path: root/fs/ext4/mballoc-test.c

// SPDX-License-Identifier: GPL-2.0
/*
 * KUnit test of ext4 multiblocks allocation.
 */

#include <kunit/test.h>
#include <kunit/static_stub.h>
#include <linux/random.h>

#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 ext4_super_block es;
	struct ext4_sb_info sbi;
	struct mbt_ctx mbt_ctx;
};

#define MBT_SB(_sb) (container_of((_sb)->s_fs_info, struct mbt_ext4_super_block, sbi))
#define MBT_CTX(_sb) (&MBT_SB(_sb)->mbt_ctx)
#define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group])

static struct inode *mbt_alloc_inode(struct super_block *sb)
{
	struct ext4_inode_info *ei;

	ei = kmalloc(sizeof(struct ext4_inode_info), GFP_KERNEL);
	if (!ei)
		return NULL;

	INIT_LIST_HEAD(&ei->i_orphan);
	init_rwsem(&ei->xattr_sem);
	init_rwsem(&ei->i_data_sem);
	inode_init_once(&ei->vfs_inode);
	ext4_fc_init_inode(&ei->vfs_inode);

	return &ei->vfs_inode;
}

static void mbt_free_inode(struct inode *inode)
{
	kfree(EXT4_I(inode));
}

static const struct super_operations mbt_sops = {
	.alloc_inode	= mbt_alloc_inode,
	.free_inode	= mbt_free_inode,
};

static void mbt_kill_sb(struct super_block *sb)
{
	generic_shutdown_super(sb);
}

static struct file_system_type mbt_fs_type = {
	.name			= "mballoc test",
	.kill_sb		= mbt_kill_sb,
};

static int mbt_mb_init(struct super_block *sb)
{
	ext4_fsblk_t block;
	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;

	block = ext4_count_free_clusters(sb);
	ret = percpu_counter_init(&EXT4_SB(sb)->s_freeclusters_counter, block,
				  GFP_KERNEL);
	if (ret != 0)
		goto err_mb_release;

	ret = percpu_counter_init(&EXT4_SB(sb)->s_dirtyclusters_counter, 0,
				  GFP_KERNEL);
	if (ret != 0)
		goto err_freeclusters;

	return 0;

err_freeclusters:
	percpu_counter_destroy(&EXT4_SB(sb)->s_freeclusters_counter);
err_mb_release:
	ext4_mb_release(sb);
err_out:
	kfree(sb->s_bdev->bd_queue);
	kfree(sb->s_bdev);
	return ret;
}

static void mbt_mb_release(struct super_block *sb)
{
	percpu_counter_destroy(&EXT4_SB(sb)->s_dirtyclusters_counter);
	percpu_counter_destroy(&EXT4_SB(sb)->s_freeclusters_counter);
	ext4_mb_release(sb);
	kfree(sb->s_bdev->bd_queue);
	kfree(sb->s_bdev);
}

static int mbt_set(struct super_block *sb, void *data)
{
	return 0;
}

static struct super_block *mbt_ext4_alloc_super_block(void)
{
	struct mbt_ext4_super_block *fsb;
	struct super_block *sb;
	struct ext4_sb_info *sbi;

	fsb = kzalloc(sizeof(*fsb), GFP_KERNEL);
	if (fsb == NULL)
		return NULL;

	sb = sget(&mbt_fs_type, NULL, mbt_set, 0, NULL);
	if (IS_ERR(sb))
		goto out;

	sbi = &fsb->sbi;

	sbi->s_blockgroup_lock =
		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
	if (!sbi->s_blockgroup_lock)
		goto out_deactivate;

	bgl_lock_init(sbi->s_blockgroup_lock);

	sbi->s_es = &fsb->es;
	sb->s_fs_info = sbi;

	up_write(&sb->s_umount);
	return sb;

out_deactivate:
	deactivate_locked_super(sb);
out:
	kfree(fsb);
	return NULL;
}

static void mbt_ext4_free_super_block(struct super_block *sb)
{
	struct mbt_ext4_super_block *fsb = MBT_SB(sb);
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	kfree(sbi->s_blockgroup_lock);
	deactivate_super(sb);
	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