Add a method to borrow the private queue data of the queue a `GenDisk` is
associated with.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 rust/kernel/block/mq/gen_disk.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
index 8a22767f1b916..fbda2f572e17f 100644
--- a/rust/kernel/block/mq/gen_disk.rs
+++ b/rust/kernel/block/mq/gen_disk.rs
@@ -246,6 +246,12 @@ pub fn queue(&self) -> &RequestQueue<T> {
         // SAFETY: By type invariant, self is a valid gendisk.
         unsafe { RequestQueue::from_raw((*self.gendisk).queue) }
     }
+
+    /// Get the queue data associated with this [`GenDisk`].
+    pub fn queue_data(&self) -> <T::QueueData as ForeignOwnable>::Borrowed<'_> {
+        // SAFETY: By type invariant, self is a valid gendisk.
+        unsafe { T::QueueData::borrow((*(*self.gendisk).queue).queuedata) }
+    }
 }
 
 // SAFETY: `GenDisk` is an owned pointer to a `struct gendisk` and an `Arc` to a

-- 
2.51.2