Struct BackingId 

pub struct BackingId { /* private fields */ }

A reference to a previously opened fd intended to be used for passthrough

You can create these via ReplyOpen::open_backing() and send them via ReplyOpen::opened_passthrough().

When working with backing IDs you need to ensure that they live “long enough”. A good practice is to create them in the Filesystem::open() impl, store them in the struct of your Filesystem impl, then drop them in the Filesystem::release() impl. Dropping them immediately after sending them in the Filesystem::open() impl can lead to the kernel returning EIO when userspace attempts to access the file.

This is implemented as a safe wrapper around the backing_id field of the fuse_backing_map struct used by the ioctls involved in fd passthrough. It is created by performing a FUSE_DEV_IOC_BACKING_OPEN ioctl on an fd and has a Drop trait impl which makes a matching FUSE_DEV_IOC_BACKING_CLOSE call. It holds a weak reference on the fuse channel to allow it to make that call (if the channel hasn’t already been closed).

Trait Implementations

impl Debug for BackingId

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

Formats the value using the given formatter.

impl Drop for BackingId

fn drop(&mut self)

Executes the destructor for this type.