Method process_queue

vhost_user_block/src/lib.rs:117–202

(
        &mut self,
        vring: &mut RwLockWriteGuard<VringState<GuestMemoryAtomic<GuestMemoryMmap>>>,
    )

    }

    fn process_queue(
        &mut self,
        vring: &mut RwLockWriteGuard<VringState<GuestMemoryAtomic<GuestMemoryMmap>>>,
    ) -> bool {
        let mut used_descs = false;

        while let Some(mut desc_chain) = vring
            .get_queue_mut()
            .pop_descriptor_chain(self.mem.memory())
        {
            debug!("got an element in the queue");
            let len = match Request::parse(&mut desc_chain, None) {
                Ok(mut request) => {
                    debug!("element is a valid request");
                    request.writeback = self.writeback.load(Ordering::Acquire);
                    let (status, len) = match request.execute(
                        &mut *self.disk_image.lock().unwrap(),
                        self.disk_nsectors,
                        desc_chain.memory(),
                        &self.serial,
                    ) {
                        Ok(_) if request.request_type() == RequestType::GetDeviceId => {
                            (VIRTIO_BLK_S_OK as u8, self.serial.len() as u32 + 1)
                        }
                        Ok(l) => (VIRTIO_BLK_S_OK as u8, l + 1),
                        Err(e) => (e.status(), 1),
                    };

                    if let Err(e) = desc_chain.memory().write_obj(status, request.status_addr()) {
                        warn!(
                            "vhost-user-blk: failed to write status to 0x{:x}: {e:?}",
                            request.status_addr().0
                        );
                        0
                    } else {
                        len
                    }
                }
                Err(err) => {
                    error!("failed to parse available descriptor chain: {err:?}");
                    0
                }
            };

            if let Err(e) =
                vring
                    .get_queue_mut()
                    .add_used(desc_chain.memory(), desc_chain.head_index(), len)
            {
                error!("vhost-user-blk: add_used failed: {e:?}");
                // Stop processing this batch — the queue is in a bad state.
                break;
            }
            used_descs = true;
        }

        let needs_signalling = if self.event_idx {
            match vring