io_uring: remove unnecessary interior mutability

src/io_uring/ops/async_cancel.rs

@@ -6,33 +6,28 @@ use {
         },
         utils::errorfmt::ErrorFmt,
     },
-    std::cell::Cell,
     uapi::c,
 };
 
+#[derive(Default)]
 pub struct AsyncCancelTask {
-    id: Cell<u64>,
-    target: Cell<u64>,
+    id: u64,
+    target: u64,
 }
 
 impl IoUringData {
     pub fn cancel_task_in_kernel(&self, target: u64) {
-        let task = self.cached_cancels.pop().unwrap_or_else(|| {
-            Box::new(AsyncCancelTask {
-                id: Cell::new(0),
-                target: Cell::new(0),
-            })
-        });
         let id = self.id_raw();
-        task.id.set(id);
-        task.target.set(target);
+        let mut task = self.cached_cancels.pop().unwrap_or_default();
+        task.id = id;
+        task.target = target;
         self.schedule(task);
     }
 }
 
 unsafe impl Task for AsyncCancelTask {
     fn id(&self) -> u64 {
-        self.id.get()
+        self.id
     }
 
     fn complete(self: Box<Self>, ring: &IoUringData, res: i32) {
@@ -46,7 +41,7 @@ unsafe impl Task for AsyncCancelTask {
 
     fn encode(&self, sqe: &mut io_uring_sqe) {
         sqe.opcode = IORING_OP_ASYNC_CANCEL;
-        sqe.u2.addr = self.target.get();
+        sqe.u2.addr = self.target;
     }
 
     fn is_cancel(&self) -> bool {

src/io_uring/ops/poll.rs

@@ -5,10 +5,7 @@ use {
         sys::{io_uring_sqe, IORING_OP_POLL_ADD},
         IoUring, IoUringData, IoUringError, Task, TaskResultExt,
     },
-    std::{
-        cell::{Cell, RefCell},
-        rc::Rc,
-    },
+    std::rc::Rc,
     uapi::{c, OwnedFd},
 };
 
@@ -18,12 +15,13 @@ impl IoUring {
         let id = self.ring.id();
         let pr = self.ring.pending_results.acquire();
         {
-            let pw = self.ring.cached_polls.pop().unwrap_or_default();
-            pw.id.set(id.id);
-            *pw.data.borrow_mut() = Some(Data {
+            let mut pw = self.ring.cached_polls.pop().unwrap_or_default();
+            pw.id = id.id;
+            pw.fd = fd.raw() as _;
+            pw.events = events as _;
+            pw.data = Some(Data {
                 pr: pr.clone(),
-                fd: fd.clone(),
-                events: events as _,
+                _fd: fd.clone(),
             });
             self.ring.schedule(pw);
         }
@@ -41,34 +39,32 @@ impl IoUring {
 
 struct Data {
     pr: PendingResult,
-    fd: Rc<OwnedFd>,
-    events: u16,
+    _fd: Rc<OwnedFd>,
 }
 
 #[derive(Default)]
 pub struct PollTask {
-    id: Cell<u64>,
-    data: RefCell<Option<Data>>,
+    id: u64,
+    events: u16,
+    fd: i32,
+    data: Option<Data>,
 }
 
 unsafe impl Task for PollTask {
     fn id(&self) -> u64 {
-        self.id.get()
+        self.id
     }
 
-    fn complete(self: Box<Self>, ring: &IoUringData, res: i32) {
-        let data = self.data.borrow_mut().take();
-        if let Some(data) = data {
+    fn complete(mut self: Box<Self>, ring: &IoUringData, res: i32) {
+        if let Some(data) = self.data.take() {
             data.pr.complete(res);
         }
         ring.cached_polls.push(self);
     }
 
     fn encode(&self, sqe: &mut io_uring_sqe) {
-        let data = self.data.borrow_mut();
-        let data = data.as_ref().unwrap();
         sqe.opcode = IORING_OP_POLL_ADD;
-        sqe.fd = data.fd.raw();
-        sqe.u3.poll_events = data.events;
+        sqe.fd = self.fd;
+        sqe.u3.poll_events = self.events;
     }
 }

src/io_uring/ops/recvmsg.rs

@@ -124,7 +124,7 @@ unsafe impl Task for RecvmsgTask {
 
     fn encode(&self, sqe: &mut io_uring_sqe) {
         sqe.opcode = IORING_OP_RECVMSG;
-        sqe.fd = self.fd;
+        sqe.fd = self.fd as _;
         sqe.u2.addr = &self.msghdr as *const _ as _;
         sqe.u3.msg_flags = c::MSG_CMSG_CLOEXEC as _;
     }

src/io_uring/ops/write.rs

@@ -10,7 +10,7 @@ use {
         utils::buf::Buf,
     },
     std::rc::Rc,
-    uapi::OwnedFd,
+    uapi::{c, OwnedFd},
 };
 
 impl IoUring {
@@ -27,9 +27,12 @@ impl IoUring {
             let mut pw = self.ring.cached_writes.pop().unwrap_or_default();
             pw.id = id.id;
             pw.has_timeout = timeout.is_some();
+            pw.fd = fd.raw();
+            pw.buf = buf.as_ptr() as _;
+            pw.len = buf.len();
             pw.data = Some(WriteTaskData {
-                fd: fd.clone(),
-                buf,
+                _fd: fd.clone(),
+                _buf: buf,
                 res: pr.clone(),
             });
             self.ring.schedule(pw);
@@ -42,8 +45,8 @@ impl IoUring {
 }
 
 struct WriteTaskData {
-    fd: Rc<OwnedFd>,
-    buf: Buf,
+    _fd: Rc<OwnedFd>,
+    _buf: Buf,
     res: PendingResult,
 }
 
@@ -51,6 +54,9 @@ struct WriteTaskData {
 pub struct WriteTask {
     id: u64,
     has_timeout: bool,
+    fd: c::c_int,
+    buf: usize,
+    len: usize,
     data: Option<WriteTaskData>,
 }
 
@@ -63,17 +69,16 @@ unsafe impl Task for WriteTask {
         if let Some(data) = self.data.take() {
             data.res.complete(res);
         }
-        ring.clone().cached_writes.push(self);
+        ring.cached_writes.push(self);
     }
 
     fn encode(&self, sqe: &mut io_uring_sqe) {
-        let data = self.data.as_ref().unwrap();
         sqe.opcode = IORING_OP_WRITE;
-        sqe.fd = data.fd.raw();
+        sqe.fd = self.fd as _;
         sqe.u1.off = !0;
-        sqe.u2.addr = data.buf.as_ptr() as _;
+        sqe.u2.addr = self.buf as _;
         sqe.u3.rw_flags = 0;
-        sqe.len = data.buf.len() as _;
+        sqe.len = self.len as _;
     }
 
     fn has_timeout(&self) -> bool {