Use libstd-provided OnceCell equivalent

Cargo.toml

@@ -110,7 +110,6 @@ lazy_static = "1.4"
 libc = "0.2"
 mockall = "0.11"
 num_enum = "0.5"
-once_cell = "1.13"
 proc-macro2 = "1.0"
 progenitor = { git = "https://github.com/oxidecomputer/progenitor", branch = "main" }
 quote = "1.0"

README.md

@@ -12,10 +12,6 @@ Propolis works best (and its CI tests run) on AMD hosts, but it can also be used
 to run VMs on Intel hosts. Live migration is primarily supported on AMD hosts
 but may work on Intel hosts as well.
 
-### Minimum Supported Rust Version (MSRV)
-
-- Rust 1.67.0
-
 ## Building
 
 To build, run:

lib/propolis/Cargo.toml

@@ -3,6 +3,7 @@ name = "propolis"
 version = "0.1.0"
 license = "MPL-2.0"
 edition = "2021"
+rust-version = "1.70"
 
 [dependencies]
 libc.workspace = true
@@ -27,7 +28,6 @@ serde_arrays.workspace = true
 erased-serde.workspace = true
 serde_json.workspace = true
 uuid.workspace = true
-once_cell.workspace = true
 crucible-client-types = { workspace = true, optional = true }
 crucible = { workspace = true, optional = true }
 oximeter = { workspace = true, optional = true }

lib/propolis/src/block/mod.rs

@@ -8,15 +8,14 @@ use std::any::Any;
 use std::collections::VecDeque;
 use std::num::NonZeroUsize;
 use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
-use std::sync::{Arc, Condvar, Mutex, Weak};
+use std::sync::{Arc, Condvar, Mutex, OnceLock, Weak};
 
 use crate::accessors::{Guard as AccessorGuard, MemAccessor};
 use crate::common::*;
 use crate::tasks::*;
 use crate::vmm::{MemCtx, SubMapping};
 
 use futures::future::BoxFuture;
-use once_cell::sync::OnceCell;
 use tokio::sync::{Mutex as TokioMutex, Notify, Semaphore};
 
 mod file;
@@ -420,8 +419,8 @@ impl Driver {
     ) -> Self {
         Self {
             inner: Arc::new(DriverInner {
-                bdev: OnceCell::new(),
-                acc_mem: OnceCell::new(),
+                bdev: OnceLock::new(),
+                acc_mem: OnceLock::new(),
                 queue: Mutex::new(VecDeque::new()),
                 cv: Condvar::new(),
                 idle_threads: Semaphore::new(0),
@@ -529,10 +528,10 @@ impl DriverCtrls {
 
 struct DriverInner {
     /// The block device providing the requests to be serviced
-    bdev: OnceCell<Arc<dyn Device>>,
+    bdev: OnceLock<Arc<dyn Device>>,
 
     /// Memory accessor through the underlying device
-    acc_mem: OnceCell<MemAccessor>,
+    acc_mem: OnceLock<MemAccessor>,
 
     /// Queue of I/O requests from the device ready to be serviced by the backend
     queue: Mutex<VecDeque<Request>>,
@@ -738,13 +737,13 @@ impl WorkerHdl {
 
 struct Inner {
     /// The block device providing the requests to be serviced
-    bdev: OnceCell<Arc<dyn Device>>,
+    bdev: OnceLock<Arc<dyn Device>>,
 
     /// Task control for work-scheduling task
     sched_ctrl: Mutex<Option<TaskCtrl>>,
 
     /// Memory accessor through the underlying device
-    acc_mem: OnceCell<MemAccessor>,
+    acc_mem: OnceLock<MemAccessor>,
 
     /// Notifier used to both respond to the block frontend when it has requests
     /// available for processing, as well as internally when waiting for workers
@@ -767,8 +766,8 @@ struct Inner {
 impl Inner {
     fn new() -> Arc<Self> {
         Arc::new(Self {
-            bdev: OnceCell::new(),
-            acc_mem: OnceCell::new(),
+            bdev: OnceLock::new(),
+            acc_mem: OnceLock::new(),
             sched_ctrl: Mutex::new(None),
 
             queue: TokioMutex::new(VecDeque::new()),