ntfs-3g/include/fuse-lite/fuse.h
Jean-Pierre André 32c27a8a4f Defined the request argument of ioctl() as unsigned long
On linux the request argument of ioctl() is defined as an unsigned long,
but the fuse protocol squashes it into a signed int. As a consequence
the value received by ntfs-3g may appear as negative and different from
the value defined by the corresponding macro.
So define the request argument as unsigned long in ntfs-3g. It has
however to be fed as unsigned from fuse until the fuse protocol is
updated.
2020-03-07 10:31:12 +01:00

698 lines
22 KiB
C

/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU LGPLv2.
See the file COPYING.LIB.
*/
#ifndef _FUSE_H_
#define _FUSE_H_
/** @file
*
* This file defines the library interface of FUSE
*/
#include "fuse_common.h"
#include <fcntl.h>
#include <time.h>
#include <utime.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#ifdef __cplusplus
extern "C" {
#endif
/* ----------------------------------------------------------- *
* Basic FUSE API *
* ----------------------------------------------------------- */
/** Handle for a FUSE filesystem */
struct fuse;
/** Structure containing a raw command */
struct fuse_cmd;
/** Function to add an entry in a readdir() operation
*
* @param buf the buffer passed to the readdir() operation
* @param name the file name of the directory entry
* @param stat file attributes, can be NULL
* @param off offset of the next entry or zero
* @return 1 if buffer is full, zero otherwise
*/
typedef int (*fuse_fill_dir_t) (void *buf, const char *name,
const struct stat *stbuf, off_t off);
/**
* The file system operations:
*
* Most of these should work very similarly to the well known UNIX
* file system operations. A major exception is that instead of
* returning an error in 'errno', the operation should return the
* negated error value (-errno) directly.
*
* All methods are optional, but some are essential for a useful
* filesystem (e.g. getattr). Open, flush, release, fsync, opendir,
* releasedir, fsyncdir, access, create, ftruncate, fgetattr, lock,
* init and destroy are special purpose methods, without which a full
* featured filesystem can still be implemented.
*
* Almost all operations take a path which can be of any length.
*
* Changed in fuse 2.8.0 (regardless of API version)
* Previously, paths were limited to a length of PATH_MAX.
*/
struct fuse_operations {
/** Get file attributes.
*
* Similar to stat(). The 'st_dev' and 'st_blksize' fields are
* ignored. The 'st_ino' field is ignored except if the 'use_ino'
* mount option is given.
*/
int (*getattr) (const char *, struct stat *);
/** Read the target of a symbolic link
*
* The buffer should be filled 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.
*/
int (*readlink) (const char *, char *, size_t);
/** Create a file node
*
* This is called for creation of all non-directory, non-symlink
* nodes. If the filesystem defines a create() method, then for
* regular files that will be called instead.
*/
int (*mknod) (const char *, mode_t, dev_t);
/** Create a directory
*
* Note that the mode argument may not have the type specification
* bits set, i.e. S_ISDIR(mode) can be false. To obtain the
* correct directory type bits use mode|S_IFDIR
* */
int (*mkdir) (const char *, mode_t);
/** Remove a file */
int (*unlink) (const char *);
/** Remove a directory */
int (*rmdir) (const char *);
/** Create a symbolic link */
int (*symlink) (const char *, const char *);
/** Rename a file */
int (*rename) (const char *, const char *);
/** Create a hard link to a file */
int (*link) (const char *, const char *);
/** Change the permission bits of a file */
int (*chmod) (const char *, mode_t);
/** Change the owner and group of a file */
int (*chown) (const char *, uid_t, gid_t);
/** Change the size of a file */
int (*truncate) (const char *, off_t);
/** Change the access and/or modification times of a file
*
* Deprecated, use utimens() instead.
*/
int (*utime) (const char *, struct utimbuf *);
/** File open operation
*
* No creation (O_CREAT, O_EXCL) and by default also no
* truncation (O_TRUNC) flags will be passed to open(). If an
* application specifies O_TRUNC, fuse first calls truncate()
* and then open(). Only if 'atomic_o_trunc' has been
* specified and kernel version is 2.6.24 or later, O_TRUNC is
* passed on to open.
*
* Unless the 'default_permissions' mount option is given,
* open should check if the operation is permitted for the
* given flags. Optionally open may also return an arbitrary
* filehandle in the fuse_file_info structure, which will be
* passed to all file operations.
*
* Changed in version 2.2
*/
int (*open) (const char *, struct fuse_file_info *);
/** Read data from an open file
*
* Read should return exactly the number of bytes requested except
* on EOF or error, otherwise the rest of the data will be
* substituted with zeroes. An exception to this is when the
* 'direct_io' mount option is specified, in which case the return
* value of the read system call will reflect the return value of
* this operation.
*
* Changed in version 2.2
*/
int (*read) (const char *, char *, size_t, off_t,
struct fuse_file_info *);
/** Write data to an open file
*
* Write should return exactly the number of bytes requested
* except on error. An exception to this is when the 'direct_io'
* mount option is specified (see read operation).
*
* Changed in version 2.2
*/
int (*write) (const char *, const char *, size_t, off_t,
struct fuse_file_info *);
/** Get file system statistics
*
* The 'f_frsize', 'f_favail', 'f_fsid' and 'f_flag' fields are ignored
*
* Replaced 'struct statfs' parameter with 'struct statvfs' in
* version 2.5
*/
int (*statfs) (const char *, struct statvfs *);
/** Possibly flush cached data
*
* BIG NOTE: This is not equivalent to fsync(). It's not a
* request to sync dirty data.
*
* Flush is called on each close() of a file descriptor. So if a
* filesystem wants to return write errors in close() and the file
* has cached dirty data, this is a good place to write back data
* and return any errors. Since many applications ignore close()
* errors this is not always useful.
*
* NOTE: The flush() method may be called more than once for each
* open(). This happens if more than one file descriptor refers
* to an opened file due to dup(), dup2() or fork() calls. It is
* not possible to determine if a flush is final, so each flush
* should be treated equally. Multiple write-flush sequences are
* relatively rare, so this shouldn't be a problem.
*
* Filesystems shouldn't assume that flush will always be called
* after some writes, or that if will be called at all.
*
* Changed in version 2.2
*/
int (*flush) (const char *, struct fuse_file_info *);
/** Release an open file
*
* Release is called when there are no more references to an open
* file: all file descriptors are closed and all memory mappings
* are unmapped.
*
* For every open() call there will be exactly one release() call
* with the same flags and file descriptor. It is possible to
* have a file opened more than once, in which case only the last
* release will mean, that no more reads/writes will happen on the
* file. The return value of release is ignored.
*
* Changed in version 2.2
*/
int (*release) (const char *, struct fuse_file_info *);
/** Synchronize file contents
*
* If the datasync parameter is non-zero, then only the user data
* should be flushed, not the meta data.
*
* Changed in version 2.2
*/
int (*fsync) (const char *, int, struct fuse_file_info *);
/** Set extended attributes */
int (*setxattr) (const char *, const char *, const char *, size_t, int);
/** Get extended attributes */
int (*getxattr) (const char *, const char *, char *, size_t);
/** List extended attributes */
int (*listxattr) (const char *, char *, size_t);
/** Remove extended attributes */
int (*removexattr) (const char *, const char *);
/** Open directory
*
* This method should check if the open operation is permitted for
* this directory
*
* Introduced in version 2.3
*/
int (*opendir) (const char *, struct fuse_file_info *);
/** Read directory
*
* The filesystem may choose between two modes of operation:
*
* 1) The readdir implementation ignores the offset parameter, and
* passes zero to the filler function's offset. The filler
* function will not return '1' (unless an error happens), so the
* whole directory is read in a single readdir operation.
*
* 2) The readdir implementation keeps track of the offsets of the
* directory entries. It uses the offset parameter and always
* passes non-zero offset to the filler function. When the buffer
* is full (or an error happens) the filler function will return
* '1'.
*
* Introduced in version 2.3
*/
int (*readdir) (const char *, void *, fuse_fill_dir_t, off_t,
struct fuse_file_info *);
/** Release directory
*
* Introduced in version 2.3
*/
int (*releasedir) (const char *, struct fuse_file_info *);
/** Synchronize directory contents
*
* If the datasync parameter is non-zero, then only the user data
* should be flushed, not the meta data
*
* Introduced in version 2.3
*/
int (*fsyncdir) (const char *, int, struct fuse_file_info *);
/**
* Initialize filesystem
*
* The return value will passed in the private_data field of
* fuse_context to all file operations and as a parameter to the
* destroy() method.
*
* Introduced in version 2.3
* Changed in version 2.6
*/
void *(*init) (struct fuse_conn_info *conn);
/**
* Clean up filesystem
*
* Called on filesystem exit.
*
* Introduced in version 2.3
*/
void (*destroy) (void *);
/**
* Check file access permissions
*
* This will be called for the access() system call. If the
* 'default_permissions' mount option is given, this method is not
* called.
*
* This method is not called under Linux kernel versions 2.4.x
*
* Introduced in version 2.5
*/
int (*access) (const char *, int);
/**
* Create and open a file
*
* If the file does not exist, first create it with the specified
* mode, and then open it.
*
* If this method is not implemented or under Linux kernel
* versions earlier than 2.6.15, the mknod() and open() methods
* will be called instead.
*
* Introduced in version 2.5
*/
int (*create) (const char *, mode_t, struct fuse_file_info *);
/**
* Change the size of an open file
*
* This method is called instead of the truncate() method if the
* truncation was invoked from an ftruncate() system call.
*
* If this method is not implemented or under Linux kernel
* versions earlier than 2.6.15, the truncate() method will be
* called instead.
*
* Introduced in version 2.5
*/
int (*ftruncate) (const char *, off_t, struct fuse_file_info *);
/**
* Get attributes from an open file
*
* This method is called instead of the getattr() method if the
* file information is available.
*
* Currently this is only called after the create() method if that
* is implemented (see above). Later it may be called for
* invocations of fstat() too.
*
* Introduced in version 2.5
*/
int (*fgetattr) (const char *, struct stat *, struct fuse_file_info *);
/**
* Perform POSIX file locking operation
*
* The cmd argument will be either F_GETLK, F_SETLK or F_SETLKW.
*
* For the meaning of fields in 'struct flock' see the man page
* for fcntl(2). The l_whence field will always be set to
* SEEK_SET.
*
* For checking lock ownership, the 'fuse_file_info->owner'
* argument must be used.
*
* For F_GETLK operation, the library will first check currently
* held locks, and if a conflicting lock is found it will return
* information without calling this method. This ensures, that
* for local locks the l_pid field is correctly filled in. The
* results may not be accurate in case of race conditions and in
* the presence of hard links, but it's unlikly that an
* application would rely on accurate GETLK results in these
* cases. If a conflicting lock is not found, this method will be
* called, and the filesystem may fill out l_pid by a meaningful
* value, or it may leave this field zero.
*
* For F_SETLK and F_SETLKW the l_pid field will be set to the pid
* of the process performing the locking operation.
*
* Note: if this method is not implemented, the kernel will still
* allow file locking to work locally. Hence it is only
* interesting for network filesystems and similar.
*
* Introduced in version 2.6
*/
int (*lock) (const char *, struct fuse_file_info *, int cmd,
struct flock *);
/**
* Change the access and modification times of a file with
* nanosecond resolution
*
* Introduced in version 2.6
*/
int (*utimens) (const char *, const struct timespec tv[2]);
/**
* Map block index within file to block index within device
*
* Note: This makes sense only for block device backed filesystems
* mounted with the 'blkdev' option
*
* Introduced in version 2.6
*/
int (*bmap) (const char *, size_t blocksize, uint64_t *idx);
/**
* Ioctl
*
* flags will have FUSE_IOCTL_COMPAT set for 32bit ioctls in
* 64bit environment. The size and direction of data is
* determined by _IOC_*() decoding of cmd. For _IOC_NONE,
* data will be NULL, for _IOC_WRITE data is out area, for
* _IOC_READ in area and if both are set in/out area. In all
* non-NULL cases, the area is of _IOC_SIZE(cmd) bytes.
*
* Introduced in version 2.8
*
* Note : the unsigned long request submitted by the application
* is truncated to 32 bits, and forwarded as a signed int.
*/
int (*ioctl) (const char *, int cmd, void *arg,
struct fuse_file_info *, unsigned int flags, void *data);
/*
* The flags below have been discarded, they should not be used
*/
unsigned int flag_nullpath_ok : 1;
/**
* Reserved flags, don't set
*/
unsigned int flag_reserved : 30;
};
/** Extra context that may be needed by some filesystems
*
* The uid, gid and pid fields are not filled in case of a writepage
* operation.
*/
struct fuse_context {
/** Pointer to the fuse object */
struct fuse *fuse;
/** User ID of the calling process */
uid_t uid;
/** Group ID of the calling process */
gid_t gid;
/** Thread ID of the calling process */
pid_t pid;
/** Private filesystem data */
void *private_data;
/** Umask of the calling process (introduced in version 2.8) */
mode_t umask;
};
/* ----------------------------------------------------------- *
* More detailed API *
* ----------------------------------------------------------- */
/**
* Create a new FUSE filesystem.
*
* @param ch the communication channel
* @param args argument vector
* @param op the filesystem operations
* @param op_size the size of the fuse_operations structure
* @param user_data user data supplied in the context during the init() method
* @return the created FUSE handle
*/
struct fuse *fuse_new(struct fuse_chan *ch, struct fuse_args *args,
const struct fuse_operations *op, size_t op_size,
void *user_data);
/**
* Destroy the FUSE handle.
*
* The communication channel attached to the handle is also destroyed.
*
* NOTE: This function does not unmount the filesystem. If this is
* needed, call fuse_unmount() before calling this function.
*
* @param f the FUSE handle
*/
void fuse_destroy(struct fuse *f);
/**
* FUSE event loop.
*
* Requests from the kernel are processed, and the appropriate
* operations are called.
*
* @param f the FUSE handle
* @return 0 if no error occurred, -1 otherwise
*/
int fuse_loop(struct fuse *f);
/**
* Exit from event loop
*
* @param f the FUSE handle
*/
void fuse_exit(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.
*
* @return the context
*/
struct fuse_context *fuse_get_context(void);
/**
* Check if a request has already been interrupted
*
* @param req request handle
* @return 1 if the request has been interrupted, 0 otherwise
*/
int fuse_interrupted(void);
/*
* Stacking API
*/
/**
* Fuse filesystem object
*
* This is opaque object represents a filesystem layer
*/
struct fuse_fs;
/*
* These functions call the relevant filesystem operation, and return
* the result.
*
* If the operation is not defined, they return -ENOSYS, with the
* exception of fuse_fs_open, fuse_fs_release, fuse_fs_opendir,
* fuse_fs_releasedir and fuse_fs_statfs, which return 0.
*/
int fuse_fs_getattr(struct fuse_fs *fs, const char *path, struct stat *buf);
int fuse_fs_fgetattr(struct fuse_fs *fs, const char *path, struct stat *buf,
struct fuse_file_info *fi);
int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath,
const char *newpath);
int fuse_fs_unlink(struct fuse_fs *fs, const char *path);
int fuse_fs_rmdir(struct fuse_fs *fs, const char *path);
int fuse_fs_symlink(struct fuse_fs *fs, const char *linkname,
const char *path);
int fuse_fs_link(struct fuse_fs *fs, const char *oldpath, const char *newpath);
int fuse_fs_release(struct fuse_fs *fs, const char *path,
struct fuse_file_info *fi);
int fuse_fs_open(struct fuse_fs *fs, const char *path,
struct fuse_file_info *fi);
int fuse_fs_read(struct fuse_fs *fs, const char *path, char *buf, size_t size,
off_t off, struct fuse_file_info *fi);
int fuse_fs_write(struct fuse_fs *fs, const char *path, const char *buf,
size_t size, off_t off, struct fuse_file_info *fi);
int fuse_fs_fsync(struct fuse_fs *fs, const char *path, int datasync,
struct fuse_file_info *fi);
int fuse_fs_flush(struct fuse_fs *fs, const char *path,
struct fuse_file_info *fi);
int fuse_fs_statfs(struct fuse_fs *fs, const char *path, struct statvfs *buf);
int fuse_fs_opendir(struct fuse_fs *fs, const char *path,
struct fuse_file_info *fi);
int fuse_fs_readdir(struct fuse_fs *fs, const char *path, void *buf,
fuse_fill_dir_t filler, off_t off,
struct fuse_file_info *fi);
int fuse_fs_fsyncdir(struct fuse_fs *fs, const char *path, int datasync,
struct fuse_file_info *fi);
int fuse_fs_releasedir(struct fuse_fs *fs, const char *path,
struct fuse_file_info *fi);
int fuse_fs_create(struct fuse_fs *fs, const char *path, mode_t mode,
struct fuse_file_info *fi);
int fuse_fs_lock(struct fuse_fs *fs, const char *path,
struct fuse_file_info *fi, int cmd, struct flock *lock);
int fuse_fs_chmod(struct fuse_fs *fs, const char *path, mode_t mode);
int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid, gid_t gid);
int fuse_fs_truncate(struct fuse_fs *fs, const char *path, off_t size);
int fuse_fs_ftruncate(struct fuse_fs *fs, const char *path, off_t size,
struct fuse_file_info *fi);
int fuse_fs_utimens(struct fuse_fs *fs, const char *path,
const struct timespec tv[2]);
int fuse_fs_access(struct fuse_fs *fs, const char *path, int mask);
int fuse_fs_readlink(struct fuse_fs *fs, const char *path, char *buf,
size_t len);
int fuse_fs_mknod(struct fuse_fs *fs, const char *path, mode_t mode,
dev_t rdev);
int fuse_fs_mkdir(struct fuse_fs *fs, const char *path, mode_t mode);
int fuse_fs_setxattr(struct fuse_fs *fs, const char *path, const char *name,
const char *value, size_t size, int flags);
int fuse_fs_getxattr(struct fuse_fs *fs, const char *path, const char *name,
char *value, size_t size);
int fuse_fs_listxattr(struct fuse_fs *fs, const char *path, char *list,
size_t size);
int fuse_fs_removexattr(struct fuse_fs *fs, const char *path,
const char *name);
int fuse_fs_bmap(struct fuse_fs *fs, const char *path, size_t blocksize,
uint64_t *idx);
int fuse_fs_ioctl(struct fuse_fs *fs, const char *path, int cmd, void *arg,
struct fuse_file_info *fi, unsigned int flags, void *data);
void fuse_fs_init(struct fuse_fs *fs, struct fuse_conn_info *conn);
void fuse_fs_destroy(struct fuse_fs *fs);
/**
* Create a new fuse filesystem object
*
* This is usually called from the factory of a fuse module to create
* a new instance of a filesystem.
*
* @param op the filesystem operations
* @param op_size the size of the fuse_operations structure
* @param user_data user data supplied in the context during the init() method
* @return a new filesystem object
*/
struct fuse_fs *fuse_fs_new(const struct fuse_operations *op, size_t op_size,
void *user_data);
#ifdef __SOLARIS__
/**
* Filesystem module
*
* Filesystem modules are registered with the FUSE_REGISTER_MODULE()
* macro.
*
* If the "-omodules=modname:..." option is present, filesystem
* objects are created and pushed onto the stack with the 'factory'
* function.
*/
struct fuse_module {
/**
* Name of filesystem
*/
const char *name;
/**
* Factory for creating filesystem objects
*
* The function may use and remove options from 'args' that belong
* to this module.
*
* For now the 'fs' vector always contains exactly one filesystem.
* This is the filesystem which will be below the newly created
* filesystem in the stack.
*
* @param args the command line arguments
* @param fs NULL terminated filesystem object vector
* @return the new filesystem object
*/
struct fuse_fs *(*factory)(struct fuse_args *args, struct fuse_fs *fs[]);
struct fuse_module *next;
struct fusemod_so *so;
int ctr;
};
#endif /* __SOLARIS__ */
/* ----------------------------------------------------------- *
* Advanced API for event handling, don't worry about this... *
* ----------------------------------------------------------- */
/* NOTE: the following functions are deprecated, and will be removed
from the 3.0 API. Use the lowlevel session functions instead */
/** Get session from fuse object */
struct fuse_session *fuse_get_session(struct fuse *f);
#ifdef __cplusplus
}
#endif
#endif /* _FUSE_H_ */