ref: 6f14d3a3a15f85c47b1b146c5b82c21f015a4536
dir: /ext4.h/
/*
* Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup lwext4
* @{
*/
/**
* @file ext4.h
* @brief Ext4 high level operations (files, directories, mountpoints...).
* Client has to include only this file.
*/
#ifndef EXT4_H_
#define EXT4_H_
#include <ext4_config.h>
#include <ext4_blockdev.h>
#include <stdint.h>
/********************************FILE OPEN FLAGS*****************************/
#ifndef O_RDONLY
#define O_RDONLY 00
#endif
#ifndef O_WRONLY
#define O_WRONLY 01
#endif
#ifndef O_RDWR
#define O_RDWR 02
#endif
#ifndef O_CREAT
#define O_CREAT 0100
#endif
#ifndef O_EXCL
#define O_EXCL 0200
#endif
#ifndef O_TRUNC
#define O_TRUNC 01000
#endif
#ifndef O_APPEND
#define O_APPEND 02000
#endif
/********************************FILE SEEK FLAGS*****************************/
#ifndef SEEK_SET
#define SEEK_SET 0
#endif
#ifndef SEEK_CUR
#define SEEK_CUR 1
#endif
#ifndef SEEK_END
#define SEEK_END 2
#endif
/********************************OS LOCK INFERFACE***************************/
/**@brief OS dependent lock interface.*/
struct ext4_lock {
/**@brief Lock access to mountpoint*/
void (*lock)(void);
/**@brief Unlock access to mountpoint*/
void (*unlock)(void);
};
/********************************FILE DESCRIPTOR*****************************/
/**@brief File descriptor*/
typedef struct ext4_file {
/**@brief Pountpoint handle.*/
struct ext4_mountpoint *mp;
/**@brief File inode id*/
uint32_t inode;
/**@brief Open flags.*/
uint32_t flags;
/**@brief File size.*/
uint64_t fsize;
/**@brief File position*/
uint64_t fpos;
}ext4_file;
/*****************************DIRECTORY DESCRIPTOR***************************/
/**@brief Directory entry types. Copy from ext4_types.h*/
enum {
EXT4_DIRENTRY_UNKNOWN = 0,
EXT4_DIRENTRY_REG_FILE,
EXT4_DIRENTRY_DIR,
EXT4_DIRENTRY_CHRDEV,
EXT4_DIRENTRY_BLKDEV,
EXT4_DIRENTRY_FIFO,
EXT4_DIRENTRY_SOCK,
EXT4_DIRENTRY_SYMLINK
};
/**@brief Directory entry descriptor. Copy from ext4_types.h*/
typedef struct {
uint32_t inode;
uint16_t entry_length;
uint8_t name_length;
union {
uint8_t name_length_high;
uint8_t inode_type;
};
uint8_t name[255];
}ext4_direntry;
typedef struct {
/**@brief File descriptor*/
ext4_file f;
/**@brief Current direntry.*/
ext4_direntry de;
}ext4_dir;
/********************************MOUNT OPERATIONS****************************/
/**@brief Register a block device to a name.
* @warning Block device has to be filled by
* @ref EXT4_BLOCKDEV_STATIC_INSTANCE. Block cache may be created
* @ref EXT4_BCACHE_STATIC_INSTANCE.
* Block cache may by created automaticly when bc parameter is 0.
* @param bd block device
* @param bd block device cache (0 = automatic cache mode)
* @param dev_name register name
* @param standard error code*/
int ext4_device_register(struct ext4_blockdev *bd, struct ext4_bcache *bc,
const char *dev_name);
/**@brief Mount a block device with EXT4 partition to the mountpoint.
* @param dev_name block device name (@ref ext4_device_register)
* @param mount_point pount point, for example
* - /
* - /my_partition/
* - /my_second_partition/
*
* @return standard error code */
int ext4_mount(const char * dev_name, char *mount_point);
/**@brief Umount operation.
* @param mount_point mount name
* @return standard error code */
int ext4_umount(char *mount_point);
/**@brief Some of the filesystem stats.*/
struct ext4_mount_stats {
uint32_t inodes_count;
uint32_t free_inodes_count;
uint64_t blocks_count;
uint64_t free_blocks_count;
uint32_t block_size;
uint32_t block_group_count;
uint32_t blocks_per_group;
uint32_t inodes_per_group;
char volume_name[16];
};
/**@brief Get file system params.
* @param mount_point mount path
* @param stats ext fs stats
* @return standard error code */
int ext4_mount_point_stats(const char *mount_point,
struct ext4_mount_stats *stats);
/**@brief Enable/disable write back cache mode.
* @warning Default model of cache is write trough. It means that when You do:
*
* ext4_fopen(...);
* ext4_fwrie(...);
* < --- data is flushed to physical drive
*
* When you do:
* ext4_cache_write_back(..., 1);
* ext4_fopen(...);
* ext4_fwrie(...);
* < --- data is NOT flushed to physical drive
* ext4_cache_write_back(..., 0);
* < --- when write back mode is disabled all
* cache data will be flushed
* To enable write back mode permanently just call this function
* once after ext4_mount (and disable before ext4_umount).
*
* Some of the function use write back cache mode internally.
* If you enable write back mode twice you have to disable it twice
* to flush all data:
*
* ext4_cache_write_back(..., 1);
* ext4_cache_write_back(..., 1);
*
* ext4_cache_write_back(..., 0);
* ext4_cache_write_back(..., 0);
*
* Write back mode is useful when you want to create a lot of empty
* files/directories.
*
* @param path moutnpoint path
* @param on enable/disable
*
* @return standard error code */
int ext4_cache_write_back(const char *path, bool on);
/********************************FILE OPERATIONS*****************************/
/**@brief Remove file by path.
* @param path path to file
* @return standard error code */
int ext4_fremove(const char *path);
/**@brief File open function.
* @param filename, (has to start from mountpoint)
* /my_partition/my_file
* @param flags open file flags
* |---------------------------------------------------------------|
* | r or rb O_RDONLY |
* |---------------------------------------------------------------|
* | w or wb O_WRONLY|O_CREAT|O_TRUNC |
* |---------------------------------------------------------------|
* | a or ab O_WRONLY|O_CREAT|O_APPEND |
* |---------------------------------------------------------------|
* | r+ or rb+ or r+b O_RDWR |
* |---------------------------------------------------------------|
* | w+ or wb+ or w+b O_RDWR|O_CREAT|O_TRUNC |
* |---------------------------------------------------------------|
* | a+ or ab+ or a+b O_RDWR|O_CREAT|O_APPEND |
* |---------------------------------------------------------------|
*
* @return standard error code*/
int ext4_fopen (ext4_file *f, const char *path, const char *flags);
/**@brief File close function.
* @param f file handle
* @return standard error code*/
int ext4_fclose(ext4_file *f);
/**@brief Read data from file.
* @param f file handle
* @param buf output buffer
* @param size bytes to read
* @param rcnt readed bytes (may be NULL)
* @return standard error code*/
int ext4_fread (ext4_file *f, void *buf, uint32_t size, uint32_t *rcnt);
/**@brief Write data to file.
* @param f file handle
* @param buf data to write
* @param size write length
* @param wcnt bytes written (may be NULL)
* @return standard error code*/
int ext4_fwrite(ext4_file *f, void *buf, uint32_t size, uint32_t *wcnt);
/**@brief File seek operation.
* @param f file handle
* @param offset offset to seek
* @param origin seek type:
* @ref SEEK_SET
* @ref SEEK_CUR
* @ref SEEK_END
* @return standard error code*/
int ext4_fseek (ext4_file *f, uint64_t offset, uint32_t origin);
/**@brief Get file position.
* @param f file handle
* @return actual file position */
uint64_t ext4_ftell (ext4_file *f);
/**@brief Get file size.
* @param f file handle
* @return file size */
uint64_t ext4_fsize (ext4_file *f);
/*********************************DIRECTORY OPERATION***********************/
/**@brief Recursive directory remove.
* @param path directory path to remove
* @return standard error code*/
int ext4_dir_rm(const char *path);
/**@brief Create new directory.
* @param name new directory name
* @return standard error code*/
int ext4_dir_mk(const char *path);
/**@brief Directory open.
* @param d directory handle
* @param path directory path
* @return standard error code*/
int ext4_dir_open (ext4_dir *d, const char *path);
/**@brief Directory close.
* @param d directory handle
* @return standard error code*/
int ext4_dir_close(ext4_dir *d);
/**@brief Return directory entry by id.
* @param d directory handle
* @param id entry id
* @return directory entry id (NULL id no entry)*/
ext4_direntry* ext4_dir_entry_get(ext4_dir *d, uint32_t id);
#endif /* EXT4_H_ */
/**
* @}
*/