ext4: Add unit test for mb_free_blocks

Add unit test for mb_free_blocks.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240103104900.464789-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index 38e3644..b68f447 100644 (file)
--- 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),
        {}
 };