/** * @file * * @brief RTEMS File System Directory Support * * @ingroup rtems_rfs * * RTEMS File System Directory Support * * This file provides the directory support functions. */ /* * COPYRIGHT (c) 2010 Chris Johns * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.rtems.org/license/LICENSE. */ #if !defined (_RTEMS_RFS_DIR_H_) #define _RTEMS_RFS_DIR_H_ #include #include #include #include #include /** * Define the offsets of the fields of a directory entry. */ #define RTEMS_RFS_DIR_ENTRY_INO (0) /**< The ino offset in a directory * entry. */ #define RTEMS_RFS_DIR_ENTRY_HASH (4) /**< The hash offset in a directory * entry. The hash is 32bits. We need at * least 16bits and given the length and * ino field are 4 the extra 2 bytes is * not a big overhead.*/ #define RTEMS_RFS_DIR_ENTRY_LEN (8) /**< The length offset in a directory * entry. */ /** * The length of the directory entry header. */ #define RTEMS_RFS_DIR_ENTRY_SIZE (4 + 4 + 2) /** * The length when the remainder of the directory block is empty. */ #define RTEMS_RFS_DIR_ENTRY_EMPTY (0xffff) /** * Return the hash of the entry. * * @param[in] _e is a pointer to the directory entry. * * @retval hash The uint32_t hash of the entry. */ #define rtems_rfs_dir_entry_hash(_e) \ rtems_rfs_read_u32 (_e + RTEMS_RFS_DIR_ENTRY_HASH) /** * Set the hash of the entry. * * @param[in] _e is a pointer to the directory entry. * * @param[in] _h is the hash of the entry. */ #define rtems_rfs_dir_set_entry_hash(_e, _h) \ rtems_rfs_write_u32 (_e + RTEMS_RFS_DIR_ENTRY_HASH, _h) /** * Return the ino of the entry. * * @param[in] _e is a pointer to the directory entry. * * @retval ino The ino of the entry. */ #define rtems_rfs_dir_entry_ino(_e) \ rtems_rfs_read_u32 (_e + RTEMS_RFS_DIR_ENTRY_INO) /** * Set the ino of the entry. * * @param[in] _e is a pointer to the directory entry. * * @param[in] _i is the ino of the entry. */ #define rtems_rfs_dir_set_entry_ino(_e, _i) \ rtems_rfs_write_u32 (_e + RTEMS_RFS_DIR_ENTRY_INO, _i) /** * Return the length of the entry. * * @param[in] _e Pointer to the directory entry. * * @retval length The length of the entry. */ #define rtems_rfs_dir_entry_length(_e) \ rtems_rfs_read_u16 (_e + RTEMS_RFS_DIR_ENTRY_LEN) /** * Set the length of the entry. * * @param[in] _e is a pointer to the directory entry. * @param[in] _l is the length. */ #define rtems_rfs_dir_set_entry_length(_e, _l) \ rtems_rfs_write_u16 (_e + RTEMS_RFS_DIR_ENTRY_LEN, _l) /** * Look up a directory entry in the directory pointed to by the inode. The look * up is local to this directory. No need to decend. * * @param[in] fs is the file system. * @param[in] inode is a pointer to the inode of the directory to search. * @param[in] name is a pointer to the name to look up. The name may not be * nul terminated. * @param[in] length is the length of the name. * @param[out] ino will be filled in with the inode number * if there is no error. * @param[in] offset is the offset in the directory for the entry. * * @retval 0 Successful operation. * @retval error_code An error occurred. */ int rtems_rfs_dir_lookup_ino (rtems_rfs_file_system* fs, rtems_rfs_inode_handle* inode, const char* name, int length, rtems_rfs_ino* ino, uint32_t* offset); /** * Add an entry to the directory returing the inode number allocated to the * entry. * * @param[in] fs is the file system data. * @param[in] dir is a pointer to the directory inode the * entry is to be added too. * @param[in] name is a pointer to the name of the entry to be added. * @param[in] length is the length of the name excluding a terminating 0. * @param[in] ino is the ino of the entry. * * @retval 0 Successful operation. * @retval error_code An error occurred. */ int rtems_rfs_dir_add_entry (rtems_rfs_file_system* fs, rtems_rfs_inode_handle* dir, const char* name, size_t length, rtems_rfs_ino ino); /** * Del an entry from the directory using an inode number as a key. * * @param[in] fs is the file system data. * @param[in] dir is a pointer to the directory inode the * entry is to be deleted from. * @param[in] ino is the ino of the entry. * @param[in] offset is the offset in the directory of the entry * to delete. If 0 search from the start for the ino. * * @retval 0 Successful operation. * @retval error_code An error occurred. */ int rtems_rfs_dir_del_entry (rtems_rfs_file_system* fs, rtems_rfs_inode_handle* dir, rtems_rfs_ino ino, uint32_t offset); /** * Read the directory entry from offset into the directory entry buffer and * return the length of space this entry uses in the directory table. * * @param[in] fs is the file system data. * @param[in] dir is a pointer to the direct inode handler. * @param[in] offset is the offset in the directory to read from. * @param[in] dirent is a ointer to the dirent structure the entry * is written into. * @param[out] length will contain the length this entry * takes in the directory. * * @retval 0 Successful operation. * @retval error_code An error occurred. */ int rtems_rfs_dir_read (rtems_rfs_file_system* fs, rtems_rfs_inode_handle* dir, rtems_rfs_pos_rel offset, struct dirent* dirent, size_t* length); /** * Check if the directory is empty. The current and parent directory entries * are ignored. * * @param[in] fs is the file system data * @param[in] dir is a pointer to the directory inode to check. * * @retval 0 Successful operation. * @retval error_code An error occurred. */ int rtems_rfs_dir_empty (rtems_rfs_file_system* fs, rtems_rfs_inode_handle* dir); #endif