forked from Imagelibrary/littlefs
106b06a457
The core algorithim that backs this filesystem's goal of fault tolerance is the alternating of "metadata pairs". Backed by a simple core function for reading and writing, makes heavy use of c99 designated initializers for passing info about multiple chunks in an erase block.
96 lines
2.0 KiB
C
96 lines
2.0 KiB
C
/*
|
|
* The little filesystem
|
|
*
|
|
* Copyright (c) 2017 Christopher Haster
|
|
* Distributed under the MIT license
|
|
*/
|
|
#ifndef LFS_H
|
|
#define LFS_H
|
|
|
|
#include "lfs_config.h"
|
|
#include "lfs_bd.h"
|
|
|
|
|
|
// Data structures
|
|
enum lfs_error {
|
|
LFS_ERROR_OK = 0,
|
|
LFS_ERROR_CORRUPT = -3,
|
|
};
|
|
|
|
typedef struct lfs_free {
|
|
lfs_disk_struct lfs_disk_free {
|
|
lfs_ino_t head;
|
|
lfs_word_t ioff;
|
|
lfs_word_t icount;
|
|
lfs_word_t rev;
|
|
} d;
|
|
} lfs_free_t;
|
|
|
|
typedef struct lfs_dir {
|
|
lfs_ino_t pair[2];
|
|
lfs_disk_struct lfs_disk_dir {
|
|
lfs_word_t rev;
|
|
lfs_size_t size;
|
|
lfs_ino_t tail[2];
|
|
lfs_ino_t parent[2];
|
|
|
|
struct lfs_disk_free free;
|
|
} d;
|
|
} lfs_dir_t;
|
|
|
|
typedef struct lfs_entry {
|
|
lfs_ino_t dir[2];
|
|
lfs_off_t off;
|
|
|
|
lfs_disk_struct lfs_disk_entry {
|
|
uint16_t type;
|
|
uint16_t len;
|
|
union {
|
|
lfs_disk_struct {
|
|
lfs_ino_t head;
|
|
lfs_size_t size;
|
|
char name[LFS_NAME_MAX];
|
|
} file;
|
|
lfs_disk_struct {
|
|
lfs_ino_t dir[2];
|
|
char name[LFS_NAME_MAX];
|
|
} dir;
|
|
lfs_disk_struct {
|
|
char magic[4];
|
|
uint32_t read_size;
|
|
uint32_t write_size;
|
|
uint32_t erase_size;
|
|
uint32_t erase_count;
|
|
} superblock;
|
|
} value;
|
|
} d;
|
|
} lfs_entry_t;
|
|
|
|
typedef struct lfs_superblock {
|
|
lfs_ino_t pair[2];
|
|
lfs_disk_struct lfs_disk_superblock {
|
|
lfs_word_t rev;
|
|
uint32_t size;
|
|
lfs_ino_t root[2];
|
|
char magic[8];
|
|
uint32_t block_size;
|
|
uint32_t block_count;
|
|
} d;
|
|
} lfs_superblock_t;
|
|
|
|
// Little filesystem type
|
|
typedef struct lfs {
|
|
lfs_bd_t *bd;
|
|
const struct lfs_bd_ops *ops;
|
|
|
|
lfs_free_t free;
|
|
struct lfs_bd_info info;
|
|
} lfs_t;
|
|
|
|
// Functions
|
|
lfs_error_t lfs_create(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops);
|
|
lfs_error_t lfs_format(lfs_t *lfs);
|
|
lfs_error_t lfs_mount(lfs_t *lfs);
|
|
|
|
#endif
|