From 7c9fa399a369546c0e0375ea4b354d642a8fe501 Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Fri, 29 Sep 2023 00:04:06 +0800 Subject: ext4: add first unit test for ext4_mb_new_blocks_simple in mballoc Here are prepared work: 1. Include mballoc-test.c to mballoc.c to be able test static function in mballoc.c. 2. Implement static stub to avoid read IO to disk. 3. Construct fake super_block. Only partial members are set, more members will be set when more functions are tested. Then unit test for ext4_mb_new_blocks_simple is added. Signed-off-by: Kemeng Shi Reviewed-by: "Ritesh Harjani (IBM)" Link: https://lore.kernel.org/r/20230928160407.142069-12-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/ext4/mballoc-test.c | 325 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/ext4/mballoc.c | 4 + 2 files changed, 329 insertions(+) create mode 100644 fs/ext4/mballoc-test.c (limited to 'fs/ext4') diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c new file mode 100644 index 000000000000..120c4944d2e1 --- /dev/null +++ b/fs/ext4/mballoc-test.c @@ -0,0 +1,325 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit test of ext4 multiblocks allocation. + */ + +#include +#include + +#include "ext4.h" + +struct mbt_grp_ctx { + struct buffer_head bitmap_bh; + /* desc and gd_bh are just the place holders for now */ + struct ext4_group_desc desc; + struct buffer_head gd_bh; +}; + +struct mbt_ctx { + struct mbt_grp_ctx *grp_ctx; +}; + +struct mbt_ext4_super_block { + struct super_block sb; + struct mbt_ctx mbt_ctx; +}; + +#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 struct super_block *mbt_ext4_alloc_super_block(void) +{ + struct ext4_super_block *es = kzalloc(sizeof(*es), GFP_KERNEL); + struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); + struct mbt_ext4_super_block *fsb = kzalloc(sizeof(*fsb), GFP_KERNEL); + + if (fsb == NULL || sbi == NULL || es == NULL) + goto out; + + sbi->s_es = es; + fsb->sb.s_fs_info = sbi; + return &fsb->sb; + +out: + kfree(fsb); + kfree(sbi); + kfree(es); + return NULL; +} + +static void mbt_ext4_free_super_block(struct super_block *sb) +{ + struct mbt_ext4_super_block *fsb = + container_of(sb, struct mbt_ext4_super_block, sb); + struct ext4_sb_info *sbi = EXT4_SB(sb); + + kfree(sbi->s_es); + kfree(sbi); + kfree(fsb); +} + +struct mbt_ext4_block_layout { + unsigned char blocksize_bits; + unsigned int cluster_bits; + uint32_t blocks_per_group; + ext4_group_t group_count; + uint16_t desc_size; +}; + +static void mbt_init_sb_layout(struct super_block *sb, + struct mbt_ext4_block_layout *layout) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + + sb->s_blocksize = 1UL << layout->blocksize_bits; + sb->s_blocksize_bits = layout->blocksize_bits; + + sbi->s_groups_count = layout->group_count; + sbi->s_blocks_per_group = layout->blocks_per_group; + sbi->s_cluster_bits = layout->cluster_bits; + sbi->s_cluster_ratio = 1U << layout->cluster_bits; + sbi->s_clusters_per_group = layout->blocks_per_group >> + layout->cluster_bits; + sbi->s_desc_size = layout->desc_size; + + es->s_first_data_block = cpu_to_le32(0); + es->s_blocks_count_lo = cpu_to_le32(layout->blocks_per_group * + layout->group_count); +} + +static int mbt_grp_ctx_init(struct super_block *sb, + struct mbt_grp_ctx *grp_ctx) +{ + grp_ctx->bitmap_bh.b_data = kzalloc(EXT4_BLOCK_SIZE(sb), GFP_KERNEL); + if (grp_ctx->bitmap_bh.b_data == NULL) + return -ENOMEM; + + return 0; +} + +static void mbt_grp_ctx_release(struct mbt_grp_ctx *grp_ctx) +{ + kfree(grp_ctx->bitmap_bh.b_data); + grp_ctx->bitmap_bh.b_data = NULL; +} + +static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group, + unsigned int start, unsigned int len) +{ + struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group); + + mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len); +} + +/* called after mbt_init_sb_layout */ +static int mbt_ctx_init(struct super_block *sb) +{ + struct mbt_ctx *ctx = MBT_CTX(sb); + ext4_group_t i, ngroups = ext4_get_groups_count(sb); + + ctx->grp_ctx = kcalloc(ngroups, sizeof(struct mbt_grp_ctx), + GFP_KERNEL); + if (ctx->grp_ctx == NULL) + return -ENOMEM; + + for (i = 0; i < ngroups; i++) + if (mbt_grp_ctx_init(sb, &ctx->grp_ctx[i])) + goto out; + + /* + * first data block(first cluster in first group) is used by + * metadata, mark it used to avoid to alloc data block at first + * block which will fail ext4_sb_block_valid check. + */ + mb_set_bits(ctx->grp_ctx[0].bitmap_bh.b_data, 0, 1); + + return 0; +out: + while (i-- > 0) + mbt_grp_ctx_release(&ctx->grp_ctx[i]); + kfree(ctx->grp_ctx); + return -ENOMEM; +} + +static void mbt_ctx_release(struct super_block *sb) +{ + struct mbt_ctx *ctx = MBT_CTX(sb); + ext4_group_t i, ngroups = ext4_get_groups_count(sb); + + for (i = 0; i < ngroups; i++) + mbt_grp_ctx_release(&ctx->grp_ctx[i]); + kfree(ctx->grp_ctx); +} + +static struct buffer_head * +ext4_read_block_bitmap_nowait_stub(struct super_block *sb, ext4_group_t block_group, + bool ignore_locked) +{ + struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group); + + /* paired with brelse from caller of ext4_read_block_bitmap_nowait */ + get_bh(&grp_ctx->bitmap_bh); + return &grp_ctx->bitmap_bh; +} + +static int ext4_wait_block_bitmap_stub(struct super_block *sb, + ext4_group_t block_group, + struct buffer_head *bh) +{ + return 0; +} + +static struct ext4_group_desc * +ext4_get_group_desc_stub(struct super_block *sb, ext4_group_t block_group, + struct buffer_head **bh) +{ + struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group); + + if (bh != NULL) + *bh = &grp_ctx->gd_bh; + + return &grp_ctx->desc; +} + +static int +ext4_mb_mark_context_stub(handle_t *handle, struct super_block *sb, bool state, + ext4_group_t group, ext4_grpblk_t blkoff, + ext4_grpblk_t len, int flags, + ext4_grpblk_t *ret_changed) +{ + struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group); + struct buffer_head *bitmap_bh = &grp_ctx->bitmap_bh; + + if (state) + mb_set_bits(bitmap_bh->b_data, blkoff, len); + else + mb_clear_bits(bitmap_bh->b_data, blkoff, len); + + return 0; +} + +#define TEST_BLOCKSIZE_BITS 10 +#define TEST_CLUSTER_BITS 3 +#define TEST_BLOCKS_PER_GROUP 8192 +#define TEST_GROUP_COUNT 4 +#define TEST_DESC_SIZE 64 +#define TEST_GOAL_GROUP 1 +static int mbt_kunit_init(struct kunit *test) +{ + struct mbt_ext4_block_layout layout = { + .blocksize_bits = TEST_BLOCKSIZE_BITS, + .cluster_bits = TEST_CLUSTER_BITS, + .blocks_per_group = TEST_BLOCKS_PER_GROUP, + .group_count = TEST_GROUP_COUNT, + .desc_size = TEST_DESC_SIZE, + }; + struct super_block *sb; + int ret; + + sb = mbt_ext4_alloc_super_block(); + if (sb == NULL) + return -ENOMEM; + + mbt_init_sb_layout(sb, &layout); + + ret = mbt_ctx_init(sb); + if (ret != 0) { + mbt_ext4_free_super_block(sb); + return ret; + } + + test->priv = sb; + kunit_activate_static_stub(test, + ext4_read_block_bitmap_nowait, + ext4_read_block_bitmap_nowait_stub); + kunit_activate_static_stub(test, + ext4_wait_block_bitmap, + ext4_wait_block_bitmap_stub); + kunit_activate_static_stub(test, + ext4_get_group_desc, + ext4_get_group_desc_stub); + kunit_activate_static_stub(test, + ext4_mb_mark_context, + ext4_mb_mark_context_stub); + return 0; +} + +static void mbt_kunit_exit(struct kunit *test) +{ + struct super_block *sb = (struct super_block *)test->priv; + + mbt_ctx_release(sb); + mbt_ext4_free_super_block(sb); +} + +static void test_new_blocks_simple(struct kunit *test) +{ + struct super_block *sb = (struct super_block *)test->priv; + struct inode inode = { .i_sb = sb, }; + struct ext4_allocation_request ar; + ext4_group_t i, goal_group = TEST_GOAL_GROUP; + int err = 0; + ext4_fsblk_t found; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + ar.inode = &inode; + + /* get block at goal */ + ar.goal = ext4_group_first_block_no(sb, goal_group); + found = ext4_mb_new_blocks_simple(&ar, &err); + KUNIT_ASSERT_EQ_MSG(test, ar.goal, found, + "failed to alloc block at goal, expected %llu found %llu", + ar.goal, found); + + /* get block after goal in goal group */ + ar.goal = ext4_group_first_block_no(sb, goal_group); + found = ext4_mb_new_blocks_simple(&ar, &err); + KUNIT_ASSERT_EQ_MSG(test, ar.goal + EXT4_C2B(sbi, 1), found, + "failed to alloc block after goal in goal group, expected %llu found %llu", + ar.goal + 1, found); + + /* get block after goal group */ + mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb)); + ar.goal = ext4_group_first_block_no(sb, goal_group); + found = ext4_mb_new_blocks_simple(&ar, &err); + KUNIT_ASSERT_EQ_MSG(test, + ext4_group_first_block_no(sb, goal_group + 1), found, + "failed to alloc block after goal group, expected %llu found %llu", + ext4_group_first_block_no(sb, goal_group + 1), found); + + /* get block before goal group */ + for (i = goal_group; i < ext4_get_groups_count(sb); i++) + mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb)); + ar.goal = ext4_group_first_block_no(sb, goal_group); + found = ext4_mb_new_blocks_simple(&ar, &err); + KUNIT_ASSERT_EQ_MSG(test, + ext4_group_first_block_no(sb, 0) + EXT4_C2B(sbi, 1), found, + "failed to alloc block before goal group, expected %llu found %llu", + ext4_group_first_block_no(sb, 0 + EXT4_C2B(sbi, 1)), found); + + /* no block available, fail to allocate block */ + for (i = 0; i < ext4_get_groups_count(sb); i++) + mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb)); + ar.goal = ext4_group_first_block_no(sb, goal_group); + found = ext4_mb_new_blocks_simple(&ar, &err); + KUNIT_ASSERT_NE_MSG(test, err, 0, + "unexpectedly get block when no block is available"); +} + + +static struct kunit_case mbt_test_cases[] = { + KUNIT_CASE(test_new_blocks_simple), + {} +}; + +static struct kunit_suite mbt_test_suite = { + .name = "ext4_mballoc_test", + .init = mbt_kunit_init, + .exit = mbt_kunit_exit, + .test_cases = mbt_test_cases, +}; + +kunit_test_suites(&mbt_test_suite); + +MODULE_LICENSE("GPL"); diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 401b8329d1e1..454d5612641e 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -6991,3 +6991,7 @@ out_unload: return error; } + +#ifdef CONFIG_EXT4_KUNIT_TESTS +#include "mballoc-test.c" +#endif -- cgit v1.2.3