Struct libfuse_sys::fuse_operations

#[repr(C)]
pub struct fuse_operations {
    pub getattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut stat) -> c_int>,
    pub readlink: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_char, arg3: usize) -> c_int>,
    pub getdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: fuse_dirh_t, arg3: fuse_dirfil_t) -> c_int>,
    pub mknod: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t, arg3: dev_t) -> c_int>,
    pub mkdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t) -> c_int>,
    pub unlink: Option<unsafe extern "C" fn(arg1: *const c_char) -> c_int>,
    pub rmdir: Option<unsafe extern "C" fn(arg1: *const c_char) -> c_int>,
    pub symlink: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>,
    pub rename: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>,
    pub link: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>,
    pub chmod: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t) -> c_int>,
    pub chown: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: uid_t, arg3: gid_t) -> c_int>,
    pub truncate: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: off_t) -> c_int>,
    pub utime: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut utimbuf) -> c_int>,
    pub open: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>,
    pub read: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_char, arg3: usize, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>,
    pub write: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char, arg3: usize, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>,
    pub statfs: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut statvfs) -> c_int>,
    pub flush: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>,
    pub release: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>,
    pub fsync: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int, arg3: *mut fuse_file_info) -> c_int>,
    pub setxattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char, arg3: *const c_char, arg4: usize, arg5: c_int) -> c_int>,
    pub getxattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char, arg3: *mut c_char, arg4: usize) -> c_int>,
    pub listxattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_char, arg3: usize) -> c_int>,
    pub removexattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>,
    pub opendir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>,
    pub readdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_void, arg3: fuse_fill_dir_t, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>,
    pub releasedir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>,
    pub fsyncdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int, arg3: *mut fuse_file_info) -> c_int>,
    pub init: Option<unsafe extern "C" fn(conn: *mut fuse_conn_info) -> *mut c_void>,
    pub destroy: Option<unsafe extern "C" fn(arg1: *mut c_void)>,
    pub access: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int) -> c_int>,
    pub create: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t, arg3: *mut fuse_file_info) -> c_int>,
    pub ftruncate: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: off_t, arg3: *mut fuse_file_info) -> c_int>,
    pub fgetattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut stat, arg3: *mut fuse_file_info) -> c_int>,
    pub lock: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info, cmd: c_int, arg3: *mut flock) -> c_int>,
    pub utimens: Option<unsafe extern "C" fn(arg1: *const c_char, tv: *const timespec) -> c_int>,
    pub bmap: Option<unsafe extern "C" fn(arg1: *const c_char, blocksize: usize, idx: *mut u64) -> c_int>,
    pub _bitfield_1: __BindgenBitfieldUnit<[u8; 4], u32>,
    pub ioctl: Option<unsafe extern "C" fn(arg1: *const c_char, cmd: c_int, arg: *mut c_void, arg2: *mut fuse_file_info, flags: c_uint, data: *mut c_void) -> c_int>,
    pub poll: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info, ph: *mut fuse_pollhandle, reventsp: *mut c_uint) -> c_int>,
    pub write_buf: Option<unsafe extern "C" fn(arg1: *const c_char, buf: *mut fuse_bufvec, off: off_t, arg2: *mut fuse_file_info) -> c_int>,
    pub read_buf: Option<unsafe extern "C" fn(arg1: *const c_char, bufp: *mut *mut fuse_bufvec, size: usize, off: off_t, arg2: *mut fuse_file_info) -> c_int>,
    pub flock: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info, op: c_int) -> c_int>,
    pub fallocate: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int, arg3: off_t, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>,
}

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.

See http://fuse.sourceforge.net/wiki/ for more information. There is also a snapshot of the relevant wiki pages in the doc/ folder.

Fields

getattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut stat) -> c_int>

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.

readlink: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_char, arg3: usize) -> c_int>

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.

getdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: fuse_dirh_t, arg3: fuse_dirfil_t) -> c_int>

mknod: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t, arg3: dev_t) -> c_int>

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.

mkdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t) -> c_int>

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

unlink: Option<unsafe extern "C" fn(arg1: *const c_char) -> c_int>

Remove a file

rmdir: Option<unsafe extern "C" fn(arg1: *const c_char) -> c_int>

Remove a directory

symlink: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>

Create a symbolic link

rename: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>

Rename a file

link: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>

Create a hard link to a file

chmod: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t) -> c_int>

Change the permission bits of a file

chown: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: uid_t, arg3: gid_t) -> c_int>

Change the owner and group of a file

truncate: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: off_t) -> c_int>

Change the size of a file

utime: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut utimbuf) -> c_int>

Change the access and/or modification times of a file

Deprecated, use utimens() instead.

open: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>

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

read: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_char, arg3: usize, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>

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

write: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char, arg3: usize, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>

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

statfs: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut statvfs) -> c_int>

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

flush: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>

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

release: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>

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

fsync: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int, arg3: *mut fuse_file_info) -> c_int>

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

setxattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char, arg3: *const c_char, arg4: usize, arg5: c_int) -> c_int>

Set extended attributes

getxattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char, arg3: *mut c_char, arg4: usize) -> c_int>

Get extended attributes

listxattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_char, arg3: usize) -> c_int>

List extended attributes

removexattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *const c_char) -> c_int>

Remove extended attributes

opendir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>

Open directory

Unless the 'default_permissions' mount option is given, this method should check if opendir is permitted for this directory. Optionally opendir may also return an arbitrary filehandle in the fuse_file_info structure, which will be passed to readdir, closedir and fsyncdir.

Introduced in version 2.3

readdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut c_void, arg3: fuse_fill_dir_t, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>

Read directory

This supersedes the old getdir() interface. New applications should use this.

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. This works just like the old getdir() method.

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

releasedir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info) -> c_int>

Release directory

Introduced in version 2.3

fsyncdir: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int, arg3: *mut fuse_file_info) -> c_int>

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

init: Option<unsafe extern "C" fn(conn: *mut fuse_conn_info) -> *mut c_void>

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

destroy: Option<unsafe extern "C" fn(arg1: *mut c_void)>

Clean up filesystem

Called on filesystem exit.

Introduced in version 2.3

access: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int) -> c_int>

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

create: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: mode_t, arg3: *mut fuse_file_info) -> c_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

ftruncate: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: off_t, arg3: *mut fuse_file_info) -> c_int>

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

fgetattr: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut stat, arg3: *mut fuse_file_info) -> c_int>

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

lock: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info, cmd: c_int, arg3: *mut flock) -> c_int>

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 unlikely 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

utimens: Option<unsafe extern "C" fn(arg1: *const c_char, tv: *const timespec) -> c_int>

Change the access and modification times of a file with nanosecond resolution

This supersedes the old utime() interface. New applications should use this.

See the utimensat(2) man page for details.

Introduced in version 2.6

bmap: Option<unsafe extern "C" fn(arg1: *const c_char, blocksize: usize, idx: *mut u64) -> c_int>

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

_bitfield_1: __BindgenBitfieldUnit<[u8; 4], u32>

ioctl: Option<unsafe extern "C" fn(arg1: *const c_char, cmd: c_int, arg: *mut c_void, arg2: *mut fuse_file_info, flags: c_uint, data: *mut c_void) -> c_int>

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.

If flags has FUSE_IOCTL_DIR then the fuse_file_info refers to a directory file handle.

Introduced in version 2.8

poll: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info, ph: *mut fuse_pollhandle, reventsp: *mut c_uint) -> c_int>

Poll for IO readiness events

Note: If ph is non-NULL, the client should notify when IO readiness events occur by calling fuse_notify_poll() with the specified ph.

Regardless of the number of times poll with a non-NULL ph is received, single notification is enough to clear all. Notifying more times incurs overhead but doesn't harm correctness.

The callee is responsible for destroying ph with fuse_pollhandle_destroy() when no longer in use.

Introduced in version 2.8

write_buf: Option<unsafe extern "C" fn(arg1: *const c_char, buf: *mut fuse_bufvec, off: off_t, arg2: *mut fuse_file_info) -> c_int>

Write contents of buffer to an open file

Similar to the write() method, but data is supplied in a generic buffer. Use fuse_buf_copy() to transfer data to the destination.

Introduced in version 2.9

read_buf: Option<unsafe extern "C" fn(arg1: *const c_char, bufp: *mut *mut fuse_bufvec, size: usize, off: off_t, arg2: *mut fuse_file_info) -> c_int>

Store data from an open file in a buffer

Similar to the read() method, but data is stored and returned in a generic buffer.

No actual copying of data has to take place, the source file descriptor may simply be stored in the buffer for later data transfer.

The buffer must be allocated dynamically and stored at the location pointed to by bufp. If the buffer contains memory regions, they too must be allocated using malloc(). The allocated memory will be freed by the caller.

Introduced in version 2.9

flock: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: *mut fuse_file_info, op: c_int) -> c_int>

Perform BSD file locking operation

The op argument will be either LOCK_SH, LOCK_EX or LOCK_UN

Nonblocking requests will be indicated by ORing LOCK_NB to the above operations

For more information see the flock(2) manual page.

Additionally fi->owner will be set to a value unique to this open file. This same value will be supplied to ->release() when the file is released.

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 2.9

fallocate: Option<unsafe extern "C" fn(arg1: *const c_char, arg2: c_int, arg3: off_t, arg4: off_t, arg5: *mut fuse_file_info) -> c_int>

Allocates space for an open file

This function ensures that required space is allocated for specified file. If this function returns success then any subsequent write request to specified range is guaranteed not to fail because of lack of space on the file system media.

Introduced in version 2.9.1

Methods

impl fuse_operations

pub fn flag_nullpath_ok(&self) -> c_uint

pub fn set_flag_nullpath_ok(&mut self, val: c_uint)

pub fn flag_nopath(&self) -> c_uint

pub fn set_flag_nopath(&mut self, val: c_uint)

pub fn flag_utime_omit_ok(&self) -> c_uint

pub fn set_flag_utime_omit_ok(&mut self, val: c_uint)

pub fn flag_reserved(&self) -> c_uint

pub fn set_flag_reserved(&mut self, val: c_uint)

pub fn new_bitfield_1(
    flag_nullpath_ok: c_uint,
    flag_nopath: c_uint,
    flag_utime_omit_ok: c_uint,
    flag_reserved: c_uint
) -> __BindgenBitfieldUnit<[u8; 4], u32>

Trait Implementations

impl Clone for fuse_operations

fn clone(&self) -> fuse_operations

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for fuse_operations

impl Debug for fuse_operations

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Default for fuse_operations

fn default() -> fuse_operations

Returns the "default value" for a type.