rcore-tutorial/os/src/syscall/fs.rs
2021-02-28 06:38:13 +08:00

111 lines
No EOL
3 KiB
Rust

use crate::mm::{
UserBuffer,
translated_byte_buffer,
translated_refmut,
translated_str,
};
use crate::task::{current_user_token, current_task};
use crate::fs::{make_pipe, OpenFlags, open_file};
use alloc::sync::Arc;
pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
let token = current_user_token();
let task = current_task().unwrap();
let inner = task.acquire_inner_lock();
if fd >= inner.fd_table.len() {
return -1;
}
if let Some(file) = &inner.fd_table[fd] {
if !file.writable() {
return -1;
}
let file = file.clone();
// release Task lock manually to avoid deadlock
drop(inner);
file.write(
UserBuffer::new(translated_byte_buffer(token, buf, len))
) as isize
} else {
-1
}
}
pub fn sys_read(fd: usize, buf: *const u8, len: usize) -> isize {
let token = current_user_token();
let task = current_task().unwrap();
let inner = task.acquire_inner_lock();
if fd >= inner.fd_table.len() {
return -1;
}
if let Some(file) = &inner.fd_table[fd] {
let file = file.clone();
if !file.readable() {
return -1;
}
// release Task lock manually to avoid deadlock
drop(inner);
file.read(
UserBuffer::new(translated_byte_buffer(token, buf, len))
) as isize
} else {
-1
}
}
pub fn sys_open(path: *const u8, flags: u32) -> isize {
let task = current_task().unwrap();
let token = current_user_token();
let path = translated_str(token, path);
if let Some(inode) = open_file(
path.as_str(),
OpenFlags::from_bits(flags).unwrap()
) {
let mut inner = task.acquire_inner_lock();
let fd = inner.alloc_fd();
inner.fd_table[fd] = Some(inode);
fd as isize
} else {
-1
}
}
pub fn sys_close(fd: usize) -> isize {
let task = current_task().unwrap();
let mut inner = task.acquire_inner_lock();
if fd >= inner.fd_table.len() {
return -1;
}
if inner.fd_table[fd].is_none() {
return -1;
}
inner.fd_table[fd].take();
0
}
pub fn sys_pipe(pipe: *mut usize) -> isize {
let task = current_task().unwrap();
let token = current_user_token();
let mut inner = task.acquire_inner_lock();
let (pipe_read, pipe_write) = make_pipe();
let read_fd = inner.alloc_fd();
inner.fd_table[read_fd] = Some(pipe_read);
let write_fd = inner.alloc_fd();
inner.fd_table[write_fd] = Some(pipe_write);
*translated_refmut(token, pipe) = read_fd;
*translated_refmut(token, unsafe { pipe.add(1) }) = write_fd;
0
}
pub fn sys_dup(fd: usize) -> isize {
let task = current_task().unwrap();
let mut inner = task.acquire_inner_lock();
if fd >= inner.fd_table.len() {
return -1;
}
if inner.fd_table[fd].is_none() {
return -1;
}
let new_fd = inner.alloc_fd();
inner.fd_table[new_fd] = Some(Arc::clone(inner.fd_table[fd].as_ref().unwrap()));
new_fd as isize
}