rtems-rfs-dir.c File Reference

RTEMS File Systems Directory RoutinesThese functions manage blocks in the directory format. A directory entry is a variable length record in the block. The entry consists of a length, hash and the string. The length allows the next entry to be located and the hash allows a simple check to be performed without a string compare. Directory entries do not span a block and removal of an entry results in the space in the block being compacted and the spare area being initialised to ones. More...

#include <inttypes.h>
#include <string.h>
#include <rtems/rfs/rtems-rfs-block.h>
#include <rtems/rfs/rtems-rfs-buffer.h>
#include <rtems/rfs/rtems-rfs-file-system.h>
#include <rtems/rfs/rtems-rfs-trace.h>
#include <rtems/rfs/rtems-rfs-dir.h>
#include <rtems/rfs/rtems-rfs-dir-hash.h>

Macros
#define	rtems_rfs_dir_entry_valid(_f, _l, _i)

Functions
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)
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)
int	rtems_rfs_dir_del_entry (rtems_rfs_file_system *fs, rtems_rfs_inode_handle *dir, rtems_rfs_ino ino, uint32_t offset)
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)
int	rtems_rfs_dir_empty (rtems_rfs_file_system *fs, rtems_rfs_inode_handle *dir)

Detailed Description

RTEMS File Systems Directory Routines

These functions manage blocks in the directory format. A directory entry is a variable length record in the block. The entry consists of a length, hash and the string. The length allows the next entry to be located and the hash allows a simple check to be performed without a string compare. Directory entries do not span a block and removal of an entry results in the space in the block being compacted and the spare area being initialised to ones.

The maximum length can be 1 or 2 bytes depending on the value in the superblock.

Macro Definition Documentation

rtems_rfs_dir_entry_valid

#define rtems_rfs_dir_entry_valid	(		_f,
			_l,
			_i
	)

Value:

(((_l) <= RTEMS_RFS_DIR_ENTRY_SIZE) || ((_l) >= rtems_rfs_fs_max_name (_f)) \
   || (_i < RTEMS_RFS_ROOT_INO) || (_i > rtems_rfs_fs_inodes (_f)))

Validate the directory entry data.

Function Documentation

rtems_rfs_dir_add_entry()

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
	)

Add an entry to the directory returing the inode number allocated to the entry.

Parameters

[in]	fs	is the file system data.
[in]	dir	is a pointer to the directory inode the entry is to be added too.
[in]	name	is a pointer to the name of the entry to be added.
[in]	length	is the length of the name excluding a terminating 0.
[in]	ino	is the ino of the entry.

Return values

0	Successful operation.
error_code	An error occurred.

rtems_rfs_dir_del_entry()

int rtems_rfs_dir_del_entry	(	rtems_rfs_file_system *	fs,
		rtems_rfs_inode_handle *	dir,
		rtems_rfs_ino	ino,
		uint32_t	offset
	)

Del an entry from the directory using an inode number as a key.

Parameters

[in]	fs	is the file system data.
[in]	dir	is a pointer to the directory inode the entry is to be deleted from.
[in]	ino	is the ino of the entry.
[in]	offset	is the offset in the directory of the entry to delete. If 0 search from the start for the ino.

Return values

0	Successful operation.
error_code	An error occurred.

rtems_rfs_dir_empty()

int rtems_rfs_dir_empty	(	rtems_rfs_file_system *	fs,
		rtems_rfs_inode_handle *	dir
	)

Check if the directory is empty. The current and parent directory entries are ignored.

Parameters

[in]	fs	is the file system data
[in]	dir	is a pointer to the directory inode to check.

Return values

0	Successful operation.
error_code	An error occurred.

rtems_rfs_dir_lookup_ino()

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
	)

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.

Parameters

[in]	fs	is the file system.
[in]	inode	is a pointer to the inode of the directory to search.
[in]	name	is a pointer to the name to look up. The name may not be nul terminated.
[in]	length	is the length of the name.
[out]	ino	will be filled in with the inode number if there is no error.
[in]	offset	is the offset in the directory for the entry.

Return values

0	Successful operation.
error_code	An error occurred.

rtems_rfs_dir_read()

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
	)

Read the directory entry from offset into the directory entry buffer and return the length of space this entry uses in the directory table.

Parameters

[in]	fs	is the file system data.
[in]	dir	is a pointer to the direct inode handler.
[in]	offset	is the offset in the directory to read from.
[in]	dirent	is a ointer to the dirent structure the entry is written into.
[out]	length	will contain the length this entry takes in the directory.

Return values

0	Successful operation.
error_code	An error occurred.