finish

Author: Docter-R

os/src/fs/inode.rs

@@ -13,7 +13,9 @@ use alloc::vec::Vec;
 use bitflags::*;
 use easy_fs::{EasyFileSystem, Inode};
 use lazy_static::*;
-
+use crate::fs::Stat;
+use crate::fs::StatMode;
+use core::any::Any;
 /// inode in memory
 /// A wrapper around a filesystem inode
 /// to implement File trait atop
@@ -53,9 +55,31 @@ impl OSInode {
         }
         v
     }
+    /// get stat information of this inode
+    pub fn get_stat(&self) -> Stat {
+        let inner = self.inner.exclusive_access();
+        let inode = &inner.inode;
+        
+        let is_dir = inode.is_dir();
+        let nlink = inode.get_nlink();
+        let inode_id = inode.get_inode_id();
+        
+        Stat {
+            dev: 0,
+            ino: inode_id as u64,
+            mode: if is_dir { 
+                StatMode::DIR 
+            } else { 
+                StatMode::FILE 
+            },
+            nlink,
+            pad: [0; 7],
+        }
+    }
 }
 
 lazy_static! {
+    /// The root inode of the file system
     pub static ref ROOT_INODE: Arc<Inode> = {
         let efs = EasyFileSystem::open(BLOCK_DEVICE.clone());
         Arc::new(EasyFileSystem::root_inode(&efs))
@@ -156,4 +180,8 @@ impl File for OSInode {
         }
         total_write_size
     }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
 }

os/src/fs/mod.rs

@@ -1,9 +1,10 @@
 //! File trait & inode(dir, file, pipe, stdin, stdout)
 
-mod inode;
+pub mod inode;
 mod stdio;
 
 use crate::mm::UserBuffer;
+use core::any::Any;
 
 /// trait File for all file types
 pub trait File: Send + Sync {
@@ -15,6 +16,9 @@ pub trait File: Send + Sync {
     fn read(&self, buf: UserBuffer) -> usize;
     /// write to the file from buf, return the number of bytes written
     fn write(&self, buf: UserBuffer) -> usize;
+
+    /// 添加 as_any 方法用于向下转换
+    fn as_any(&self) -> &dyn Any;
 }
 
 /// The stat of a inode
@@ -33,6 +37,29 @@ pub struct Stat {
     pad: [u64; 7],
 }
 
+impl Stat {
+    /// 为特殊文件类型创建默认的 Stat 信息
+    pub fn for_special_file() -> Self {
+        Self {
+            dev: 0,
+            ino: 0,
+            mode: StatMode::FILE,
+            nlink: 1,
+            pad: [0; 7],
+        }
+    }
+
+    /// 判断是否是目录
+    pub fn is_dir(&self) -> bool {
+        self.mode.contains(StatMode::DIR)
+    }
+
+    /// 判断是否是文件
+    pub fn is_file(&self) -> bool {
+        self.mode.contains(StatMode::FILE)
+    }
+}
+
 bitflags! {
     /// The mode of a inode
     /// whether a directory or a file

os/src/fs/stdio.rs

@@ -6,7 +6,7 @@ use crate::task::suspend_current_and_run_next;
 
 /// stdin file for getting chars from console
 pub struct Stdin;
-
+use core::any::Any;
 /// stdout file for putting chars to console
 pub struct Stdout;
 
@@ -39,6 +39,9 @@ impl File for Stdin {
     fn write(&self, _user_buf: UserBuffer) -> usize {
         panic!("Cannot write to stdin!");
     }
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
 }
 
 impl File for Stdout {
@@ -57,4 +60,8 @@ impl File for Stdout {
         }
         user_buf.len()
     }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
 }

os/src/syscall/fs.rs

@@ -1,8 +1,9 @@
 //! File and filesystem-related syscalls
 use crate::fs::{open_file, OpenFlags, Stat};
-use crate::mm::{translated_byte_buffer, translated_str, UserBuffer};
+use crate::mm::{translated_byte_buffer, translated_str, UserBuffer, translated_refmut};
 use crate::task::{current_task, current_user_token};
-
+use crate::fs::inode::ROOT_INODE;
+use crate::fs::OSInode;
 
 pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
     trace!("kernel:pid[{}] sys_write", current_task().unwrap().pid.0);
@@ -51,6 +52,7 @@ pub fn sys_open(path: *const u8, flags: u32) -> isize {
     trace!("kernel:pid[{}] sys_open", current_task().unwrap().pid.0);
     let task = current_task().unwrap();
     let token = current_user_token();
+    // 通过页表将另一个地址空间中的C风格字符串（以\0结尾的字节数组）转换为Rust的String
     let path = translated_str(token, path);
     if let Some(inode) = open_file(path.as_str(), OpenFlags::from_bits(flags).unwrap()) {
         let mut inner = task.inner_exclusive_access();
@@ -77,28 +79,85 @@ pub fn sys_close(fd: usize) -> isize {
 }
 
 /// YOUR JOB: Implement fstat.
-pub fn sys_fstat(_fd: usize, _st: *mut Stat) -> isize {
+pub fn sys_fstat(fd: usize, st: *mut Stat) -> isize {
     trace!(
         "kernel:pid[{}] sys_fstat NOT IMPLEMENTED",
         current_task().unwrap().pid.0
     );
+    let task = current_task().unwrap();
+    let token = current_user_token();
+    
+    if let Some(file) = task.get_file(fd) {
+        // 只处理 OSInode（普通文件）
+        if let Some(os_inode) = file.as_any().downcast_ref::<OSInode>() {
+            let stat = os_inode.get_stat();
+            let st_buf = translated_refmut(token, st);
+            *st_buf = stat;
+            return 0;
+        }
+        // 对于其他类型的文件（Stdin/Stdout），暂时返回错误
+        // 等普通文件工作后再扩展
+        else {
+            return -1;
+        }
+    }
+    
     -1
 }
 
 /// YOUR JOB: Implement linkat.
-pub fn sys_linkat(_old_name: *const u8, _new_name: *const u8) -> isize {
+pub fn sys_linkat(old_name: *const u8, new_name: *const u8) -> isize {
     trace!(
         "kernel:pid[{}] sys_linkat NOT IMPLEMENTED",
         current_task().unwrap().pid.0
     );
-    -1
+        
+    let token = current_user_token();
+    let old_path = translated_str(token, old_name);
+    let new_path = translated_str(token, new_name);
+    
+    // 检查路径是否相同
+    if old_path == new_path {
+        return -1;
+    }
+    
+    // 查找原文件
+    let old_inode = match ROOT_INODE.find(&old_path) {
+        Some(inode) => inode,
+        None => return -1, // 原文件不存在
+    };
+    
+    // 检查新文件是否已存在
+    if ROOT_INODE.find(&new_path).is_some() {
+        return -1; // 新文件已存在
+    }
+    // 创建硬链接
+    match ROOT_INODE.create_hardlink(&new_path, &old_inode) {
+        Some(_) => {
+            0
+        },
+        None => {
+            -1
+        }
+    }
 }
 
 /// YOUR JOB: Implement unlinkat.
-pub fn sys_unlinkat(_name: *const u8) -> isize {
+pub fn sys_unlinkat(name: *const u8) -> isize {
     trace!(
         "kernel:pid[{}] sys_unlinkat NOT IMPLEMENTED",
         current_task().unwrap().pid.0
     );
-    -1
+        
+    
+    let token = current_user_token();
+    let path = translated_str(token, name);
+    
+    // 检查路径是否为空
+    if path.is_empty() {
+        return -1;
+    }
+    
+    // 直接调用 ROOT_INODE 的 unlink 方法
+    ROOT_INODE.unlink(&path)
 }

os/src/task/task.rs

@@ -397,6 +397,16 @@ impl TaskControlBlock {
         // 返回新任务
         new_task
     }
+
+    /// Get file by file descriptor
+    pub fn get_file(&self, fd: usize) -> Option<Arc<dyn File + Send + Sync>> {
+        let inner = self.inner_exclusive_access();
+        if fd < inner.fd_table.len() {
+            inner.fd_table[fd].clone()
+        } else {
+            None
+        }
+    }
 }
 
 #[derive(Copy, Clone, PartialEq)]