Struct DirCache 

pub struct DirCache {
    entries: RwLock<HashMap<(u64, Vec<u8>), Arc<OwnedFd>>>,
    enabled: bool,
}

O_PATH descriptors of canonical guest directories already walked, shared by every view of one supervisor.

Lets the walk skip the openat of an intermediate component, and pins the directory the component named when it was walked: a later lookup through the entry lands in that directory whatever the name now points to. Entries are keyed by the view they were resolved in, since the same guest path names different host directories in different views, and the whole cache is flushed by DirCache::flush after any syscall that may replace a directory, whichever view made it: the host directories are shared.

Fields

entries: RwLock<HashMap<(u64, Vec<u8>), Arc<OwnedFd>>>

enabled: bool

False when PROOT_NO_PATH_CACHE is set.

Implementations

impl DirCache

pub fn new() -> DirCache

Creates an empty cache, disabled when PROOT_NO_PATH_CACHE is set.

pub fn flush(&self)

Forgets every cached directory of every view.

Call after mkdir, rmdir, rename, unlink, symlink, link, mknod or any other syscall that can turn a directory into something else (or the reverse); changes made from outside PRoot are not seen until then, and a lookup through a stale entry stays in the directory it pinned.

Trait Implementations

impl Debug for DirCache

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

Formats the value using the given formatter.

impl Default for DirCache

fn default() -> Self

Returns the “default value” for a type.