ref: f4685b430f80c18bbe1f865464599cbfeecd9afb
dir: /include/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, mount points...).
* Client has to include only this file.
*/
#ifndef EXT4_H_
#define EXT4_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stddef.h>
#include <ext4_config.h>
#include <ext4_types.h>
#include <ext4_errno.h>
#include <ext4_oflags.h>
#include <ext4_debug.h>
#include <ext4_blockdev.h>
/********************************OS LOCK INFERFACE***************************/
/**@brief OS dependent lock interface.*/
struct ext4_lock {
/**@brief Lock access to mount point.*/
void (*lock)(void);
/**@brief Unlock access to mount point.*/
void (*unlock)(void);
};
/********************************FILE DESCRIPTOR*****************************/
/**@brief File descriptor. */
typedef struct ext4_file {
/**@brief Mount point 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 Actual file position.*/
uint64_t fpos;
} ext4_file;
/*****************************DIRECTORY DESCRIPTOR***************************/
/**@brief Directory entry descriptor. */
typedef struct ext4_direntry {
uint32_t inode;
uint16_t entry_length;
uint8_t name_length;
uint8_t inode_type;
uint8_t name[255];
} ext4_direntry;
/**@brief Directory descriptor. */
typedef struct ext4_dir {
/**@brief File descriptor.*/
ext4_file f;
/**@brief Current directory entry.*/
ext4_direntry de;
/**@brief Next entry offset.*/
uint64_t next_off;
} ext4_dir;
/********************************MOUNT OPERATIONS****************************/
/**@brief Register block device.
*
* @param bd Block device.
* @param dev_name Block device name.
*
* @return Standard error code.*/
int ext4_device_register(struct ext4_blockdev *bd,
const char *dev_name);
/**@brief Un-register block device.
*
* @param dev_name Block device name.
*
* @return Standard error code.*/
int ext4_device_unregister(const char *dev_name);
/**@brief Un-register all block devices.
*
* @return Standard error code.*/
int ext4_device_unregister_all(void);
/**@brief Mount a block device with EXT4 partition to the mount point.
*
* @param dev_name Block device name (@ref ext4_device_register).
* @param mount_point Mount point, for example:
* - /
* - /my_partition/
* - /my_second_partition/
* @param read_only mount as read-only mode.
*
* @return Standard error code */
int ext4_mount(const char *dev_name,
const char *mount_point,
bool read_only);
/**@brief Umount operation.
*
* @param mount_pount Mount point.
*
* @return Standard error code */
int ext4_umount(const char *mount_point);
/**@brief Starts journaling. Journaling start/stop functions are transparent
* and might be used on filesystems without journaling support.
* @warning Usage:
* ext4_mount("sda1", "/");
* ext4_journal_start("/");
*
* //File operations here...
*
* ext4_journal_stop("/");
* ext4_umount("/");
* @param mount_pount Mount point.
*
* @return Standard error code. */
int ext4_journal_start(const char *mount_point);
/**@brief Stops journaling. Journaling start/stop functions are transparent
* and might be used on filesystems without journaling support.
*
* @param mount_pount Mount point name.
*
* @return Standard error code. */
int ext4_journal_stop(const char *mount_point);
/**@brief Journal recovery.
* @warning Must be called after @ref ext4_mount.
*
* @param mount_pount Mount point.
*
* @return Standard error code. */
int ext4_recover(const 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 mount point stats.
*
* @param mount_pount Mount point.
* @param stats Filesystem stats.
*
* @return Standard error code. */
int ext4_mount_point_stats(const char *mount_point,
struct ext4_mount_stats *stats);
/**@brief Setup OS lock routines.
*
* @param mount_pount Mount point.
* @param locks Lock and unlock functions
*
* @return Standard error code. */
int ext4_mount_setup_locks(const char *mount_point,
const struct ext4_lock *locks);
/**@brief Acquire the filesystem superblock pointer of a mp.
*
* @param mount_pount Mount point.
* @param sb Superblock handle
*
* @return Standard error code. */
int ext4_get_sblock(const char *mount_point, struct ext4_sblock **sb);
/**@brief Enable/disable write back cache mode.
* @warning Default model of cache is write trough. It means that when You do:
*
* ext4_fopen(...);
* ext4_fwrite(...);
* < --- data is flushed to physical drive
*
* When you do:
* ext4_cache_write_back(..., 1);
* ext4_fopen(...);
* ext4_fwrite(...);
* < --- 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 mount_pount Mount point.
* @param on Enable/disable cache writeback mode.
*
* @return Standard error code. */
int ext4_cache_write_back(const char *path, bool on);
/**@brief Force cache flush.
*
* @param mount_pount Mount point.
*
* @return Standard error code. */
int ext4_cache_flush(const char *path);
/********************************FILE OPERATIONS*****************************/
/**@brief Remove file by path.
*
* @param path Path to file.
*
* @return Standard error code. */
int ext4_fremove(const char *path);
/**@brief Create a hardlink for a file.
*
* @param path Path to file.
* @param hardlink_path Path of hardlink.
*
* @return Standard error code. */
int ext4_flink(const char *path, const char *hardlink_path);
/**@brief Rename file.
* @param path Source.
* @param new_path Destination.
* @return Standard error code. */
int ext4_frename(const char *path, const char *new_path);
/**@brief File open function.
*
* @param file File handle.
* @param path File path, has to start from mount point:/my_partition/file.
* @param flags File open 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 *file, const char *path, const char *flags);
/**@brief Alternate file open function.
*
* @param file File handle.
* @param path File path, has to start from mount point:/my_partition/file.
* @param flags File open flags.
*
* @return Standard error code.*/
int ext4_fopen2(ext4_file *file, const char *path, int flags);
/**@brief File close function.
*
* @param file File handle.
*
* @return Standard error code.*/
int ext4_fclose(ext4_file *file);
/**@brief File truncate function.
*
* @param file File handle.
* @param size New file size.
*
* @return Standard error code.*/
int ext4_ftruncate(ext4_file *file, uint64_t size);
/**@brief Read data from file.
*
* @param file File handle.
* @param buf Output buffer.
* @param size Bytes to read.
* @param rcnt Bytes read (NULL allowed).
*
* @return Standard error code.*/
int ext4_fread(ext4_file *file, void *buf, size_t size, size_t *rcnt);
/**@brief Write data to file.
*
* @param file File handle.
* @param buf Data to write
* @param size Write length..
* @param wcnt Bytes written (NULL allowed).
*
* @return Standard error code.*/
int ext4_fwrite(ext4_file *file, const void *buf, size_t size, size_t *wcnt);
/**@brief File seek operation.
*
* @param file 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 *file, int64_t offset, uint32_t origin);
/**@brief Get file position.
*
* @param file File handle.
*
* @return Actual file position */
uint64_t ext4_ftell(ext4_file *file);
/**@brief Get file size.
*
* @param file File handle.
*
* @return File size. */
uint64_t ext4_fsize(ext4_file *file);
/**@brief Get inode of file/directory/link.
*
* @param path Parh to file/dir/link.
* @param ret_ino Inode number.
* @param inode Inode internals.
*
* @return Standard error code.*/
int ext4_raw_inode_fill(const char *path, uint32_t *ret_ino,
struct ext4_inode *inode);
/**@brief Check if inode exists.
*
* @param path Parh to file/dir/link.
* @param type Inode type.
* @ref EXT4_DIRENTRY_UNKNOWN
* @ref EXT4_DE_REG_FILE
* @ref EXT4_DE_DIR
* @ref EXT4_DE_CHRDEV
* @ref EXT4_DE_BLKDEV
* @ref EXT4_DE_FIFO
* @ref EXT4_DE_SOCK
* @ref EXT4_DE_SYMLINK
*
* @return Standard error code.*/
int ext4_inode_exist(const char *path, int type);
/**@brief Change file/directory/link mode bits.
*
* @param path Path to file/dir/link.
* @param mode New mode bits (for example 0777).
*
* @return Standard error code.*/
int ext4_mode_set(const char *path, uint32_t mode);
/**@brief Get file/directory/link mode bits.
*
* @param path Path to file/dir/link.
* @param mode New mode bits (for example 0777).
*
* @return Standard error code.*/
int ext4_mode_get(const char *path, uint32_t *mode);
/**@brief Change file owner and group.
*
* @param path Path to file/dir/link.
* @param uid User id.
* @param gid Group id.
*
* @return Standard error code.*/
int ext4_owner_set(const char *path, uint32_t uid, uint32_t gid);
/**@brief Get file/directory/link owner and group.
*
* @param path Path to file/dir/link.
* @param uid User id.
* @param gid Group id.
*
* @return Standard error code.*/
int ext4_owner_get(const char *path, uint32_t *uid, uint32_t *gid);
/**@brief Set file/directory/link access time.
*
* @param path Path to file/dir/link.
* @param atime Access timestamp.
*
* @return Standard error code.*/
int ext4_atime_set(const char *path, uint32_t atime);
/**@brief Set file/directory/link modify time.
*
* @param path Path to file/dir/link.
* @param mtime Modify timestamp.
*
* @return Standard error code.*/
int ext4_mtime_set(const char *path, uint32_t mtime);
/**@brief Set file/directory/link change time.
*
* @param path Path to file/dir/link.
* @param ctime Change timestamp.
*
* @return Standard error code.*/
int ext4_ctime_set(const char *path, uint32_t ctime);
/**@brief Get file/directory/link access time.
*
* @param path Path to file/dir/link.
* @param atime Access timestamp.
*
* @return Standard error code.*/
int ext4_atime_get(const char *path, uint32_t *atime);
/**@brief Get file/directory/link modify time.
*
* @param path Path to file/dir/link.
* @param mtime Modify timestamp.
*
* @return Standard error code.*/
int ext4_mtime_get(const char *path, uint32_t *mtime);
/**@brief Get file/directory/link change time.
*
* @param path Pathto file/dir/link.
* @param ctime Change timestamp.
*
* @return standard error code*/
int ext4_ctime_get(const char *path, uint32_t *ctime);
/**@brief Create symbolic link.
*
* @param target Destination entry path.
* @param path Source entry path.
*
* @return Standard error code.*/
int ext4_fsymlink(const char *target, const char *path);
/**@brief Create special file.
* @param path Path to new special file.
* @param filetype Filetype of the new special file.
* (that must not be regular file, directory, or unknown type)
* @param dev If filetype is char device or block device,
* the device number will become the payload in the inode.
* @return Standard error code.*/
int ext4_mknod(const char *path, int filetype, uint32_t dev);
/**@brief Read symbolic link payload.
*
* @param path Path to symlink.
* @param buf Output buffer.
* @param bufsize Output buffer max size.
* @param rcnt Bytes read.
*
* @return Standard error code.*/
int ext4_readlink(const char *path, char *buf, size_t bufsize, size_t *rcnt);
/**@brief Set extended attribute.
*
* @param path Path to file/directory
* @param name Name of the entry to add.
* @param name_len Length of @name in bytes.
* @param data Data of the entry to add.
* @param data_size Size of data to add.
*
* @return Standard error code.*/
int ext4_setxattr(const char *path, const char *name, size_t name_len,
const void *data, size_t data_size);
/**@brief Get extended attribute.
*
* @param path Path to file/directory.
* @param name Name of the entry to get.
* @param name_len Length of @name in bytes.
* @param data Data of the entry to get.
* @param data_size Size of data to get.
*
* @return Standard error code.*/
int ext4_getxattr(const char *path, const char *name, size_t name_len,
void *buf, size_t buf_size, size_t *data_size);
/**@brief List extended attributes.
*
* @param path Path to file/directory.
* @param list List to hold the name of entries.
* @param size Size of @list in bytes.
* @param ret_size Used bytes of @list.
*
* @return Standard error code.*/
int ext4_listxattr(const char *path, char *list, size_t size, size_t *ret_size);
/**@brief Remove extended attribute.
*
* @param path Path to file/directory.
* @param name Name of the entry to remove.
* @param name_len Length of @name in bytes.
*
* @return Standard error code.*/
int ext4_removexattr(const char *path, const char *name, size_t name_len);
/*********************************DIRECTORY OPERATION***********************/
/**@brief Recursive directory remove.
*
* @param path Directory path to remove
*
* @return Standard error code.*/
int ext4_dir_rm(const char *path);
/**@brief Rename/move directory.
*
* @param path Source path.
* @param new_path Destination path.
*
* @return Standard error code. */
int ext4_dir_mv(const char *path, const char *new_path);
/**@brief Create new directory.
*
* @param path Directory name.
*
* @return Standard error code.*/
int ext4_dir_mk(const char *path);
/**@brief Directory open.
*
* @param dir Directory handle.
* @param path Directory path.
*
* @return Standard error code.*/
int ext4_dir_open(ext4_dir *dir, const char *path);
/**@brief Directory close.
*
* @param dir directory handle.
*
* @return Standard error code.*/
int ext4_dir_close(ext4_dir *dir);
/**@brief Return next directory entry.
*
* @param dir Directory handle.
*
* @return Directory entry id (NULL if no entry)*/
const ext4_direntry *ext4_dir_entry_next(ext4_dir *dir);
/**@brief Rewine directory entry offset.
*
* @param dir Directory handle.*/
void ext4_dir_entry_rewind(ext4_dir *dir);
#ifdef __cplusplus
}
#endif
#endif /* EXT4_H_ */
/**
* @}
*/