Pipe OK.

os/src/syscall/fs.rs

@@ -1,5 +1,6 @@
-use crate::mm::{UserBuffer, translated_byte_buffer};
+use crate::mm::{UserBuffer, translated_byte_buffer, translated_refmut};
 use crate::task::{current_user_token, current_task};
+use crate::fs::{make_pipe};
 
 pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
     let token = current_user_token();
@@ -12,9 +13,9 @@ pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
         let file = file.clone();
         // release Task lock manually to avoid deadlock
         drop(inner);
-        file.write(UserBuffer {
-            buffers: translated_byte_buffer(token, buf, len),
-        }) as isize
+        file.write(
+            UserBuffer::new(translated_byte_buffer(token, buf, len))
+        ) as isize
     } else {
         -1
     }
@@ -31,10 +32,37 @@ pub fn sys_read(fd: usize, buf: *const u8, len: usize) -> isize {
         let file = file.clone();
         // release Task lock manually to avoid deadlock
         drop(inner);
-        file.read(UserBuffer {
-            buffers: translated_byte_buffer(token, buf, len),
-        }) as isize
+        file.read(
+            UserBuffer::new(translated_byte_buffer(token, buf, len))
+        ) 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
 }