[PATCH] binder: use irrefutable let patterns

[PATCH] binder: use irrefutable let patterns

[Alexandre Courbot]

Replace matches on infallible results with irrefutable let patterns,
which are available since Rust 1.82.

This removes boilerplate for handling impossible error variants.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/android/binder/freeze.rs       |  6 ++----
 drivers/android/binder/node/wrapper.rs |  6 ++----
 drivers/android/binder/process.rs      | 17 ++++-------------
 3 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/android/binder/freeze.rs b/drivers/android/binder/freeze.rs
index 66912b4cb527..d4fa017063dc 100644
--- a/drivers/android/binder/freeze.rs
+++ b/drivers/android/binder/freeze.rs
@@ -75,10 +75,8 @@ fn new(flags: kernel::alloc::Flags) -> Result<UninitFM, AllocError> {
     }
 
     fn init(ua: UninitFM, cookie: FreezeCookie, pid: i32) -> DLArc<FreezeMessage> {
-        match ua.pin_init_with(DTRWrap::new(FreezeMessage { cookie, pid })) {
-            Ok(msg) => ListArc::from(msg),
-            Err(err) => match err {},
-        }
+        let Ok(msg) = ua.pin_init_with(DTRWrap::new(FreezeMessage { cookie, pid }));
+        ListArc::from(msg)
     }
 }
 
diff --git a/drivers/android/binder/node/wrapper.rs b/drivers/android/binder/node/wrapper.rs
index 6e4ca01c941a..1240b558983d 100644
--- a/drivers/android/binder/node/wrapper.rs
+++ b/drivers/android/binder/node/wrapper.rs
@@ -20,10 +20,8 @@ pub(crate) fn new() -> Result<Self> {
     }
 
     pub(super) fn init(self, node: DArc<Node>) -> DLArc<dyn DeliverToRead> {
-        match self.inner.pin_init_with(DTRWrap::new(NodeWrapper { node })) {
-            Ok(initialized) => ListArc::from(initialized) as DLArc<dyn DeliverToRead>,
-            Err(err) => match err {},
-        }
+        let Ok(initialized) = self.inner.pin_init_with(DTRWrap::new(NodeWrapper { node }));
+        ListArc::from(initialized) as DLArc<dyn DeliverToRead>
     }
 }
 
diff --git a/drivers/android/binder/process.rs b/drivers/android/binder/process.rs
index 5372bfbd93b3..67b07cbf9048 100644
--- a/drivers/android/binder/process.rs
+++ b/drivers/android/binder/process.rs
@@ -892,11 +892,8 @@ pub(crate) fn insert_or_update_handle(
 
         let (info_proc, info_node) = {
             let info_init = NodeRefInfo::new(node_ref, handle, self.into());
-            match info.pin_init_with(info_init) {
-                Ok(info) => ListArc::pair_from_pin_unique(info),
-                // error is infallible
-                Err(err) => match err {},
-            }
+            let Ok(info) = info.pin_init_with(info_init);
+            ListArc::pair_from_pin_unique(info)
         };
 
         // Ensure the process is still alive while we insert a new reference.
@@ -1294,14 +1291,8 @@ pub(crate) fn request_death(
             return Ok(());
         }
 
-        let death = {
-            let death_init = NodeDeath::new(info.node_ref().node.clone(), self.clone(), cookie);
-            match death.pin_init_with(death_init) {
-                Ok(death) => death,
-                // error is infallible
-                Err(err) => match err {},
-            }
-        };
+        let death_init = NodeDeath::new(info.node_ref().node.clone(), self.clone(), cookie);
+        let Ok(death) = death.pin_init_with(death_init);
 
         // Register the death notification.
         {

---
base-commit: 40288c9206c17eb66a603262e06a58d300d0f279
change-id: 20260921-binder_let-d6c7446e0327

Best regards,
--  
Alexandre Courbot <acourbot@nvidia.com>

Re: [PATCH] binder: use irrefutable let patterns

[Gary Guo]

On Sun Sep 20, 2026 at 4:49 PM BST, Alexandre Courbot wrote:
> Replace matches on infallible results with irrefutable let patterns,
> which are available since Rust 1.82.
> 
> This removes boilerplate for handling impossible error variants.
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

FWIW, this pattern can be served by `into_ok()` which is in the process of being
stabilized right now. This is also available in 1.85 unstably, however the
methods expect real never type (!) and does not work with `Infallible`.

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  drivers/android/binder/freeze.rs       |  6 ++----
>  drivers/android/binder/node/wrapper.rs |  6 ++----
>  drivers/android/binder/process.rs      | 17 ++++-------------
>  3 files changed, 8 insertions(+), 21 deletions(-)