/************************************************************ * fs.h * * Copyright (C) 2007 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include /************************************************************ * 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 */