Trait Fuse

pub trait Fuse {
    // Provided methods
    fn lookup(
        &self,
        _request: &Request,
        _name: &LxStr,
    ) -> Result<fuse_entry_out> { ... }
    fn forget(&self, _node_id: u64, _lookup_count: u64) { ... }
    fn get_attr(
        &self,
        _request: &Request,
        _flags: u32,
        _fh: u64,
    ) -> Result<fuse_attr_out> { ... }
    fn set_attr(
        &self,
        _request: &Request,
        _arg: &fuse_setattr_in,
    ) -> Result<fuse_attr_out> { ... }
    fn read_link(&self, _request: &Request) -> Result<LxString> { ... }
    fn symlink(
        &self,
        _request: &Request,
        _name: &LxStr,
        _target: &LxStr,
    ) -> Result<fuse_entry_out> { ... }
    fn mknod(
        &self,
        _request: &Request,
        _name: &LxStr,
        _arg: &fuse_mknod_in,
    ) -> Result<fuse_entry_out> { ... }
    fn mkdir(
        &self,
        _request: &Request,
        _name: &LxStr,
        _arg: &fuse_mkdir_in,
    ) -> Result<fuse_entry_out> { ... }
    fn unlink(&self, _request: &Request, _name: &LxStr) -> Result<()> { ... }
    fn rmdir(&self, _request: &Request, _name: &LxStr) -> Result<()> { ... }
    fn rename(
        &self,
        _request: &Request,
        _name: &LxStr,
        _new_dir: u64,
        _new_name: &LxStr,
        _flags: u32,
    ) -> Result<()> { ... }
    fn link(
        &self,
        _request: &Request,
        _name: &LxStr,
        _target: u64,
    ) -> Result<fuse_entry_out> { ... }
    fn open(&self, _request: &Request, _flags: u32) -> Result<fuse_open_out> { ... }
    fn read(&self, _request: &Request, _arg: &fuse_read_in) -> Result<Vec<u8>> { ... }
    fn write(
        &self,
        _request: &Request,
        _arg: &fuse_write_in,
        _data: &[u8],
    ) -> Result<usize> { ... }
    fn statfs(&self, _request: &Request) -> Result<fuse_kstatfs> { ... }
    fn release(&self, _request: &Request, _arg: &fuse_release_in) -> Result<()> { ... }
    fn fsync(&self, _request: &Request, _fh: u64, _flags: u32) -> Result<()> { ... }
    fn set_xattr(
        &self,
        _request: &Request,
        _name: &LxStr,
        _value: &[u8],
        _flags: u32,
    ) -> Result<()> { ... }
    fn get_xattr(
        &self,
        _request: &Request,
        _name: &LxStr,
        _size: u32,
    ) -> Result<Vec<u8>> { ... }
    fn get_xattr_size(&self, _request: &Request, _name: &LxStr) -> Result<u32> { ... }
    fn list_xattr(&self, _request: &Request, _size: u32) -> Result<Vec<u8>> { ... }
    fn list_xattr_size(&self, _request: &Request) -> Result<u32> { ... }
    fn remove_xattr(&self, _request: &Request, _name: &LxStr) -> Result<()> { ... }
    fn flush(&self, _request: &Request, _arg: &fuse_flush_in) -> Result<()> { ... }
    fn init(&self, _info: &mut SessionInfo) { ... }
    fn open_dir(&self, _request: &Request, _flags: u32) -> Result<fuse_open_out> { ... }
    fn read_dir(
        &self,
        _request: &Request,
        _arg: &fuse_read_in,
    ) -> Result<Vec<u8>> { ... }
    fn release_dir(
        &self,
        _request: &Request,
        _arg: &fuse_release_in,
    ) -> Result<()> { ... }
    fn fsync_dir(&self, _request: &Request, _fh: u64, _flags: u32) -> Result<()> { ... }
    fn get_lock(
        &self,
        _request: &Request,
        _arg: &fuse_lk_in,
    ) -> Result<fuse_file_lock> { ... }
    fn set_lock(
        &self,
        _request: &Request,
        _arg: &fuse_lk_in,
        _sleep: bool,
    ) -> Result<()> { ... }
    fn access(&self, _request: &Request, _mask: u32) -> Result<()> { ... }
    fn create(
        &self,
        _request: &Request,
        _name: &LxStr,
        _arg: &fuse_create_in,
    ) -> Result<CreateOut> { ... }
    fn block_map(
        &self,
        _request: &Request,
        _block: u64,
        _block_size: u32,
    ) -> Result<u64> { ... }
    fn destroy(&self) { ... }
    fn ioctl(
        &self,
        _request: &Request,
        _arg: &fuse_ioctl_in,
        _data: &[u8],
    ) -> Result<(i32, Vec<u8>)> { ... }
    fn fallocate(
        &self,
        _request: &Request,
        _arg: &fuse_fallocate_in,
    ) -> Result<()> { ... }
    fn read_dir_plus(
        &self,
        _request: &Request,
        _arg: &fuse_read_in,
    ) -> Result<Vec<u8>> { ... }
    fn lseek(
        &self,
        _request: &Request,
        _fh: u64,
        _offset: u64,
        _whence: u32,
    ) -> Result<u64> { ... }
    fn copy_file_range(
        &self,
        _request: &Request,
        _arg: &fuse_copy_file_range_in,
    ) -> Result<usize> { ... }
    fn setup_mapping(
        &self,
        request: &Request,
        mapper: &dyn Mapper,
        arg: &fuse_setupmapping_in,
    ) -> Result<()> { ... }
    fn remove_mapping(
        &self,
        request: &Request,
        mapper: &dyn Mapper,
        moffset: u64,
        len: u64,
    ) -> Result<()> { ... }
}

Trait that FUSE file systems must implement.

Most operations are loosely based on fuse_lowlevel_ops in libfuse, so check the official libfuse documentation for more information on how these operations should behave.

For many operations, a reply of ENOSYS is taken as permanent failure, preventing the client from ever issuing that operation again.

Provided Methods

fn lookup(&self, _request: &Request, _name: &LxStr) -> Result<fuse_entry_out>

Looks up a child of an inode.

This increases the lookup count of the found entry by one.

fn forget(&self, _node_id: u64, _lookup_count: u64)

Tells the FUSE file system to reduce the lookup count of an inode by the specified amount.

Note

The client is not guaranteed to send a forget message for every inode if the file system is unmounted.

fn get_attr( &self, _request: &Request, _flags: u32, _fh: u64, ) -> Result<fuse_attr_out>

Retrieves the attributes of a file.

Note

If attributes are retrieved through an open file descriptor (i.e. using fstat), the fh parameter will be set to the file handle returned by the open call.

fn set_attr( &self, _request: &Request, _arg: &fuse_setattr_in, ) -> Result<fuse_attr_out>

Changes the attributes of a file.

fn read_link(&self, _request: &Request) -> Result<LxString>

Reads the target of a symbolic link.

fn symlink( &self, _request: &Request, _name: &LxStr, _target: &LxStr, ) -> Result<fuse_entry_out>

Creates a symbolic link as a child of the specified inode.

fn mknod( &self, _request: &Request, _name: &LxStr, _arg: &fuse_mknod_in, ) -> Result<fuse_entry_out>

Creates a regular file, fifo, socket, or character or block device node as a child of the specified inode.

fn mkdir( &self, _request: &Request, _name: &LxStr, _arg: &fuse_mkdir_in, ) -> Result<fuse_entry_out>

Creates a directory as a child of the specified inode.

fn unlink(&self, _request: &Request, _name: &LxStr) -> Result<()>

Removes a non-directory child from the specified inode.

fn rmdir(&self, _request: &Request, _name: &LxStr) -> Result<()>

Removes a directory child from the specified inode.

fn rename( &self, _request: &Request, _name: &LxStr, _new_dir: u64, _new_name: &LxStr, _flags: u32, ) -> Result<()>

Renames a file.

The file’s original parent is the request’s inode, while the new parent is indicated using new_dir.

fn link( &self, _request: &Request, _name: &LxStr, _target: u64, ) -> Result<fuse_entry_out>

Creates a hard-link to an existing inode, as a child of the specified inode..

fn open(&self, _request: &Request, _flags: u32) -> Result<fuse_open_out>

Opens a file.

If not implemented, this call will succeed, which can be used if the file system doesn’t need any state for open files, since the inode number is also provided to functions such as read and write.

fn read(&self, _request: &Request, _arg: &fuse_read_in) -> Result<Vec<u8>>

Reads data from an open file.

fn write( &self, _request: &Request, _arg: &fuse_write_in, _data: &[u8], ) -> Result<usize>

Writes data to an open file.

fn statfs(&self, _request: &Request) -> Result<fuse_kstatfs>

Retrieves the attributes of the file system.

fn release(&self, _request: &Request, _arg: &fuse_release_in) -> Result<()>

Closes an open file.

If not implemented, this call will succeed. Won’t be called if open returned ENOSYS (the default).

fn fsync(&self, _request: &Request, _fh: u64, _flags: u32) -> Result<()>

Synchronize file contents.

fn set_xattr( &self, _request: &Request, _name: &LxStr, _value: &[u8], _flags: u32, ) -> Result<()>

Add or change an extended attribute on an inode.

fn get_xattr( &self, _request: &Request, _name: &LxStr, _size: u32, ) -> Result<Vec<u8>>

Retrieve an extended attribute on an inode.

fn get_xattr_size(&self, _request: &Request, _name: &LxStr) -> Result<u32>

Retrieve the size of an extended attribute on an inode.

fn list_xattr(&self, _request: &Request, _size: u32) -> Result<Vec<u8>>

List all extended attributes on an inode.

fn list_xattr_size(&self, _request: &Request) -> Result<u32>

Retrieve the size of the list of extended attributes on an inode.

fn remove_xattr(&self, _request: &Request, _name: &LxStr) -> Result<()>

Remove an extended attribute from an inode.

fn flush(&self, _request: &Request, _arg: &fuse_flush_in) -> Result<()>

Called on each close() of a file descriptor for an opened file.

This is called for every file descriptor, so may be called more than once.

Use release to know when the last file descriptor was closed.

fn init(&self, _info: &mut SessionInfo)

Negotiate file system parameters with the client.

fn open_dir(&self, _request: &Request, _flags: u32) -> Result<fuse_open_out>

Opens a directory.

If not implemented, this call will succeed, which can be used if the file system doesn’t need any state for open files, since the inode number is also provided to functions such as read_dir.

fn read_dir(&self, _request: &Request, _arg: &fuse_read_in) -> Result<Vec<u8>>

Reads the contents of a directory.

Use DirEntryWriter to create a buffer containing directory entries.

fn release_dir(&self, _request: &Request, _arg: &fuse_release_in) -> Result<()>

Closes a directory.

If not implemented, this call will succeed. Won’t be called if opendir returned ENOSYS (the default).

fn fsync_dir(&self, _request: &Request, _fh: u64, _flags: u32) -> Result<()>

Synchronize directory contents.

fn get_lock( &self, _request: &Request, _arg: &fuse_lk_in, ) -> Result<fuse_file_lock>

Test for a POSIX file lock.

fn set_lock( &self, _request: &Request, _arg: &fuse_lk_in, _sleep: bool, ) -> Result<()>

Acquire, modify or release a POSIX file lock.

If not implemented, the client still allows for local file locking.

fn access(&self, _request: &Request, _mask: u32) -> Result<()>

Check file access permissions.

fn create( &self, _request: &Request, _name: &LxStr, _arg: &fuse_create_in, ) -> Result<CreateOut>

Create and open a file.

If not implemented, the client will use mknod followed by open.

fn block_map( &self, _request: &Request, _block: u64, _block_size: u32, ) -> Result<u64>

Map a file block index to a device block index.

This method is only relevant for file systems mounted using fuseblk.

fn destroy(&self)

Clean up the file system.

For regular FUSE, the client only calls this for file systems mounted using fuseblk, but for other file systems Connection will call it when the /dev/fuse connection is closed.

For virtio-fs, the client will call this when the file system is unmounted. After receiving destroy, another init call can be received if the file system is mounted again.

fn ioctl( &self, _request: &Request, _arg: &fuse_ioctl_in, _data: &[u8], ) -> Result<(i32, Vec<u8>)>

Submit an ioctl.

Note

This is a somewhat limited subset of the ioctl functionality of libfuse; the additional functionality seems to only apply to CUSE, however.

fn fallocate(&self, _request: &Request, _arg: &fuse_fallocate_in) -> Result<()>

Allocate requested space.

fn read_dir_plus( &self, _request: &Request, _arg: &fuse_read_in, ) -> Result<Vec<u8>>

Reads the contents of a directory, and performs a lookup on each entry.

This function increases the lookup count of each entry in the directory by one.

If you implement this, you must set FUSE_DO_READDIRPLUS in init. If you implement both read_dir_plus and read_dir, also set FUSE_READDIRPLUS_AUTO.

fn lseek( &self, _request: &Request, _fh: u64, _offset: u64, _whence: u32, ) -> Result<u64>

Find data holes in a sparse file.

fn copy_file_range( &self, _request: &Request, _arg: &fuse_copy_file_range_in, ) -> Result<usize>

Copy data from one file to another without needing to send data through the FUSE kernel module.

fn setup_mapping( &self, request: &Request, mapper: &dyn Mapper, arg: &fuse_setupmapping_in, ) -> Result<()>

Create a DAX memory mapping.

fn remove_mapping( &self, request: &Request, mapper: &dyn Mapper, moffset: u64, len: u64, ) -> Result<()>

Remove a DAX memory mapping.

Implementors