battfs.c File Reference

BattFS: a filesystem for embedded platforms (implementation). More...

#include "battfs.h"
#include "cfg/cfg_battfs.h"
#include <cfg/debug.h>
#include <cfg/macros.h>
#include <cfg/test.h>
#include <cpu/byteorder.h>
#include <cfg/log.h>
#include <string.h>

Go to the source code of this file.

Functions
void	battfs_to_disk (struct BattFsPageHeader *hdr, uint8_t *buf)
	Convert from memory representation to disk structure.
void	disk_to_battfs (uint8_t *buf, struct BattFsPageHeader *hdr)
	Convert from disk structure to memory representation.
static fcs_t	computeFcs (struct BattFsPageHeader *hdr)
	Compute the fcs of the header.
static size_t	diskRead (struct BattFsSuper *disk, pgcnt_t page, pgaddr_t addr, void *buf, size_t size)
	Read from disk.
static bool	readHdr (struct BattFsSuper *disk, pgcnt_t page, struct BattFsPageHeader *hdr)
	Read header of page in hdr.
static bool	setBufferHdr (struct BattFsSuper *disk, struct BattFsPageHeader *hdr)
	Set header on current disk page buffer.
static pgcnt_t	countPages (pgoff_t *filelen_table, inode_t inode)
	Count the number of pages from inode 0 to inode in filelen_table.
static void	movePages (struct BattFsSuper *disk, pgcnt_t src, int offset)
	Move all pages in page allocation array from src to src + offset.
static bool	countDiskFilePages (struct BattFsSuper *disk, pgoff_t *filelen_table)
	Count number of pages per file on disk.
static bool	fillPageArray (struct BattFsSuper *disk, pgoff_t *filelen_table)
	Fill page allocation array of disk using file lenghts in filelen_table.
static bool	flushBuffer (struct BattFsSuper *disk)
	Flush the current disk buffer.
static bool	loadPage (struct BattFsSuper *disk, pgcnt_t new_page, BattFsPageHeader *new_hdr)
	Load new_page from disk in disk page buffer.
bool	battfs_mount (struct BattFsSuper *disk)
	Initialize and mount disk described by disk.
bool	battfs_fsck (struct BattFsSuper *disk)
	Check the filesystem.
static int	battfs_flush (struct KFile *fd)
	Flush file fd.
static int	battfs_fileclose (struct KFile *fd)
	Close file fd.
static size_t	battfs_write (struct KFile *fd, const void *_buf, size_t size)
	Write to file fd size bytes from buf.
static size_t	battfs_read (struct KFile *fd, void *_buf, size_t size)
	Read from file fd size bytes in buf.
static bool	findFile (BattFsSuper *disk, inode_t inode, pgcnt_t *last)
	Search file inode in disk using a binary search.
bool	battfs_fileExists (BattFsSuper *disk, inode_t inode)
static file_size_t	countFileSize (BattFsSuper *disk, pgcnt_t *start, inode_t inode)
	Count size of file inode on disk, starting at pointer start in disk->page_array.
bool	battfs_fileopen (BattFsSuper *disk, BattFs *fd, inode_t inode, filemode_t mode)
	Open file inode from disk in mode.
bool	battfs_umount (struct BattFsSuper *disk)
	Umount disk.

---

Detailed Description

BattFS: a filesystem for embedded platforms (implementation).

Version:

Id

battfs.c 2886 2009-09-07 13:39:46Z batt

Author:

Francesco Sacchi <batt@develer.com>

Definition in file battfs.c.

---

Function Documentation

static int battfs_fileclose

(

struct KFile *

fd

)

[static]

Close file fd.

Returns:

0 if ok, EOF on errors.

Definition at line 585 of file battfs.c.

bool battfs_fileExists	(	BattFsSuper *	disk,
		inode_t	inode
	)

Returns:

true if file inode exists on disk, false otherwise.

Definition at line 894 of file battfs.c.

bool battfs_fileopen	(	BattFsSuper *	disk,
		BattFs *	fd,
		inode_t	inode,
		filemode_t	mode
	)

Open file inode from disk in mode.

File context is stored in fd.

Returns:

true if ok, false otherwise.

Definition at line 940 of file battfs.c.

static int battfs_flush

(

struct KFile *

fd

)

[static]

Flush file fd.

Returns:

0 if ok, EOF on errors.

Definition at line 568 of file battfs.c.

bool battfs_fsck

(

struct BattFsSuper *

disk

)

Check the filesystem.

Returns:

true if ok, false on errors.

Definition at line 510 of file battfs.c.

bool battfs_mount

(

struct BattFsSuper *

disk

)

Initialize and mount disk described by disk.

Returns:

false on errors, true otherwise.

Definition at line 442 of file battfs.c.

static size_t battfs_read	(	struct KFile *	fd,
		void *	_buf,
		size_t	size
	)			[static]

Read from file fd size bytes in buf.

Returns:

The number of bytes read.

Definition at line 805 of file battfs.c.

void battfs_to_disk	(	struct BattFsPageHeader *	hdr,
		uint8_t *	buf
	)			[inline]

Convert from memory representation to disk structure.

Note:

filesystem is in little-endian format.

Definition at line 72 of file battfs.c.

static size_t battfs_write	(	struct KFile *	fd,
		const void *	_buf,
		size_t	size
	)			[static]

Write to file fd size bytes from buf.

Returns:

The number of bytes written.

Definition at line 637 of file battfs.c.

static bool countDiskFilePages	(	struct BattFsSuper *	disk,
		pgoff_t *	filelen_table
	)			[static]

Count number of pages per file on disk.

This information is registered in filelen_table. Array index represent file inode, while value contained is the number of pages used by that file.

Returns:

true if ok, false on disk read errors.

Note:

The whole disk is scanned once.

Definition at line 256 of file battfs.c.

static file_size_t countFileSize	(	BattFsSuper *	disk,
		pgcnt_t *	start,
		inode_t	inode
	)			[static]

Count size of file inode on disk, starting at pointer start in disk->page_array.

Size is written in size.

Returns:

true if all s ok, false on disk read errors.

Definition at line 905 of file battfs.c.

void disk_to_battfs	(	uint8_t *	buf,
		struct BattFsPageHeader *	hdr
	)			[inline]

Convert from disk structure to memory representation.

Note:

filesystem is in little-endian format.

Definition at line 106 of file battfs.c.

static size_t diskRead	(	struct BattFsSuper *	disk,
		pgcnt_t	page,
		pgaddr_t	addr,
		void *	buf,
		size_t	size
	)			[static]

Read from disk.

If available, the cache will be used.

Returns:

the number of bytes read.

Definition at line 136 of file battfs.c.

static bool fillPageArray	(	struct BattFsSuper *	disk,
		pgoff_t *	filelen_table
	)			[static]

Fill page allocation array of disk using file lenghts in filelen_table.

The page allocation array is an array containings all file infos. Is ordered by file, and within each file is ordered by page offset inside file. e.g. : at page array[0] you will find page address of the first page of the first file (if present). Free blocks are allocated after the last file.

Returns:

true if ok, false on disk read errors.

Note:

The whole disk is scanned at max twice.

Definition at line 302 of file battfs.c.

static bool findFile	(	BattFsSuper *	disk,
		inode_t	inode,
		pgcnt_t *	last
	)			[static]

Search file inode in disk using a binary search.

last is filled with array offset of file start in disk->page_array if file is found, otherwise last is filled with the correct insert position for creating a file with the given inode.

Returns:

true if file is found, false otherwisr.

Definition at line 861 of file battfs.c.

static bool flushBuffer

(

struct BattFsSuper *

disk

)

[static]

Flush the current disk buffer.

Returns:

true if ok, false on errors.

Definition at line 398 of file battfs.c.

static bool loadPage	(	struct BattFsSuper *	disk,
		pgcnt_t	new_page,
		BattFsPageHeader *	new_hdr
	)			[static]

Load new_page from disk in disk page buffer.

If a previuos page is still dirty in the buffer, will be flushed first. The new page header loaded will be put in new_hdr.

Returns:

true if ok, false on errors.

Definition at line 419 of file battfs.c.

static void movePages	(	struct BattFsSuper *	disk,
		pgcnt_t	src,
		int	offset
	)			[static]

Move all pages in page allocation array from src to src + offset.

The number of pages moved is page_count - MAX(dst, src).

Definition at line 233 of file battfs.c.

static bool readHdr	(	struct BattFsSuper *	disk,
		pgcnt_t	page,
		struct BattFsPageHeader *	hdr
	)			[static]

Read header of page in hdr.

Returns:

true on success, false otherwise.

Definition at line 151 of file battfs.c.

static bool setBufferHdr	(	struct BattFsSuper *	disk,
		struct BattFsPageHeader *	hdr
	)			[static]

Set header on current disk page buffer.

Returns:

true on success, false otherwise.

Definition at line 176 of file battfs.c.