Eulerfs 块分配数据结构

### 数据结构

##### eufs_allocator

分配器

```c
struct eufs_free_list {
        struct list_head free_blocks;
        unsigned int n_free_blocks;
};

struct eufs_mem_pool {
        spinlock_t lock;
        struct eufs_free_list list[NODE_CNT - 1];
};

struct eufs_allocator {
        u8 __pmem *huge_page_map;
        /* total space */
        unsigned long size;
        /* total huge pages */
        unsigned int total_huge_pages;
        /* start addr for allocator */
        void __pmem *start_addr;
        /* protect huge pages list */
        spinlock_t lock;
    	/* free huge page list */
		struct eufs_free_list huge_page_list;
        /* percpu memory pool */
        struct eufs_mem_pool __percpu *pool;
};
```

##### eufs_mem_node

表示空闲块的链表节点

```c
enum mem_node_type {
        HUGE_PAGE_NODE = 0,
        BIG_PAGE_NODE = 1,
        PAGE_NODE = 2,
        LINE4_NODE = 3,
        LINE_NODE = 4,
        NODE_CNT = 5,
};

ssize_t eufs_node_size[NODE_CNT] = {
        HUGE_PAGE_SIZE,
        BIG_PAGE_SIZE,
        PAGE_SIZE,
        LINE4_SIZE,
        CACHELINE_SIZE,
};

struct eufs_mem_node {
        struct list_head node;
        enum mem_node_type type;
        unsigned long index;
};
```

##### page_map

存放在huge_page中的第一个big_page里，要远小于一个big_page的大小

> 多余的空间用来作为page?

```c
struct page_map {
        u8 big_page_map[BIG_PAGES_PER_HUGE_PAGE];
        u8 page_map[BIG_PAGES_PER_HUGE_PAGE][PAGES_PER_BIG_PAGE];
};
```

##### line_map

一共256字节，正好存放在page的第一个line4里面

```c
struct line_map {
    	u8 line4_map[LINE4S_PER_PAGE];
        u8 line_map[LINE4S_PER_PAGE][LINES_PER_LINE4];
};
```

##### file mapping

暂时和之前保持一致，512叉树

#### 接口

##### eufs_node_addr(type, index)

计算分配块对应的物理地址， start_addr + node size * node index

##### eufs_addr_to_index(addr, mem_node_type)

根据分配出来的地址，计算index

##### eufs_init_allocator(struct super_block *sb, bool is_format)

format初始化按1G划分

> 不足部分按4k划分，存到cpu0对应的mem_pool?

非format初始化遍历map，相同huge_page的空闲块放到同一个cpu的mem_pool中

##### void *eufs_alloc(struct super_block *sb,  enum eufs_mem_type type)

实现拆分接口

- eufs_split

根据用途封装成不同的接口

- inode
- dentry
- htable
- file mapping
- file data

##### void eufs_free(struct super_block *sb, const void *addr, enum eufs_mem_type type)

暂时不考虑碎片化问题

##### u8 eufs_node_state(struct super_block *sb, enum eufs_mem_type type, unsigned long index)

读取块状态(空闲，已分配，被拆分，...)

##### void eufs_set_node_state(struct super_block *sb, struct eufs_mem_type type, unsigned long index)

设置块状态

##### ssize_t eufs_file_read()

##### ssize_t eufs_file_write()

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