Struct DirEntry 

pub struct DirEntry {
    pub node: FsNodeHandle,
    /* private fields */
}

An entry in a directory.

This structure assigns a name to an FsNode in a given file system. An FsNode might have multiple directory entries, for example if there are more than one hard link to the same FsNode. In those cases, each hard link will have a different parent and a different local_name because each hard link has its own DirEntry object.

A directory cannot have more than one hard link, which means there is a single DirEntry for each Directory FsNode. That invariant lets us store the children for a directory in the DirEntry rather than in the FsNode.

Fields

node: FsNodeHandle

The FsNode referenced by this DirEntry.

A given FsNode can be referenced by multiple DirEntry objects, for example if there are multiple hard links to a given FsNode.

Implementations

impl DirEntry

pub fn read<'a>(self: &'a DirEntry) -> DirEntryReadGuard<'a>

pub fn write<'a>(self: &'a DirEntry) -> DirEntryWriteGuard<'a>

pub fn new_uncached( node: FsNodeHandle, parent: Option<DirEntryHandle>, local_name: FsString, ) -> DirEntryHandle

pub fn new( node: FsNodeHandle, parent: Option<DirEntryHandle>, local_name: FsString, ) -> DirEntryHandle

pub fn new_unrooted(node: FsNodeHandle) -> DirEntryHandle

Returns a new DirEntry for the given node without parent. The entry has no local name and is not cached.

pub fn new_deleted( node: FsNodeHandle, parent: Option<DirEntryHandle>, local_name: FsString, ) -> DirEntryHandle

Returns a new DirEntry that is ready marked as having been deleted.

pub fn open_anonymous<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, flags: OpenFlags, ) -> Result<FileHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Returns a file handle to this entry, associated with an anonymous namespace.

pub fn set_children( self: &DirEntryHandle, children: BTreeMap<FsString, DirEntryHandle>, )

Set the children of this DirEntry to the given children. This should only ever be called when children is empty.

pub fn parent_or_self(self: &DirEntryHandle) -> DirEntryHandle

The parent DirEntry object or this DirEntry if this entry is the root.

Useful when traversing up the tree if you always want to find a parent (e.g., for “..”).

Be aware that the root of one file system might be mounted as a child in another file system. For that reason, consider walking the NamespaceNode tree (which understands mounts) rather than the DirEntry tree.

pub fn is_reserved_name(name: &FsStr) -> bool

Whether the given name has special semantics as a directory entry.

Specifically, whether the name is empty (which means “self”), dot (which also means “self”), or dot dot (which means “parent”).

pub fn component_lookup<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, mount: &MountInfo, name: &FsStr, ) -> Result<DirEntryHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Look up a directory entry with the given name as direct child of this entry.

pub fn create_entry<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, mount: &MountInfo, name: &FsStr, create_node_fn: impl FnOnce(&mut Locked<L>, &FsNodeHandle, &MountInfo, &FsStr) -> Result<FsNodeHandle, Errno>, ) -> Result<DirEntryHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Creates a new DirEntry

The create_node_fn function is called to create the underlying FsNode for the DirEntry.

If the entry already exists, create_node_fn is not called, and EEXIST is returned.

pub fn get_or_create_entry<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, mount: &MountInfo, name: &FsStr, create_node_fn: impl FnOnce(&mut Locked<L>, &FsNodeHandle, &MountInfo, &FsStr) -> Result<FsNodeHandle, Errno>, ) -> Result<DirEntryHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Creates a new DirEntry. Works just like create_entry, except if the entry already exists, it is returned.

pub fn create_dir_for_testing<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, name: &FsStr, ) -> Result<DirEntryHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

pub fn create_tmpfile<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, mount: &MountInfo, mode: FileMode, owner: FsCred, flags: OpenFlags, ) -> Result<DirEntryHandle, Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Creates an anonymous file.

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

Used by O_TMPFILE.

pub fn unlink<L>( self: &DirEntryHandle, locked: &mut Locked<L>, current_task: &CurrentTask, mount: &MountInfo, name: &FsStr, kind: UnlinkKind, must_be_directory: bool, ) -> Result<(), Errno>

where L: LockEqualOrBefore<FileOpsCore>,

pub fn is_descendant_of(self: &DirEntryHandle, other: &DirEntryHandle) -> bool

Returns whether this entry is a descendant of |other|.

pub fn rename<L>( locked: &mut Locked<L>, current_task: &CurrentTask, old_parent: &DirEntryHandle, old_mount: &MountInfo, old_basename: &FsStr, new_parent: &DirEntryHandle, new_mount: &MountInfo, new_basename: &FsStr, flags: RenameFlags, ) -> Result<(), Errno>

where L: LockEqualOrBefore<FileOpsCore>,

Rename the file with old_basename in old_parent to new_basename in new_parent.

old_parent and new_parent must belong to the same file system.

pub fn get_children<F, T>(&self, callback: F) -> T

where F: FnOnce(&BTreeMap<FsString, Weak<DirEntry>>) -> T,

pub fn remove_child(&self, name: &FsStr, mounts: &Mounts)

Remove the child with the given name from the children cache. The child must not have any mounts.

pub fn notify(&self, event_mask: InotifyMask)

Notifies watchers on the current node and its parent about an event.

pub fn notify_ignoring_excl_unlink(&self, event_mask: InotifyMask)

Notifies watchers on the current node and its parent about an event.

Used for FSNOTIFY_EVENT_INODE events, which ignore IN_EXCL_UNLINK.

pub fn has_mounts(&self) -> bool

Returns true if this entry has mounts.

pub fn set_has_mounts(&self, v: bool)

Records whether or not the entry has mounts.

Trait Implementations

impl Debug for DirEntry

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

Formats the value using the given formatter.

impl Drop for DirEntry

The Drop trait for DirEntry removes the entry from the child list of the parent entry, which means we cannot drop DirEntry objects while holding a lock on the parent’s child list.

fn drop(&mut self)

Executes the destructor for this type.

impl<'a> From<&'a DirEntry> for Auditable<'a>

fn from(value: &'a DirEntry) -> Self

Converts to this type from the input type.