ext4: Add unit test of ext4_mb_generate_buddy

Add unit test of ext4_mb_generate_buddy

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240103104900.464789-3-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 3aac42ea6a36b3721a8ea7d2855733f57463b86e..6964974fa5365f6d2bc20842134af9a49bcdf6a2 100644 (file)
--- 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),
        {}
 };