xref: /linux/fs/ext4/mballoc-test.c (revision fe833e4397fbdc3ae13a60202dfc7c335b032499)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * KUnit test of ext4 multiblocks allocation.
4  */
5 
6 #include <kunit/test.h>
7 #include <kunit/static_stub.h>
8 #include <linux/random.h>
9 
10 #include "ext4.h"
11 
12 struct mbt_grp_ctx {
13 	struct buffer_head bitmap_bh;
14 	/* desc and gd_bh are just the place holders for now */
15 	struct ext4_group_desc desc;
16 	struct buffer_head gd_bh;
17 };
18 
19 struct mbt_ctx {
20 	struct mbt_grp_ctx *grp_ctx;
21 };
22 
23 struct mbt_ext4_super_block {
24 	struct ext4_super_block es;
25 	struct ext4_sb_info sbi;
26 	struct mbt_ctx mbt_ctx;
27 };
28 
29 #define MBT_SB(_sb) (container_of((_sb)->s_fs_info, struct mbt_ext4_super_block, sbi))
30 #define MBT_CTX(_sb) (&MBT_SB(_sb)->mbt_ctx)
31 #define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group])
32 
33 static struct inode *mbt_alloc_inode(struct super_block *sb)
34 {
35 	struct ext4_inode_info *ei;
36 
37 	ei = kmalloc(sizeof(struct ext4_inode_info), GFP_KERNEL);
38 	if (!ei)
39 		return NULL;
40 
41 	INIT_LIST_HEAD(&ei->i_orphan);
42 	init_rwsem(&ei->xattr_sem);
43 	init_rwsem(&ei->i_data_sem);
44 	inode_init_once(&ei->vfs_inode);
45 	ext4_fc_init_inode(&ei->vfs_inode);
46 
47 	return &ei->vfs_inode;
48 }
49 
50 static void mbt_free_inode(struct inode *inode)
51 {
52 	kfree(EXT4_I(inode));
53 }
54 
55 static const struct super_operations mbt_sops = {
56 	.alloc_inode	= mbt_alloc_inode,
57 	.free_inode	= mbt_free_inode,
58 };
59 
60 static void mbt_kill_sb(struct super_block *sb)
61 {
62 	generic_shutdown_super(sb);
63 }
64 
65 static struct file_system_type mbt_fs_type = {
66 	.name			= "mballoc test",
67 	.kill_sb		= mbt_kill_sb,
68 };
69 
70 static int mbt_mb_init(struct super_block *sb)
71 {
72 	ext4_fsblk_t block;
73 	int ret;
74 
75 	/* needed by ext4_mb_init->bdev_nonrot(sb->s_bdev) */
76 	sb->s_bdev = kzalloc(sizeof(*sb->s_bdev), GFP_KERNEL);
77 	if (sb->s_bdev == NULL)
78 		return -ENOMEM;
79 
80 	sb->s_bdev->bd_queue = kzalloc(sizeof(struct request_queue), GFP_KERNEL);
81 	if (sb->s_bdev->bd_queue == NULL) {
82 		kfree(sb->s_bdev);
83 		return -ENOMEM;
84 	}
85 
86 	/*
87 	 * needed by ext4_mb_init->ext4_mb_init_backend-> sbi->s_buddy_cache =
88 	 * new_inode(sb);
89 	 */
90 	INIT_LIST_HEAD(&sb->s_inodes);
91 	sb->s_op = &mbt_sops;
92 
93 	ret = ext4_mb_init(sb);
94 	if (ret != 0)
95 		goto err_out;
96 
97 	block = ext4_count_free_clusters(sb);
98 	ret = percpu_counter_init(&EXT4_SB(sb)->s_freeclusters_counter, block,
99 				  GFP_KERNEL);
100 	if (ret != 0)
101 		goto err_mb_release;
102 
103 	ret = percpu_counter_init(&EXT4_SB(sb)->s_dirtyclusters_counter, 0,
104 				  GFP_KERNEL);
105 	if (ret != 0)
106 		goto err_freeclusters;
107 
108 	return 0;
109 
110 err_freeclusters:
111 	percpu_counter_destroy(&EXT4_SB(sb)->s_freeclusters_counter);
112 err_mb_release:
113 	ext4_mb_release(sb);
114 err_out:
115 	kfree(sb->s_bdev->bd_queue);
116 	kfree(sb->s_bdev);
117 	return ret;
118 }
119 
120 static void mbt_mb_release(struct super_block *sb)
121 {
122 	percpu_counter_destroy(&EXT4_SB(sb)->s_dirtyclusters_counter);
123 	percpu_counter_destroy(&EXT4_SB(sb)->s_freeclusters_counter);
124 	ext4_mb_release(sb);
125 	kfree(sb->s_bdev->bd_queue);
126 	kfree(sb->s_bdev);
127 }
128 
129 static int mbt_set(struct super_block *sb, void *data)
130 {
131 	return 0;
132 }
133 
134 static struct super_block *mbt_ext4_alloc_super_block(void)
135 {
136 	struct mbt_ext4_super_block *fsb;
137 	struct super_block *sb;
138 	struct ext4_sb_info *sbi;
139 
140 	fsb = kzalloc(sizeof(*fsb), GFP_KERNEL);
141 	if (fsb == NULL)
142 		return NULL;
143 
144 	sb = sget(&mbt_fs_type, NULL, mbt_set, 0, NULL);
145 	if (IS_ERR(sb))
146 		goto out;
147 
148 	sbi = &fsb->sbi;
149 
150 	sbi->s_blockgroup_lock =
151 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
152 	if (!sbi->s_blockgroup_lock)
153 		goto out_deactivate;
154 
155 	bgl_lock_init(sbi->s_blockgroup_lock);
156 
157 	sbi->s_es = &fsb->es;
158 	sb->s_fs_info = sbi;
159 
160 	up_write(&sb->s_umount);
161 	return sb;
162 
163 out_deactivate:
164 	deactivate_locked_super(sb);
165 out:
166 	kfree(fsb);
167 	return NULL;
168 }
169 
170 static void mbt_ext4_free_super_block(struct super_block *sb)
171 {
172 	struct mbt_ext4_super_block *fsb = MBT_SB(sb);
173 	struct ext4_sb_info *sbi = EXT4_SB(sb);
174 
175 	kfree(sbi->s_blockgroup_lock);
176 	deactivate_super(sb);
177 	kfree(fsb);
178 }
179 
180 struct mbt_ext4_block_layout {
181 	unsigned char blocksize_bits;
182 	unsigned int cluster_bits;
183 	uint32_t blocks_per_group;
184 	ext4_group_t group_count;
185 	uint16_t desc_size;
186 };
187 
188 static void mbt_init_sb_layout(struct super_block *sb,
189 			       struct mbt_ext4_block_layout *layout)
190 {
191 	struct ext4_sb_info *sbi = EXT4_SB(sb);
192 	struct ext4_super_block *es = sbi->s_es;
193 
194 	sb->s_blocksize = 1UL << layout->blocksize_bits;
195 	sb->s_blocksize_bits = layout->blocksize_bits;
196 
197 	sbi->s_groups_count = layout->group_count;
198 	sbi->s_blocks_per_group = layout->blocks_per_group;
199 	sbi->s_cluster_bits = layout->cluster_bits;
200 	sbi->s_cluster_ratio = 1U << layout->cluster_bits;
201 	sbi->s_clusters_per_group = layout->blocks_per_group >>
202 				    layout->cluster_bits;
203 	sbi->s_desc_size = layout->desc_size;
204 	sbi->s_desc_per_block_bits =
205 		sb->s_blocksize_bits - (fls(layout->desc_size) - 1);
206 	sbi->s_desc_per_block = 1 << sbi->s_desc_per_block_bits;
207 
208 	es->s_first_data_block = cpu_to_le32(0);
209 	es->s_blocks_count_lo = cpu_to_le32(layout->blocks_per_group *
210 					    layout->group_count);
211 }
212 
213 static int mbt_grp_ctx_init(struct super_block *sb,
214 			    struct mbt_grp_ctx *grp_ctx)
215 {
216 	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
217 
218 	grp_ctx->bitmap_bh.b_data = kzalloc(EXT4_BLOCK_SIZE(sb), GFP_KERNEL);
219 	if (grp_ctx->bitmap_bh.b_data == NULL)
220 		return -ENOMEM;
221 	mb_set_bits(grp_ctx->bitmap_bh.b_data, max, sb->s_blocksize * 8 - max);
222 	ext4_free_group_clusters_set(sb, &grp_ctx->desc, max);
223 
224 	return 0;
225 }
226 
227 static void mbt_grp_ctx_release(struct mbt_grp_ctx *grp_ctx)
228 {
229 	kfree(grp_ctx->bitmap_bh.b_data);
230 	grp_ctx->bitmap_bh.b_data = NULL;
231 }
232 
233 static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group,
234 			      unsigned int start, unsigned int len)
235 {
236 	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
237 
238 	mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len);
239 }
240 
241 static void *mbt_ctx_bitmap(struct super_block *sb, ext4_group_t group)
242 {
243 	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
244 
245 	return grp_ctx->bitmap_bh.b_data;
246 }
247 
248 /* called after mbt_init_sb_layout */
249 static int mbt_ctx_init(struct super_block *sb)
250 {
251 	struct mbt_ctx *ctx = MBT_CTX(sb);
252 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
253 
254 	ctx->grp_ctx = kcalloc(ngroups, sizeof(struct mbt_grp_ctx),
255 			       GFP_KERNEL);
256 	if (ctx->grp_ctx == NULL)
257 		return -ENOMEM;
258 
259 	for (i = 0; i < ngroups; i++)
260 		if (mbt_grp_ctx_init(sb, &ctx->grp_ctx[i]))
261 			goto out;
262 
263 	/*
264 	 * first data block(first cluster in first group) is used by
265 	 * metadata, mark it used to avoid to alloc data block at first
266 	 * block which will fail ext4_sb_block_valid check.
267 	 */
268 	mb_set_bits(ctx->grp_ctx[0].bitmap_bh.b_data, 0, 1);
269 	ext4_free_group_clusters_set(sb, &ctx->grp_ctx[0].desc,
270 				     EXT4_CLUSTERS_PER_GROUP(sb) - 1);
271 
272 	return 0;
273 out:
274 	while (i-- > 0)
275 		mbt_grp_ctx_release(&ctx->grp_ctx[i]);
276 	kfree(ctx->grp_ctx);
277 	return -ENOMEM;
278 }
279 
280 static void mbt_ctx_release(struct super_block *sb)
281 {
282 	struct mbt_ctx *ctx = MBT_CTX(sb);
283 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
284 
285 	for (i = 0; i < ngroups; i++)
286 		mbt_grp_ctx_release(&ctx->grp_ctx[i]);
287 	kfree(ctx->grp_ctx);
288 }
289 
290 static struct buffer_head *
291 ext4_read_block_bitmap_nowait_stub(struct super_block *sb, ext4_group_t block_group,
292 				   bool ignore_locked)
293 {
294 	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
295 
296 	/* paired with brelse from caller of ext4_read_block_bitmap_nowait */
297 	get_bh(&grp_ctx->bitmap_bh);
298 	return &grp_ctx->bitmap_bh;
299 }
300 
301 static int ext4_wait_block_bitmap_stub(struct super_block *sb,
302 				       ext4_group_t block_group,
303 				       struct buffer_head *bh)
304 {
305 	/*
306 	 * real ext4_wait_block_bitmap will set these flags and
307 	 * functions like ext4_mb_init_cache will verify the flags.
308 	 */
309 	set_buffer_uptodate(bh);
310 	set_bitmap_uptodate(bh);
311 	set_buffer_verified(bh);
312 	return 0;
313 }
314 
315 static struct ext4_group_desc *
316 ext4_get_group_desc_stub(struct super_block *sb, ext4_group_t block_group,
317 			 struct buffer_head **bh)
318 {
319 	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
320 
321 	if (bh != NULL)
322 		*bh = &grp_ctx->gd_bh;
323 
324 	return &grp_ctx->desc;
325 }
326 
327 static int
328 ext4_mb_mark_context_stub(handle_t *handle, struct super_block *sb, bool state,
329 			  ext4_group_t group, ext4_grpblk_t blkoff,
330 			  ext4_grpblk_t len, int flags,
331 			  ext4_grpblk_t *ret_changed)
332 {
333 	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
334 	struct buffer_head *bitmap_bh = &grp_ctx->bitmap_bh;
335 
336 	if (state)
337 		mb_set_bits(bitmap_bh->b_data, blkoff, len);
338 	else
339 		mb_clear_bits(bitmap_bh->b_data, blkoff, len);
340 
341 	return 0;
342 }
343 
344 #define TEST_GOAL_GROUP 1
345 static int mbt_kunit_init(struct kunit *test)
346 {
347 	struct mbt_ext4_block_layout *layout =
348 		(struct mbt_ext4_block_layout *)(test->param_value);
349 	struct super_block *sb;
350 	int ret;
351 
352 	sb = mbt_ext4_alloc_super_block();
353 	if (sb == NULL)
354 		return -ENOMEM;
355 
356 	mbt_init_sb_layout(sb, layout);
357 
358 	ret = mbt_ctx_init(sb);
359 	if (ret != 0) {
360 		mbt_ext4_free_super_block(sb);
361 		return ret;
362 	}
363 
364 	test->priv = sb;
365 	kunit_activate_static_stub(test,
366 				   ext4_read_block_bitmap_nowait,
367 				   ext4_read_block_bitmap_nowait_stub);
368 	kunit_activate_static_stub(test,
369 				   ext4_wait_block_bitmap,
370 				   ext4_wait_block_bitmap_stub);
371 	kunit_activate_static_stub(test,
372 				   ext4_get_group_desc,
373 				   ext4_get_group_desc_stub);
374 	kunit_activate_static_stub(test,
375 				   ext4_mb_mark_context,
376 				   ext4_mb_mark_context_stub);
377 
378 	/* stub function will be called in mbt_mb_init->ext4_mb_init */
379 	if (mbt_mb_init(sb) != 0) {
380 		mbt_ctx_release(sb);
381 		mbt_ext4_free_super_block(sb);
382 		return -ENOMEM;
383 	}
384 
385 	return 0;
386 }
387 
388 static void mbt_kunit_exit(struct kunit *test)
389 {
390 	struct super_block *sb = (struct super_block *)test->priv;
391 
392 	mbt_mb_release(sb);
393 	mbt_ctx_release(sb);
394 	mbt_ext4_free_super_block(sb);
395 }
396 
397 static void test_new_blocks_simple(struct kunit *test)
398 {
399 	struct super_block *sb = (struct super_block *)test->priv;
400 	struct inode *inode;
401 	struct ext4_allocation_request ar;
402 	ext4_group_t i, goal_group = TEST_GOAL_GROUP;
403 	int err = 0;
404 	ext4_fsblk_t found;
405 	struct ext4_sb_info *sbi = EXT4_SB(sb);
406 
407 	inode = kunit_kzalloc(test, sizeof(*inode), GFP_KERNEL);
408 	if (!inode)
409 		return;
410 
411 	inode->i_sb = sb;
412 	ar.inode = inode;
413 
414 	/* get block at goal */
415 	ar.goal = ext4_group_first_block_no(sb, goal_group);
416 	found = ext4_mb_new_blocks_simple(&ar, &err);
417 	KUNIT_ASSERT_EQ_MSG(test, ar.goal, found,
418 		"failed to alloc block at goal, expected %llu found %llu",
419 		ar.goal, found);
420 
421 	/* get block after goal in goal group */
422 	ar.goal = ext4_group_first_block_no(sb, goal_group);
423 	found = ext4_mb_new_blocks_simple(&ar, &err);
424 	KUNIT_ASSERT_EQ_MSG(test, ar.goal + EXT4_C2B(sbi, 1), found,
425 		"failed to alloc block after goal in goal group, expected %llu found %llu",
426 		ar.goal + 1, found);
427 
428 	/* get block after goal group */
429 	mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
430 	ar.goal = ext4_group_first_block_no(sb, goal_group);
431 	found = ext4_mb_new_blocks_simple(&ar, &err);
432 	KUNIT_ASSERT_EQ_MSG(test,
433 		ext4_group_first_block_no(sb, goal_group + 1), found,
434 		"failed to alloc block after goal group, expected %llu found %llu",
435 		ext4_group_first_block_no(sb, goal_group + 1), found);
436 
437 	/* get block before goal group */
438 	for (i = goal_group; i < ext4_get_groups_count(sb); i++)
439 		mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
440 	ar.goal = ext4_group_first_block_no(sb, goal_group);
441 	found = ext4_mb_new_blocks_simple(&ar, &err);
442 	KUNIT_ASSERT_EQ_MSG(test,
443 		ext4_group_first_block_no(sb, 0) + EXT4_C2B(sbi, 1), found,
444 		"failed to alloc block before goal group, expected %llu found %llu",
445 		ext4_group_first_block_no(sb, 0 + EXT4_C2B(sbi, 1)), found);
446 
447 	/* no block available, fail to allocate block */
448 	for (i = 0; i < ext4_get_groups_count(sb); i++)
449 		mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
450 	ar.goal = ext4_group_first_block_no(sb, goal_group);
451 	found = ext4_mb_new_blocks_simple(&ar, &err);
452 	KUNIT_ASSERT_NE_MSG(test, err, 0,
453 		"unexpectedly get block when no block is available");
454 }
455 
456 #define TEST_RANGE_COUNT 8
457 
458 struct test_range {
459 	ext4_grpblk_t start;
460 	ext4_grpblk_t len;
461 };
462 
463 static void
464 mbt_generate_test_ranges(struct super_block *sb, struct test_range *ranges,
465 			 int count)
466 {
467 	ext4_grpblk_t start, len, max;
468 	int i;
469 
470 	max = EXT4_CLUSTERS_PER_GROUP(sb) / count;
471 	for (i = 0; i < count; i++) {
472 		start = get_random_u32() % max;
473 		len = get_random_u32() % max;
474 		len = min(len, max - start);
475 
476 		ranges[i].start = start + i * max;
477 		ranges[i].len = len;
478 	}
479 }
480 
481 static void
482 validate_free_blocks_simple(struct kunit *test, struct super_block *sb,
483 			    ext4_group_t goal_group, ext4_grpblk_t start,
484 			    ext4_grpblk_t len)
485 {
486 	void *bitmap;
487 	ext4_grpblk_t bit, max = EXT4_CLUSTERS_PER_GROUP(sb);
488 	ext4_group_t i;
489 
490 	for (i = 0; i < ext4_get_groups_count(sb); i++) {
491 		if (i == goal_group)
492 			continue;
493 
494 		bitmap = mbt_ctx_bitmap(sb, i);
495 		bit = mb_find_next_zero_bit(bitmap, max, 0);
496 		KUNIT_ASSERT_EQ_MSG(test, bit, max,
497 				    "free block on unexpected group %d", i);
498 	}
499 
500 	bitmap = mbt_ctx_bitmap(sb, goal_group);
501 	bit = mb_find_next_zero_bit(bitmap, max, 0);
502 	KUNIT_ASSERT_EQ(test, bit, start);
503 
504 	bit = mb_find_next_bit(bitmap, max, bit + 1);
505 	KUNIT_ASSERT_EQ(test, bit, start + len);
506 }
507 
508 static void
509 test_free_blocks_simple_range(struct kunit *test, ext4_group_t goal_group,
510 			      ext4_grpblk_t start, ext4_grpblk_t len)
511 {
512 	struct super_block *sb = (struct super_block *)test->priv;
513 	struct ext4_sb_info *sbi = EXT4_SB(sb);
514 	struct inode *inode;
515 	ext4_fsblk_t block;
516 
517 	inode = kunit_kzalloc(test, sizeof(*inode), GFP_KERNEL);
518 	if (!inode)
519 		return;
520 	inode->i_sb = sb;
521 
522 	if (len == 0)
523 		return;
524 
525 	block = ext4_group_first_block_no(sb, goal_group) +
526 		EXT4_C2B(sbi, start);
527 	ext4_free_blocks_simple(inode, block, len);
528 	validate_free_blocks_simple(test, sb, goal_group, start, len);
529 	mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
530 }
531 
532 static void test_free_blocks_simple(struct kunit *test)
533 {
534 	struct super_block *sb = (struct super_block *)test->priv;
535 	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
536 	ext4_group_t i;
537 	struct test_range ranges[TEST_RANGE_COUNT];
538 
539 	for (i = 0; i < ext4_get_groups_count(sb); i++)
540 		mbt_ctx_mark_used(sb, i, 0, max);
541 
542 	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
543 	for (i = 0; i < TEST_RANGE_COUNT; i++)
544 		test_free_blocks_simple_range(test, TEST_GOAL_GROUP,
545 			ranges[i].start, ranges[i].len);
546 }
547 
548 static void
549 test_mark_diskspace_used_range(struct kunit *test,
550 			       struct ext4_allocation_context *ac,
551 			       ext4_grpblk_t start,
552 			       ext4_grpblk_t len)
553 {
554 	struct super_block *sb = (struct super_block *)test->priv;
555 	int ret;
556 	void *bitmap;
557 	ext4_grpblk_t i, max;
558 
559 	/* ext4_mb_mark_diskspace_used will BUG if len is 0 */
560 	if (len == 0)
561 		return;
562 
563 	ac->ac_b_ex.fe_group = TEST_GOAL_GROUP;
564 	ac->ac_b_ex.fe_start = start;
565 	ac->ac_b_ex.fe_len = len;
566 
567 	bitmap = mbt_ctx_bitmap(sb, TEST_GOAL_GROUP);
568 	memset(bitmap, 0, sb->s_blocksize);
569 	ret = ext4_mb_mark_diskspace_used(ac, NULL, 0);
570 	KUNIT_ASSERT_EQ(test, ret, 0);
571 
572 	max = EXT4_CLUSTERS_PER_GROUP(sb);
573 	i = mb_find_next_bit(bitmap, max, 0);
574 	KUNIT_ASSERT_EQ(test, i, start);
575 	i = mb_find_next_zero_bit(bitmap, max, i + 1);
576 	KUNIT_ASSERT_EQ(test, i, start + len);
577 	i = mb_find_next_bit(bitmap, max, i + 1);
578 	KUNIT_ASSERT_EQ(test, max, i);
579 }
580 
581 static void test_mark_diskspace_used(struct kunit *test)
582 {
583 	struct super_block *sb = (struct super_block *)test->priv;
584 	struct inode *inode;
585 	struct ext4_allocation_context ac;
586 	struct test_range ranges[TEST_RANGE_COUNT];
587 	int i;
588 
589 	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
590 
591 	inode = kunit_kzalloc(test, sizeof(*inode), GFP_KERNEL);
592 	if (!inode)
593 		return;
594 	inode->i_sb = sb;
595 
596 	ac.ac_status = AC_STATUS_FOUND;
597 	ac.ac_sb = sb;
598 	ac.ac_inode = inode;
599 	for (i = 0; i < TEST_RANGE_COUNT; i++)
600 		test_mark_diskspace_used_range(test, &ac, ranges[i].start,
601 					       ranges[i].len);
602 }
603 
604 static void mbt_generate_buddy(struct super_block *sb, void *buddy,
605 			       void *bitmap, struct ext4_group_info *grp)
606 {
607 	struct ext4_sb_info *sbi = EXT4_SB(sb);
608 	uint32_t order, off;
609 	void *bb, *bb_h;
610 	int max;
611 
612 	memset(buddy, 0xff, sb->s_blocksize);
613 	memset(grp, 0, offsetof(struct ext4_group_info,
614 				 bb_counters[MB_NUM_ORDERS(sb)]));
615 
616 	bb = bitmap;
617 	max = EXT4_CLUSTERS_PER_GROUP(sb);
618 	bb_h = buddy + sbi->s_mb_offsets[1];
619 
620 	off = mb_find_next_zero_bit(bb, max, 0);
621 	grp->bb_first_free = off;
622 	while (off < max) {
623 		grp->bb_counters[0]++;
624 		grp->bb_free++;
625 
626 		if (!(off & 1) && !mb_test_bit(off + 1, bb)) {
627 			grp->bb_free++;
628 			grp->bb_counters[0]--;
629 			mb_clear_bit(off >> 1, bb_h);
630 			grp->bb_counters[1]++;
631 			grp->bb_largest_free_order = 1;
632 			off++;
633 		}
634 
635 		off = mb_find_next_zero_bit(bb, max, off + 1);
636 	}
637 
638 	for (order = 1; order < MB_NUM_ORDERS(sb) - 1; order++) {
639 		bb = buddy + sbi->s_mb_offsets[order];
640 		bb_h = buddy + sbi->s_mb_offsets[order + 1];
641 		max = max >> 1;
642 		off = mb_find_next_zero_bit(bb, max, 0);
643 
644 		while (off < max) {
645 			if (!(off & 1) && !mb_test_bit(off + 1, bb)) {
646 				mb_set_bits(bb, off, 2);
647 				grp->bb_counters[order] -= 2;
648 				mb_clear_bit(off >> 1, bb_h);
649 				grp->bb_counters[order + 1]++;
650 				grp->bb_largest_free_order = order + 1;
651 				off++;
652 			}
653 
654 			off = mb_find_next_zero_bit(bb, max, off + 1);
655 		}
656 	}
657 
658 	max = EXT4_CLUSTERS_PER_GROUP(sb);
659 	off = mb_find_next_zero_bit(bitmap, max, 0);
660 	while (off < max) {
661 		grp->bb_fragments++;
662 
663 		off = mb_find_next_bit(bitmap, max, off + 1);
664 		if (off + 1 >= max)
665 			break;
666 
667 		off = mb_find_next_zero_bit(bitmap, max, off + 1);
668 	}
669 }
670 
671 static void
672 mbt_validate_group_info(struct kunit *test, struct ext4_group_info *grp1,
673 			struct ext4_group_info *grp2)
674 {
675 	struct super_block *sb = (struct super_block *)test->priv;
676 	int i;
677 
678 	KUNIT_ASSERT_EQ(test, grp1->bb_first_free,
679 			grp2->bb_first_free);
680 	KUNIT_ASSERT_EQ(test, grp1->bb_fragments,
681 			grp2->bb_fragments);
682 	KUNIT_ASSERT_EQ(test, grp1->bb_free, grp2->bb_free);
683 	KUNIT_ASSERT_EQ(test, grp1->bb_largest_free_order,
684 			grp2->bb_largest_free_order);
685 
686 	for (i = 1; i < MB_NUM_ORDERS(sb); i++) {
687 		KUNIT_ASSERT_EQ_MSG(test, grp1->bb_counters[i],
688 				    grp2->bb_counters[i],
689 				    "bb_counters[%d] diffs, expected %d, generated %d",
690 				    i, grp1->bb_counters[i],
691 				    grp2->bb_counters[i]);
692 	}
693 }
694 
695 static void
696 do_test_generate_buddy(struct kunit *test, struct super_block *sb, void *bitmap,
697 			   void *mbt_buddy, struct ext4_group_info *mbt_grp,
698 			   void *ext4_buddy, struct ext4_group_info *ext4_grp)
699 {
700 	int i;
701 
702 	mbt_generate_buddy(sb, mbt_buddy, bitmap, mbt_grp);
703 
704 	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
705 		ext4_grp->bb_counters[i] = 0;
706 	/* needed by validation in ext4_mb_generate_buddy */
707 	ext4_grp->bb_free = mbt_grp->bb_free;
708 	memset(ext4_buddy, 0xff, sb->s_blocksize);
709 	ext4_mb_generate_buddy(sb, ext4_buddy, bitmap, TEST_GOAL_GROUP,
710 			       ext4_grp);
711 
712 	KUNIT_ASSERT_EQ(test, memcmp(mbt_buddy, ext4_buddy, sb->s_blocksize),
713 			0);
714 	mbt_validate_group_info(test, mbt_grp, ext4_grp);
715 }
716 
717 static void test_mb_generate_buddy(struct kunit *test)
718 {
719 	struct super_block *sb = (struct super_block *)test->priv;
720 	void *bitmap, *expected_bb, *generate_bb;
721 	struct ext4_group_info *expected_grp, *generate_grp;
722 	struct test_range ranges[TEST_RANGE_COUNT];
723 	int i;
724 
725 	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
726 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
727 	expected_bb = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
728 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_bb);
729 	generate_bb = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
730 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, generate_bb);
731 	expected_grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
732 				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
733 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_grp);
734 	generate_grp = ext4_get_group_info(sb, TEST_GOAL_GROUP);
735 	KUNIT_ASSERT_NOT_NULL(test, generate_grp);
736 
737 	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
738 	for (i = 0; i < TEST_RANGE_COUNT; i++) {
739 		mb_set_bits(bitmap, ranges[i].start, ranges[i].len);
740 		do_test_generate_buddy(test, sb, bitmap, expected_bb,
741 				       expected_grp, generate_bb, generate_grp);
742 	}
743 }
744 
745 static void
746 test_mb_mark_used_range(struct kunit *test, struct ext4_buddy *e4b,
747 			ext4_grpblk_t start, ext4_grpblk_t len, void *bitmap,
748 			void *buddy, struct ext4_group_info *grp)
749 {
750 	struct super_block *sb = (struct super_block *)test->priv;
751 	struct ext4_free_extent ex;
752 	int i;
753 
754 	/* mb_mark_used only accepts non-zero len */
755 	if (len == 0)
756 		return;
757 
758 	ex.fe_start = start;
759 	ex.fe_len = len;
760 	ex.fe_group = TEST_GOAL_GROUP;
761 
762 	ext4_lock_group(sb, TEST_GOAL_GROUP);
763 	mb_mark_used(e4b, &ex);
764 	ext4_unlock_group(sb, TEST_GOAL_GROUP);
765 
766 	mb_set_bits(bitmap, start, len);
767 	/* bypass bb_free validatoin in ext4_mb_generate_buddy */
768 	grp->bb_free -= len;
769 	memset(buddy, 0xff, sb->s_blocksize);
770 	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
771 		grp->bb_counters[i] = 0;
772 	ext4_mb_generate_buddy(sb, buddy, bitmap, 0, grp);
773 
774 	KUNIT_ASSERT_EQ(test, memcmp(buddy, e4b->bd_buddy, sb->s_blocksize),
775 			0);
776 	mbt_validate_group_info(test, grp, e4b->bd_info);
777 }
778 
779 static void test_mb_mark_used(struct kunit *test)
780 {
781 	struct ext4_buddy e4b;
782 	struct super_block *sb = (struct super_block *)test->priv;
783 	void *bitmap, *buddy;
784 	struct ext4_group_info *grp;
785 	int ret;
786 	struct test_range ranges[TEST_RANGE_COUNT];
787 	int i;
788 
789 	/* buddy cache assumes that each page contains at least one block */
790 	if (sb->s_blocksize > PAGE_SIZE)
791 		kunit_skip(test, "blocksize exceeds pagesize");
792 
793 	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
794 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
795 	buddy = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
796 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy);
797 	grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
798 				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
799 
800 	ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b);
801 	KUNIT_ASSERT_EQ(test, ret, 0);
802 
803 	grp->bb_free = EXT4_CLUSTERS_PER_GROUP(sb);
804 	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
805 	for (i = 0; i < TEST_RANGE_COUNT; i++)
806 		test_mb_mark_used_range(test, &e4b, ranges[i].start,
807 					ranges[i].len, bitmap, buddy, grp);
808 
809 	ext4_mb_unload_buddy(&e4b);
810 }
811 
812 static void
813 test_mb_free_blocks_range(struct kunit *test, struct ext4_buddy *e4b,
814 			  ext4_grpblk_t start, ext4_grpblk_t len, void *bitmap,
815 			  void *buddy, struct ext4_group_info *grp)
816 {
817 	struct super_block *sb = (struct super_block *)test->priv;
818 	int i;
819 
820 	/* mb_free_blocks will WARN if len is 0 */
821 	if (len == 0)
822 		return;
823 
824 	ext4_lock_group(sb, e4b->bd_group);
825 	mb_free_blocks(NULL, e4b, start, len);
826 	ext4_unlock_group(sb, e4b->bd_group);
827 
828 	mb_clear_bits(bitmap, start, len);
829 	/* bypass bb_free validatoin in ext4_mb_generate_buddy */
830 	grp->bb_free += len;
831 	memset(buddy, 0xff, sb->s_blocksize);
832 	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
833 		grp->bb_counters[i] = 0;
834 	ext4_mb_generate_buddy(sb, buddy, bitmap, 0, grp);
835 
836 	KUNIT_ASSERT_EQ(test, memcmp(buddy, e4b->bd_buddy, sb->s_blocksize),
837 			0);
838 	mbt_validate_group_info(test, grp, e4b->bd_info);
839 
840 }
841 
842 static void test_mb_free_blocks(struct kunit *test)
843 {
844 	struct ext4_buddy e4b;
845 	struct super_block *sb = (struct super_block *)test->priv;
846 	void *bitmap, *buddy;
847 	struct ext4_group_info *grp;
848 	struct ext4_free_extent ex;
849 	int ret;
850 	int i;
851 	struct test_range ranges[TEST_RANGE_COUNT];
852 
853 	/* buddy cache assumes that each page contains at least one block */
854 	if (sb->s_blocksize > PAGE_SIZE)
855 		kunit_skip(test, "blocksize exceeds pagesize");
856 
857 	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
858 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
859 	buddy = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
860 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy);
861 	grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
862 				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
863 
864 	ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b);
865 	KUNIT_ASSERT_EQ(test, ret, 0);
866 
867 	ex.fe_start = 0;
868 	ex.fe_len = EXT4_CLUSTERS_PER_GROUP(sb);
869 	ex.fe_group = TEST_GOAL_GROUP;
870 
871 	ext4_lock_group(sb, TEST_GOAL_GROUP);
872 	mb_mark_used(&e4b, &ex);
873 	ext4_unlock_group(sb, TEST_GOAL_GROUP);
874 
875 	grp->bb_free = 0;
876 	memset(bitmap, 0xff, sb->s_blocksize);
877 
878 	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
879 	for (i = 0; i < TEST_RANGE_COUNT; i++)
880 		test_mb_free_blocks_range(test, &e4b, ranges[i].start,
881 					  ranges[i].len, bitmap, buddy, grp);
882 
883 	ext4_mb_unload_buddy(&e4b);
884 }
885 
886 #define COUNT_FOR_ESTIMATE 100000
887 static void test_mb_mark_used_cost(struct kunit *test)
888 {
889 	struct ext4_buddy e4b;
890 	struct super_block *sb = (struct super_block *)test->priv;
891 	struct ext4_free_extent ex;
892 	int ret;
893 	struct test_range ranges[TEST_RANGE_COUNT];
894 	int i, j;
895 	unsigned long start, end, all = 0;
896 
897 	/* buddy cache assumes that each page contains at least one block */
898 	if (sb->s_blocksize > PAGE_SIZE)
899 		kunit_skip(test, "blocksize exceeds pagesize");
900 
901 	ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b);
902 	KUNIT_ASSERT_EQ(test, ret, 0);
903 
904 	ex.fe_group = TEST_GOAL_GROUP;
905 	for (j = 0; j < COUNT_FOR_ESTIMATE; j++) {
906 		mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
907 		start = jiffies;
908 		for (i = 0; i < TEST_RANGE_COUNT; i++) {
909 			if (ranges[i].len == 0)
910 				continue;
911 
912 			ex.fe_start = ranges[i].start;
913 			ex.fe_len = ranges[i].len;
914 			ext4_lock_group(sb, TEST_GOAL_GROUP);
915 			mb_mark_used(&e4b, &ex);
916 			ext4_unlock_group(sb, TEST_GOAL_GROUP);
917 		}
918 		end = jiffies;
919 		all += (end - start);
920 
921 		for (i = 0; i < TEST_RANGE_COUNT; i++) {
922 			if (ranges[i].len == 0)
923 				continue;
924 
925 			ext4_lock_group(sb, TEST_GOAL_GROUP);
926 			mb_free_blocks(NULL, &e4b, ranges[i].start,
927 				       ranges[i].len);
928 			ext4_unlock_group(sb, TEST_GOAL_GROUP);
929 		}
930 	}
931 
932 	kunit_info(test, "costed jiffies %lu\n", all);
933 	ext4_mb_unload_buddy(&e4b);
934 }
935 
936 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
937 	{
938 		.blocksize_bits = 10,
939 		.cluster_bits = 3,
940 		.blocks_per_group = 8192,
941 		.group_count = 4,
942 		.desc_size = 64,
943 	},
944 	{
945 		.blocksize_bits = 12,
946 		.cluster_bits = 3,
947 		.blocks_per_group = 8192,
948 		.group_count = 4,
949 		.desc_size = 64,
950 	},
951 	{
952 		.blocksize_bits = 16,
953 		.cluster_bits = 3,
954 		.blocks_per_group = 8192,
955 		.group_count = 4,
956 		.desc_size = 64,
957 	},
958 };
959 
960 static void mbt_show_layout(const struct mbt_ext4_block_layout *layout,
961 			    char *desc)
962 {
963 	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "block_bits=%d cluster_bits=%d "
964 		 "blocks_per_group=%d group_count=%d desc_size=%d\n",
965 		 layout->blocksize_bits, layout->cluster_bits,
966 		 layout->blocks_per_group, layout->group_count,
967 		 layout->desc_size);
968 }
969 KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
970 
971 static struct kunit_case mbt_test_cases[] = {
972 	KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
973 	KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
974 	KUNIT_CASE_PARAM(test_mb_generate_buddy, mbt_layouts_gen_params),
975 	KUNIT_CASE_PARAM(test_mb_mark_used, mbt_layouts_gen_params),
976 	KUNIT_CASE_PARAM(test_mb_free_blocks, mbt_layouts_gen_params),
977 	KUNIT_CASE_PARAM(test_mark_diskspace_used, mbt_layouts_gen_params),
978 	KUNIT_CASE_PARAM_ATTR(test_mb_mark_used_cost, mbt_layouts_gen_params,
979 			      { .speed = KUNIT_SPEED_SLOW }),
980 	{}
981 };
982 
983 static struct kunit_suite mbt_test_suite = {
984 	.name = "ext4_mballoc_test",
985 	.init = mbt_kunit_init,
986 	.exit = mbt_kunit_exit,
987 	.test_cases = mbt_test_cases,
988 };
989 
990 kunit_test_suites(&mbt_test_suite);
991 
992 MODULE_LICENSE("GPL");
993