Simple filetest passed on qemu/k210.

easy-fs/build.rs

@@ -0,0 +1,6 @@
+static TARGET_PATH: &str = "../user/target/riscv64gc-unknown-none-elf/release/";
+
+fn main() {
+    println!("cargo:rerun-if-changed=../user/src/");
+    println!("cargo:rerun-if-changed={}", TARGET_PATH);
+}

os/Makefile

@@ -7,6 +7,7 @@ KERNEL_ENTRY_PA := 0x80020000
 DISASM_TMP := target/$(TARGET)/$(MODE)/asm
 FS_IMG := ../user/target/$(TARGET)/$(MODE)/fs.img
 SDCARD := /dev/sdb
+APPS := ../user/src/bin
 
 # BOARD
 BOARD		?= qemu
@@ -33,12 +34,13 @@ sdcard: $(FS_IMG)
 $(KERNEL_BIN): kernel
 	@$(OBJCOPY) $(KERNEL_ELF) --strip-all -O binary $@
 
-$(FS_IMG):
-	@echo "hello, world!"
+$(FS_IMG): $(APPS)
+	@cd ../user && make build
 	@cd ../easy-fs && cargo run --release
 
+$(APPS):
+
 kernel:
-	@cd ../user && make build
 	@cargo build --release --features "board_$(BOARD)"
 
 clean:

os/src/fs/inode.rs

@@ -8,6 +8,9 @@ use lazy_static::*;
 use bitflags::*;
 use alloc::vec::Vec;
 use spin::Mutex;
+use super::File;
+use crate::mm::UserBuffer;
+use core::any::Any;
 
 pub struct OSInode {
     readable: bool,
@@ -92,13 +95,67 @@ impl OpenFlags {
 
 pub fn open_file(name: &str, flags: OpenFlags) -> Option<Arc<OSInode>> {
     let (readable, writable) = flags.read_write();
-    // TODO: do not support CREATE or TRUNC flags now
-    ROOT_INODE.find(name)
-        .map(|inode| {
-            Arc::new(OSInode::new(
+    if flags.contains(OpenFlags::CREATE) {
+        if let Some(inode) = ROOT_INODE.find(name) {
+            // clear size
+            inode.clear();
+            Some(Arc::new(OSInode::new(
                 readable,
                 writable,
-                inode
-            ))
-        })
+                inode,
+            )))
+        } else {
+            // create file
+            ROOT_INODE.create(name)
+                .map(|inode| {
+                    Arc::new(OSInode::new(
+                        readable,
+                        writable,
+                        inode,
+                    ))
+                })
+        }
+    } else {
+        ROOT_INODE.find(name)
+            .map(|inode| {
+                if flags.contains(OpenFlags::TRUNC) {
+                    inode.clear();
+                }
+                Arc::new(OSInode::new(
+                    readable,
+                    writable,
+                    inode
+                ))
+            })
+    }
 }
+
+impl File for OSInode {
+    fn readable(&self) -> bool { self.readable }
+    fn writable(&self) -> bool { self.writable }
+    fn read(&self, mut buf: UserBuffer) -> usize {
+        let mut inner = self.inner.lock();
+        let mut total_read_size = 0usize;
+        for slice in buf.buffers.iter_mut() {
+            let read_size = inner.inode.read_at(inner.offset, *slice);
+            if read_size == 0 {
+                break;
+            }
+            inner.offset += read_size;
+            total_read_size += read_size;
+        }
+        total_read_size
+    }
+    fn write(&self, buf: UserBuffer) -> usize {
+        let mut inner = self.inner.lock();
+        let mut total_write_size = 0usize;
+        for slice in buf.buffers.iter() {
+            let write_size = inner.inode.write_at(inner.offset, *slice);
+            assert_eq!(write_size, slice.len());
+            inner.offset += write_size;
+            total_write_size += write_size;
+        }
+        total_write_size
+    }
+    fn as_any_ref(&self) -> &dyn Any { self }
+}

os/src/main.rs

@@ -46,17 +46,7 @@ pub fn rust_main() -> ! {
     trap::enable_timer_interrupt();
     timer::set_next_trigger();
     fs::list_apps();
-    //println!("after listing apps");
     task::add_initproc();
-    /*
-    println!("after adding initproc!");
-    println!("list apps again!");
-    fs::list_apps();
-    println!("test user_shell now!");
-    let user_shell = fs::open_file("user_shell", fs::OpenFlags::RDONLY).unwrap();
-    println!("user_shell size = {}", user_shell.read_all().len());
-    println!("before running tasks!");
-     */
     task::run_tasks();
     panic!("Unreachable in rust_main!");
 }

os/src/syscall/fs.rs

@@ -1,6 +1,11 @@
-use crate::mm::{UserBuffer, translated_byte_buffer, translated_refmut};
+use crate::mm::{
+    UserBuffer,
+    translated_byte_buffer,
+    translated_refmut,
+    translated_str,
+};
 use crate::task::{current_user_token, current_task};
-use crate::fs::{make_pipe};
+use crate::fs::{make_pipe, OpenFlags, open_file};
 
 pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
     let token = current_user_token();
@@ -46,6 +51,23 @@ pub fn sys_read(fd: usize, buf: *const u8, len: usize) -> isize {
     }
 }
 
+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();

os/src/syscall/mod.rs

@@ -1,3 +1,4 @@
+const SYSCALL_OPEN: usize = 56;
 const SYSCALL_CLOSE: usize = 57;
 const SYSCALL_PIPE: usize = 59;
 const SYSCALL_READ: usize = 63;
@@ -18,6 +19,7 @@ use process::*;
 
 pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
     match syscall_id {
+        SYSCALL_OPEN => sys_open(args[0] as *const u8, args[1] as u32),
         SYSCALL_CLOSE => sys_close(args[0]),
         SYSCALL_PIPE => sys_pipe(args[0] as *mut usize),
         SYSCALL_READ => sys_read(args[0], args[1] as *const u8, args[2]),

os/src/task/processor.rs

@@ -61,7 +61,6 @@ lazy_static! {
 }
 
 pub fn run_tasks() {
-    println!("into Processor::run_tasks!");
     PROCESSOR.run();
 }
 

user/Cargo.toml

@@ -7,4 +7,5 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-buddy_system_allocator = "0.6"
+buddy_system_allocator = "0.6"
+bitflags = "1.2.1"

user/src/bin/filetest_simple.rs

@@ -0,0 +1,38 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{
+    open,
+    close,
+    read,
+    write,
+    OpenFlags,
+};
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let test_str = "Hello, world!";
+    let filea = "filea\0";
+    let fd = open(filea, OpenFlags::CREATE | OpenFlags::WRONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    write(fd, test_str.as_bytes());
+    close(fd);
+
+    let fd = open(filea, OpenFlags::RDONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    let mut buffer = [0u8; 100];
+    let read_len = read(fd, &mut buffer) as usize;
+    close(fd);
+
+    assert_eq!(
+        test_str,
+        core::str::from_utf8(&buffer[..read_len]).unwrap(),
+    );
+    println!("file_test passed!");
+    0
+}

user/src/lib.rs

@@ -10,6 +10,8 @@ mod syscall;
 mod lang_items;
 
 extern crate alloc;
+#[macro_use]
+extern crate bitflags;
 
 use syscall::*;
 use buddy_system_allocator::LockedHeap;
@@ -42,6 +44,17 @@ fn main() -> i32 {
     panic!("Cannot find main!");
 }
 
+bitflags! {
+    pub struct OpenFlags: u32 {
+        const RDONLY = 0;
+        const WRONLY = 1 << 0;
+        const RDWR = 1 << 1;
+        const CREATE = 1 << 9;
+        const TRUNC = 1 << 10;
+    }
+}
+
+pub fn open(path: &str, flags: OpenFlags) -> isize { sys_open(path, flags.bits) }
 pub fn close(fd: usize) -> isize { sys_close(fd) }
 pub fn pipe(pipe_fd: &mut [usize]) -> isize { sys_pipe(pipe_fd) }
 pub fn read(fd: usize, buf: &mut [u8]) -> isize { sys_read(fd, buf) }

user/src/syscall.rs

@@ -1,3 +1,4 @@
+const SYSCALL_OPEN: usize = 56;
 const SYSCALL_CLOSE: usize = 57;
 const SYSCALL_PIPE: usize = 59;
 const SYSCALL_READ: usize = 63;
@@ -23,6 +24,10 @@ fn syscall(id: usize, args: [usize; 3]) -> isize {
     ret
 }
 
+pub fn sys_open(path: &str, flags: u32) -> isize {
+    syscall(SYSCALL_OPEN, [path.as_ptr() as usize, flags as usize, 0])
+}
+
 pub fn sys_close(fd: usize) -> isize {
     syscall(SYSCALL_CLOSE, [fd, 0, 0])
 }