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Kemeng Shitytso
Kemeng Shi
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tytso
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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 <[email protected]> Reviewed-by: "Ritesh Harjani (IBM)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
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‎fs/ext4/mballoc-test.c

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// SPDX-License-Identifier: GPL-2.0
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/*
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* KUnit test of ext4 multiblocks allocation.
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*/
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#include <kunit/test.h>
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#include <kunit/static_stub.h>
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#include "ext4.h"
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struct mbt_grp_ctx {
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struct buffer_head bitmap_bh;
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/* desc and gd_bh are just the place holders for now */
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struct ext4_group_desc desc;
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struct buffer_head gd_bh;
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};
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struct mbt_ctx {
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struct mbt_grp_ctx *grp_ctx;
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};
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struct mbt_ext4_super_block {
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struct super_block sb;
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struct mbt_ctx mbt_ctx;
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};
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#define MBT_CTX(_sb) (&(container_of((_sb), struct mbt_ext4_super_block, sb)->mbt_ctx))
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#define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group])
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static struct super_block *mbt_ext4_alloc_super_block(void)
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{
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struct ext4_super_block *es = kzalloc(sizeof(*es), GFP_KERNEL);
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struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
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struct mbt_ext4_super_block *fsb = kzalloc(sizeof(*fsb), GFP_KERNEL);
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if (fsb == NULL || sbi == NULL || es == NULL)
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goto out;
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sbi->s_es = es;
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fsb->sb.s_fs_info = sbi;
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return &fsb->sb;
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out:
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kfree(fsb);
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kfree(sbi);
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kfree(es);
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return NULL;
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}
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static void mbt_ext4_free_super_block(struct super_block *sb)
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{
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struct mbt_ext4_super_block *fsb =
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container_of(sb, struct mbt_ext4_super_block, sb);
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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kfree(sbi->s_es);
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kfree(sbi);
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kfree(fsb);
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}
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struct mbt_ext4_block_layout {
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unsigned char blocksize_bits;
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unsigned int cluster_bits;
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uint32_t blocks_per_group;
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ext4_group_t group_count;
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uint16_t desc_size;
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};
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static void mbt_init_sb_layout(struct super_block *sb,
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struct mbt_ext4_block_layout *layout)
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{
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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struct ext4_super_block *es = sbi->s_es;
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sb->s_blocksize = 1UL << layout->blocksize_bits;
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sb->s_blocksize_bits = layout->blocksize_bits;
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sbi->s_groups_count = layout->group_count;
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sbi->s_blocks_per_group = layout->blocks_per_group;
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sbi->s_cluster_bits = layout->cluster_bits;
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sbi->s_cluster_ratio = 1U << layout->cluster_bits;
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sbi->s_clusters_per_group = layout->blocks_per_group >>
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layout->cluster_bits;
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sbi->s_desc_size = layout->desc_size;
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es->s_first_data_block = cpu_to_le32(0);
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es->s_blocks_count_lo = cpu_to_le32(layout->blocks_per_group *
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layout->group_count);
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}
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static int mbt_grp_ctx_init(struct super_block *sb,
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struct mbt_grp_ctx *grp_ctx)
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{
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grp_ctx->bitmap_bh.b_data = kzalloc(EXT4_BLOCK_SIZE(sb), GFP_KERNEL);
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if (grp_ctx->bitmap_bh.b_data == NULL)
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return -ENOMEM;
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return 0;
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}
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static void mbt_grp_ctx_release(struct mbt_grp_ctx *grp_ctx)
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{
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kfree(grp_ctx->bitmap_bh.b_data);
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grp_ctx->bitmap_bh.b_data = NULL;
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}
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static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group,
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unsigned int start, unsigned int len)
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{
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struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
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mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len);
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}
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/* called after mbt_init_sb_layout */
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static int mbt_ctx_init(struct super_block *sb)
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{
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struct mbt_ctx *ctx = MBT_CTX(sb);
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ext4_group_t i, ngroups = ext4_get_groups_count(sb);
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ctx->grp_ctx = kcalloc(ngroups, sizeof(struct mbt_grp_ctx),
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GFP_KERNEL);
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if (ctx->grp_ctx == NULL)
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return -ENOMEM;
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for (i = 0; i < ngroups; i++)
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if (mbt_grp_ctx_init(sb, &ctx->grp_ctx[i]))
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goto out;
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/*
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* first data block(first cluster in first group) is used by
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* metadata, mark it used to avoid to alloc data block at first
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* block which will fail ext4_sb_block_valid check.
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*/
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mb_set_bits(ctx->grp_ctx[0].bitmap_bh.b_data, 0, 1);
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return 0;
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out:
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while (i-- > 0)
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mbt_grp_ctx_release(&ctx->grp_ctx[i]);
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kfree(ctx->grp_ctx);
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return -ENOMEM;
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}
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static void mbt_ctx_release(struct super_block *sb)
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{
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struct mbt_ctx *ctx = MBT_CTX(sb);
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ext4_group_t i, ngroups = ext4_get_groups_count(sb);
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for (i = 0; i < ngroups; i++)
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mbt_grp_ctx_release(&ctx->grp_ctx[i]);
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kfree(ctx->grp_ctx);
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}
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static struct buffer_head *
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ext4_read_block_bitmap_nowait_stub(struct super_block *sb, ext4_group_t block_group,
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bool ignore_locked)
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{
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struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
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/* paired with brelse from caller of ext4_read_block_bitmap_nowait */
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get_bh(&grp_ctx->bitmap_bh);
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return &grp_ctx->bitmap_bh;
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}
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static int ext4_wait_block_bitmap_stub(struct super_block *sb,
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ext4_group_t block_group,
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struct buffer_head *bh)
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{
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return 0;
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}
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static struct ext4_group_desc *
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ext4_get_group_desc_stub(struct super_block *sb, ext4_group_t block_group,
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struct buffer_head **bh)
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{
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struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
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if (bh != NULL)
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*bh = &grp_ctx->gd_bh;
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return &grp_ctx->desc;
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}
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static int
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ext4_mb_mark_context_stub(handle_t *handle, struct super_block *sb, bool state,
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ext4_group_t group, ext4_grpblk_t blkoff,
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ext4_grpblk_t len, int flags,
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ext4_grpblk_t *ret_changed)
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{
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struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
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struct buffer_head *bitmap_bh = &grp_ctx->bitmap_bh;
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if (state)
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mb_set_bits(bitmap_bh->b_data, blkoff, len);
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else
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mb_clear_bits(bitmap_bh->b_data, blkoff, len);
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return 0;
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}
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#define TEST_BLOCKSIZE_BITS 10
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#define TEST_CLUSTER_BITS 3
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#define TEST_BLOCKS_PER_GROUP 8192
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#define TEST_GROUP_COUNT 4
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#define TEST_DESC_SIZE 64
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#define TEST_GOAL_GROUP 1
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static int mbt_kunit_init(struct kunit *test)
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{
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struct mbt_ext4_block_layout layout = {
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.blocksize_bits = TEST_BLOCKSIZE_BITS,
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.cluster_bits = TEST_CLUSTER_BITS,
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.blocks_per_group = TEST_BLOCKS_PER_GROUP,
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.group_count = TEST_GROUP_COUNT,
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.desc_size = TEST_DESC_SIZE,
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};
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struct super_block *sb;
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int ret;
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sb = mbt_ext4_alloc_super_block();
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if (sb == NULL)
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return -ENOMEM;
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mbt_init_sb_layout(sb, &layout);
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ret = mbt_ctx_init(sb);
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if (ret != 0) {
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mbt_ext4_free_super_block(sb);
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return ret;
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}
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test->priv = sb;
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kunit_activate_static_stub(test,
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ext4_read_block_bitmap_nowait,
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ext4_read_block_bitmap_nowait_stub);
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kunit_activate_static_stub(test,
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ext4_wait_block_bitmap,
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ext4_wait_block_bitmap_stub);
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kunit_activate_static_stub(test,
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ext4_get_group_desc,
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ext4_get_group_desc_stub);
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kunit_activate_static_stub(test,
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ext4_mb_mark_context,
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ext4_mb_mark_context_stub);
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return 0;
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}
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static void mbt_kunit_exit(struct kunit *test)
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{
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struct super_block *sb = (struct super_block *)test->priv;
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mbt_ctx_release(sb);
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mbt_ext4_free_super_block(sb);
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}
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static void test_new_blocks_simple(struct kunit *test)
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{
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struct super_block *sb = (struct super_block *)test->priv;
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struct inode inode = { .i_sb = sb, };
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struct ext4_allocation_request ar;
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ext4_group_t i, goal_group = TEST_GOAL_GROUP;
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int err = 0;
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ext4_fsblk_t found;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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ar.inode = &inode;
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/* get block at goal */
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ar.goal = ext4_group_first_block_no(sb, goal_group);
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found = ext4_mb_new_blocks_simple(&ar, &err);
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KUNIT_ASSERT_EQ_MSG(test, ar.goal, found,
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"failed to alloc block at goal, expected %llu found %llu",
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ar.goal, found);
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/* get block after goal in goal group */
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ar.goal = ext4_group_first_block_no(sb, goal_group);
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found = ext4_mb_new_blocks_simple(&ar, &err);
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KUNIT_ASSERT_EQ_MSG(test, ar.goal + EXT4_C2B(sbi, 1), found,
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"failed to alloc block after goal in goal group, expected %llu found %llu",
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ar.goal + 1, found);
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/* get block after goal group */
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mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
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ar.goal = ext4_group_first_block_no(sb, goal_group);
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found = ext4_mb_new_blocks_simple(&ar, &err);
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KUNIT_ASSERT_EQ_MSG(test,
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ext4_group_first_block_no(sb, goal_group + 1), found,
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"failed to alloc block after goal group, expected %llu found %llu",
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ext4_group_first_block_no(sb, goal_group + 1), found);
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/* get block before goal group */
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for (i = goal_group; i < ext4_get_groups_count(sb); i++)
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mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
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ar.goal = ext4_group_first_block_no(sb, goal_group);
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found = ext4_mb_new_blocks_simple(&ar, &err);
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KUNIT_ASSERT_EQ_MSG(test,
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ext4_group_first_block_no(sb, 0) + EXT4_C2B(sbi, 1), found,
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"failed to alloc block before goal group, expected %llu found %llu",
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ext4_group_first_block_no(sb, 0 + EXT4_C2B(sbi, 1)), found);
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/* no block available, fail to allocate block */
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for (i = 0; i < ext4_get_groups_count(sb); i++)
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mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
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ar.goal = ext4_group_first_block_no(sb, goal_group);
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found = ext4_mb_new_blocks_simple(&ar, &err);
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KUNIT_ASSERT_NE_MSG(test, err, 0,
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"unexpectedly get block when no block is available");
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}
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static struct kunit_case mbt_test_cases[] = {
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KUNIT_CASE(test_new_blocks_simple),
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{}
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};
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static struct kunit_suite mbt_test_suite = {
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.name = "ext4_mballoc_test",
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.init = mbt_kunit_init,
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.exit = mbt_kunit_exit,
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.test_cases = mbt_test_cases,
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};
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kunit_test_suites(&mbt_test_suite);
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MODULE_LICENSE("GPL");

‎fs/ext4/mballoc.c

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -6991,3 +6991,7 @@ ext4_mballoc_query_range(
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69926992
return error;
69936993
}
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#ifdef CONFIG_EXT4_KUNIT_TESTS
6996+
#include "mballoc-test.c"
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#endif

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