StupidFS/include/stupidfs.h

174 lines
No EOL
8 KiB
C

/**
* \file stupidfs.h
*
* StupidFS Filesystem
*
* ```
* ┌──────────┬───────────┬──────┬───┬──────┬────┬───┬────┐
* │Boot block│Super block│Inodes│...│Inodes│Data│...│Data│
* └──────────┴───────────┴──────┴───┴──────┴────┴───┴────┘
* ```
*/
#ifndef STUPIDFS_H
# define STUPIDFS_H 1
# ifndef __KERNEL__
# include <stdint.h>
# include <stddef.h>
# endif
# define STPDFS_BLOCK_SIZE 512 /**< StupidFS block size */
# define STPDFS_INODES_PER_BLOCK (STPDFS_BLOCK_SIZE / (sizeof(struct stpdfs_inode)))
# define STPDFS_ZONES_PER_BLOCK (STPDFS_BLOCK_SIZE / sizeof(uint32_t))
# define STPDFS_DIRENT_PER_BLOCK (STPDFS_BLOCK_SIZE / (sizeof(struct stpdfs_dirent)))
# define STPDFS_SB_BLOCK 1
# define STPDFS_SB_MAGIC 0x44505453 /**< Superblock magic number */
# define STPDFS_SB_REV STPDFS_SB_REV_1 /**< current revision */
# define STPDFS_SB_REV_1 1
# define STPDFS_BADINO 0 /**< StupidFS bad inode number */
# define STPDFS_ROOTINO 1 /**< StupidFS root inode number */
# define STPDFS_NAME_MAX 28 /**< Max filename length */
/**
* \brief free block list
* ```
* ┌──────────┐
* │ block 99 │
* ├──────────┤
* │ block 98 │
* ├──────────┤
* │ ... │
* ├──────────┤
* │ block 2 │
* ├──────────┤
* │ block 1 │
* ├──────────┤ ┌──────────┐
* │ block 0 ├───►│ block 99 │
* └──────────┘ ├──────────┤
* │ ... │
* ├──────────┤ ┌──────────┐
* │ block 0 ├──►│ block 99 │
* └──────────┘ ├──────────┤
* │ ... │
* ├──────────┤
* │ block 0 │
* └──────────┘
* ```
*/
struct stpdfs_free {
uint32_t free[100]; /**< List of free block (0-99), index 0 point to next freelist */
uint8_t nfree; /**< index */
} __attribute__((packed));
enum stpdfs_state {
STPDFS_CLEANLY_UNMOUNTED = 0,
STPDFS_ERROR = 1,
STPDFS_DIRTY = 1,
};
/**
* \brief StupidFS Superblock
*/
struct stpdfs_sb {
uint32_t magic; /**< MUST be \ref STPDFS_SB_MAGIC */
uint32_t isize; /**< Size in block of the I list */
uint32_t fsize; /**< Size in block of the entire volume */
struct stpdfs_free freelist; /**< \see stpdfs_free */
uint8_t revision; /**< MUST be \ref STPDFS_SB_REV */
uint16_t state; /**< \see stpdfs_state */
uint64_t time; /**< Last time the superblock was modified */
} __attribute__((packed));
#define STPDFS_SB_SIZE sizeof(struct stpdfs_sb)
/**
* \brief StupidFS I-node
*
* ```
* ┌────────┐
* │ │
* ┌───────►│ │
* │ │ │
* ┌──────┐ Direct│ └────────┘
* │zone 0├───────┘
* ├──────┤
* │... │
* ├──────┤ ┌────────┐ ┌────────┐
* │zone 6│ │ ├─────►│ │
* ├──────┤ Indirect │ │ │ │
* │zone 7├─────────►│ │ │ │
* ├──────┤ └────────┘ └────────┘
* │zone 8├───────┐
* ├──────┤ │Double indirect┌────────┐ ┌────────┐ ┌────────┐
* │zone 9│ └──────────────►│ ├───►│ ├───►│ │
* └──┬───┘ │ │ │ │ │ │
* │ │ │ │ │ │ │
* │ └────────┘ └────────┘ └────────┘
* │ Triple indirect ┌────────┐
* └────────────────►│ │ ┌────────┐ ┌────────┐ ┌────────┐
* │ ├───►│ │ │ │ │ │
* │ │ │ ├─────►│ ├─────►│ │
* └────────┘ │ │ │ │ │ │
* └────────┘ └────────┘ └────────┘
* ```
*/
struct stpdfs_inode {
uint16_t mode; /**< File mode */
uint16_t nlink; /**< Link count */
uint16_t uid; /**< Owner user id */
uint16_t gid; /**< Group id */
uint16_t flags; /** File flags */
uint32_t size; /** Data size in byte */
uint32_t zones[10];
uint64_t actime; /**< Access time */
uint64_t modtime; /**< Modification time */
} __attribute__((packed));
#define STPDFS_INODE_SIZE sizeof(struct inode)
# define STPDFS_NDIR 7 /**< Number of direct block */
# define STPDFS_INO_FLAG_ALOC (1 << 15)
# define STPDFS_INO_FLAG_LZP (1 << 1)
# define STPDFS_INO_FLAG_ENC (1 << 2)
# define STPDFS_S_IFMT 0xF000
# define STPDFS_S_IFSOCK 0xA000
# define STPDFS_S_IFLNK 0xC000
# define STPDFS_S_IFREG 0x8000
# define STPDFS_S_IFBLK 0x6000
# define STPDFS_S_IFDIR 0x4000
# define STPDFS_S_ISUID 0x0800
# define STPDFS_S_ISGID 0x0400
# define STPDFS_S_ISVTX 0x0200
# define STPDFS_S_IRWXU 0x01C0
# define STPDFS_S_IRUSR 0x0100
# define STPDFS_S_IWUSR 0x0080
# define STPDFS_S_IXUSR 0x0040
# define STPDFS_S_IRWXG 0x0038
# define STPDFS_S_IRGRP 0x0020
# define STPDFS_S_IWGRP 0x0010
# define STPDFS_S_IXGRP 0x0008
# define STPDFS_S_IRWXO 0x0007
# define STPDFS_S_IROTH 0x0004
# define STPDFS_S_IWOTH 0x0002
# define STPDFS_S_IXOTH 0x0001
/**
* \brief StupidFS directory entry
*/
struct stpdfs_dirent {
uint32_t inode; /**< inode containing file */
char filename[STPDFS_NAME_MAX]; /** null terminated file name (\see STPDFS_NAME_MAX) */
};
#define STPDFS_DIRENT_SIZE sizeof(struct stpdfs_dirent)
#endif /* !STPIDFS_H */