"Gary Guo" <gary@xxxxxxxxxxx> writes: > Currently there's a custom reference counting in `block::mq`, which uses > `AtomicU64` Rust atomics, and this type doesn't exist on some 32-bit > architectures. We cannot just change it to use 32-bit atomics, because > doing so will make it vulnerable to refcount overflow. So switch it to > use the kernel refcount `kernel::sync::Refcount` instead. > > There is an operation needed by `block::mq`, atomically decreasing > refcount from 2 to 0, which is not available through refcount.h, so > I exposed `Refcount::as_atomic` which allows accessing the refcount > directly. > > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Boqun Feng <boqun.feng@xxxxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Signed-off-by: Gary Guo <gary@xxxxxxxxxxx> Acked-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
