/**************************************************************************** * include/nuttx/fs/fs.h * * Copyright (C) 2007-2009, 2011-2012 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 __INCLUDE_NUTTX_FS_FS_H #define __INCLUDE_NUTTX_FS_FS_H /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #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, bool 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 { bool geo_available; /* true: The device is vailable */ bool geo_mediachanged; /* true: The media has changed since last query */ bool 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 fs_dirent_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 fs_dirent_s *dir); int (*closedir)(FAR struct inode *mountpt, FAR struct fs_dirent_s *dir); int (*readdir)(FAR struct inode *mountpt, FAR struct fs_dirent_s *dir); int (*rewinddir)(FAR struct inode *mountpt, FAR struct fs_dirent_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 pseudo-file system */ struct inode { FAR struct inode *i_peer; /* Pointer to same level inode */ FAR struct inode *i_child; /* Pointer to lower level inode */ int16_t i_crefs; /* References to inode */ uint16_t 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 */ int16_t 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 */ uint16_t fs_oflags; /* Open mode flags */ #if CONFIG_NUNGET_CHARS > 0 uint8_t 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 */ /* Callback used by foreach_mountpoints to traverse all mountpoints in the * pseudo-file system. */ #ifndef CONFIG_DISABLE_MOUNTPOUNT struct statfs; /* Forward reference */ typedef int (*foreach_mountpoint_t)(FAR const char *mountpoint, FAR struct statfs *statbuf, FAR void *arg); #endif /**************************************************************************** * Global Function Prototypes ****************************************************************************/ #undef EXTERN #if defined(__cplusplus) #define EXTERN extern "C" extern "C" { #else #define EXTERN extern #endif /* fs_inode.c ***************************************************************/ /**************************************************************************** * Name: fs_initialize * * Description: * This is called from the OS initialization logic to configure the file * system. * ****************************************************************************/ EXTERN void weak_function fs_initialize(void); /* fs_foreachmountpoint.c ***************************************************/ /**************************************************************************** * Name: foreach_mountpoint * * Description: * Visit each mountpoint in the pseudo-file system. The traversal is * terminated when the callback 'handler' returns a non-zero value, or when * all of the mountpoints have been visited. * * This is just a front end "filter" to foreach_inode() that forwards only * mountpoint inodes. It is intended to support the mount() command to * when the mount command is used to enumerate mounts. * * NOTE 1: Use with caution... The pseudo-file system is locked throughout * the traversal. * NOTE 2: The search algorithm is recursive and could, in principle, use * an indeterminant amount of stack space. This will not usually be a * real work issue. * ****************************************************************************/ #ifndef CONFIG_DISABLE_MOUNTPOUNT EXTERN int foreach_mountpoint(foreach_mountpoint_t handler, FAR void *arg); #endif /* fs_registerdriver.c ******************************************************/ /**************************************************************************** * Name: register_driver * * Description: * Register a character driver inode the pseudo file system. * * Input parameters: * path - The path to the inode to create * fops - The file operations structure * mode - inmode priviledges (not used) * priv - Private, user data that will be associated with the inode. * * Returned Value: * Zero on success (with the inode point in 'inode'); A negated errno * value is returned on a failure (all error values returned by * inode_reserve): * * EINVAL - 'path' is invalid for this operation * EEXIST - An inode already exists at 'path' * ENOMEM - Failed to allocate in-memory resources for the operation * ****************************************************************************/ EXTERN int register_driver(const char *path, const struct file_operations *fops, mode_t mode, void *priv); /* fs_registerblockdriver.c *************************************************/ /**************************************************************************** * Name: register_blockdriver * * Description: * Register a block driver inode the pseudo file system. * * Input parameters: * path - The path to the inode to create * bops - The block driver operations structure * mode - inmode priviledges (not used) * priv - Private, user data that will be associated with the inode. * * Returned Value: * Zero on success (with the inode point in 'inode'); A negated errno * value is returned on a failure (all error values returned by * inode_reserve): * * EINVAL - 'path' is invalid for this operation * EEXIST - An inode already exists at 'path' * ENOMEM - Failed to allocate in-memory resources for the operation * ****************************************************************************/ EXTERN int register_blockdriver(const char *path, const struct block_operations *bops, mode_t mode, void *priv); /* fs_unregisterdriver.c ****************************************************/ /**************************************************************************** * Name: unregister_driver * * Description: * Remove the character driver inode at 'path' from the pseudo-file system * ****************************************************************************/ EXTERN int unregister_driver(const char *path); /* fs_unregisterblockdriver.c ***********************************************/ /**************************************************************************** * Name: unregister_blockdriver * * Description: * Remove the block driver inode at 'path' from the pseudo-file system * ****************************************************************************/ EXTERN int unregister_blockdriver(const char *path); /* fs_open.c ****************************************************************/ /**************************************************************************** * Name: inode_checkflags * * Description: * Check if the access described by 'oflags' is supported on 'inode' * ****************************************************************************/ EXTERN int inode_checkflags(FAR struct inode *inode, int oflags); /* fs_files.c ***************************************************************/ /**************************************************************************** * Name: files_alloclist * * Description: Allocate a list of files for a new task * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN FAR struct filelist *files_alloclist(void); #endif /**************************************************************************** * Name: files_addreflist * * Description: * Increase the reference count on a file list * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN int files_addreflist(FAR struct filelist *list); #endif /**************************************************************************** * Name: files_releaselist * * Description: * Release a reference to the file list * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN int files_releaselist(FAR struct filelist *list); #endif /**************************************************************************** * Name: files_dup * * Description: * Assign an inode to a specific files structure. This is the heart of * dup2. * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN int files_dup(FAR struct file *filep1, FAR struct file *filep2); #endif /* fs_filedup.c *************************************************************/ /**************************************************************************** * Name: file_dup OR dup * * Description: * Clone a file descriptor 'fd' to an arbitray descriptor number (any value * greater than or equal to 'minfd'). If socket descriptors are * implemented, then this is called by dup() for the case of file * descriptors. If socket descriptors are not implemented, then this * function IS dup(). * * This alternative naming is used when dup could operate on both file and * socket descritors to avoid drawing unused socket support into the link. * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN int file_dup(int fd, int minfd); #endif /* fs_filedup2.c ************************************************************/ /**************************************************************************** * Name: file_dup2 OR dup2 * * Description: * Clone a file descriptor to a specific descriptor number. If socket * descriptors are implemented, then this is called by dup2() for the * case of file descriptors. If socket descriptors are not implemented, * then this function IS dup2(). * * This alternative naming is used when dup2 could operate on both file and * socket descritors to avoid drawing unused socket support into the link. * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 #if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0 EXTERN int file_dup2(int fd1, int fd2); #else # define file_dup2(fd1, fd2) dup2(fd1, fd2) #endif #endif /* fs_openblockdriver.c *****************************************************/ /**************************************************************************** * Name: open_blockdriver * * Description: * Return the inode of the block driver specified by 'pathname' * * Inputs: * pathname - the full path to the block driver to be opened * mountflags - if MS_RDONLY is not set, then driver must support write * operations (see include/sys/mount.h) * ppinode - address of the location to return the inode reference * * Return: * Returns zero on success or a negated errno on failure: * * EINVAL - pathname or pinode is NULL * ENOENT - No block driver of this name is registered * ENOTBLK - The inode associated with the pathname is not a block driver * EACCESS - The MS_RDONLY option was not set but this driver does not * support write access * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN int open_blockdriver(FAR const char *pathname, int mountflags, FAR struct inode **ppinode); #endif /* fs_closeblockdriver.c ****************************************************/ /**************************************************************************** * Name: close_blockdriver * * Description: * Call the close method and release the inode * * Inputs: * inode - reference to the inode of a block driver opened by open_blockdriver * * Return: * Returns zero on success or a negated errno on failure: * * EINVAL - inode is NULL * ENOTBLK - The inode is not a block driver * ****************************************************************************/ #if CONFIG_NFILE_DESCRIPTORS > 0 EXTERN int close_blockdriver(FAR struct inode *inode); #endif /* fs_fdopen.c **************************************************************/ /**************************************************************************** * Name: fs_fdopen * * Description: * This function does the core operations for fopen and fdopen. It is * used by the OS to clone stdin, stdout, stderr * ****************************************************************************/ #if CONFIG_NFILE_STREAMS > 0 #ifndef __TCB_DEFINED__ typedef struct _TCB _TCB; #define __TCB_DEFINED__ #endif EXTERN FAR struct file_struct *fs_fdopen(int fd, int oflags, FAR _TCB *tcb); #endif /* lib/stdio/lib_fflush.c **************************************************/ /**************************************************************************** * Name: lib_flushall * * Description: * Called either (1) by the OS when a task exits, or (2) from fflush() * when a NULL stream argument is provided. * ****************************************************************************/ #if CONFIG_NFILE_STREAMS > 0 EXTERN int lib_flushall(FAR struct streamlist *list); #endif /* drivers/dev_null.c *******************************************************/ /**************************************************************************** * Name: devnull_register * * Description: * Register /dev/null * ****************************************************************************/ EXTERN void devnull_register(void); /* drivers/dev_zero.c *******************************************************/ /**************************************************************************** * Name: devzero_register * * Description: * Register /dev/zero * ****************************************************************************/ EXTERN void devzero_register(void); /* drivers/loop.c ***********************************************************/ /**************************************************************************** * Name: losetup * * Description: * Setup the loop device so that it exports the file referenced by 'filename' * as a block device. * ****************************************************************************/ EXTERN int losetup(FAR const char *devname, FAR const char *filename, uint16_t sectsize, off_t offset, bool readonly); /**************************************************************************** * Name: loteardown * * Description: * Undo the setup performed by losetup * ****************************************************************************/ EXTERN int loteardown(FAR const char *devname); /* drivers/bch/bchdev_register.c ********************************************/ /**************************************************************************** * Name: bchdev_register * * Description: * Setup so that it exports the block driver referenced by 'blkdev' as a * character device 'chardev' * ****************************************************************************/ EXTERN int bchdev_register(FAR const char *blkdev, FAR const char *chardev, bool readonly); /* drivers/bch/bchdev_unregister.c ******************************************/ /**************************************************************************** * Name: bchdev_unregister * * Description: * Unregister character driver access to a block device that was created * by a previous call to bchdev_register(). * ****************************************************************************/ EXTERN int bchdev_unregister(FAR 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. */ /* drivers/bch/bchlib_setup.c ***********************************************/ /**************************************************************************** * Name: bchlib_setup * * Description: * Setup so that the block driver referenced by 'blkdev' can be accessed * similar to a character device. * ****************************************************************************/ EXTERN int bchlib_setup(FAR const char *blkdev, bool readonly, FAR void **handle); /* drivers/bch/bchlib_teardown.c ********************************************/ /**************************************************************************** * Name: bchlib_teardown * * Description: * Setup so that the block driver referenced by 'blkdev' can be accessed * similar to a character device. * ****************************************************************************/ EXTERN int bchlib_teardown(FAR void *handle); /* drivers/bch/bchlib_read.c ************************************************/ /**************************************************************************** * Name: bchlib_read * * Description: * Read from the block device set-up by bchlib_setup as if it were a * character device. * ****************************************************************************/ EXTERN ssize_t bchlib_read(FAR void *handle, FAR char *buffer, size_t offset, size_t len); /* drivers/bch/bchlib_write.c ***********************************************/ /**************************************************************************** * Name: bchlib_write * * Description: * Write to the block device set-up by bchlib_setup as if it were a * character device. * ****************************************************************************/ 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 /* __INCLUDE_NUTTX_FS_FS_H */