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/*
FUSE: Filesystem in Userspace
Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#ifndef _FUSE_H_
#define _FUSE_H_
/* This file defines the library interface of FUSE */
#include <sys/types.h>
#include <sys/stat.h>
#include <utime.h>
/* ----------------------------------------------------------- *
* Basic FUSE API *
* ----------------------------------------------------------- */
/** Handle for a FUSE filesystem */
struct fuse;
/* Statfs structure used by FUSE */
struct fuse_statfs {
long block_size;
long blocks;
long blocks_free;
long files;
long files_free;
long namelen;
};
/** Handle for a getdir() operation */
typedef struct fuse_dirhandle *fuse_dirh_t;
/** Function to add an entry in a getdir() operation */
typedef int (*fuse_dirfil_t) (fuse_dirh_t, const char *, int type);
/**
* The file system operations:
*
* Most of these should work very similarly to the well known UNIX
* file system operations. Exceptions are:
*
* - All operations should return the negated error value (-errno) on
* error.
*
* - Getattr() doesn't need to fill in the following fields:
* st_ino
* st_dev
* st_blksize
*
* - readlink() should fill the buffer with a null terminated string. The
* buffer size argument includes the space for the terminating null
* character. If the linkname is too long to fit in the buffer, it should
* be truncated. The return value should be 0 for success.
*
* - getdir() is the opendir(), readdir(), ..., closedir() sequence
* in one call. For each directory entry the filldir parameter should
* be called.
*
* - There is no create() operation, mknod() will be called for
* creation of all non directory, non symlink nodes.
*
* - open() should not return a filehandle, but 0 on success. No
* creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) will be
* passed to open(). Open should only check if the operation is
* permitted for the given flags.
*
* - read(), write() are not passed a filehandle, but rather a
* pathname. The offset of the read and write is passed as the last
* argument, like the pread() and pwrite() system calls.
*/
struct fuse_operations {
int (*getattr) (const char *, struct stat *);
int (*readlink) (const char *, char *, size_t);
int (*getdir) (const char *, fuse_dirh_t, fuse_dirfil_t);
int (*mknod) (const char *, mode_t, dev_t);
int (*mkdir) (const char *, mode_t);
int (*unlink) (const char *);
int (*rmdir) (const char *);
int (*symlink) (const char *, const char *);
int (*rename) (const char *, const char *);
int (*link) (const char *, const char *);
int (*chmod) (const char *, mode_t);
int (*chown) (const char *, uid_t, gid_t);
int (*truncate) (const char *, off_t);
int (*utime) (const char *, struct utimbuf *);
int (*open) (const char *, int);
int (*read) (const char *, char *, size_t, off_t);
int (*write) (const char *, const char *, size_t, off_t);
int (*statfs) (struct fuse_statfs *);
};
/** Extra context that may be needed by some filesystems */
struct fuse_context {
uid_t uid;
gid_t gid;
};
/* FUSE flags: */
/** Enable debuging output */
#define FUSE_DEBUG (1 << 1)
#ifdef __cplusplus
extern "C" {
#endif
/*
* Create a FUSE mountpoint
*
* Returns a control file descriptor suitable for passing to
* fuse_new()
*
* @param mountpoint the mount point path
* @param args array of arguments to be passed to fusermount (NULL
* terminated). Can be NULL if no arguments are needed.
* @return the control file descriptor on success, -1 on failure
*/
int fuse_mount(const char *mountpoint, const char *args[]);
/**
* Create a new FUSE filesystem.
*
* @param fd the control file descriptor
* @param flags any combination of the FUSE flags defined above, or 0
* @param op the operations
* @return the created FUSE handle
*/
struct fuse *fuse_new(int fd, int flags, const struct fuse_operations *op);
/**
* FUSE event loop.
*
* Requests from the kernel are processed, and the apropriate
* operations are called.
*
* @param f the FUSE handle
*/
void fuse_loop(struct fuse *f);
/**
* FUSE event loop with multiple threads
*
* Requests from the kernel are processed, and the apropriate
* operations are called. Request are processed in parallel by
* distributing them between multiple threads.
*
* Calling this function requires the pthreads library to be linked to
* the application.
*
* @param f the FUSE handle
*/
void fuse_loop_mt(struct fuse *f);
/**
* Destroy the FUSE handle.
*
* The filesystem is not unmounted.
*
* @param f the FUSE handle
*/
void fuse_destroy(struct fuse *f);
/**
* Get the current context
*
* The context is only valid for the duration of a filesystem
* operation, and thus must not be stored and used later.
*
* @param f the FUSE handle
* @return the context
*/
struct fuse_context *fuse_get_context(struct fuse *f);
/* ----------------------------------------------------------- *
* Miscellaneous helper fuctions *
* ----------------------------------------------------------- */
/*
* Main function of FUSE.
*
* This is for the lazy. This is all that has to be called from the
* main() function.
*
* This function does the following:
* - mounts the filesystem
* - installs signal handlers for INT, HUP, TERM and PIPE
* - registers an exit handler to unmount the filesystem on program exit
* - parses command line options (-d -s and -h)
* - creates a fuse handle
* - registers the operations
* - calls either the single-threaded or the multi-threaded event loop
*
* @param argc the argument counter passed to the main() function
* @param argv the argument vector passed to the main() function
* @param op the file system operation
*/
void fuse_main(int argc, char *argv[], const struct fuse_operations *op);
/* ----------------------------------------------------------- *
* Advanced API for event handling, don't worry about this... *
* ----------------------------------------------------------- */
struct fuse_cmd;
typedef void (*fuse_processor_t)(struct fuse *, struct fuse_cmd *, void *);
struct fuse_cmd *__fuse_read_cmd(struct fuse *f);
void __fuse_process_cmd(struct fuse *f, struct fuse_cmd *cmd);
void __fuse_loop_mt(struct fuse *f, fuse_processor_t proc, void *data);
#ifdef __cplusplus
}
#endif
#endif /* _FUSE_H_ */
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