refactor: axio (#99)

* refactor: axio

* update axio to 0.3.0-pre.1

* refactor: simplify FileLike with downcast-rs

Author: AsakuraMizu

Cargo.lock

@@ -50,7 +50,7 @@ axtask = { path = "arceos/modules/axtask" }
 axbacktrace = "0.1"
 axerrno = "0.2"
 axfs-ng-vfs = "0.1"
-axio = { version = "0.2", git = "https://github.com/arceos-org/axio.git", tag = "dev-v02" }
+axio = "0.3.0-pre.1"
 axpoll = "0.1"
 bitflags = "2.10"
 bytemuck = { version = "1.23", features = ["unsound_ptr_pod_impl"] }

Cargo.toml

@@ -37,6 +37,7 @@ bitmaps = { version = "3.2.1", default-features = false }
 bytemuck.workspace = true
 cfg-if.workspace = true
 chrono = { version = "0.4.41", default-features = false }
+downcast-rs = { version = "2.0", default-features = false, features = ["sync"] }
 event-listener.workspace = true
 flatten_objects = "0.2.4"
 gimli = { version = "*", default-features = false, optional = true }

api/Cargo.toml

@@ -13,7 +13,6 @@ use alloc::{
     task::Wake,
 };
 use core::{
-    any::Any,
     hash::{Hash, Hasher},
     sync::atomic::{AtomicBool, Ordering},
     task::{Context, Waker},
@@ -26,7 +25,7 @@ use hashbrown::HashMap;
 use kspin::SpinNoPreempt;
 use linux_raw_sys::general::{EPOLLET, EPOLLONESHOT, epoll_event};
 
-use crate::file::{FileLike, Kstat, SealedBuf, SealedBufMut, get_file_like};
+use crate::file::{FileLike, get_file_like};
 
 pub struct EpollEvent {
     pub events: IoEvents,
@@ -434,25 +433,9 @@ impl Epoll {
 }
 
 impl FileLike for Epoll {
-    fn read(&self, _dst: &mut SealedBufMut) -> AxResult<usize> {
-        Err(AxError::InvalidInput)
-    }
-
-    fn write(&self, _src: &mut SealedBuf) -> AxResult<usize> {
-        Err(AxError::InvalidInput)
-    }
-
-    fn stat(&self) -> AxResult<Kstat> {
-        Ok(Kstat::default())
-    }
-
     fn path(&self) -> Cow<'_, str> {
         "anon_inode:[eventpoll]".into()
     }
-
-    fn into_any(self: Arc<Self>) -> Arc<dyn Any + Send + Sync> {
-        self
-    }
 }
 
 impl Pollable for Epoll {

api/src/file/epoll.rs

@@ -1,16 +1,14 @@
 use alloc::{borrow::Cow, sync::Arc};
 use core::{
-    any::Any,
     sync::atomic::{AtomicBool, AtomicU64, Ordering},
     task::Context,
 };
 
 use axerrno::AxError;
-use axio::{Buf, BufMut, Read, Write};
 use axpoll::{IoEvents, PollSet, Pollable};
 use axtask::future::{block_on, poll_io};
 
-use crate::file::{FileLike, Kstat, SealedBuf, SealedBufMut};
+use crate::file::{FileLike, IoDst, IoSrc};
 
 pub struct EventFd {
     count: AtomicU64,
@@ -35,7 +33,7 @@ impl EventFd {
 }
 
 impl FileLike for EventFd {
-    fn read(&self, dst: &mut SealedBufMut) -> axio::Result<usize> {
+    fn read(&self, dst: &mut IoDst) -> axio::Result<usize> {
         if dst.remaining_mut() < size_of::<u64>() {
             return Err(AxError::InvalidInput);
         }
@@ -62,7 +60,7 @@ impl FileLike for EventFd {
         }))
     }
 
-    fn write(&self, src: &mut SealedBuf) -> axio::Result<usize> {
+    fn write(&self, src: &mut IoSrc) -> axio::Result<usize> {
         if src.remaining() < size_of::<u64>() {
             return Err(AxError::InvalidInput);
         }
@@ -94,10 +92,6 @@ impl FileLike for EventFd {
         }))
     }
 
-    fn stat(&self) -> axio::Result<Kstat> {
-        Ok(Kstat::default())
-    }
-
     fn nonblocking(&self) -> bool {
         self.non_blocking.load(Ordering::Acquire)
     }
@@ -110,10 +104,6 @@ impl FileLike for EventFd {
     fn path(&self) -> Cow<'_, str> {
         "anon_inode:[eventfd]".into()
     }
-
-    fn into_any(self: Arc<Self>) -> Arc<dyn Any + Send + Sync> {
-        self
-    }
 }
 
 impl Pollable for EventFd {

api/src/file/event.rs

@@ -1,6 +1,5 @@
 use alloc::{borrow::Cow, string::ToString, sync::Arc};
 use core::{
-    any::Any,
     ffi::c_int,
     hint::likely,
     sync::atomic::{AtomicBool, Ordering},
@@ -16,7 +15,7 @@ use axtask::future::{block_on, poll_io};
 use linux_raw_sys::general::{AT_EMPTY_PATH, AT_FDCWD, AT_SYMLINK_NOFOLLOW};
 
 use super::{FileLike, Kstat, get_file_like};
-use crate::file::{SealedBuf, SealedBufMut};
+use crate::file::{IoDst, IoSrc};
 
 pub fn with_fs<R>(dirfd: c_int, f: impl FnOnce(&mut FsContext) -> AxResult<R>) -> AxResult<R> {
     let mut fs = FS_CONTEXT.lock();
@@ -56,7 +55,7 @@ pub fn resolve_at(dirfd: c_int, path: Option<&str>, flags: u32) -> AxResult<Reso
                 return Err(AxError::NotFound);
             }
             let file_like = get_file_like(dirfd)?;
-            let f = file_like.clone().into_any();
+            let f = file_like.clone();
             Ok(if let Some(file) = f.downcast_ref::<File>() {
                 ResolveAtResult::File(file.inner().backend()?.location().clone())
             } else if let Some(dir) = f.downcast_ref::<Directory>() {
@@ -126,24 +125,24 @@ fn path_for(loc: &Location) -> Cow<'static, str> {
 }
 
 impl FileLike for File {
-    fn read(&self, dst: &mut SealedBufMut) -> AxResult<usize> {
+    fn read(&self, dst: &mut IoDst) -> AxResult<usize> {
         let inner = self.inner();
         if likely(self.is_blocking()) {
             inner.read(dst)
         } else {
             block_on(poll_io(self, IoEvents::IN, self.nonblocking(), || {
-                inner.read(dst)
+                inner.read(&mut *dst)
             }))
         }
     }
 
-    fn write(&self, src: &mut SealedBuf) -> AxResult<usize> {
+    fn write(&self, src: &mut IoSrc) -> AxResult<usize> {
         let inner = self.inner();
         if likely(self.is_blocking()) {
             inner.write(src)
         } else {
             block_on(poll_io(self, IoEvents::OUT, self.nonblocking(), || {
-                inner.write(src)
+                inner.write(&mut *src)
             }))
         }
     }
@@ -152,10 +151,6 @@ impl FileLike for File {
         Ok(metadata_to_kstat(&self.inner().location().metadata()?))
     }
 
-    fn into_any(self: Arc<Self>) -> Arc<dyn Any + Send + Sync> {
-        self
-    }
-
     fn ioctl(&self, cmd: u32, arg: usize) -> AxResult<usize> {
         self.inner().backend()?.location().ioctl(cmd, arg)
     }
@@ -177,9 +172,7 @@ impl FileLike for File {
     where
         Self: Sized + 'static,
     {
-        let any = get_file_like(fd)?.into_any();
-
-        any.downcast::<Self>().map_err(|any| {
+        get_file_like(fd)?.downcast_arc().map_err(|any| {
             if any.is::<Directory>() {
                 AxError::IsADirectory
             } else {
@@ -219,11 +212,11 @@ impl Directory {
 }
 
 impl FileLike for Directory {
-    fn read(&self, _dst: &mut SealedBufMut) -> AxResult<usize> {
+    fn read(&self, _dst: &mut IoDst) -> AxResult<usize> {
         Err(AxError::BadFileDescriptor)
     }
 
-    fn write(&self, _src: &mut SealedBuf) -> AxResult<usize> {
+    fn write(&self, _src: &mut IoSrc) -> AxResult<usize> {
         Err(AxError::BadFileDescriptor)
     }
 
@@ -235,14 +228,9 @@ impl FileLike for Directory {
         path_for(&self.inner)
     }
 
-    fn into_any(self: Arc<Self>) -> Arc<dyn Any + Send + Sync> {
-        self
-    }
-
     fn from_fd(fd: c_int) -> AxResult<Arc<Self>> {
         get_file_like(fd)?
-            .into_any()
-            .downcast::<Self>()
+            .downcast_arc()
             .map_err(|_| AxError::NotADirectory)
     }
 }