ref: a45154a49b743eba4669442e6993c50583329d99
dir: /include/ext4.h/
/* * Copyright (c) 2013 Grzegorz Kostka ([email protected]) * 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_errno.h" #include "ext4_oflags.h" #include "ext4_types.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 File position*/ uint64_t fpos; } ext4_file; /*****************************DIRECTORY DESCRIPTOR***************************/ /**@brief Directory entry descriptor. Copy from ext4_types.h*/ 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; 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 a block device to a name. * @warning Block device has to be filled by * Block cache may by created automatically when bc parameter is NULL. * @param bd block device * @param bd block device cache * @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 mount point. * @param dev_name block device name (@ref ext4_device_register) * @param mount_point mount point, for example * - / * - /my_partition/ * - /my_second_partition/ * * @return standard error code */ int ext4_mount(const char *dev_name, const char *mount_point); /**@brief Umount operation. * @param mount_point mount name * @return standard error code */ int ext4_umount(const char *mount_point); /**@brief Start 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_point mount name * @return standard error code */ int ext4_journal_start(const char *mount_point); /**@brief Stop journaling. Journaling start/stop functions are transparent * and might be used on filesystems without journaling support. * @param mount_point mount name * @return standard error code */ int ext4_journal_stop(const char *mount_point); /**@brief Journal recovery. * @param mount_point mount point * @warning Must be called after @ref ext4_mount * @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 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 Setup OS lock routines. * @param mount_point mount path * @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_point mount path * @param superblock pointer * @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_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 mount point 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 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 path filename (has to start from mount point) * /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 Alternate file open function. * @param filename, (has to start from mount point) * /my_partition/my_file * @param flags open file flags * @return standard error code*/ int ext4_fopen2(ext4_file *f, const char *path, int flags); /**@brief File close function. * @param f file handle * @return standard error code*/ int ext4_fclose(ext4_file *f); /**@brief Fill in the ext4_inode buffer. * @param path fetch inode data of the path * @param ret_ino the inode id of the path * @param ext4_inode buffer * @return standard error code*/ int ext4_fill_raw_inode(const char *path, uint32_t *ret_ino, struct ext4_inode *inode); /**@brief File truncate function. * @param f file handle * @param new file size * @return standard error code*/ int ext4_ftruncate(ext4_file *f, uint64_t size); /**@brief Read data from file. * @param f file handle * @param buf output buffer * @param size bytes to read * @param rcnt bytes read (may be NULL) * @return standard error code*/ int ext4_fread(ext4_file *f, void *buf, size_t size, size_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, const void *buf, size_t size, size_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); /**@brief Change file/directory/link mode bits * @param path to file/dir/link * @param mode new mode bits (for example 0777) * @return standard error code*/ int ext4_chmod(const char *path, uint32_t mode); /**@brief Change file owner and group * @param path to file/dir/link * @param uid user id * @param gid group id * @return standard error code*/ int ext4_chown(const char *path, uint32_t uid, uint32_t gid); /**@brief Set file access time * @param path to file/dir/link * @param atime access timestamp * @return standard error code*/ int ext4_file_set_atime(const char *path, uint32_t atime); /**@brief Set file modify time * @param path to file/dir/link * @param mtime modify timestamp * @return standard error code*/ int ext4_file_set_mtime(const char *path, uint32_t mtime); /**@brief Set file change time * @param path to file/dir/link * @param ctime change timestamp * @return standard error code*/ int ext4_file_set_ctime(const char *path, uint32_t ctime); /**@brief Create symbolic link * @param target destination path * @param path source entry * @return standard error code*/ int ext4_fsymlink(const char *target, const char *path); /**@brief Read symbolic link payload * @param 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 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 * @param replace whether existing entries should be replaced * @return standard error code*/ int ext4_setxattr(const char *path, const char *name, size_t name_len, const void *data, size_t data_size, bool replace); /**@brief Get extended attribute * @param 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 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 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 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 next directory entry. * @param d directory handle * @param id entry id * @return directory entry id (NULL if no entry)*/ const ext4_direntry *ext4_dir_entry_next(ext4_dir *d); /**@brief Rewine directory entry offset. * @param d directory handle*/ void ext4_dir_entry_rewind(ext4_dir *d); #ifdef __cplusplus } #endif #endif /* EXT4_H_ */ /** * @} */