Trait FsNodeOps 

pub trait FsNodeOps:
    Send
    + Sync
    + AsAny
    + 'static {
    // Required methods
    fn create_file_ops(
        &self,
        locked: &mut Locked<FileOpsCore>,
        node: &FsNode,
        _current_task: &CurrentTask,
        flags: OpenFlags,
    ) -> Result<Box<dyn FileOps>, Errno>;
    fn mknod(
        &self,
        locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _mode: FileMode,
        _dev: DeviceType,
        _owner: FsCred,
    ) -> Result<FsNodeHandle, Errno>;
    fn mkdir(
        &self,
        locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _mode: FileMode,
        _owner: FsCred,
    ) -> Result<FsNodeHandle, Errno>;
    fn create_symlink(
        &self,
        locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _target: &FsStr,
        _owner: FsCred,
    ) -> Result<FsNodeHandle, Errno>;
    fn unlink(
        &self,
        locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _child: &FsNodeHandle,
    ) -> Result<(), Errno>;

    // Provided methods
    fn check_access(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        node: &FsNode,
        current_task: &CurrentTask,
        access: PermissionFlags,
        info: &RwLock<FsNodeInfo>,
        reason: CheckAccessReason,
        audit_context: Auditable<'_>,
    ) -> Result<(), Errno> { ... }
    fn create_dir_entry_ops(&self) -> Box<dyn DirEntryOps> { ... }
    fn lookup(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        name: &FsStr,
    ) -> Result<FsNodeHandle, Errno> { ... }
    fn create_tmpfile(
        &self,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _mode: FileMode,
        _owner: FsCred,
    ) -> Result<FsNodeHandle, Errno> { ... }
    fn readlink(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
    ) -> Result<SymlinkTarget, Errno> { ... }
    fn link(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _child: &FsNodeHandle,
    ) -> Result<(), Errno> { ... }
    fn append_lock_read<'a>(
        &'a self,
        locked: &'a mut Locked<BeforeFsNodeAppend>,
        node: &'a FsNode,
        current_task: &CurrentTask,
    ) -> Result<(RwQueueReadGuard<'a, FsNodeAppend>, &'a mut Locked<FsNodeAppend>), Errno> { ... }
    fn truncate(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _guard: &AppendLockGuard<'_>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _length: u64,
    ) -> Result<(), Errno> { ... }
    fn allocate(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _guard: &AppendLockGuard<'_>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _mode: FallocMode,
        _offset: u64,
        _length: u64,
    ) -> Result<(), Errno> { ... }
    fn initial_info(&self, _info: &mut FsNodeInfo) { ... }
    fn fetch_and_refresh_info<'a>(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        info: &'a RwLock<FsNodeInfo>,
    ) -> Result<RwLockReadGuard<'a, FsNodeInfo>, Errno> { ... }
    fn update_attributes(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _current_task: &CurrentTask,
        _info: &FsNodeInfo,
        _has: zxio_node_attr_has_t,
    ) -> Result<(), Errno> { ... }
    fn get_xattr(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _max_size: usize,
    ) -> Result<ValueOrSize<FsString>, Errno> { ... }
    fn set_xattr(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
        _value: &FsStr,
        _op: XattrOp,
    ) -> Result<(), Errno> { ... }
    fn remove_xattr(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _name: &FsStr,
    ) -> Result<(), Errno> { ... }
    fn list_xattrs(
        &self,
        _locked: &mut Locked<FileOpsCore>,
        _node: &FsNode,
        _current_task: &CurrentTask,
        _max_size: usize,
    ) -> Result<ValueOrSize<Vec<FsString>>, Errno> { ... }
    fn forget(
        self: Box<Self>,
        _locked: &mut Locked<FileOpsCore>,
        _current_task: &CurrentTask,
        _info: FsNodeInfo,
    ) -> Result<(), Errno> { ... }
    fn enable_fsverity(
        &self,
        _descriptor: &fsverity_descriptor,
    ) -> Result<(), Errno> { ... }
    fn get_fsverity_descriptor(
        &self,
        _log_blocksize: u8,
    ) -> Result<fsverity_descriptor, Errno> { ... }
    fn internal_name(&self, _node: &FsNode) -> Option<FsString> { ... }
    fn node_key(&self, node: &FsNode) -> ino_t { ... }
}

Required Methods

fn create_file_ops( &self, locked: &mut Locked<FileOpsCore>, node: &FsNode, _current_task: &CurrentTask, flags: OpenFlags, ) -> Result<Box<dyn FileOps>, Errno>

Build the FileOps for the file associated to this node.

The returned FileOps will be used to create a FileObject, which might be assigned an FdNumber.

fn mknod( &self, locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _mode: FileMode, _dev: DeviceType, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

Create and return the given child node.

The mode field of the FsNodeInfo indicates what kind of child to create.

This function is never called with FileMode::IFDIR. The mkdir function is used to create directories instead.

fn mkdir( &self, locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _mode: FileMode, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

Create and return the given child node as a subdirectory.

fn create_symlink( &self, locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _target: &FsStr, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

Creates a symlink with the given target path.

fn unlink( &self, locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _child: &FsNodeHandle, ) -> Result<(), Errno>

Remove the child with the given name, if the child exists.

The UnlinkKind parameter indicates whether the caller intends to unlink a directory or a non-directory child.

Provided Methods

fn check_access( &self, _locked: &mut Locked<FileOpsCore>, node: &FsNode, current_task: &CurrentTask, access: PermissionFlags, info: &RwLock<FsNodeInfo>, reason: CheckAccessReason, audit_context: Auditable<'_>, ) -> Result<(), Errno>

Delegate the access check to the node.

fn create_dir_entry_ops(&self) -> Box<dyn DirEntryOps>

Build the DirEntryOps for a new [DirEntry] that will be associated to this node.

fn lookup( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, ) -> Result<FsNodeHandle, Errno>

Find an existing child node and populate the child parameter. Return the node.

The child parameter is an empty node. Operations other than initialize may panic before initialize is called.

fn create_tmpfile( &self, _node: &FsNode, _current_task: &CurrentTask, _mode: FileMode, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

Creates an anonymous file.

The FileMode::IFMT of the FileMode is always FileMode::IFREG.

Used by O_TMPFILE.

fn readlink( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, ) -> Result<SymlinkTarget, Errno>

Reads the symlink from this node.

fn link( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _child: &FsNodeHandle, ) -> Result<(), Errno>

Create a hard link with the given name to the given child.

fn append_lock_read<'a>( &'a self, locked: &'a mut Locked<BeforeFsNodeAppend>, node: &'a FsNode, current_task: &CurrentTask, ) -> Result<(RwQueueReadGuard<'a, FsNodeAppend>, &'a mut Locked<FsNodeAppend>), Errno>

Acquire the necessary append lock for the operations that depend on them. Should be done before calling allocate or truncate to avoid lock ordering issues.

fn truncate( &self, _locked: &mut Locked<FileOpsCore>, _guard: &AppendLockGuard<'_>, _node: &FsNode, _current_task: &CurrentTask, _length: u64, ) -> Result<(), Errno>

Change the length of the file.

fn allocate( &self, _locked: &mut Locked<FileOpsCore>, _guard: &AppendLockGuard<'_>, _node: &FsNode, _current_task: &CurrentTask, _mode: FallocMode, _offset: u64, _length: u64, ) -> Result<(), Errno>

Manipulate allocated disk space for the file.

fn initial_info(&self, _info: &mut FsNodeInfo)

Update the supplied info with initial state (e.g. size) for the node.

FsNode calls this method when created, to allow the FsNodeOps to set appropriate initial values in the FsNodeInfo.

fn fetch_and_refresh_info<'a>( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, info: &'a RwLock<FsNodeInfo>, ) -> Result<RwLockReadGuard<'a, FsNodeInfo>, Errno>

Update node.info as needed.

FsNode calls this method before converting the FsNodeInfo struct into the uapi::stat struct to give the file system a chance to update this data before it is used by clients.

File systems that keep the FsNodeInfo up-to-date do not need to override this function.

Return a read guard for the updated information.

fn update_attributes( &self, _locked: &mut Locked<FileOpsCore>, _current_task: &CurrentTask, _info: &FsNodeInfo, _has: zxio_node_attr_has_t, ) -> Result<(), Errno>

Update node attributes persistently.

fn get_xattr( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _max_size: usize, ) -> Result<ValueOrSize<FsString>, Errno>

Get an extended attribute on the node.

An implementation can systematically return a value. Otherwise, if max_size is 0, it can instead return the size of the attribute, and can return an ERANGE error if max_size is not 0, and lesser than the required size.

fn set_xattr( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _value: &FsStr, _op: XattrOp, ) -> Result<(), Errno>

Set an extended attribute on the node.

fn remove_xattr( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, ) -> Result<(), Errno>

fn list_xattrs( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _max_size: usize, ) -> Result<ValueOrSize<Vec<FsString>>, Errno>

An implementation can systematically return a value. Otherwise, if max_size is 0, it can instead return the size of the 0 separated string needed to represent the value, and can return an ERANGE error if max_size is not 0, and lesser than the required size.

fn forget( self: Box<Self>, _locked: &mut Locked<FileOpsCore>, _current_task: &CurrentTask, _info: FsNodeInfo, ) -> Result<(), Errno>

Called when the FsNode is freed by the Kernel.

fn enable_fsverity( &self, _descriptor: &fsverity_descriptor, ) -> Result<(), Errno>

Marks that FS-Verity is being built. Writes fsverity descriptor and merkle tree, the latter computed by the filesystem. This should ensure there are no writable file handles. Returns EEXIST if the file was already fsverity-enabled. Returns EBUSY if this ioctl was already running on this file.

fn get_fsverity_descriptor( &self, _log_blocksize: u8, ) -> Result<fsverity_descriptor, Errno>

Read fsverity descriptor, if the node is fsverity-enabled. Else returns ENODATA.

fn internal_name(&self, _node: &FsNode) -> Option<FsString>

Returns a descriptive name for this node, suitable to report to userspace in situations where the node’s path is unavailable (e.g. because it is anonymous, and has no path). If no name is returned then a default name of the form “<class:[<node_id>]” will be used.

fn node_key(&self, node: &FsNode) -> ino_t

The key used to identify this node in the file system’s node cache.

For many file systems, this will be the same as the inode number. However, some file systems, such as FUSE, sometimes use different node_key and inode numbers.

Trait Implementations

impl<T> From<T> for Box<dyn FsNodeOps>

where T: FsNodeOps,

fn from(ops: T) -> Box<dyn FsNodeOps>

Converts to this type from the input type.

Implementations on Foreign Types

impl FsNodeOps for Arc<SimpleDirectory>

fn check_access( &self, _locked: &mut Locked<FileOpsCore>, node: &FsNode, current_task: &CurrentTask, permission_flags: PermissionFlags, info: &RwLock<FsNodeInfo>, reason: CheckAccessReason, audit_context: Auditable<'_>, ) -> Result<(), Errno>

fn mkdir( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, _mode: FileMode, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

fn mknod( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, _mode: FileMode, _dev: DeviceType, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

fn create_symlink( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, _target: &FsStr, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

fn link( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, _child: &FsNodeHandle, ) -> Result<(), Errno>

fn unlink( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, _child: &FsNodeHandle, ) -> Result<(), Errno>

fn create_file_ops( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _flags: OpenFlags, ) -> Result<Box<dyn FileOps>, Errno>

fn lookup( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, name: &FsStr, ) -> Result<FsNodeHandle, Errno>

impl FsNodeOps for Arc<Namespace>

fn lookup( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, ) -> Result<FsNodeHandle, Errno>

fn mknod( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _mode: FileMode, _dev: DeviceType, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

fn mkdir( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _mode: FileMode, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

fn create_symlink( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _target: &FsStr, _owner: FsCred, ) -> Result<FsNodeHandle, Errno>

fn unlink( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _name: &FsStr, _child: &FsNodeHandle, ) -> Result<(), Errno>

fn create_file_ops( &self, _locked: &mut Locked<FileOpsCore>, _node: &FsNode, _current_task: &CurrentTask, _flags: OpenFlags, ) -> Result<Box<dyn FileOps>, Errno>

Implementors

impl FsNodeOps for BpfFsDir

impl FsNodeOps for BpfFsObject

impl FsNodeOps for UEventFsNode

impl FsNodeOps for RemoteNode

impl FsNodeOps for TmpFsDirectory

impl FsNodeOps for PanickingFsNode

impl FsNodeOps for Anon

impl FsNodeOps for MemoryRegularNode

impl FsNodeOps for SpecialNode

impl FsNodeOps for SymlinkNode

impl<F> FsNodeOps for CallbackSymlinkNode<F>

where F: Fn() -> Result<SymlinkTarget, Errno> + Send + Sync + 'static,

impl<F, O> FsNodeOps for SimpleFileNode<F, O>

where F: Fn() -> Result<O, Errno> + Send + Sync + 'static, O: FileOps,