Fix clippy/lint nits for rust 1.77.0

Author: pfmooney

bin/propolis-server/src/lib/vm/mod.rs

@@ -865,7 +865,7 @@ impl VmController {
         &self,
         name: &String,
     ) -> Option<Arc<dyn propolis::common::Lifecycle>> {
-        self.vm_objects.devices.get(name).map(Arc::clone)
+        self.vm_objects.devices.get(name).cloned()
     }
 }
 

bin/propolis-standalone/src/main.rs

@@ -78,6 +78,9 @@ impl From<propolis::exits::Suspend> for InstEvent {
 }
 
 #[derive(Clone, Debug)]
+// Silence the lint about detail fields being unused, since rustc ignores the
+// derived Debug impl which does read those bits.
+#[allow(dead_code)]
 enum EventCtx {
     Vcpu(i32),
     Pin(String),

lib/propolis/src/hw/nvme/mod.rs

@@ -285,21 +285,15 @@ impl NvmeCtrl {
         if (cqid as usize) >= MAX_NUM_QUEUES {
             return Err(NvmeError::InvalidCompQueue(cqid));
         }
-        self.cqs[cqid as usize]
-            .as_ref()
-            .map(Arc::clone)
-            .ok_or(NvmeError::InvalidCompQueue(cqid))
+        self.cqs[cqid as usize].clone().ok_or(NvmeError::InvalidCompQueue(cqid))
     }
 
     /// Returns a reference to the [`SubQueue`] which corresponds to the given submission queue id (`cqid`).
     fn get_sq(&self, sqid: QueueId) -> Result<Arc<SubQueue>, NvmeError> {
         if (sqid as usize) >= MAX_NUM_QUEUES {
             return Err(NvmeError::InvalidSubQueue(sqid));
         }
-        self.sqs[sqid as usize]
-            .as_ref()
-            .map(Arc::clone)
-            .ok_or(NvmeError::InvalidSubQueue(sqid))
+        self.sqs[sqid as usize].clone().ok_or(NvmeError::InvalidSubQueue(sqid))
     }
 
     /// Returns a reference to the Admin [`CompQueue`].

lib/propolis/src/hw/pci/bus.rs

@@ -162,8 +162,7 @@ impl Inner {
     fn device_at(&self, location: BusLocation) -> Option<Arc<dyn Endpoint>> {
         let res = self.slots[location.dev.get() as usize].funcs
             [location.func.get() as usize]
-            .as_ref()
-            .map(Arc::clone);
+            .clone();
         res
     }
     fn attach(

lib/propolis/src/vmm/mem.rs

@@ -344,6 +344,9 @@ unsafe impl Send for Mapping {}
 unsafe impl Sync for Mapping {}
 
 #[derive(Debug)]
+// Backing resources (Mapping or SubMapping) must remain held, even though we do
+// not reference them directly as a field.
+#[allow(dead_code)]
 enum Backing<'a> {
     Base(Arc<Mapping>),
     Sub(&'a SubMapping<'a>),