rust: bindings: derive Zeroable for bindgen's opaque array wrappers

bindgen 0.73 emits the blob of some opaque types, such as ones aligned
to more than 4 bytes, as a `__BindgenOpaqueArray` or
`__BindgenOpaqueArray<align>` newtype instead of a plain array. The
newtype only derives `PartialEq`, `Eq`, `Copy`, `Clone`, `Debug` and
`Hash`, and the `MaybeZeroable` custom derive does not reach it, so a
struct that embeds such an opaque type is no longer `Zeroable`.

`spinlock` is opaque (see rust/bindgen_parameters), and with lockdep its
blob becomes a `__BindgenOpaqueArray8<[u8; 72]>`. Commit 71ec3c7d6db8
("blk-mq: quiesce a queue that joins a quiesced tag set") added a
`spinlock_t` to `struct blk_mq_tag_set`, so an allmodconfig build with
bindgen 0.73 now fails:

  error[E0277]: the trait bound `bindings::__BindgenOpaqueArray8<[u8; 72]>: pin_init::Zeroable` is not satisfied
    --> rust/kernel/block/mq/tag_set.rs:41:49

Which wrappers exist depends on the bindgen version and on the opaque
types of the configuration, so they cannot be covered by unconditional
impls in rust/bindings/lib.rs like `__BindgenBitfieldUnit` is. Derive
`Zeroable` for each wrapper in the generated bindings instead. The
pattern allows for the spacing of bindgen's output when rustfmt is not
available.

Fixes: 71ec3c7d6db8 ("blk-mq: quiesce a queue that joins a quiesced tag set")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/rust-for-linux/20261030223702.GA1673281@ax162/
Link: https://patch.msgid.link/20261031152846.746656-1-sashal@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

0 files changed, 0 insertions, 0 deletions