Struct fuse_backend_rs::api::vfs::Vfs

pub struct Vfs { /* private fields */ }

A union fs that combines multiple backend file systems.

Implementations

impl Vfs

pub fn new(opts: VfsOptions) -> Self

Create a new vfs instance

pub fn initialized(&self) -> bool

For sake of live-upgrade, only after negotiation is done, it’s safe to persist state of vfs.

pub fn options(&self) -> VfsOptions

Get a snapshot of the current vfs options.

pub fn mount(&self, fs: BackFileSystem, path: &str) -> VfsResult<VfsIndex>

Mount a backend file system to path

pub fn umount(&self, path: &str) -> VfsResult<()>

Umount a backend file system at path

pub fn get_rootfs(&self, path: &str) -> VfsResult<Option<Arc<BackFileSystem>>>

Get the mounted backend file system alongside the path if there’s one.

Trait Implementations

impl AsyncFileSystem for Vfs

fn async_lookup<'life0, 'life1, 'life2, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    parent: <Self as FileSystem>::Inode,
    name: &'life2 CStr
) -> Pin<Box<dyn Future<Output = Result<Entry>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,
    'life2: 'async_trait,

Look up a directory entry by name and get its attributes.

fn async_getattr<'life0, 'life1, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    handle: Option<<Self as FileSystem>::Handle>
) -> Pin<Box<dyn Future<Output = Result<(stat64, Duration)>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,

Get attributes for a file / directory.

fn async_setattr<'life0, 'life1, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    attr: stat64,
    handle: Option<<Self as FileSystem>::Handle>,
    valid: SetattrValid
) -> Pin<Box<dyn Future<Output = Result<(stat64, Duration)>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,

Set attributes for a file / directory.

fn async_open<'life0, 'life1, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    flags: u32,
    fuse_flags: u32
) -> Pin<Box<dyn Future<Output = Result<(Option<<Self as FileSystem>::Handle>, OpenOptions)>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,

Open a file.

fn async_create<'life0, 'life1, 'life2, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    parent: <Self as FileSystem>::Inode,
    name: &'life2 CStr,
    args: CreateIn
) -> Pin<Box<dyn Future<Output = Result<(Entry, Option<<Self as FileSystem>::Handle>, OpenOptions)>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,
    'life2: 'async_trait,

Create and open a file.

fn async_read<'life0, 'life1, 'life2, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    handle: <Self as FileSystem>::Handle,
    w: &'life2 mut (dyn AsyncZeroCopyWriter + Send),
    size: u32,
    offset: u64,
    lock_owner: Option<u64>,
    flags: u32
) -> Pin<Box<dyn Future<Output = Result<usize>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,
    'life2: 'async_trait,

Read data from a file.

fn async_write<'life0, 'life1, 'life2, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    handle: <Self as FileSystem>::Handle,
    r: &'life2 mut (dyn AsyncZeroCopyReader + Send),
    size: u32,
    offset: u64,
    lock_owner: Option<u64>,
    delayed_write: bool,
    flags: u32,
    fuse_flags: u32
) -> Pin<Box<dyn Future<Output = Result<usize>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,
    'life2: 'async_trait,

Write data to a file.

fn async_fsync<'life0, 'life1, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    datasync: bool,
    handle: <Self as FileSystem>::Handle
) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,

Synchronize file contents.

fn async_fallocate<'life0, 'life1, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    handle: <Self as FileSystem>::Handle,
    mode: u32,
    offset: u64,
    length: u64
) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,

Allocate requested space for file data.

fn async_fsyncdir<'life0, 'life1, 'async_trait>(
    &'life0 self,
    ctx: &'life1 Context,
    inode: <Self as FileSystem>::Inode,
    datasync: bool,
    handle: <Self as FileSystem>::Handle
) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>where
    Self: 'async_trait,
    'life0: 'async_trait,
    'life1: 'async_trait,

Synchronize the contents of a directory.

impl Default for Vfs

fn default() -> Self

Returns the “default value” for a type.

impl FileSystem for Vfs

type Inode = VfsInode

Represents a location in the filesystem tree and can be used to perform operations that act on the metadata of a file/directory (e.g., getattr and setattr). Can also be used as the starting point for looking up paths in the filesystem tree. An Inode may support operating directly on the content of the path that to which it points. FileSystem implementations that support this should set the FsOptions::ZERO_MESSAGE_OPEN option in the return value of the init function. On linux based systems, an Inode is equivalent to opening a file or directory with the libc::O_PATH flag.

type Handle = u64

Represents a file or directory that is open for reading/writing.

fn init(&self, opts: FsOptions) -> Result<FsOptions>

Initialize the file system.

fn destroy(&self)

Clean up the file system.

fn lookup(&self, ctx: &Context, parent: VfsInode, name: &CStr) -> Result<Entry>

Look up a directory entry by name and get its attributes.

fn forget(&self, ctx: &Context, inode: VfsInode, count: u64)

Forget about an inode.

fn getattr(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: Option<u64>
) -> Result<(stat64, Duration)>

Get attributes for a file / directory.

fn setattr(
    &self,
    ctx: &Context,
    inode: VfsInode,
    attr: stat64,
    handle: Option<u64>,
    valid: SetattrValid
) -> Result<(stat64, Duration)>

Set attributes for a file / directory.

fn readlink(&self, ctx: &Context, inode: VfsInode) -> Result<Vec<u8>>

Read a symbolic link.

fn symlink(
    &self,
    ctx: &Context,
    linkname: &CStr,
    parent: VfsInode,
    name: &CStr
) -> Result<Entry>

Create a symbolic link.

fn mknod(
    &self,
    ctx: &Context,
    inode: VfsInode,
    name: &CStr,
    mode: u32,
    rdev: u32,
    umask: u32
) -> Result<Entry>

Create a file node.

fn mkdir(
    &self,
    ctx: &Context,
    parent: VfsInode,
    name: &CStr,
    mode: u32,
    umask: u32
) -> Result<Entry>

Create a directory.

fn unlink(&self, ctx: &Context, parent: VfsInode, name: &CStr) -> Result<()>

Remove a file.

fn rmdir(&self, ctx: &Context, parent: VfsInode, name: &CStr) -> Result<()>

Remove a directory.

fn rename(
    &self,
    ctx: &Context,
    olddir: VfsInode,
    oldname: &CStr,
    newdir: VfsInode,
    newname: &CStr,
    flags: u32
) -> Result<()>

Rename a file / directory.

fn link(
    &self,
    ctx: &Context,
    inode: VfsInode,
    newparent: VfsInode,
    newname: &CStr
) -> Result<Entry>

Create a hard link.

fn open(
    &self,
    ctx: &Context,
    inode: VfsInode,
    flags: u32,
    fuse_flags: u32
) -> Result<(Option<u64>, OpenOptions)>

Open a file.

fn create(
    &self,
    ctx: &Context,
    parent: VfsInode,
    name: &CStr,
    args: CreateIn
) -> Result<(Entry, Option<u64>, OpenOptions)>

Create and open a file.

fn read(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    w: &mut dyn ZeroCopyWriter,
    size: u32,
    offset: u64,
    lock_owner: Option<u64>,
    flags: u32
) -> Result<usize>

Read data from a file.

fn write(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    r: &mut dyn ZeroCopyReader,
    size: u32,
    offset: u64,
    lock_owner: Option<u64>,
    delayed_write: bool,
    flags: u32,
    fuse_flags: u32
) -> Result<usize>

Write data to a file.

fn flush(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    lock_owner: u64
) -> Result<()>

Flush the contents of a file.

fn fsync(
    &self,
    ctx: &Context,
    inode: VfsInode,
    datasync: bool,
    handle: u64
) -> Result<()>

Synchronize file contents.

fn fallocate(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    mode: u32,
    offset: u64,
    length: u64
) -> Result<()>

Allocate requested space for file data.

fn release(
    &self,
    ctx: &Context,
    inode: VfsInode,
    flags: u32,
    handle: u64,
    flush: bool,
    flock_release: bool,
    lock_owner: Option<u64>
) -> Result<()>

Release an open file.

fn statfs(&self, ctx: &Context, inode: VfsInode) -> Result<statvfs64>

Get information about the file system.

fn setxattr(
    &self,
    ctx: &Context,
    inode: VfsInode,
    name: &CStr,
    value: &[u8],
    flags: u32
) -> Result<()>

Set an extended attribute.

fn getxattr(
    &self,
    ctx: &Context,
    inode: VfsInode,
    name: &CStr,
    size: u32
) -> Result<GetxattrReply>

Get an extended attribute.

fn listxattr(
    &self,
    ctx: &Context,
    inode: VfsInode,
    size: u32
) -> Result<ListxattrReply>

List extended attribute names.

fn removexattr(&self, ctx: &Context, inode: VfsInode, name: &CStr) -> Result<()>

Remove an extended attribute.

fn opendir(
    &self,
    ctx: &Context,
    inode: VfsInode,
    flags: u32
) -> Result<(Option<u64>, OpenOptions)>

Open a directory for reading.

fn readdir(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    size: u32,
    offset: u64,
    add_entry: &mut dyn FnMut(DirEntry<'_>) -> Result<usize>
) -> Result<()>

Read a directory.

fn readdirplus(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    size: u32,
    offset: u64,
    add_entry: &mut dyn FnMut(DirEntry<'_>, Entry) -> Result<usize>
) -> Result<()>

Read a directory with entry attributes.

fn fsyncdir(
    &self,
    ctx: &Context,
    inode: VfsInode,
    datasync: bool,
    handle: u64
) -> Result<()>

Synchronize the contents of a directory.

fn releasedir(
    &self,
    ctx: &Context,
    inode: VfsInode,
    flags: u32,
    handle: u64
) -> Result<()>

Release an open directory.

fn access(&self, ctx: &Context, inode: VfsInode, mask: u32) -> Result<()>

Check file access permissions.

fn setupmapping(
    &self,
    ctx: &Context,
    inode: VfsInode,
    handle: u64,
    foffset: u64,
    len: u64,
    flags: u64,
    moffset: u64,
    req: &mut dyn FsCacheReqHandler
) -> Result<()>

Setup a mapping so that guest can access files in DAX style.

fn removemapping(
    &self,
    ctx: &Context,
    inode: VfsInode,
    requests: Vec<RemovemappingOne>,
    req: &mut dyn FsCacheReqHandler
) -> Result<()>

Teardown a mapping which was setup for guest DAX style access.

fn batch_forget(&self, ctx: &Context, requests: Vec<(Self::Inode, u64)>)

Forget about multiple inodes.

fn lseek(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    handle: Self::Handle,
    offset: u64,
    whence: u32
) -> Result<u64>

Reposition read/write file offset.

fn getlk(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    handle: Self::Handle,
    owner: u64,
    lock: FileLock,
    flags: u32
) -> Result<FileLock>

Query file lock status

fn setlk(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    handle: Self::Handle,
    owner: u64,
    lock: FileLock,
    flags: u32
) -> Result<()>

Grab a file read lock

fn setlkw(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    handle: Self::Handle,
    owner: u64,
    lock: FileLock,
    flags: u32
) -> Result<()>

Grab a file write lock

fn ioctl(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    handle: Self::Handle,
    flags: u32,
    cmd: u32,
    data: IoctlData<'_>,
    out_size: u32
) -> Result<IoctlData<'_>>

send ioctl to the file

fn bmap(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    block: u64,
    blocksize: u32
) -> Result<u64>

Query a file’s block mapping info

fn poll(
    &self,
    ctx: &Context,
    inode: Self::Inode,
    handle: Self::Handle,
    khandle: Self::Handle,
    flags: u32,
    events: u32
) -> Result<u32>

Poll a file’s events

fn notify_reply(&self) -> Result<()>

TODO: support this