[PATCH 0/5] More unit test for mballoc

[PATCH 0/5] More unit test for mballoc

[Kemeng Shi]

Sorry for the late update as I was busy on my own things.
This series covers more function to mark on-disk bitmap. Besides, some
code which is relevant to buddy cache is also tested.
Before more work is done, I want to be sure I'm not on a wrong
direction!

Kemeng Shi (5):
  ext4: Add unit test for test_free_blocks_simple
  ext4: Add unit test of ext4_mb_generate_buddy
  ext4: Add unit test for mb_mark_used
  ext4: Add unit test for mb_free_blocks
  ext4: Add unit test for ext4_mb_mark_diskspace_used

 fs/ext4/mballoc-test.c | 504 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 504 insertions(+)

-- 
2.30.0

[PATCH 1/5] ext4: Add unit test for test_free_blocks_simple

[Kemeng Shi]

Add unit test for test_free_blocks_simple.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/mballoc-test.c | 96 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index f94901fd3..3aac42ea6 100644
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -5,6 +5,7 @@
 
 #include <kunit/test.h>
 #include <kunit/static_stub.h>
+#include <linux/random.h>
 
 #include "ext4.h"
 
@@ -112,6 +113,13 @@ static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group,
 	mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len);
 }
 
+static void *mbt_ctx_bitmap(struct super_block *sb, ext4_group_t group)
+{
+	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
+
+	return grp_ctx->bitmap_bh.b_data;
+}
+
 /* called after mbt_init_sb_layout */
 static int mbt_ctx_init(struct super_block *sb)
 {
@@ -297,6 +305,93 @@ static void test_new_blocks_simple(struct kunit *test)
 		"unexpectedly get block when no block is available");
 }
 
+#define TEST_RANGE_COUNT 8
+
+struct test_range {
+	ext4_grpblk_t start;
+	ext4_grpblk_t len;
+};
+
+static void
+mbt_generate_test_ranges(struct super_block *sb, struct test_range *ranges,
+			 int count)
+{
+	ext4_grpblk_t start, len, max;
+	int i;
+
+	max = EXT4_CLUSTERS_PER_GROUP(sb) / count;
+	for (i = 0; i < count; i++) {
+		start = get_random_u32() % max;
+		len = get_random_u32() % max;
+		len = min(len, max - start);
+
+		ranges[i].start = start + i * max;
+		ranges[i].len = len;
+	}
+}
+
+static void
+validate_free_blocks_simple(struct kunit *test, struct super_block *sb,
+			    ext4_group_t goal_group, ext4_grpblk_t start,
+			    ext4_grpblk_t len)
+{
+	void *bitmap;
+	ext4_grpblk_t bit, max = EXT4_CLUSTERS_PER_GROUP(sb);
+	ext4_group_t i;
+
+	for (i = 0; i < ext4_get_groups_count(sb); i++) {
+		if (i == goal_group)
+			continue;
+
+		bitmap = mbt_ctx_bitmap(sb, i);
+		bit = mb_find_next_zero_bit(bitmap, max, 0);
+		KUNIT_ASSERT_EQ_MSG(test, bit, max,
+				    "free block on unexpected group %d", i);
+	}
+
+	bitmap = mbt_ctx_bitmap(sb, goal_group);
+	bit = mb_find_next_zero_bit(bitmap, max, 0);
+	KUNIT_ASSERT_EQ(test, bit, start);
+
+	bit = mb_find_next_bit(bitmap, max, bit + 1);
+	KUNIT_ASSERT_EQ(test, bit, start + len);
+}
+
+static void
+test_free_blocks_simple_range(struct kunit *test, ext4_group_t goal_group,
+			      ext4_grpblk_t start, ext4_grpblk_t len)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct inode inode = { .i_sb = sb, };
+	ext4_fsblk_t block;
+
+	if (len == 0)
+		return;
+
+	block = ext4_group_first_block_no(sb, goal_group) +
+		EXT4_C2B(sbi, start);
+	ext4_free_blocks_simple(&inode, block, len);
+	validate_free_blocks_simple(test, sb, goal_group, start, len);
+	mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
+}
+
+static void test_free_blocks_simple(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
+	ext4_group_t i;
+	struct test_range ranges[TEST_RANGE_COUNT];
+
+	for (i = 0; i < ext4_get_groups_count(sb); i++)
+		mbt_ctx_mark_used(sb, i, 0, max);
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_free_blocks_simple_range(test, TEST_GOAL_GROUP,
+			ranges[i].start, ranges[i].len);
+}
+
 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
 	{
 		.blocksize_bits = 10,
@@ -334,6 +429,7 @@ KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
 
 static struct kunit_case mbt_test_cases[] = {
 	KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
 	{}
 };
 
-- 
2.30.0

[PATCH 2/5] ext4: Add unit test of ext4_mb_generate_buddy

[Kemeng Shi]

Add unit test of ext4_mb_generate_buddy

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/mballoc-test.c | 207 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 207 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index 3aac42ea6..6964974fa 100644
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -28,6 +28,50 @@ struct mbt_ext4_super_block {
 #define MBT_CTX(_sb) (&(container_of((_sb), struct mbt_ext4_super_block, sb)->mbt_ctx))
 #define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group])
 
+static const struct super_operations mbt_sops = {
+};
+
+static int mbt_mb_init(struct super_block *sb)
+{
+	int ret;
+
+	/* needed by ext4_mb_init->bdev_nonrot(sb->s_bdev) */
+	sb->s_bdev = kzalloc(sizeof(*sb->s_bdev), GFP_KERNEL);
+	if (sb->s_bdev == NULL)
+		return -ENOMEM;
+
+	sb->s_bdev->bd_queue = kzalloc(sizeof(struct request_queue), GFP_KERNEL);
+	if (sb->s_bdev->bd_queue == NULL) {
+		kfree(sb->s_bdev);
+		return -ENOMEM;
+	}
+
+	/*
+	 * needed by ext4_mb_init->ext4_mb_init_backend-> sbi->s_buddy_cache =
+	 * new_inode(sb);
+	 */
+	INIT_LIST_HEAD(&sb->s_inodes);
+	sb->s_op = &mbt_sops;
+
+	ret = ext4_mb_init(sb);
+	if (ret != 0)
+		goto err_out;
+
+	return 0;
+
+err_out:
+	kfree(sb->s_bdev->bd_queue);
+	kfree(sb->s_bdev);
+	return ret;
+}
+
+static void mbt_mb_release(struct super_block *sb)
+{
+	ext4_mb_release(sb);
+	kfree(sb->s_bdev->bd_queue);
+	kfree(sb->s_bdev);
+}
+
 static struct super_block *mbt_ext4_alloc_super_block(void)
 {
 	struct ext4_super_block *es = kzalloc(sizeof(*es), GFP_KERNEL);
@@ -37,8 +81,16 @@ static struct super_block *mbt_ext4_alloc_super_block(void)
 	if (fsb == NULL || sbi == NULL || es == NULL)
 		goto out;
 
+	sbi->s_blockgroup_lock =
+		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
+	if (!sbi->s_blockgroup_lock)
+		goto out;
+
+	bgl_lock_init(sbi->s_blockgroup_lock);
+
 	sbi->s_es = es;
 	fsb->sb.s_fs_info = sbi;
+
 	return &fsb->sb;
 
 out:
@@ -54,6 +106,7 @@ static void mbt_ext4_free_super_block(struct super_block *sb)
 		container_of(sb, struct mbt_ext4_super_block, sb);
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
+	kfree(sbi->s_blockgroup_lock);
 	kfree(sbi->s_es);
 	kfree(sbi);
 	kfree(fsb);
@@ -83,6 +136,9 @@ static void mbt_init_sb_layout(struct super_block *sb,
 	sbi->s_clusters_per_group = layout->blocks_per_group >>
 				    layout->cluster_bits;
 	sbi->s_desc_size = layout->desc_size;
+	sbi->s_desc_per_block_bits =
+		sb->s_blocksize_bits - (fls(layout->desc_size) - 1);
+	sbi->s_desc_per_block = 1 << sbi->s_desc_per_block_bits;
 
 	es->s_first_data_block = cpu_to_le32(0);
 	es->s_blocks_count_lo = cpu_to_le32(layout->blocks_per_group *
@@ -240,6 +296,14 @@ static int mbt_kunit_init(struct kunit *test)
 	kunit_activate_static_stub(test,
 				   ext4_mb_mark_context,
 				   ext4_mb_mark_context_stub);
+
+	/* stub function will be called in mt_mb_init->ext4_mb_init */
+	if (mbt_mb_init(sb) != 0) {
+		mbt_ctx_release(sb);
+		mbt_ext4_free_super_block(sb);
+		return -ENOMEM;
+	}
+
 	return 0;
 }
 
@@ -247,6 +311,7 @@ static void mbt_kunit_exit(struct kunit *test)
 {
 	struct super_block *sb = (struct super_block *)test->priv;
 
+	mbt_mb_release(sb);
 	mbt_ctx_release(sb);
 	mbt_ext4_free_super_block(sb);
 }
@@ -392,6 +457,147 @@ static void test_free_blocks_simple(struct kunit *test)
 			ranges[i].start, ranges[i].len);
 }
 
+static void mbt_generate_buddy(struct super_block *sb, void *buddy,
+			       void *bitmap, struct ext4_group_info *grp)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	uint32_t order, off;
+	void *bb, *bb_h;
+	int max;
+
+	memset(buddy, 0xff, sb->s_blocksize);
+	memset(grp, 0, offsetof(struct ext4_group_info,
+				 bb_counters[MB_NUM_ORDERS(sb)]));
+
+	bb = bitmap;
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	bb_h = buddy + sbi->s_mb_offsets[1];
+
+	off = mb_find_next_zero_bit(bb, max, 0);
+	grp->bb_first_free = off;
+	while (off < max) {
+		grp->bb_counters[0]++;
+		grp->bb_free++;
+
+		if (!(off & 1) && !mb_test_bit(off + 1, bb)) {
+			grp->bb_free++;
+			grp->bb_counters[0]--;
+			mb_clear_bit(off >> 1, bb_h);
+			grp->bb_counters[1]++;
+			grp->bb_largest_free_order = 1;
+			off++;
+		}
+
+		off = mb_find_next_zero_bit(bb, max, off + 1);
+	}
+
+	for (order = 1; order < MB_NUM_ORDERS(sb) - 1; order++) {
+		bb = buddy + sbi->s_mb_offsets[order];
+		bb_h = buddy + sbi->s_mb_offsets[order + 1];
+		max = max >> 1;
+		off = mb_find_next_zero_bit(bb, max, 0);
+
+		while (off < max) {
+			if (!(off & 1) && !mb_test_bit(off + 1, bb)) {
+				mb_set_bits(bb, off, 2);
+				grp->bb_counters[order] -= 2;
+				mb_clear_bit(off >> 1, bb_h);
+				grp->bb_counters[order + 1]++;
+				grp->bb_largest_free_order = order + 1;
+				off++;
+			}
+
+			off = mb_find_next_zero_bit(bb, max, off + 1);
+		}
+	}
+
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	off = mb_find_next_zero_bit(bitmap, max, 0);
+	while (off < max) {
+		grp->bb_fragments++;
+
+		off = mb_find_next_bit(bitmap, max, off + 1);
+		if (off + 1 >= max)
+			break;
+
+		off = mb_find_next_zero_bit(bitmap, max, off + 1);
+	}
+}
+
+static void
+mbt_validate_group_info(struct kunit *test, struct ext4_group_info *grp1,
+			struct ext4_group_info *grp2)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	int i;
+
+	KUNIT_ASSERT_EQ(test, grp1->bb_first_free,
+			grp2->bb_first_free);
+	KUNIT_ASSERT_EQ(test, grp1->bb_fragments,
+			grp2->bb_fragments);
+	KUNIT_ASSERT_EQ(test, grp1->bb_free, grp2->bb_free);
+	KUNIT_ASSERT_EQ(test, grp1->bb_largest_free_order,
+			grp2->bb_largest_free_order);
+
+	for (i = 1; i < MB_NUM_ORDERS(sb); i++) {
+		KUNIT_ASSERT_EQ_MSG(test, grp1->bb_counters[i],
+				    grp2->bb_counters[i],
+				    "bb_counters[%d] diffs, expected %d, generated %d",
+				    i, grp1->bb_counters[i],
+				    grp2->bb_counters[i]);
+	}
+}
+
+static void
+do_test_generate_buddy(struct kunit *test, struct super_block *sb, void *bitmap,
+			   void *mbt_buddy, struct ext4_group_info *mbt_grp,
+			   void *ext4_buddy, struct ext4_group_info *ext4_grp)
+{
+	int i;
+
+	mbt_generate_buddy(sb, mbt_buddy, bitmap, mbt_grp);
+
+	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
+		ext4_grp->bb_counters[i] = 0;
+	/* needed by validation in ext4_mb_generate_buddy */
+	ext4_grp->bb_free = mbt_grp->bb_free;
+	memset(ext4_buddy, 0xff, sb->s_blocksize);
+	ext4_mb_generate_buddy(sb, ext4_buddy, bitmap, TEST_GOAL_GROUP,
+			       ext4_grp);
+
+	KUNIT_ASSERT_EQ(test, memcmp(mbt_buddy, ext4_buddy, sb->s_blocksize),
+			0);
+	mbt_validate_group_info(test, mbt_grp, ext4_grp);
+}
+
+static void test_mb_generate_buddy(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	void *bitmap, *expected_bb, *generate_bb;
+	struct ext4_group_info *expected_grp, *generate_grp;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i;
+
+	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
+	expected_bb = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_bb);
+	generate_bb = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, generate_bb);
+	expected_grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
+				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_grp);
+	generate_grp = ext4_get_group_info(sb, TEST_GOAL_GROUP);
+	KUNIT_ASSERT_NOT_NULL(test, generate_grp);
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++) {
+		mb_set_bits(bitmap, ranges[i].start, ranges[i].len);
+		do_test_generate_buddy(test, sb, bitmap, expected_bb,
+				       expected_grp, generate_bb, generate_grp);
+	}
+}
+
 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
 	{
 		.blocksize_bits = 10,
@@ -430,6 +636,7 @@ KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
 static struct kunit_case mbt_test_cases[] = {
 	KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mb_generate_buddy, mbt_layouts_gen_params),
 	{}
 };
 
-- 
2.30.0

[PATCH 3/5] ext4: Add unit test for mb_mark_used

[Kemeng Shi]

Add unit test for mb_mark_used

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/mballoc-test.c | 78 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index 6964974fa..38e3644cb 100644
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -148,9 +148,13 @@ static void mbt_init_sb_layout(struct super_block *sb,
 static int mbt_grp_ctx_init(struct super_block *sb,
 			    struct mbt_grp_ctx *grp_ctx)
 {
+	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
+
 	grp_ctx->bitmap_bh.b_data = kzalloc(EXT4_BLOCK_SIZE(sb), GFP_KERNEL);
 	if (grp_ctx->bitmap_bh.b_data == NULL)
 		return -ENOMEM;
+	mb_set_bits(grp_ctx->bitmap_bh.b_data, max, sb->s_blocksize * 8 - max);
+	ext4_free_group_clusters_set(sb, &grp_ctx->desc, max);
 
 	return 0;
 }
@@ -197,6 +201,8 @@ static int mbt_ctx_init(struct super_block *sb)
 	 * block which will fail ext4_sb_block_valid check.
 	 */
 	mb_set_bits(ctx->grp_ctx[0].bitmap_bh.b_data, 0, 1);
+	ext4_free_group_clusters_set(sb, &ctx->grp_ctx[0].desc,
+				     EXT4_CLUSTERS_PER_GROUP(sb) - 1);
 
 	return 0;
 out:
@@ -231,6 +237,13 @@ static int ext4_wait_block_bitmap_stub(struct super_block *sb,
 				       ext4_group_t block_group,
 				       struct buffer_head *bh)
 {
+	/*
+	 * real ext4_wait_block_bitmap will set these flags and
+	 * functions like ext4_mb_init_cache will verify the flags.
+	 */
+	set_buffer_uptodate(bh);
+	set_bitmap_uptodate(bh);
+	set_buffer_verified(bh);
 	return 0;
 }
 
@@ -598,6 +611,70 @@ static void test_mb_generate_buddy(struct kunit *test)
 	}
 }
 
+static void
+test_mb_mark_used_range(struct kunit *test, struct ext4_buddy *e4b,
+			ext4_grpblk_t start, ext4_grpblk_t len, void *bitmap,
+			void *buddy, struct ext4_group_info *grp)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct ext4_free_extent ex;
+	int i;
+
+	/* mb_mark_used only accepts non-zero len */
+	if (len == 0)
+		return;
+
+	ex.fe_start = start;
+	ex.fe_len = len;
+	ex.fe_group = TEST_GOAL_GROUP;
+	mb_mark_used(e4b, &ex);
+
+	mb_set_bits(bitmap, start, len);
+	/* bypass bb_free validatoin in ext4_mb_generate_buddy */
+	grp->bb_free -= len;
+	memset(buddy, 0xff, sb->s_blocksize);
+	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
+		grp->bb_counters[i] = 0;
+	ext4_mb_generate_buddy(sb, buddy, bitmap, 0, grp);
+
+	KUNIT_ASSERT_EQ(test, memcmp(buddy, e4b->bd_buddy, sb->s_blocksize),
+			0);
+	mbt_validate_group_info(test, grp, e4b->bd_info);
+}
+
+static void test_mb_mark_used(struct kunit *test)
+{
+	struct ext4_buddy e4b;
+	struct super_block *sb = (struct super_block *)test->priv;
+	void *bitmap, *buddy;
+	struct ext4_group_info *grp;
+	int ret;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i;
+
+	/* buddy cache assumes that each page contains at least one block */
+	if (sb->s_blocksize > PAGE_SIZE)
+		kunit_skip(test, "blocksize exceeds pagesize");
+
+	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
+	buddy = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy);
+	grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
+				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
+
+	ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	grp->bb_free = EXT4_CLUSTERS_PER_GROUP(sb);
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_mb_mark_used_range(test, &e4b, ranges[i].start,
+					ranges[i].len, bitmap, buddy, grp);
+
+	ext4_mb_unload_buddy(&e4b);
+}
+
 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
 	{
 		.blocksize_bits = 10,
@@ -637,6 +714,7 @@ static struct kunit_case mbt_test_cases[] = {
 	KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_mb_generate_buddy, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mb_mark_used, mbt_layouts_gen_params),
 	{}
 };
 
-- 
2.30.0

[PATCH 4/5] ext4: Add unit test for mb_free_blocks

[Kemeng Shi]

Add unit test for mb_free_blocks.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/mballoc-test.c | 69 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index 38e3644cb..b68f44740 100644
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -675,6 +675,74 @@ static void test_mb_mark_used(struct kunit *test)
 	ext4_mb_unload_buddy(&e4b);
 }
 
+static void
+test_mb_free_blocks_range(struct kunit *test, struct ext4_buddy *e4b,
+			  ext4_grpblk_t start, ext4_grpblk_t len, void *bitmap,
+			  void *buddy, struct ext4_group_info *grp)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	int i;
+
+	/* mb_free_blocks will WARN if len is 0 */
+	if (len == 0)
+		return;
+
+	mb_free_blocks(NULL, e4b, start, len);
+
+	mb_clear_bits(bitmap, start, len);
+	/* bypass bb_free validatoin in ext4_mb_generate_buddy */
+	grp->bb_free += len;
+	memset(buddy, 0xff, sb->s_blocksize);
+	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
+		grp->bb_counters[i] = 0;
+	ext4_mb_generate_buddy(sb, buddy, bitmap, 0, grp);
+
+	KUNIT_ASSERT_EQ(test, memcmp(buddy, e4b->bd_buddy, sb->s_blocksize),
+			0);
+	mbt_validate_group_info(test, grp, e4b->bd_info);
+
+}
+
+static void test_mb_free_blocks(struct kunit *test)
+{
+	struct ext4_buddy e4b;
+	struct super_block *sb = (struct super_block *)test->priv;
+	void *bitmap, *buddy;
+	struct ext4_group_info *grp;
+	struct ext4_free_extent ex;
+	int ret;
+	int i;
+	struct test_range ranges[TEST_RANGE_COUNT];
+
+	/* buddy cache assumes that each page contains at least one block */
+	if (sb->s_blocksize > PAGE_SIZE)
+		kunit_skip(test, "blocksize exceeds pagesize");
+
+	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
+	buddy = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy);
+	grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
+				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
+
+	ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ex.fe_start = 0;
+	ex.fe_len = EXT4_CLUSTERS_PER_GROUP(sb);
+	ex.fe_group = TEST_GOAL_GROUP;
+	mb_mark_used(&e4b, &ex);
+	grp->bb_free = 0;
+	memset(bitmap, 0xff, sb->s_blocksize);
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_mb_free_blocks_range(test, &e4b, ranges[i].start,
+					  ranges[i].len, bitmap, buddy, grp);
+
+	ext4_mb_unload_buddy(&e4b);
+}
+
 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
 	{
 		.blocksize_bits = 10,
@@ -715,6 +783,7 @@ static struct kunit_case mbt_test_cases[] = {
 	KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_mb_generate_buddy, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_mb_mark_used, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mb_free_blocks, mbt_layouts_gen_params),
 	{}
 };
 
-- 
2.30.0

[PATCH 5/5] ext4: Add unit test for ext4_mb_mark_diskspace_used

[Kemeng Shi]

Add unit test for ext4_mb_mark_diskspace_used

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/mballoc-test.c | 54 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index b68f44740..8d5d27ab5 100644
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -470,6 +470,59 @@ static void test_free_blocks_simple(struct kunit *test)
 			ranges[i].start, ranges[i].len);
 }
 
+static void
+test_mark_diskspace_used_range(struct kunit *test,
+			       struct ext4_allocation_context *ac,
+			       ext4_grpblk_t start,
+			       ext4_grpblk_t len)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	int ret;
+	void *bitmap;
+	ext4_grpblk_t i, max;
+
+	/* ext4_mb_mark_diskspace_used will BUG if len is 0 */
+	if (len == 0)
+		return;
+
+	ac->ac_b_ex.fe_group = TEST_GOAL_GROUP;
+	ac->ac_b_ex.fe_start = start;
+	ac->ac_b_ex.fe_len = len;
+
+	bitmap = mbt_ctx_bitmap(sb, TEST_GOAL_GROUP);
+	memset(bitmap, 0, sb->s_blocksize);
+	ret = ext4_mb_mark_diskspace_used(ac, NULL, 0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	i = mb_find_next_bit(bitmap, max, 0);
+	KUNIT_ASSERT_EQ(test, i, start);
+	i = mb_find_next_zero_bit(bitmap, max, i + 1);
+	KUNIT_ASSERT_EQ(test, i, start + len);
+	i = mb_find_next_bit(bitmap, max, i + 1);
+	KUNIT_ASSERT_EQ(test, max, i);
+}
+
+static void test_mark_diskspace_used(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct inode inode = { .i_sb = sb, };
+	ext4_grpblk_t max;
+	struct ext4_allocation_context ac;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i;
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+
+	ac.ac_status = AC_STATUS_FOUND;
+	ac.ac_sb = sb;
+	ac.ac_inode = &inode;
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_mark_diskspace_used_range(test, &ac, ranges[i].start,
+					       ranges[i].len);
+}
+
 static void mbt_generate_buddy(struct super_block *sb, void *buddy,
 			       void *bitmap, struct ext4_group_info *grp)
 {
@@ -784,6 +837,7 @@ static struct kunit_case mbt_test_cases[] = {
 	KUNIT_CASE_PARAM(test_mb_generate_buddy, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_mb_mark_used, mbt_layouts_gen_params),
 	KUNIT_CASE_PARAM(test_mb_free_blocks, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mark_diskspace_used, mbt_layouts_gen_params),
 	{}
 };
 
-- 
2.30.0

Re: [PATCH 5/5] ext4: Add unit test for ext4_mb_mark_diskspace_used

[kernel test robot]

Hi Kemeng,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tytso-ext4/dev]
[also build test WARNING on linus/master v6.7-rc2 next-20231124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kemeng-Shi/ext4-Add-unit-test-for-test_free_blocks_simple/20231125-154444
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
patch link:    https://lore.kernel.org/r/20231125154144.3943442-6-shikemeng%40huaweicloud.com
patch subject: [PATCH 5/5] ext4: Add unit test for ext4_mb_mark_diskspace_used
config: i386-buildonly-randconfig-004-20231125 (https://download.01.org/0day-ci/archive/20231125/202311252009.Z6vrLAjg-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231125/202311252009.Z6vrLAjg-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311252009.Z6vrLAjg-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from fs/ext4/mballoc.c:6996:
   fs/ext4/mballoc-test.c: In function 'test_mark_diskspace_used':
>> fs/ext4/mballoc-test.c:510:23: warning: variable 'max' set but not used [-Wunused-but-set-variable]
     510 |         ext4_grpblk_t max;
         |                       ^~~


vim +/max +510 fs/ext4/mballoc-test.c

   505	
   506	static void test_mark_diskspace_used(struct kunit *test)
   507	{
   508		struct super_block *sb = (struct super_block *)test->priv;
   509		struct inode inode = { .i_sb = sb, };
 > 510		ext4_grpblk_t max;
   511		struct ext4_allocation_context ac;
   512		struct test_range ranges[TEST_RANGE_COUNT];
   513		int i;
   514	
   515		mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
   516	
   517		ac.ac_status = AC_STATUS_FOUND;
   518		ac.ac_sb = sb;
   519		ac.ac_inode = &inode;
   520		max = EXT4_CLUSTERS_PER_GROUP(sb);
   521		for (i = 0; i < TEST_RANGE_COUNT; i++)
   522			test_mark_diskspace_used_range(test, &ac, ranges[i].start,
   523						       ranges[i].len);
   524	}
   525	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 5/5] ext4: Add unit test for ext4_mb_mark_diskspace_used

[kernel test robot]

Hi Kemeng,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tytso-ext4/dev]
[also build test WARNING on linus/master v6.7-rc2 next-20231124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kemeng-Shi/ext4-Add-unit-test-for-test_free_blocks_simple/20231125-154444
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
patch link:    https://lore.kernel.org/r/20231125154144.3943442-6-shikemeng%40huaweicloud.com
patch subject: [PATCH 5/5] ext4: Add unit test for ext4_mb_mark_diskspace_used
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20231126/202311260042.kMxL6DnL-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231126/202311260042.kMxL6DnL-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311260042.kMxL6DnL-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from fs/ext4/mballoc.c:6996:
   fs/ext4/mballoc-test.c:510:16: warning: variable 'max' set but not used [-Wunused-but-set-variable]
           ext4_grpblk_t max;
                         ^
>> fs/ext4/mballoc-test.c:506:13: warning: stack frame size (1036) exceeds limit (1024) in 'test_mark_diskspace_used' [-Wframe-larger-than]
   static void test_mark_diskspace_used(struct kunit *test)
               ^
   39/1036 (3.76%) spills, 997/1036 (96.24%) variables
   2 warnings generated.


vim +/test_mark_diskspace_used +506 fs/ext4/mballoc-test.c

   505	
 > 506	static void test_mark_diskspace_used(struct kunit *test)
   507	{
   508		struct super_block *sb = (struct super_block *)test->priv;
   509		struct inode inode = { .i_sb = sb, };
   510		ext4_grpblk_t max;
   511		struct ext4_allocation_context ac;
   512		struct test_range ranges[TEST_RANGE_COUNT];
   513		int i;
   514	
   515		mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
   516	
   517		ac.ac_status = AC_STATUS_FOUND;
   518		ac.ac_sb = sb;
   519		ac.ac_inode = &inode;
   520		max = EXT4_CLUSTERS_PER_GROUP(sb);
   521		for (i = 0; i < TEST_RANGE_COUNT; i++)
   522			test_mark_diskspace_used_range(test, &ac, ranges[i].start,
   523						       ranges[i].len);
   524	}
   525	

-- 
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https://github.com/intel/lkp-tests/wiki