feat(procfs): 增强procfs文件系统功能 (#1713)

* feat(procfs): 增强procfs文件系统功能

- 在meminfo文件中添加SwapTotal和SwapFree字段
- 为/proc/<pid>目录实现动态owner方法，支持实时UID/GID查询
- 在pid/stat文件中改进tty_nr字段的获取逻辑
- 在procfs模板中为DirOps、FileOps和SymOps添加owner方法支持

Signed-off-by: longjin <longjin@DragonOS.org>

kernel/src/filesystem/procfs/meminfo.rs

@@ -64,6 +64,8 @@ impl MeminfoFileOps {
                 .as_bytes()
                 .to_owned(),
         );
+        data.append(&mut format!("SwapTotal:\t{} kB\n", 0u64).as_bytes().to_owned());
+        data.append(&mut format!("SwapFree:\t{} kB\n", 0u64).as_bytes().to_owned());
         data.append(
             &mut format!("Dirty:\t\t{} kB\n", stats.file_dirty * page_kb)
                 .as_bytes()

kernel/src/filesystem/procfs/pid/mod.rs

@@ -156,6 +156,15 @@ impl PidDirOps {
 }
 
 impl DirOps for PidDirOps {
+    fn owner(&self) -> Option<(usize, usize)> {
+        let pcb = ProcessManager::find(self.pid)?;
+        if pcb.is_kthread() {
+            return Some((0, 0));
+        }
+        let cred = pcb.cred();
+        Some((cred.euid.data(), cred.egid.data()))
+    }
+
     fn lookup_child(
         &self,
         dir: &ProcDir<Self>,

kernel/src/filesystem/procfs/pid/stat.rs

@@ -77,7 +77,11 @@ fn generate_linux_proc_stat_line(
     // 尽量填真实值；拿不到的先填 0
     let pgrp: usize = 0;
     let session: usize = 0;
-    let tty_nr: i32 = 0;
+    let tty_nr: i32 = pcb
+        .sig_info_irqsave()
+        .tty()
+        .map(|tty| tty.core().device_number().new_encode_dev() as i32)
+        .unwrap_or(0);
     let tpgid: i32 = 0;
     let flags: u64 = 0;
     let minflt: u64 = 0;

kernel/src/filesystem/procfs/template/dir.rs

@@ -94,9 +94,17 @@ impl<Ops: DirOps> ProcDir<Ops> {
 impl<Ops: DirOps + 'static> IndexNode for ProcDir<Ops> {
     fn fs(&self) -> Arc<dyn FileSystem>;
     fn as_any_ref(&self) -> &dyn core::any::Any;
-    fn metadata(&self) -> Result<Metadata, SystemError>;
     fn set_metadata(&self, metadata: &Metadata) -> Result<(), SystemError>;
 
+    fn metadata(&self) -> Result<Metadata, SystemError> {
+        let mut metadata = self.common.metadata()?;
+        if let Some((uid, gid)) = self.inner.owner() {
+            metadata.uid = uid;
+            metadata.gid = gid;
+        }
+        Ok(metadata)
+    }
+
     fn read_at(
         &self,
         _offset: usize,
@@ -241,6 +249,11 @@ pub trait DirOps: Sync + Send + Sized + Debug {
     fn validate_child(&self, _child: &dyn IndexNode) -> bool {
         true
     }
+
+    /// 返回动态 owner（用于 /proc/<pid> 等需要实时 UID/GID 的场景）
+    fn owner(&self) -> Option<(usize, usize)> {
+        None
+    }
 }
 
 pub fn lookup_child_from_table<Fp, F>(

kernel/src/filesystem/procfs/template/file.rs

@@ -105,6 +105,11 @@ pub trait FileOps: Sync + Send + Sized + Debug {
     ) -> Result<usize, SystemError> {
         Err(SystemError::EPERM)
     }
+
+    /// 返回动态 owner（用于 /proc/<pid> 等需要实时 UID/GID 的场景）
+    fn owner(&self) -> Option<(usize, usize)> {
+        None
+    }
 }
 
 /// 为 ProcFile 实现 IndexNode trait
@@ -113,9 +118,17 @@ pub trait FileOps: Sync + Send + Sized + Debug {
 impl<F: FileOps + 'static> IndexNode for ProcFile<F> {
     fn fs(&self) -> Arc<dyn FileSystem>;
     fn as_any_ref(&self) -> &dyn core::any::Any;
-    fn metadata(&self) -> Result<Metadata, SystemError>;
     fn set_metadata(&self, metadata: &Metadata) -> Result<(), SystemError>;
 
+    fn metadata(&self) -> Result<Metadata, SystemError> {
+        let mut metadata = self.common.metadata()?;
+        if let Some((uid, gid)) = self.inner.owner() {
+            metadata.uid = uid;
+            metadata.gid = gid;
+        }
+        Ok(metadata)
+    }
+
     fn read_at(
         &self,
         offset: usize,

kernel/src/filesystem/procfs/template/sym.rs

@@ -118,6 +118,11 @@ pub trait SymOps: Sync + Send + Sized + Debug {
     fn dynamic_inode_id(&self) -> Option<InodeId> {
         None
     }
+
+    /// 返回动态 owner（用于 /proc/<pid> 等需要实时 UID/GID 的场景）
+    fn owner(&self) -> Option<(usize, usize)> {
+        None
+    }
 }
 
 /// 为 ProcSym 实现 IndexNode trait
@@ -131,6 +136,11 @@ impl<S: SymOps + 'static> IndexNode for ProcSym<S> {
     fn metadata(&self) -> Result<Metadata, SystemError> {
         let mut metadata = self.common.metadata()?;
 
+        if let Some((uid, gid)) = self.inner.owner() {
+            metadata.uid = uid;
+            metadata.gid = gid;
+        }
+
         // 如果 inner 提供了动态 inode ID（如命名空间文件），使用它
         if let Some(dynamic_id) = self.inner.dynamic_inode_id() {
             metadata.inode_id = dynamic_id;