In-Memory File System Support. More...

Topics
	IMFS Device IO Handler

Files
file	cpukit/libfs/src/imfs/deviceio.c
	IMFS Device Node Handlers.
file	cpukit/libfs/src/imfs/imfs_add_node.c
	IMFS Add a Node.
file	cpukit/libfs/src/imfs/imfs_chown.c
	IMFS Change Owner.
file	cpukit/libfs/src/imfs/imfs_config.c
	IMFS Limits and Options.
file	cpukit/libfs/src/imfs/imfs_creat.c
	Create an IMFS Node.
file	cpukit/libfs/src/imfs/imfs_dir.c
file	cpukit/libfs/src/imfs/imfs_dir_default.c
file	cpukit/libfs/src/imfs/imfs_dir_minimal.c
file	cpukit/libfs/src/imfs/imfs_eval.c
	Evaluation IMFS Node Support.
file	cpukit/libfs/src/imfs/imfs_fchmod.c
	Change IMFS File Mode.
file	cpukit/libfs/src/imfs/imfs_fifo.c
	FIFO Support.
file	cpukit/libfs/src/imfs/imfs_fsunmount.c
	Unmount this Instance of IMFS.
file	cpukit/libfs/src/imfs/imfs_handlers_device.c
	Device Operations Table.
file	cpukit/libfs/src/imfs/imfs_initsupp.c
	IMFS Node Support.
file	cpukit/libfs/src/imfs/imfs_linfile.c
file	cpukit/libfs/src/imfs/imfs_link.c
	IMFS Create a New Link Node.
file	cpukit/libfs/src/imfs/imfs_load_tar.c
	RTEMS Load Tarfs.
file	cpukit/libfs/src/imfs/imfs_make_generic_node.c
	IMFS Make a Generic Node.
file	cpukit/libfs/src/imfs/imfs_memfile.c
	IMFS Memory File Handlers.
file	cpukit/libfs/src/imfs/imfs_mknod.c
	Create a IMFS Node.
file	cpukit/libfs/src/imfs/imfs_mount.c
	Mount an IMFS.
file	cpukit/libfs/src/imfs/imfs_node.c
	IMFS Node Support.
file	cpukit/libfs/src/imfs/imfs_node_destroy_default.c
	IMFS Default Node Destruction.
file	cpukit/libfs/src/imfs/imfs_rename.c
	IMFS Rename.
file	cpukit/libfs/src/imfs/imfs_rmnod.c
	IMFS Node Removal Handler.
file	cpukit/libfs/src/imfs/imfs_stat.c
	IMFS Stat.
file	cpukit/libfs/src/imfs/imfs_stat_file.c
file	cpukit/libfs/src/imfs/imfs_symlink.c
	IMFS Create a New Symbolic Link Node.
file	cpukit/libfs/src/imfs/imfs_unmount.c
	Unmount an IMFS.
file	cpukit/libfs/src/imfs/imfs_utimens.c
	Set IMFS File Access and Modification Times.

Data Structures
struct	IMFS_jnode_tt
struct	IMFS_directory_t
struct	IMFS_device_t
struct	IMFS_link_t
struct	IMFS_sym_link_t
struct	IMFS_filebase_t
struct	IMFS_memfile_t
struct	IMFS_linearfile_t
union	IMFS_file_t
struct	IMFS_fifo_t
struct	IMFS_generic_t
struct	IMFS_linearfile_context
struct	IMFS_mknod_controls
struct	IMFS_fs_info_t
struct	IMFS_mount_data

Macros
#define	IMFS_MEMFILE_DEFAULT_BYTES_PER_BLOCK 128
#define	IMFS_MEMFILE_BYTES_PER_BLOCK imfs_memfile_bytes_per_block
#define	IMFS_MEMFILE_BLOCK_SLOTS (IMFS_MEMFILE_BYTES_PER_BLOCK / sizeof(void *))
#define	FIRST_INDIRECT (0)
#define	LAST_INDIRECT (IMFS_MEMFILE_BLOCK_SLOTS - 1)
#define	FIRST_DOUBLY_INDIRECT (LAST_INDIRECT + 1)
#define	LAST_DOUBLY_INDIRECT
#define	FIRST_TRIPLY_INDIRECT (LAST_DOUBLY_INDIRECT + 1)
#define	LAST_TRIPLY_INDIRECT
#define	IMFS_MEMFILE_MAXIMUM_SIZE (LAST_TRIPLY_INDIRECT * IMFS_MEMFILE_BYTES_PER_BLOCK)
#define	IMFS_NAME_MAX _POSIX_NAME_MAX
#define	IMFS_NODE_CONTROL_INITIALIZER(handlers, init, destroy)
	Initializer for an IMFS node control.
#define	IMFS_NODE_INITIALIZER(node_control, name, namelen, mode)
	Initializer for an IMFS node.
#define	IMFS_assert(_x)
#define	IMFS_STAT_FMT_HARD_LINK 0

Typedefs
typedef struct IMFS_jnode_tt	IMFS_jnode_t
typedef uint8_t *	block_p
typedef block_p *	block_ptr

Functions
int	IMFS_initialize (rtems_filesystem_mount_table_entry_t mt_entry, const void data)
int	IMFS_initialize_support (rtems_filesystem_mount_table_entry_t mt_entry, const void data)
void	IMFS_fsunmount (rtems_filesystem_mount_table_entry_t *mt_entry)
	Unmount this instance of IMFS.
int	rtems_tarfs_load (const char mountpoint, const void tar_image, size_t tar_size)
	RTEMS load tarfs.
void	IMFS_node_destroy (IMFS_jnode_t *node)
	Destroy an IMFS node.
int	IMFS_node_clone (rtems_filesystem_location_info_t *loc)
	Clone an IMFS node.
void	IMFS_node_free (const rtems_filesystem_location_info_t *loc)
	Free an IMFS node.
int	IMFS_stat (const rtems_filesystem_location_info_t loc, struct stat buf)
	Perform a status processing for the IMFS.
int	IMFS_stat_file (const rtems_filesystem_location_info_t loc, struct stat buf)
void	IMFS_eval_path (rtems_filesystem_eval_path_context_t *ctx)
	IMFS evaluation node support.
void	IMFS_eval_path_devfs (rtems_filesystem_eval_path_context_t *ctx)
	IMFS device filesystem evaluation node support.
int	IMFS_link (const rtems_filesystem_location_info_t parentloc, const rtems_filesystem_location_info_t targetloc, const char *name, size_t namelen)
	Create a new IMFS link node.
int	IMFS_chown (const rtems_filesystem_location_info_t *loc, uid_t owner, gid_t group)
	Change the owner of IMFS.
int	IMFS_mknod (const rtems_filesystem_location_info_t parentloc, const char name, size_t namelen, mode_t mode, dev_t dev)
	Create an IMFS node.
IMFS_jnode_t *	IMFS_initialize_node (IMFS_jnode_t node, const IMFS_node_control node_control, const char name, size_t namelen, mode_t mode, void arg)
IMFS_jnode_t *	IMFS_create_node (const rtems_filesystem_location_info_t parentloc, const IMFS_node_control node_control, size_t node_size, const char name, size_t namelen, mode_t mode, void arg)
	Create an IMFS node.
int	IMFS_add_node (const char path, IMFS_jnode_t node, void *arg)
	Adds an IMFS node.
int	IMFS_make_node (const char path, mode_t mode, const IMFS_node_control node_control, size_t node_size, void *context)
int	IMFS_make_linearfile (const char path, mode_t mode, const void data, size_t size)
	Makes a linear IMFS file.
int	IMFS_mount (rtems_filesystem_mount_table_entry_t *mt_entry)
	Mount an IMFS.
int	IMFS_unmount (rtems_filesystem_mount_table_entry_t *mt_entry)
	Unmount an IMFS.
int	IMFS_utimens (const rtems_filesystem_location_info_t *loc, struct timespec times[2])
	Set IMFS file access and modification times.
int	IMFS_fchmod (const rtems_filesystem_location_info_t *loc, mode_t mode)
	Change the IMFS file mode.
int	IMFS_symlink (const rtems_filesystem_location_info_t parentloc, const char name, size_t namelen, const char *target)
	Create a new IMFS symbolic link node.
ssize_t	IMFS_readlink (const rtems_filesystem_location_info_t loc, char buf, size_t bufsize)
	Put IMFS symbolic link into buffer.
int	IMFS_rename (const rtems_filesystem_location_info_t oldparentloc, const rtems_filesystem_location_info_t oldloc, const rtems_filesystem_location_info_t newparentloc, const char name, size_t namelen)
	Rename the IMFS.
int	IMFS_rmnod (const rtems_filesystem_location_info_t parentloc, const rtems_filesystem_location_info_t loc)
	IMFS node removal handler.

Variables
const int	imfs_memfile_bytes_per_block
const IMFS_mknod_control	IMFS_mknod_control_dir_default
const IMFS_mknod_control	IMFS_mknod_control_dir_minimal
const IMFS_mknod_control	IMFS_mknod_control_device
const IMFS_mknod_control	IMFS_mknod_control_memfile
const IMFS_node_control	IMFS_node_control_linfile
const IMFS_mknod_control	IMFS_mknod_control_fifo
const IMFS_mknod_control	IMFS_mknod_control_enosys
const rtems_filesystem_limits_and_options_t	IMFS_LIMITS_AND_OPTIONS

IMFS Memory File Handlers
This section contains the set of handlers used to process operations on IMFS memory file nodes. The memory files are created in memory using malloc'ed memory. Thus any data stored in one of these files is lost at system shutdown unless special arrangements to copy the data to some type of non-volailte storage are made by the application.
ssize_t	IMFS_memfile_write (IMFS_memfile_t memfile, off_t start, const unsigned char source, unsigned int length)

IMFS Device Node Handlers
This section contains the set of handlers used to map operations on IMFS device nodes onto calls to the RTEMS Classic API IO Manager.
int	device_open (rtems_libio_t iop, const char pathname, int oflag, mode_t mode)
int	device_close (rtems_libio_t *iop)
ssize_t	device_read (rtems_libio_t iop, void buffer, size_t count)
ssize_t	device_write (rtems_libio_t iop, const void buffer, size_t count)
int	device_ioctl (rtems_libio_t iop, ioctl_command_t command, void buffer)
int	device_ftruncate (rtems_libio_t *iop, off_t length)

Detailed Description

In-Memory File System Support.

Macro Definition Documentation

◆ IMFS_MEMFILE_DEFAULT_BYTES_PER_BLOCK

#define IMFS_MEMFILE_DEFAULT_BYTES_PER_BLOCK 128

IMFS "memfile" information

The data structure for the in-memory "memfiles" is based on classic UNIX.

block_ptr is a pointer to a block of IMFS_MEMFILE_BYTES_PER_BLOCK in length which could be data or a table of pointers to blocks.

Setting IMFS_MEMFILE_BYTES_PER_BLOCK to different values has a significant impact on the maximum file size supported as well as the amount of memory wasted due to internal file fragmentation. The following is a list of maximum file sizes based on various settings

max_filesize with blocks of   16 is         1,328
max_filesize with blocks of   32 is        18,656
max_filesize with blocks of   64 is       279,488
max_filesize with blocks of  128 is     4,329,344
max_filesize with blocks of  256 is    68,173,568
max_filesize with blocks of  512 is 1,082,195,456

◆ IMFS_NODE_CONTROL_INITIALIZER

#define IMFS_NODE_CONTROL_INITIALIZER	(	handlers,
		init,
		destroy )

Value:

{ \
  ( handlers ), \
  ( init ), \
  IMFS_node_remove_default, \
  ( destroy ) \
}

Initializer for an IMFS node control.

Parameters

handlers	The file system node handlers.
init	The node initialization method.
destroy	The node destruction method.

◆ IMFS_NODE_INITIALIZER

#define IMFS_NODE_INITIALIZER	(	node_control,
		name,
		namelen,
		mode )

Value:

{ \
  { NULL, NULL }, \
  NULL, \
  ( name ), \
  ( namelen ), \
  ( mode ), \
  0, \
  0, \
  0, \
  0, \
  0, \
  0, \
  0, \
  ( node_control ) \
}

Initializer for an IMFS node.

Initialize the node control with IMFS_NODE_CONTROL_INITIALIZER().

Parameters

node_control	The node control of the IMFS node.
name	The name of the IMFS node.
namelen	The length of the name of the IMFS node.
mode	The mode of the IMFS node.

See also: IMFS_node_preinitialize().

◆ LAST_DOUBLY_INDIRECT

#define LAST_DOUBLY_INDIRECT

Value:

(LAST_INDIRECT + \

(IMFS_MEMFILE_BLOCK_SLOTS * IMFS_MEMFILE_BLOCK_SLOTS))

◆ LAST_TRIPLY_INDIRECT

#define LAST_TRIPLY_INDIRECT

Value:

(LAST_DOUBLY_INDIRECT +\
  (IMFS_MEMFILE_BLOCK_SLOTS * \
     IMFS_MEMFILE_BLOCK_SLOTS * IMFS_MEMFILE_BLOCK_SLOTS))

Function Documentation

◆ IMFS_add_node()

int IMFS_add_node	(	const char *	path,
		IMFS_jnode_t *	node,
		void *	arg )

Adds an IMFS node.

Initialize the node with IMFS_NODE_INITIALIZER(), IMFS_node_preinitialize(), IMFS_GENERIC_NODE_INITIALIZER(), or IMFS_generic_node_preinitialize().

Parameters

path	The path of parent directories for the IMFS node to add.
node	The IMFS node to add.
arg	The argument passed to the node initialization method.

Return values

0	Successful operation.
-1	An error occurred. The `errno` indicates the error.

◆ IMFS_chown()

int IMFS_chown	(	const rtems_filesystem_location_info_t *	loc,
		uid_t	owner,
		gid_t	group )

extern

Change the owner of IMFS.

This routine is the implementation of the chown() system call for the IMFS.

◆ IMFS_create_node()

IMFS_jnode_t * IMFS_create_node	(	const rtems_filesystem_location_info_t *	parentloc,
		const IMFS_node_control *	node_control,
		size_t	node_size,
		const char *	name,
		size_t	namelen,
		mode_t	mode,
		void *	arg )

extern

Create an IMFS node.

Create an IMFS filesystem node of an arbitrary type that is NOT the root directory node.

◆ IMFS_link()

int IMFS_link	(	const rtems_filesystem_location_info_t *	parentloc,
		const rtems_filesystem_location_info_t *	targetloc,
		const char *	name,
		size_t	namelen )

extern

Create a new IMFS link node.

The following rouine creates a new link node under parent with the name given in name. The link node is set to point to the node at to_loc.

◆ IMFS_make_linearfile()

int IMFS_make_linearfile	(	const char *	path,
		mode_t	mode,
		const void *	data,
		size_t	size )

extern

Makes a linear IMFS file.

Parameters

path	The path to the new linear IMFS file.
mode	The file mode permissions. S_IFREG is set by the function.
data	The begin of linear file data area.
size	The size of the linear file data area in bytes.

Return values

0	Successful operation.
-1	An error occurred. The `errno` indicates the error.

◆ IMFS_mknod()

int IMFS_mknod	(	const rtems_filesystem_location_info_t *	parentloc,
		const char *	name,
		size_t	namelen,
		mode_t	mode,
		dev_t	dev )

extern

Create an IMFS node.

Routine to create a node in the IMFS file system.

◆ IMFS_readlink()

ssize_t IMFS_readlink	(	const rtems_filesystem_location_info_t *	loc,
		char *	buf,
		size_t	bufsize )

extern

Put IMFS symbolic link into buffer.

The following rouine puts the symbolic links destination name into buff.

◆ IMFS_rename()

int IMFS_rename	(	const rtems_filesystem_location_info_t *	oldparentloc,
		const rtems_filesystem_location_info_t *	oldloc,
		const rtems_filesystem_location_info_t *	newparentloc,
		const char *	name,
		size_t	namelen )

extern

Rename the IMFS.

The following rouine creates a new link node under parent with the name given in name and removes the old.

◆ IMFS_rmnod()

int IMFS_rmnod	(	const rtems_filesystem_location_info_t *	parentloc,
		const rtems_filesystem_location_info_t *	loc )

extern

IMFS node removal handler.

This file contains the handler used to remove a node when a file type does not require special actions.

◆ IMFS_stat()

int IMFS_stat	(	const rtems_filesystem_location_info_t *	loc,
		struct stat *	buf )

extern

Perform a status processing for the IMFS.

This routine provides a stat for the IMFS file system.

◆ IMFS_symlink()

int IMFS_symlink	(	const rtems_filesystem_location_info_t *	parentloc,
		const char *	name,
		size_t	namelen,
		const char *	target )

extern

Create a new IMFS symbolic link node.

The following rouine creates a new symbolic link node under parent with the name given in name. The node is set to point to the node at to_loc.

◆ IMFS_utimens()

int IMFS_utimens	(	const rtems_filesystem_location_info_t *	loc,
		struct timespec	times[2] )

extern

Set IMFS file access and modification times.

This routine is the implementation of the utime() system call for the IMFS.

◆ rtems_tarfs_load()

int rtems_tarfs_load	(	const char *	mountpoint,
		const void *	tar_image,
		size_t	tar_size )

extern

RTEMS load tarfs.

This file implements the "mount" procedure for tar-based IMFS extensions. The TAR is not actually mounted under the IMFS. Directories from the TAR file are created as usual in the IMFS. File entries are created as IMFS_LINEAR_FILE nodes with their nods pointing to addresses in the TAR image.

Here we create the mountpoint directory and load the tarfs at that node. Once the IMFS has been mounted, we work through the tar image and perform as follows:

For directories, simply call mkdir(). The IMFS creates nodes as needed.
For files, we make our own calls to IMFS eval_for_make and create_node.

TAR file format:

Offset   Length                 Contents
  100  bytes  File name ('\0' terminated, 99 maxmum length)
    8  bytes  File mode (in octal ascii)
    8  bytes  User ID (in octal ascii)
    8  bytes  Group ID (in octal ascii)
   12  bytes  File size (s) (in octal ascii)
   12  bytes  Modify time (in octal ascii)
    8  bytes  Header checksum (in octal ascii)
    1  bytes  Link flag
  100  bytes  Linkname ('\0' terminated, 99 maxmum length)
    8  bytes  Magic PAX ("ustar\0" + 2 bytes padding)
    8  bytes  Magic GNU tar ("ustar  \0")
   32  bytes  User name ('\0' terminated, 31 maxmum length)
   32  bytes  Group name ('\0' terminated, 31 maxmum length)
    8  bytes  Major device ID (in octal ascii)
    8  bytes  Minor device ID (in octal ascii)
  167  bytes  Padding
 (s+p) bytes  File contents (s+p) := (((s) + 511) & ~511),
                   round up to 512 bytes

Checksum:

int   i, sum;
char *header = tar_header_pointer;
 
sum = 0;
for (i = 0; i < 512; i++)
    sum += 0xFF & header[i];

Topics

Files

Data Structures

Macros

Typedefs

Functions

Variables

IMFS Memory File Handlers

IMFS Device Node Handlers

Detailed Description

Macro Definition Documentation

◆ IMFS_MEMFILE_DEFAULT_BYTES_PER_BLOCK

◆ IMFS_NODE_CONTROL_INITIALIZER

◆ IMFS_NODE_INITIALIZER

◆ LAST_DOUBLY_INDIRECT

◆ LAST_TRIPLY_INDIRECT

Function Documentation

◆ IMFS_add_node()

◆ IMFS_chown()

◆ IMFS_create_node()

◆ IMFS_link()

◆ IMFS_make_linearfile()

◆ IMFS_mknod()

◆ IMFS_readlink()

◆ IMFS_rename()

◆ IMFS_rmnod()

◆ IMFS_stat()

◆ IMFS_symlink()

◆ IMFS_utimens()

◆ rtems_tarfs_load()