Refactor project structure

kernel/aster-nix/src/syscall/read.rs

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use super::{SyscallReturn, SYS_READ};
+use crate::{
+    fs::file_table::FileDescripter, log_syscall_entry, prelude::*, util::write_bytes_to_user,
+};
+
+pub fn sys_read(fd: FileDescripter, user_buf_addr: Vaddr, buf_len: usize) -> Result<SyscallReturn> {
+    log_syscall_entry!(SYS_READ);
+    debug!(
+        "fd = {}, user_buf_ptr = 0x{:x}, buf_len = 0x{:x}",
+        fd, user_buf_addr, buf_len
+    );
+    let current = current!();
+    let file_table = current.file_table().lock();
+    let file = file_table.get_file(fd)?;
+    let mut read_buf = vec![0u8; buf_len];
+    let read_len = file.read(&mut read_buf)?;
+    write_bytes_to_user(user_buf_addr, &read_buf)?;
+    Ok(SyscallReturn::Return(read_len as _))
+}