source: mainline/uspace/lib/ext4/libext4_balloc.c@ a872fc09

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since a872fc09 was e63ce679, checked in by Frantisek Princ <frantisek.princ@…>, 13 years ago

Some TODOs solved (mostly in error handling)
  • Property mode set to 100644
File size: 14.3 KB
Line 
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
33/**
34 * @file libext4_balloc.c
35 * @brief Physical block allocator.
36 */
37
38#include <errno.h>
39#include <sys/types.h>
40#include "libext4.h"
41
42static uint32_t ext4_balloc_blockaddr2_index_in_group(ext4_superblock_t *sb,
43 uint32_t block_addr)
44{
45 uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
46 uint32_t first_block = ext4_superblock_get_first_data_block(sb);
47
48 // First block == 0 or 1
49 if (first_block == 0) {
50 return block_addr % blocks_per_group;
51 } else {
52 return (block_addr - 1) % blocks_per_group;
53 }
54}
55
56static uint32_t ext4_balloc_index_in_group2blockaddr(ext4_superblock_t *sb,
57 uint32_t index, uint32_t bgid)
58{
59 uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
60
61 if (ext4_superblock_get_first_data_block(sb) == 0) {
62 return bgid * blocks_per_group + index;
63 } else {
64 return bgid * blocks_per_group + index + 1;
65 }
66
67}
68
69static uint32_t ext4_balloc_get_bgid_of_block(ext4_superblock_t *sb,
70 uint32_t block_addr)
71{
72 uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
73 uint32_t first_block = ext4_superblock_get_first_data_block(sb);
74
75 // First block == 0 or 1
76 if (first_block == 0) {
77 return block_addr / blocks_per_group;
78 } else {
79 return (block_addr - 1) / blocks_per_group;
80 }
81}
82
83
84int ext4_balloc_free_block(ext4_filesystem_t *fs, ext4_inode_ref_t *inode_ref, uint32_t block_addr)
85{
86 int rc;
87
88 uint32_t block_group = ext4_balloc_get_bgid_of_block(fs->superblock, block_addr);
89 uint32_t index_in_group = ext4_balloc_blockaddr2_index_in_group(fs->superblock, block_addr);
90
91 ext4_block_group_ref_t *bg_ref;
92 rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
93 if (rc != EOK) {
94 EXT4FS_DBG("error in loading bg_ref \%d", rc);
95 return rc;
96 }
97
98 uint32_t bitmap_block_addr = ext4_block_group_get_block_bitmap(
99 bg_ref->block_group, fs->superblock);
100 block_t *bitmap_block;
101 rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
102 if (rc != EOK) {
103 EXT4FS_DBG("error in loading bitmap \%d", rc);
104 return rc;
105 }
106
107 ext4_bitmap_free_bit(bitmap_block->data, index_in_group);
108 bitmap_block->dirty = true;
109
110 rc = block_put(bitmap_block);
111 if (rc != EOK) {
112 // Error in saving bitmap
113 ext4_filesystem_put_block_group_ref(bg_ref);
114 EXT4FS_DBG("error in saving bitmap \%d", rc);
115 return rc;
116 }
117
118 uint32_t block_size = ext4_superblock_get_block_size(fs->superblock);
119
120 // Update superblock free blocks count
121 uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(fs->superblock);
122 sb_free_blocks--;
123 ext4_superblock_set_free_blocks_count(fs->superblock, sb_free_blocks);
124
125 // Update inode blocks count
126 uint64_t ino_blocks = ext4_inode_get_blocks_count(fs->superblock, inode_ref->inode);
127 ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
128 ext4_inode_set_blocks_count(fs->superblock, inode_ref->inode, ino_blocks);
129 inode_ref->dirty = true;
130
131 // Update block group free blocks count
132 uint32_t free_blocks = ext4_block_group_get_free_blocks_count(
133 bg_ref->block_group, fs->superblock);
134 free_blocks++;
135 ext4_block_group_set_free_blocks_count(bg_ref->block_group,
136 fs->superblock, free_blocks);
137 bg_ref->dirty = true;
138
139 rc = ext4_filesystem_put_block_group_ref(bg_ref);
140 if (rc != EOK) {
141 EXT4FS_DBG("error in saving bg_ref \%d", rc);
142 // TODO error
143 return rc;
144 }
145
146 return EOK;
147}
148
149static uint32_t ext4_balloc_get_first_data_block_in_group(
150 ext4_superblock_t *sb, ext4_block_group_t *bg, uint32_t bgid)
151{
152 uint32_t block_group_count = ext4_superblock_get_block_group_count(sb);
153 uint32_t inode_table_first_block = ext4_block_group_get_inode_table_first_block(
154 bg, sb);
155 uint16_t inode_table_item_size = ext4_superblock_get_inode_size(sb);
156 uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(sb);
157 uint32_t block_size = ext4_superblock_get_block_size(sb);
158 uint32_t inode_table_bytes;
159
160 if (bgid < block_group_count - 1) {
161 inode_table_bytes = inodes_per_group * inode_table_item_size;
162 } else {
163 // last block group could be smaller
164 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(sb);
165 inode_table_bytes =
166 (inodes_count_total - ((block_group_count - 1) * inodes_per_group))
167 * inode_table_item_size;
168 }
169
170 uint32_t inode_table_blocks = inode_table_bytes / block_size;
171
172 if (inode_table_bytes % block_size) {
173 inode_table_blocks++;
174 }
175
176 return inode_table_first_block + inode_table_blocks;
177}
178
179
180static uint32_t ext4_balloc_find_goal(ext4_filesystem_t *fs, ext4_inode_ref_t *inode_ref)
181{
182 int rc;
183 uint32_t goal = 0;
184
185 uint64_t inode_size = ext4_inode_get_size(fs->superblock, inode_ref->inode);
186 uint32_t block_size = ext4_superblock_get_block_size(fs->superblock);
187 uint32_t inode_block_count = inode_size / block_size;
188
189 if (inode_size % block_size != 0) {
190 inode_block_count++;
191 }
192
193 if (inode_block_count > 0) {
194 // TODO check retval
195 ext4_filesystem_get_inode_data_block_index(fs, inode_ref->inode, inode_block_count - 1, &goal);
196
197 // TODO
198 // If goal == 0 -> SPARSE file !!!
199
200 goal++;
201 return goal;
202 }
203
204 // Identify block group of inode
205 uint32_t inodes_per_group = ext4_superblock_get_inodes_per_group(fs->superblock);
206 uint32_t block_group = (inode_ref->index - 1) / inodes_per_group;
207 block_size = ext4_superblock_get_block_size(fs->superblock);
208
209 ext4_block_group_ref_t *bg_ref;
210 rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
211 if (rc != EOK) {
212 return 0;
213 }
214
215 uint32_t block_group_count = ext4_superblock_get_block_group_count(fs->superblock);
216 uint32_t inode_table_first_block = ext4_block_group_get_inode_table_first_block(
217 bg_ref->block_group, fs->superblock);
218 uint16_t inode_table_item_size = ext4_superblock_get_inode_size(fs->superblock);
219 uint32_t inode_table_bytes;
220
221 if (block_group < block_group_count - 1) {
222 inode_table_bytes = inodes_per_group * inode_table_item_size;
223 } else {
224 // last block group could be smaller
225 uint32_t inodes_count_total = ext4_superblock_get_inodes_count(fs->superblock);
226 inode_table_bytes =
227 (inodes_count_total - ((block_group_count - 1) * inodes_per_group))
228 * inode_table_item_size;
229 }
230
231 uint32_t inode_table_blocks = inode_table_bytes / block_size;
232
233 if (inode_table_bytes % block_size) {
234 inode_table_blocks++;
235 }
236
237 goal = inode_table_first_block + inode_table_blocks;
238
239 ext4_filesystem_put_block_group_ref(bg_ref);
240
241 return goal;
242}
243
244int ext4_balloc_alloc_block(ext4_filesystem_t *fs,
245 ext4_inode_ref_t *inode_ref, uint32_t *fblock)
246{
247 int rc;
248 uint32_t allocated_block = 0;
249
250 uint32_t bitmap_block_addr;
251 block_t *bitmap_block;
252 uint32_t rel_block_idx = 0;
253
254 // Find GOAL
255 uint32_t goal = ext4_balloc_find_goal(fs, inode_ref);
256 if (goal == 0) {
257 // TODO
258 EXT4FS_DBG("ERRORR (goal == 0)");
259 return ENOSPC;
260 }
261
262 // Load block group number for goal and relative index
263 uint32_t block_group = ext4_balloc_get_bgid_of_block(fs->superblock, goal);
264 uint32_t index_in_group = ext4_balloc_blockaddr2_index_in_group(fs->superblock, goal);
265
266
267 ext4_block_group_ref_t *bg_ref;
268 rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
269 if (rc != EOK) {
270 EXT4FS_DBG("initial BG ref not loaded");
271 return rc;
272 }
273
274 uint32_t first_in_group =
275 ext4_balloc_get_first_data_block_in_group(fs->superblock,
276 bg_ref->block_group, block_group);
277
278 uint32_t first_in_group_index = ext4_balloc_blockaddr2_index_in_group(
279 fs->superblock, first_in_group);
280
281 if (index_in_group < first_in_group_index) {
282 index_in_group = first_in_group_index;
283 }
284
285 // Load bitmap
286 bitmap_block_addr = ext4_block_group_get_block_bitmap(bg_ref->block_group,
287 fs->superblock);
288
289 rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
290 if (rc != EOK) {
291 ext4_filesystem_put_block_group_ref(bg_ref);
292 EXT4FS_DBG("initial bitmap not loaded");
293 return rc;
294 }
295
296 // Check if goal is free
297 if (ext4_bitmap_is_free_bit(bitmap_block->data, index_in_group)) {
298 ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
299 bitmap_block->dirty = true;
300 rc = block_put(bitmap_block);
301 if (rc != EOK) {
302 // TODO error
303 EXT4FS_DBG("goal check: error in saving initial bitmap \%d", rc);
304 ext4_filesystem_put_block_group_ref(bg_ref);
305 return rc;
306 }
307
308 allocated_block = goal;
309 goto success;
310
311 }
312
313 uint32_t blocks_in_group = ext4_superblock_get_blocks_in_group(fs->superblock, block_group);
314
315 uint32_t end_idx = (index_in_group + 63) & ~63;
316 if (end_idx > blocks_in_group) {
317 end_idx = blocks_in_group;
318 }
319
320 // Try to find free block near to goal
321 for (uint32_t tmp_idx = index_in_group + 1; tmp_idx < end_idx; ++tmp_idx) {
322 if (ext4_bitmap_is_free_bit(bitmap_block->data, tmp_idx)) {
323
324 ext4_bitmap_set_bit(bitmap_block->data, tmp_idx);
325 bitmap_block->dirty = true;
326 rc = block_put(bitmap_block);
327 if (rc != EOK) {
328 // TODO error
329 EXT4FS_DBG("near blocks: error in saving initial bitmap \%d", rc);
330 }
331
332 allocated_block = ext4_balloc_index_in_group2blockaddr(
333 fs->superblock, tmp_idx, block_group);
334
335 goto success;
336 }
337
338 }
339
340 // Find free BYTE in bitmap
341 rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
342 if (rc == EOK) {
343 bitmap_block->dirty = true;
344 rc = block_put(bitmap_block);
345 if (rc != EOK) {
346 // TODO error
347 EXT4FS_DBG("free byte: error in saving initial bitmap \%d", rc);
348 }
349
350 allocated_block = ext4_balloc_index_in_group2blockaddr(
351 fs->superblock, rel_block_idx, block_group);
352
353 goto success;
354 }
355
356 // Find free bit in bitmap
357 rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
358 if (rc == EOK) {
359 bitmap_block->dirty = true;
360 rc = block_put(bitmap_block);
361 if (rc != EOK) {
362 // TODO error
363 EXT4FS_DBG("free bit: error in saving initial bitmap \%d", rc);
364 }
365
366 allocated_block = ext4_balloc_index_in_group2blockaddr(
367 fs->superblock, rel_block_idx, block_group);
368
369 goto success;
370 }
371
372 // No free block found yet
373 block_put(bitmap_block);
374 ext4_filesystem_put_block_group_ref(bg_ref);
375
376 // Try other block groups
377 uint32_t block_group_count = ext4_superblock_get_block_group_count(fs->superblock);
378
379 uint32_t bgid = (block_group + 1) % block_group_count;
380 uint32_t count = block_group_count;
381
382 while (count > 0) {
383 rc = ext4_filesystem_get_block_group_ref(fs, bgid, &bg_ref);
384 if (rc != EOK) {
385 EXT4FS_DBG("errrrrrrrrrrr");
386 return rc;
387 }
388
389 // Load bitmap
390 bitmap_block_addr = ext4_block_group_get_block_bitmap(
391 bg_ref->block_group, fs->superblock);
392
393 rc = block_get(&bitmap_block, fs->device, bitmap_block_addr, 0);
394 if (rc != EOK) {
395 ext4_filesystem_put_block_group_ref(bg_ref);
396 EXT4FS_DBG("errrrrrrrrrr");
397 return rc;
398 }
399
400 first_in_group = ext4_balloc_get_first_data_block_in_group(
401 fs->superblock, bg_ref->block_group, bgid);
402 index_in_group = ext4_balloc_blockaddr2_index_in_group(fs->superblock,
403 first_in_group);
404 blocks_in_group = ext4_superblock_get_blocks_in_group(fs->superblock, bgid);
405
406 first_in_group_index = ext4_balloc_blockaddr2_index_in_group(
407 fs->superblock, first_in_group);
408
409 if (index_in_group < first_in_group_index) {
410 index_in_group = first_in_group_index;
411 }
412
413
414 rc = ext4_bitmap_find_free_byte_and_set_bit(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
415 if (rc == EOK) {
416 bitmap_block->dirty = true;
417 rc = block_put(bitmap_block);
418 if (rc != EOK) {
419 // TODO error
420 EXT4FS_DBG("error in saving bitmap \%d", rc);
421 }
422
423 allocated_block = ext4_balloc_index_in_group2blockaddr(
424 fs->superblock, rel_block_idx, bgid);
425
426 goto success;
427 }
428
429 // Find free bit in bitmap
430 rc = ext4_bitmap_find_free_bit_and_set(bitmap_block->data, index_in_group, &rel_block_idx, blocks_in_group);
431 if (rc == EOK) {
432 bitmap_block->dirty = true;
433 rc = block_put(bitmap_block);
434 if (rc != EOK) {
435 // TODO error
436 EXT4FS_DBG("error in saving bitmap \%d", rc);
437 }
438
439 allocated_block = ext4_balloc_index_in_group2blockaddr(
440 fs->superblock, rel_block_idx, bgid);
441
442 goto success;
443 }
444
445
446 // Next group
447 block_put(bitmap_block);
448 ext4_filesystem_put_block_group_ref(bg_ref);
449 bgid = (bgid + 1) % block_group_count;
450 count--;
451 }
452
453 return ENOSPC;
454
455success:
456 ; // Empty command - because of syntax
457
458 uint32_t block_size = ext4_superblock_get_block_size(fs->superblock);
459
460 // Update superblock free blocks count
461 uint32_t sb_free_blocks = ext4_superblock_get_free_blocks_count(fs->superblock);
462 sb_free_blocks--;
463 ext4_superblock_set_free_blocks_count(fs->superblock, sb_free_blocks);
464
465 // Update inode blocks (different block size!) count
466
467 uint64_t ino_blocks = ext4_inode_get_blocks_count(fs->superblock, inode_ref->inode);
468 ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
469 ext4_inode_set_blocks_count(fs->superblock, inode_ref->inode, ino_blocks);
470 inode_ref->dirty = true;
471
472 // Update block group free blocks count
473 uint32_t bg_free_blocks = ext4_block_group_get_free_blocks_count(
474 bg_ref->block_group, fs->superblock);
475 bg_free_blocks--;
476 ext4_block_group_set_free_blocks_count(bg_ref->block_group,
477 fs->superblock, bg_free_blocks);
478 bg_ref->dirty = true;
479
480 ext4_filesystem_put_block_group_ref(bg_ref);
481
482 *fblock = allocated_block;
483 return EOK;
484}
485
486
487/**
488 * @}
489 */
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