io_uring cleanups and updates for new flags in Linux 6.2 (#553)

- Rename `IoringSetupFlags`'s `SETUP_SINGLE_ISSUER` and `SETUP_DEFER_TASKRUN`
   to `SINGLE_ISSUER` and `DEFER_TASKRUN`, because the `SETUP_` is omitted in
   the other `IoringSetupFlags` flags.

 - Split `IoringRecvsendFlags` into `IoringSendFlags` and
   `IoringRecvFlags`, and add the new `ZC_REPORT_USAGE` send flag.

 - Add a public re-export of the new `IORING_NOTIF_USAGE_ZC_COPIED`
   flag. In theory we could convert `cqe.res` into a union and use a
   bitflags type for `IORING_NOTIF_USAGE_ZC_COPIED`, though my rough
   guess is that that's not worth it until it gets more complex.

Author: sunfishcode

src/io_uring.rs

@@ -439,10 +439,10 @@ bitflags::bitflags! {
         const TASKRUN_FLAG = sys::IORING_SETUP_TASKRUN_FLAG;
 
         /// `IORING_SETUP_SINGLE_ISSUER`
-        const SETUP_SINGLE_ISSUER = sys::IORING_SETUP_SINGLE_ISSUER;
+        const SINGLE_ISSUER = sys::IORING_SETUP_SINGLE_ISSUER;
 
         /// `IORING_SETUP_DEFER_TASKRUN`
-        const SETUP_DEFER_TASKRUN = sys::IORING_SETUP_DEFER_TASKRUN;
+        const DEFER_TASKRUN = sys::IORING_SETUP_DEFER_TASKRUN;
     }
 }
 
@@ -673,16 +673,39 @@ bitflags::bitflags! {
 }
 
 bitflags::bitflags! {
-    /// send/sendmsg & recv/recvmsg flags (`sqe.ioprio`)
+    /// send/sendmsg flags (`sqe.ioprio`)
     #[derive(Default)]
-    pub struct IoringRecvsendFlags: u16 {
+    pub struct IoringSendFlags: u16 {
+        /// `IORING_RECVSEND_POLL_FIRST`.
+        ///
+        /// See also [`IoringRecvFlags::POLL_FIRST`].
+        const POLL_FIRST = sys::IORING_RECVSEND_POLL_FIRST as _;
+
+        /// `IORING_RECVSEND_FIXED_BUF`
+        ///
+        /// See also [`IoringRecvFlags::FIXED_BUF`].
+        const FIXED_BUF = sys::IORING_RECVSEND_FIXED_BUF as _;
+
+        /// `IORING_SEND_ZC_REPORT_USAGE`
+        const ZC_REPORT_USAGE = sys::IORING_SEND_ZC_REPORT_USAGE as _;
+    }
+}
+
+bitflags::bitflags! {
+    /// recv/recvmsg flags (`sqe.ioprio`)
+    #[derive(Default)]
+    pub struct IoringRecvFlags: u16 {
         /// `IORING_RECVSEND_POLL_FIRST`
+        ///
+        /// See also [`IoringSendFlags::POLL_FIRST`].
         const POLL_FIRST = sys::IORING_RECVSEND_POLL_FIRST as _;
 
         /// `IORING_RECV_MULTISHOT`
         const MULTISHOT = sys::IORING_RECV_MULTISHOT as _;
 
         /// `IORING_RECVSEND_FIXED_BUF`
+        ///
+        /// See also [`IoringSendFlags::FIXED_BUF`].
         const FIXED_BUF = sys::IORING_RECVSEND_FIXED_BUF as _;
     }
 }
@@ -742,6 +765,9 @@ pub const fn io_uring_register_files_skip() -> BorrowedFd<'static> {
     unsafe { BorrowedFd::<'static>::borrow_raw(files_skip) }
 }
 
+/// `IORING_NOTIF_USAGE_ZC_COPIED`
+pub const IORING_NOTIF_USAGE_ZC_COPIED: i32 = sys::IORING_NOTIF_USAGE_ZC_COPIED as _;
+
 /// A pointer in the io_uring API.
 ///
 /// `io_uring`'s native API represents pointers as `u64` values. In order to
@@ -878,7 +904,8 @@ pub struct io_uring_sqe {
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub union ioprio_union {
-    pub recvsend_flags: IoringRecvsendFlags,
+    pub recv_flags: IoringRecvFlags,
+    pub send_flags: IoringSendFlags,
     pub accept_flags: IoringAcceptFlags,
     pub ioprio: u16,
 }