/**************************************************************************** * include/nuttx/fs.h * * Copyright (C) 2007, 2008 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 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 __NUTTX_FS_H #define __NUTTX_FS_H /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include /**************************************************************************** * Definitions ****************************************************************************/ /**************************************************************************** * Type Definitions ****************************************************************************/ /* This structure is provided by devices when they are registered with the * system. It is used to call back to perform device specific operations. */ struct file; struct pollfd; struct file_operations { /* The device driver open method differs from the mountpoint open method */ int (*open)(FAR struct file *filp); /* The following methods must be identical in signature and position because * the struct file_operations and struct mountp_operations are treated like * unions. */ int (*close)(FAR struct file *filp); ssize_t (*read)(FAR struct file *filp, FAR char *buffer, size_t buflen); ssize_t (*write)(FAR struct file *filp, FAR const char *buffer, size_t buflen); off_t (*seek)(FAR struct file *filp, off_t offset, int whence); int (*ioctl)(FAR struct file *filp, int cmd, unsigned long arg); #ifndef CONFIG_DISABLE_POLL int (*poll)(FAR struct file *filp, struct pollfd *fds, boolean setup); #endif /* The two structures need not be common after this point */ }; /* This structure provides information about the state of a block driver */ #ifndef CONFIG_DISABLE_MOUNTPOUNT struct geometry { boolean geo_available; /* TRUE: The device is vailable */ boolean geo_mediachanged; /* TRUE: The media has changed since last query */ boolean geo_writeenabled; /* TRUE: It is okay to write to this device */ size_t geo_nsectors; /* Number of sectors on the device */ size_t geo_sectorsize; /* Size of one sector */ }; /* This structure is provided by block devices when they register with the * system. It is used by file systems to perform filesystem transfers. It * differs from the normal driver vtable in several ways -- most notably in * that it deals in struct inode vs. struct filep. */ struct inode; struct block_operations { int (*open)(FAR struct inode *inode); int (*close)(FAR struct inode *inode); ssize_t (*read)(FAR struct inode *inode, FAR unsigned char *buffer, size_t start_sector, unsigned int nsectors); ssize_t (*write)(FAR struct inode *inode, FAR const unsigned char *buffer, size_t start_sector, unsigned int nsectors); int (*geometry)(FAR struct inode *inode, FAR struct geometry *geometry); int (*ioctl)(FAR struct inode *inode, int cmd, unsigned long arg); }; /* This structure is provided by a filesystem to describe a mount point. * Note that this structure differs from file_operations ONLY in the form of * the open method. Once the file is opened, it can be accessed either as a * struct file_operations or struct mountpt_operations */ struct inode; struct internal_dir_s; struct stat; struct statfs; struct mountpt_operations { /* The mountpoint open method differs from the driver open method * because it receives (1) the inode that contains the mountpoint * private data, (2) the relative path into the mountpoint, and (3) * information to manage privileges. */ int (*open)(FAR struct file *filp, FAR const char *relpath, int oflags, mode_t mode); /* The following methods must be identical in signature and position because * the struct file_operations and struct mountp_operations are treated like * unions. */ int (*close)(FAR struct file *filp); ssize_t (*read)(FAR struct file *filp, FAR char *buffer, size_t buflen); ssize_t (*write)(FAR struct file *filp, FAR const char *buffer, size_t buflen); off_t (*seek)(FAR struct file *filp, off_t offset, int whence); int (*ioctl)(FAR struct file *filp, int cmd, unsigned long arg); /* The two structures need not be common after this point. The following * are extended methods needed to deal with the unique needs of mounted * file systems. * * Additional open-file-specific mountpoint operations: */ int (*sync)(FAR struct file *filp); /* Directory operations */ int (*opendir)(FAR struct inode *mountpt, FAR const char *relpath, FAR struct internal_dir_s *dir); int (*closedir)(FAR struct inode *mountpt, FAR struct internal_dir_s *dir); int (*readdir)(FAR struct inode *mountpt, FAR struct internal_dir_s *dir); int (*rewinddir)(FAR struct inode *mountpt, FAR struct internal_dir_s *dir); /* General volume-related mountpoint operations: */ int (*bind)(FAR struct inode *blkdriver, FAR const void *data, FAR void **handle); int (*unbind)(FAR void *handle, FAR struct inode **blkdriver); int (*statfs)(FAR struct inode *mountpt, FAR struct statfs *buf); /* Operations on pathes */ int (*unlink)(FAR struct inode *mountpt, FAR const char *relpath); int (*mkdir)(FAR struct inode *mountpt, FAR const char *relpath, mode_t mode); int (*rmdir)(FAR struct inode *mountpt, FAR const char *relpath); int (*rename)(FAR struct inode *mountpt, FAR const char *oldrelpath, FAR const char *newrelpath); int (*stat)(FAR struct inode *mountpt, FAR const char *relpath, FAR struct stat *buf); /* NOTE: More operations will be needed here to support: disk usage stats * file stat(), file attributes, file truncation, etc. */ }; #endif /* CONFIG_DISABLE_MOUNTPOUNT */ /* These are the various kinds of operations that can be associated with * an inode. */ union inode_ops_u { FAR const struct file_operations *i_ops; /* Driver operations for inode */ #ifndef CONFIG_DISABLE_MOUNTPOUNT FAR const struct block_operations *i_bops; /* Block driver operations */ FAR const struct mountpt_operations *i_mops; /* Operations on a mountpoint */ #endif }; /* This structure represents one inode in the Nuttx psuedo-file system */ struct inode { FAR struct inode *i_peer; /* Pointer to same level inode */ FAR struct inode *i_child; /* Pointer to lower level inode */ sint16 i_crefs; /* References to inode */ uint16 i_flags; /* Flags for inode */ union inode_ops_u u; /* Inode operations */ #ifdef CONFIG_FILE_MODE mode_t i_mode; /* Access mode flags */ #endif FAR void *i_private; /* Per inode driver private data */ char i_name[1]; /* Name of inode (variable) */ }; #define FSNODE_SIZE(n) (sizeof(struct inode) + (n)) /* This is the underlying representation of an open 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 */ void *f_priv; /* Per file driver private data */ }; /* 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 /* The following structure defines the list of files used for standard C I/O. * Note that NuttX can support the standard C APIs without or without buffering * * When buffering us used, the following described the usage of the I/O buffer. * The buffer can be used for reading or writing -- but not both at the same time. * An fflush is implied between each change in directionof access. * * The field fs_bufread determines whether the buffer is being used for reading or * for writing as fillows: * * BUFFER * +----------------------+ <- fs_bufstart Points to the beginning of the buffer. * | WR: Buffered data | WR: Start of buffered write data. * | RD: Already read | RD: Start of already read data. * +----------------------+ * | WR: Available buffer | <- fs_bufpos Points to next byte: * | RD: Read-ahead data | WR: End+1 of buffered write data. * | | RD: Points to next char to return * +----------------------+ * | WR: Available | <- fs_bufread Top+1 of buffered read data * | RD: Available | WR: =bufstart buffer used for writing. * | | RD: Pointer to last buffered read char+1 * +----------------------+ * <- fs_bufend Points to end end of the buffer+1 */ #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); /* fs_registerdriver.c ******************************************************/ EXTERN STATUS register_driver(const char *path, const struct file_operations *fops, mode_t mode, void *private); /* fs_registerdriver.c ******************************************************/ EXTERN STATUS register_blockdriver(const char *path, const struct block_operations *bops, mode_t mode, void *private); /* fs_unregisterdriver.c ****************************************************/ EXTERN STATUS unregister_driver(const char *path); /* fs_unregisterblockdriver.c ***********************************************/ EXTERN STATUS unregister_blockdriver(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); /* fs_openblockdriver.c ******************************************************/ EXTERN int open_blockdriver(FAR const char *pathname, int mountflags, FAR struct inode **ppinode); /* fs_closeblockdriver.c *****************************************************/ EXTERN int close_blockdriver(FAR struct inode *inode); #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 int lib_flushall(FAR struct streamlist *list); #endif /* drivers ******************************************************************/ /* Call any of these to register the corresponding drivers in the drivers/ * subdirectory */ /* Register /dev/null and /dev/zero */ EXTERN void devnull_register(void); EXTERN void devzero_register(void); /* Setup the loop device so that it exports the file referenced by 'filename' * as a block device. */ EXTERN int losetup(const char *devname, const char *filename, uint16 sectsize, off_t offset, boolean readonly); EXTERN int loteardown(const char *devname); /* Setup so that the block driver referenced by 'blkdev' can be accessed * similar to a character device. * * Access via a character device: */ EXTERN int bchdev_register(const char *blkdev, const char *chardev, boolean readonly); EXTERN int bchdev_unregister(const char *chardev); /* Low level, direct access. NOTE: low-level access and character driver access * are incompatible. One and only one access method should be implemented. */ EXTERN int bchlib_setup(const char *blkdev, boolean readonly, FAR void **handle); EXTERN int bchlib_teardown(FAR void *handle); EXTERN ssize_t bchlib_read(FAR void *handle, FAR char *buffer, size_t offset, size_t len); EXTERN ssize_t bchlib_write(FAR void *handle, FAR const char *buffer, size_t offset, size_t len); #undef EXTERN #if defined(__cplusplus) } #endif #endif /* __NUTTX_FS_H */