaded");
[2674db6]448 return rc;
449 }
450
[b12ca16]451 // Check if goal is free
[528e5b3]452 if (ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group)) {
453 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
454 bitmap_block->dirty = true;
455 rc = block_put(bitmap_block);
[2674db6]456 if (rc != EOK) {
[95947d24]457 EXT4FS_DBG("goal check: error in saving bitmap \%d", rc);
[b12ca16]458 ext4_filesystem_put_block_group_ref(bg_ref);
459 return rc;
[2674db6]460 }
461
462 allocated_block = goal;
[b12ca16]463 goto success;
[2674db6]464
465 }
466
[1ac1ab4]467 uint32_t blocks_in_group = ext4_superblock_get_blocks_in_group(sb, block_group);
[2674db6]468
[b12ca16]469 uint32_t end_idx = (index_in_group + 63) & ~63;
470 if (end_idx > blocks_in_group) {
471 end_idx = blocks_in_group;
472 }
[2674db6]473
[b12ca16]474 // Try to find free block near to goal
475 for (uint32_t tmp_idx = index_in_group + 1; tmp_idx < end_idx; ++tmp_idx) {
[528e5b3]476 if (ext4_bitmap_is_free_bit(bitmap_block->data, tmp_idx)) {
[2674db6]477
[528e5b3]478 ext4_bitmap_set_bit(bitmap_block->data, tmp_idx);
479 bitmap_block->dirty = true;
480 rc = block_put(bitmap_block);
[2674db6]481 if (rc != EOK) {
[b12ca16]482 EXT4FS_DBG("near blocks: error in saving initial bitmap \%d", rc);
[95947d24]483 return rc;
[2674db6]484 }
485
[b12ca16]486 allocated_block = ext4_balloc_index_in_group2blockaddr(
[1ac1ab4]487 sb, tmp_idx, block_group);
[b12ca16]488
489 goto success;
[2674db6]490 }
491
[b12ca16]492 }
[2674db6]493
494 // Find free BYTE in bitmap
[528e5b3]495 rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
[2674db6]496 if (rc == EOK) {
[528e5b3]497 bitmap_block->dirty = true;
498 rc = block_put(bitmap_block);
[2674db6]499 if (rc != EOK) {
[b12ca16]500 EXT4FS_DBG("free byte: error in saving initial bitmap \%d", rc);
[95947d24]501 return rc;
[2674db6]502 }
503
[b12ca16]504 allocated_block = ext4_balloc_index_in_group2blockaddr(
[1ac1ab4]505 sb, rel_block_idx, block_group);
[2674db6]506
[b12ca16]507 goto success;
508 }
[2674db6]509
510 // Find free bit in bitmap
[528e5b3]511 rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
[2674db6]512 if (rc == EOK) {
[528e5b3]513 bitmap_block->dirty = true;
514 rc = block_put(bitmap_block);
[2674db6]515 if (rc != EOK) {
[b12ca16]516 EXT4FS_DBG("free bit: error in saving initial bitmap \%d", rc);
[95947d24]517 return rc;
[2674db6]518 }
519
[b12ca16]520 allocated_block = ext4_balloc_index_in_group2blockaddr(
[1ac1ab4]521 sb, rel_block_idx, block_group);
[2674db6]522
[b12ca16]523 goto success;
[2674db6]524 }
525
[e63ce679]526 // No free block found yet
[528e5b3]527 block_put(bitmap_block);
[b12ca16]528 ext4_filesystem_put_block_group_ref(bg_ref);
529
530 // Try other block groups
[1ac1ab4]531 uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
[b12ca16]532
533 uint32_t bgid = (block_group + 1) % block_group_count;
534 uint32_t count = block_group_count;
535
536 while (count > 0) {
[1ac1ab4]537 rc = ext4_filesystem_get_block_group_ref(inode_ref->fs, bgid, &bg_ref);
[b12ca16]538 if (rc != EOK) {
[95947d24]539 EXT4FS_DBG("ERROR: unable to load block group \%u", bgid);
[b12ca16]540 return rc;
541 }
542
[4358513]543 // Load block with bitmap
[fe27eb4]544 bitmap_block_addr = ext4_block_group_get_block_bitmap(
[1ac1ab4]545 bg_ref->block_group, sb);
[b12ca16]546
[1ac1ab4]547 rc = block_get(&bitmap_block, inode_ref->fs->device, bitmap_block_addr, 0);
[b12ca16]548 if (rc != EOK) {
549 ext4_filesystem_put_block_group_ref(bg_ref);
[95947d24]550 EXT4FS_DBG("ERROR: unable to load bitmap block");
[b12ca16]551 return rc;
552 }
553
[4358513]554 // Compute indexes
[b12ca16]555 first_in_group = ext4_balloc_get_first_data_block_in_group(
[1ac1ab4]556 sb, bg_ref->block_group, bgid);
557 index_in_group = ext4_balloc_blockaddr2_index_in_group(sb,
[b12ca16]558 first_in_group);
[1ac1ab4]559 blocks_in_group = ext4_superblock_get_blocks_in_group(sb, bgid);
[b12ca16]560
[528e5b3]561 first_in_group_index = ext4_balloc_blockaddr2_index_in_group(
[1ac1ab4]562 sb, first_in_group);
[528e5b3]563
564 if (index_in_group < first_in_group_index) {
565 index_in_group = first_in_group_index;
[b12ca16]566 }
567
[4358513]568 // Try to find free byte in bitmap
[528e5b3]569 rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
[b12ca16]570 if (rc == EOK) {
[528e5b3]571 bitmap_block->dirty = true;
572 rc = block_put(bitmap_block);
[b12ca16]573 if (rc != EOK) {
[95947d24]574 EXT4FS_DBG("ERROR: unable to save bitmap block");
575 return rc;
[b12ca16]576 }
577
578 allocated_block = ext4_balloc_index_in_group2blockaddr(
[1ac1ab4]579 sb, rel_block_idx, bgid);
[b12ca16]580
581 goto success;
582 }
583
[4358513]584 // Try to find free bit in bitmap
[528e5b3]585 rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
[b12ca16]586 if (rc == EOK) {
[528e5b3]587 bitmap_block->dirty = true;
588 rc = block_put(bitmap_block);
[b12ca16]589 if (rc != EOK) {
[95947d24]590 EXT4FS_DBG("ERROR: unable to save bitmap block");
591 return rc;
[b12ca16]592 }
593
594 allocated_block = ext4_balloc_index_in_group2blockaddr(
[1ac1ab4]595 sb, rel_block_idx, bgid);
[b12ca16]596
597 goto success;
598 }
599
[528e5b3]600 block_put(bitmap_block);
[b12ca16]601 ext4_filesystem_put_block_group_ref(bg_ref);
[4358513]602
603 // Goto next group
[b12ca16]604 bgid = (bgid + 1) % block_group_count;
605 count--;
606 }
607
[2674db6]608 return ENOSPC;
609
[b12ca16]610success:
[528e5b3]611 ; // Empty command - because of syntax
612
[1ac1ab4]613 uint32_t block_size = ext4_superblock_get_block_size(sb);
[b12ca16]614
[ae3d4f8]615 // Update superblock free blocks count
[1ac1ab4]616 uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
[ae3d4f8]617 sb_free_blocks--;
[1ac1ab4]618 ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
[2674db6]619
[ae3d4f8]620 // Update inode blocks (different block size!) count
[1ac1ab4]621 uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
[2674db6]622 ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
[1ac1ab4]623 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
[2674db6]624 inode_ref->dirty = true;
625
[ae3d4f8]626 // Update block group free blocks count
[fe27eb4]627 uint32_t bg_free_blocks = ext4_block_group_get_free_blocks_count(
[1ac1ab4]628 bg_ref->block_group, sb);
[2674db6]629 bg_free_blocks--;
[1ac1ab4]630 ext4_block_group_set_free_blocks_count(bg_ref->block_group, sb, bg_free_blocks);
[2674db6]631 bg_ref->dirty = true;
632
633 ext4_filesystem_put_block_group_ref(bg_ref);
634
635 *fblock = allocated_block;
636 return EOK;
637}
638
[4358513]639/** Try to allocate concrete block.
640 *
641 * @param inode_ref inode to allocate block for
642 * @param fblock block address to allocate
643 * @param free output value - if target block is free
644 * @return error code
645 */
[82cb6768]646int ext4_balloc_try_alloc_block(ext4_inode_ref_t *inode_ref,
647 uint32_t fblock, bool *free)
[b73530a]648{
[4358513]649 int rc = EOK;
[b73530a]650
651 ext4_filesystem_t *fs = inode_ref->fs;
652 ext4_superblock_t *sb = fs->superblock;
653
[4358513]654 // Compute indexes
[b73530a]655 uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, fblock);
656 uint32_t index_in_group = ext4_balloc_blockaddr2_index_in_group(sb, fblock);
657
[4358513]658 // Load block group reference
[b73530a]659 ext4_block_group_ref_t *bg_ref;
660 rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
661 if (rc != EOK) {
662 EXT4FS_DBG("error in loading bg_ref \%d", rc);
663 return rc;
664 }
665
[4358513]666 // Load block with bitmap
[b73530a]667 uint32_t bitmap_block_addr = ext4_block_group_get_block_bitmap(
668 bg_ref->block_group, sb);
669 block_t *bitmap_block;
670 rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
671 if (rc != EOK) {
672 EXT4FS_DBG("error in loading bitmap \%d", rc);
673 return rc;
674 }
675
[4358513]676 // Check if block is free
[82cb6768]677 *free = ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group);
[b73530a]678
[4358513]679 // Allocate block if possible
[82cb6768]680 if (*free) {
[b73530a]681 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
682 bitmap_block->dirty = true;
683 }
684
[4358513]685 // Release block with bitmap
[b73530a]686 rc = block_put(bitmap_block);
687 if (rc != EOK) {
688 // Error in saving bitmap
689 ext4_filesystem_put_block_group_ref(bg_ref);
690 EXT4FS_DBG("error in saving bitmap \%d", rc);
691 return rc;
692 }
693
[4358513]694 // If block is not free, return
[82cb6768]695 if (!(*free)) {
[b73530a]696 goto terminate;
697 }
698
699 uint32_t block_size = ext4_superblock_get_block_size(sb);
700
701 // Update superblock free blocks count
702 uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(sb);
703 sb_free_blocks--;
704 ext4_superblock_set_free_blocks_count(sb, sb_free_blocks);
705
706 // Update inode blocks count
707 uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
708 ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
709 ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
710 inode_ref->dirty = true;
711
712 // Update block group free blocks count
713 uint32_t free_blocks = ext4_block_group_get_free_blocks_count(
714 bg_ref->block_group, sb);
715 free_blocks--;
716 ext4_block_group_set_free_blocks_count(bg_ref->block_group,
717 sb, free_blocks);
718 bg_ref->dirty = true;
719
720terminate:
721
722 rc = ext4_filesystem_put_block_group_ref(bg_ref);
723 if (rc != EOK) {
724 EXT4FS_DBG("error in saving bg_ref \%d", rc);
725 return rc;
726 }
727
728 return rc;
729}
[2674db6]730
731/**
732 * @}
733 */
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