incubator-nuttx/include/nuttx/fs.h

214 lines
7.3 KiB
C

/************************************************************
* fs.h
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 Gregory Nutt 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_H
#define __FS_H
/************************************************************
* Included Files
************************************************************/
#include <sys/types.h>
#include <semaphore.h>
#include <nuttx/compiler.h>
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Type Definitions
************************************************************/
/* This structure is provided by filesystems when they are
* registered with the system. It is used to call back to
* perform fs/device specific operations.
*/
struct file;
struct file_operations
{
int (*open)(FAR struct file *);
int (*close)(FAR struct file *);
ssize_t (*read)(FAR struct file *, char *, size_t);
ssize_t (*write)(FAR struct file *, const char *, size_t);
int (*ioctl)(FAR struct file *, int, unsigned long);
};
/* This structure represents one inode in the Nuttx psuedo-file system */
struct inode
{
FAR struct inode *i_peer; /* Pointer to inode at same level */
FAR struct inode *i_child; /* Pointer to inode at lower level */
struct file_operations *i_ops; /* Driver file operations for inode */
sint16 i_crefs; /* References to inode */
uint16 i_flags; /* flags for inode */
#ifdef CONFIG_FILE_MODE
mode_t i_mode; /* Access mode flags */
#endif
FAR void *i_private; /* Driver private data */
char i_name[1]; /* Name of inode (variable length) */
};
#define FSNODE_SIZE(n) (sizeof(struct inode) + (n))
/* This is the underlying representation of a ropen file.
* A file descriptor is an index into an array of such types.
* The type associates the file descriptor to the file state
* and to a set of inode operations.
*/
struct file
{
int f_oflags; /* Open mode flags */
off_t f_pos; /* File position */
FAR struct inode *f_inode; /* Driver interface */
};
/* This defines a list of files indexed by the file descriptor */
#if CONFIG_NFILE_DESCRIPTORS > 0
struct filelist
{
sem_t fl_sem; /* Manage access to the file list */
sint16 fl_crefs; /* Reference count */
struct file fl_files[CONFIG_NFILE_DESCRIPTORS];
};
#endif
/* This defines the list of files used for standard C I/O
* We can support the standard C APIs without or without buffering
*/
/* Buffered file I/O structure */
#if CONFIG_NFILE_STREAMS > 0
struct file_struct
{
int fs_filedes; /* File descriptor associated with stream */
mode_t fs_oflags; /* Open mode flags */
#if CONFIG_NUNGET_CHARS > 0
uint8 fs_nungotten; /* The number of characters buffered for ungetc */
unsigned char fs_ungotten[CONFIG_NUNGET_CHARS];
#endif
#if CONFIG_STDIO_BUFFER_SIZE > 0
sem_t fs_sem; /* For thread safety */
pid_t fs_holder; /* Holder of sem */
int fs_counts; /* Number of times sem is held */
FAR unsigned char *fs_bufstart; /* Pointer to start of buffer */
FAR unsigned char *fs_bufend; /* Pointer to 1 past end of buffer */
FAR unsigned char *fs_bufpos; /* Current position in buffer */
FAR unsigned char *fs_bufread; /* Pointer to 1 past last buffered read char. */
#endif
};
struct streamlist
{
int sl_crefs; /* Reference count */
sem_t sl_sem; /* For thread safety */
struct file_struct sl_streams[CONFIG_NFILE_STREAMS];
};
#endif /* CONFIG_NFILE_STREAMS */
/************************************************************
* Global Function Prototypes
************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/* fs_inode.c ***********************************************/
/* These interfaces are used by drivers to register their
* inodes in the inode tree.
*/
EXTERN void weak_function fs_initialize(void);
EXTERN STATUS register_inode(const char *path,
struct file_operations *fops,
mode_t mode, void *private);
EXTERN STATUS unregister_inode(const char *path);
/* fs_open.c ************************************************/
EXTERN int inode_checkflags(FAR struct inode *inode, int oflags);
/* fs_files.c ***********************************************/
#if CONFIG_NFILE_DESCRIPTORS >0
EXTERN FAR struct filelist *files_alloclist(void);
EXTERN int files_addreflist(FAR struct filelist *list);
EXTERN int files_releaselist(FAR struct filelist *list);
EXTERN int files_dup(FAR struct file *filep1, FAR struct file *filep2);
#endif
/* lib_fopen.c **********************************************/
/* Used by the OS to clone stdin, stdout, stderr */
#if CONFIG_NFILE_STREAMS > 0
EXTERN FAR struct file_struct *lib_fdopen(int fd,
const char *mode,
FAR struct filelist *flist,
FAR struct streamlist *slist);
#endif
/* lib_fflush.c *********************************************/
#if CONFIG_NFILE_STREAMS > 0
EXTERN void lib_flushall(FAR struct streamlist *list);
#endif
/* drivers **************************************************/
/* Call in of these to register the corresponding default
* default drivers in the drivers/ subdirectory
*/
EXTERN void devnull_register(void);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __FS_H */