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incubator-nuttx/fs/smartfs/smartfs.h

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/****************************************************************************
* fs/smartfs/smartfs.h
*
* Copyright (C) 2013 Ken Pettit. All rights reserved.
* Author: Ken Pettit <pettitkd@gmail.com>
*
* References: Linux/Documentation/filesystems/romfs.txt
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
#ifndef __FS_SMARTFS_SMARTFS_H
#define __FS_SMARTFS_SMARTFS_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <semaphore.h>
#include <nuttx/mtd/mtd.h>
#include <nuttx/fs/smart.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* SMART Definitions ********************************************************/
/* General SMART organization. The following example assumes 4 logical
* sectors per FLASH erase block. The actual relationship is determined by
* the FLASH geometry reported by the MTD driver.
*
* ERASE LOGICAL Sectors begin with a sector header. Sectors may
* BLOCK SECTOR CONTENTS be marked as "released," pending garbage collection
* n 4*n --+---------------+
* Hdr |LLLLLLLLLLLLLLL| Logical sector number (2 bytes)
* |QQQQQQQQQQQQQQQ| Sequence number (2 bytes)
* |SSSSSSSSSSSSSSS| Status bits (1 byte)
* +---------------+
* |TTTTTTTTTTTTTTT| Sector Type (dir or file) (1 byte)
* |NNNNNNNNNNNNNNN| Number of next logical sector in chain
* |UUUUUUUUUUUUUUU| Number of bytes used in this sector
* | |
* | (Sector Data) |
* | |
* 4*n+1 --+---------------+
* Sector Hdr |LLLLLLLLLLLLLLL| Logical sector number (2 bytes)
* |QQQQQQQQQQQQQQQ| Sequence number (2 bytes)
* |SSSSSSSSSSSSSSS| Status bits (1 byte)
* +---------------+
* FS Hdr |TTTTTTTTTTTTTTT| Sector Type (dir or file) (1 byte)
* |NNNNNNNNNNNNNNN| Number of next logical sector in chain
* |UUUUUUUUUUUUUUU| Number of bytes used in this sector
* | |
* | (Sector Data) |
* | |
* 4*n+2 --+---------------+
* Sector Hdr |LLLLLLLLLLLLLLL| Logical sector number (2 bytes)
* |QQQQQQQQQQQQQQQ| Sequence number (2 bytes)
* |SSSSSSSSSSSSSSS| Status bits (1 byte)
* +---------------+
* FS Hdr |TTTTTTTTTTTTTTT| Sector Type (dir or file) (1 byte)
* |NNNNNNNNNNNNNNN| Number of next logical sector in chain
* |UUUUUUUUUUUUUUU| Number of bytes used in this sector
* | |
* | (Sector Data) |
* | |
* 4*n+3 --+---------------+
* Sector Hdr |LLLLLLLLLLLLLLL| Logical sector number (2 bytes)
* |QQQQQQQQQQQQQQQ| Sequence number (2 bytes)
* |SSSSSSSSSSSSSSS| Status bits (1 byte)
* +---------------+
* FS Hdr |TTTTTTTTTTTTTTT| Sector Type (dir or file) (1 byte)
* |NNNNNNNNNNNNNNN| Number of next logical sector in chain
* |UUUUUUUUUUUUUUU| Number of bytes used in this sector
* | |
* | (Sector Data) |
* | |
* n+1 4*(n+1) --+---------------+
* Sector Hdr |LLLLLLLLLLLLLLL| Logical sector number (2 bytes)
* |QQQQQQQQQQQQQQQ| Sequence number (2 bytes)
* |SSSSSSSSSSSSSSS| Status bits (1 byte)
* +---------------+
* FS Hdr |TTTTTTTTTTTTTTT| Sector Type (dir or file) (1 byte)
* |NNNNNNNNNNNNNNN| Number of next logical sector in chain
* |UUUUUUUUUUUUUUU| Number of bytes used in this sector
* | |
* | |
* | |
* --+---------------+
*
* General operation:
* Physical sectors are allocated and assigned a logical sector number
* and a starting sequence number of zero.
*
* SECTOR HEADER:
* The sector header (first 5 bytes) tracks the state of each sector and
* is used by the SMART MTD block driver. At the block level, there is
* no notion of sector chaining, only allocated sectors within erase
* blocks.
*
* FILE SYSTEM (FS) HEADER:
* The file system header (next 5 bytes) tracks file and directory entries
* and chains.
*
* SMART Limitations:
* 1. SMART currently depends on the underlying MTD block driver supporting
* single-byte programming operation. This is due to the method it
* uses for marking a sector as "released", committed, etc.
* 2. Garbage collection can occur when a new sector is allocated or when
* existing sector data is overwritten with new data. Thus, occasionally,
* file writing may take longer than other times.
* 3. The implementation curently does not track bad blocks on the device.
* 4. There is no true wear-leveling implemented yet, though provesion have
* been made to reserve logical sectors to allow it to be added using
* a "sector aging" tracking mechanism.
*/
/* Values for SMART inode state.
*
* SMART_STATE_FILE - The inode is a valid usuable, file
* INODE_STATE_DELETED - The inode has been deleted.
* Other values - The inode is bad and has an invalid state.
*
* Care is taken so that the VALID to DELETED transition only involves burning
* bits from the erased to non-erased state.
*/
#define INODE_STATE_FILE (CONFIG_NXFFS_ERASEDSTATE ^ 0x22)
#define INODE_STATE_DELETED (CONFIG_NXFFS_ERASEDSTATE ^ 0xaa)
/* Directory entry flag definitions */
#define SMARTFS_DIRENT_EMPTY 0x8000 /* Set to non-erase state when entry used */
#define SMARTFS_DIRENT_ACTIVE 0x4000 /* Set to erase state when entry is active */
#define SMARTFS_DIRENT_TYPE 0x2000 /* Indicates the type of entry (file/dir) */
#define SMARTFS_DIRENT_DELETING 0x1000 /* Directory entry is being deleted */
#define SMARTFS_DIRENT_RESERVED 0x0E00 /* Reserved bits */
#define SMARTFS_DIRENT_MODE 0x01FF /* Mode the file was created with */
#define SMARTFS_DIRENT_TYPE_DIR 0x2000
#define SMARTFS_DIRENT_TYPE_FILE 0x0000
/* Number of bytes in the SMART magic sequences */
#define SMART_MAGICSIZE 4
/* Quasi-standard definitions */
#ifndef MIN
# define MIN(a,b) (a < b ? a : b)
#endif
#ifndef MAX
# define MAX(a,b) (a > b ? a : b)
#endif
/* Underlying MTD Block driver access functions */
#define FS_BOPS(f) (f)->fs_blkdriver->u.i_bops
#define FS_IOCTL(f,c,a) (FS_BOPS(f)->ioctl ? FS_BOPS(f)->ioctl((f)->fs_blkdriver,c,a) : (-ENOSYS))
/* The logical sector number of the root directory. */
#define SMARTFS_ROOT_DIR_SECTOR 3
/* Defines the sector types */
#define SMARTFS_SECTOR_TYPE_DIR 1
#define SMARTFS_SECTOR_TYPE_FILE 2
#ifndef CONFIG_SMARTFS_DIRDEPTH
#define CONFIG_SMARTFS_DIRDEPTH 8
#endif
#define SMARTFS_ERASEDSTATE_16BIT (uint16_t) ((CONFIG_SMARTFS_ERASEDSTATE << 8) | \
CONFIG_SMARTFS_ERASEDSTATE)
#ifndef offsetof
#define offsetof(type, member) ( (size_t) &( ( (type *) 0)->member))
#endif
#define SMARTFS_NEXTSECTOR(h) ( *((uint16_t *) h->nextsector))
#define SMARTFS_USED(h) ( *((uint16_t *) h->used))
/****************************************************************************
* Public Types
****************************************************************************/
/* This structure defines each packed block on the FLASH media */
/* This is an in-memory representation of the SMART inode as extracted from
* FLASH and with additional state information.
*/
struct smartfs_entry_s
{
uint16_t firstsector; /* Sector number of the name */
uint16_t dsector; /* Sector number of the directory entry */
uint16_t doffset; /* Offset of the directory entry */
uint16_t dfirst; /* 1st sector number of the directory entry */
uint16_t flags; /* Flags, including mode */
FAR char *name; /* inode name */
uint32_t utc; /* Time stamp */
uint32_t datlen; /* Length of inode data */
};
/* This is an on-device representation of the SMART inode it esists on
* the FLASH.
*/
struct smartfs_entry_header_s
{
uint16_t flags; /* Flags, including permissions:
15: Empty entry
14: Active entry
12-0: Permissions bits */
int16_t firstsector; /* Sector number of the name */
uint32_t utc; /* Time stamp */
char name[0]; /* inode name */
};
/* This structure describes the smartfs header at the start of each
* sector. It manages the sector chain and used bytes in the sector.
*/
struct smartfs_chain_header_s
{
uint8_t type; /* Type of sector entry (file or dir) */
uint8_t nextsector[2];/* Next logical sector in the chain */
uint8_t used[2]; /* Number of bytes used in this sector */
};
/* This structure describes the state of one open file. This structure
* is protected by the volume semaphore.
*/
struct smartfs_ofile_s
{
struct smartfs_ofile_s *fnext; /* Supports a singly linked list */
int16_t crefs; /* Reference count */
mode_t oflags; /* Open mode */
struct smartfs_entry_s entry; /* Describes the SMARTFS inode entry */
size_t filepos; /* Current file position */
uint16_t currsector; /* Current sector of filepos */
uint16_t curroffset; /* Current offset in sector */
uint16_t byteswritten;/* Count of bytes written to currsector
* that have not been recorded in the
* sector yet. We delay updating the
* used field until the file is closed,
* a seek, or more data is written that
* causes the sector to change. */
};
/* This structure represents the overall mountpoint state. An instance of this
* structure is retained as inode private data on each mountpoint that is
* mounted with a smartfs filesystem.
*/
struct smartfs_mountpt_s
{
#ifdef CONFIG_SMARTFS_MULTI_ROOT_DIRS
struct smartfs_mountpt_s *fs_next; /* Pointer to next SMART filesystem */
#endif
FAR struct inode *fs_blkdriver; /* Our underlying block device */
sem_t *fs_sem; /* Used to assure thread-safe access */
FAR struct smartfs_ofile_s *fs_head; /* A singly-linked list of open files */
bool fs_mounted; /* true: The file system is ready */
struct smart_format_s fs_llformat; /* Low level device format info */
char *fs_rwbuffer; /* Read/Write working buffer */
char *fs_workbuffer;/* Working buffer */
uint8_t fs_rootsector;/* Root directory sector num */
};
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Internal function prototypes
****************************************************************************/
/* Semaphore access for internal use */
void smartfs_semtake(struct smartfs_mountpt_s *fs);
void smartfs_semgive(struct smartfs_mountpt_s *fs);
/* Forward references for utility functions */
struct smartfs_mountpt_s;
/* Utility functions */
int smartfs_mount(struct smartfs_mountpt_s *fs, bool writeable);
int smartfs_unmount(struct smartfs_mountpt_s *fs);
int smartfs_finddirentry(struct smartfs_mountpt_s *fs,
struct smartfs_entry_s *direntry, const char *relpath,
uint16_t *parentdirsector, const char **filename);
int smartfs_createentry(struct smartfs_mountpt_s *fs,
uint16_t parentdirsector, const char* filename,
uint16_t type,
mode_t mode, struct smartfs_entry_s *direntry,
uint16_t sectorno);
int smartfs_deleteentry(struct smartfs_mountpt_s *fs,
struct smartfs_entry_s *entry);
int smartfs_countdirentries(struct smartfs_mountpt_s *fs,
struct smartfs_entry_s *entry);
int smartfs_truncatefile(struct smartfs_mountpt_s *fs,
struct smartfs_entry_s *entry);
struct file; /* Forward references */
struct inode;
struct fs_dirent_s;
struct statfs;
struct stat;
#endif /* __FS_SMARTFS_SMARTFS_H */
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