Add support for lseek syscall

src/services/libs/jinux-std/src/fs/file_handle/file.rs

@@ -2,7 +2,7 @@ use crate::prelude::*;
 use crate::tty::get_n_tty;
 use core::any::Any;
 
-use crate::fs::utils::{IoEvents, IoctlCmd, Metadata};
+use crate::fs::utils::{IoEvents, IoctlCmd, Metadata, SeekFrom};
 
 /// The basic operations defined on a file
 pub trait File: Send + Sync + Any {
@@ -36,4 +36,8 @@ pub trait File: Send + Sync + Any {
     fn metadata(&self) -> Metadata {
         panic!("metadata unsupported");
     }
+
+    fn seek(&self, seek_from: SeekFrom) -> Result<usize> {
+        panic!("seek unsupported");
+    }
 }

src/services/libs/jinux-std/src/fs/file_handle/inode_handle/mod.rs

@@ -70,28 +70,28 @@ impl InodeHandle_ {
 
     pub fn seek(&self, pos: SeekFrom) -> Result<usize> {
         let mut offset = self.offset.lock();
-        let new_offset: i64 = match pos {
-            SeekFrom::Start(off /* as u64 */) => {
-                if off > i64::max_value() as u64 {
+        let new_offset: isize = match pos {
+            SeekFrom::Start(off /* as usize */) => {
+                if off > isize::max_value() as usize {
                     return_errno_with_message!(Errno::EINVAL, "file offset is too large");
                 }
-                off as i64
+                off as isize
             }
-            SeekFrom::End(off /* as i64 */) => {
-                let file_size = self.dentry.vnode().inode().metadata().size as i64;
+            SeekFrom::End(off /* as isize */) => {
+                let file_size = self.dentry.vnode().inode().metadata().size as isize;
                 assert!(file_size >= 0);
                 file_size
                     .checked_add(off)
                     .ok_or_else(|| Error::with_message(Errno::EOVERFLOW, "file offset overflow"))?
             }
-            SeekFrom::Current(off /* as i64 */) => (*offset as i64)
+            SeekFrom::Current(off /* as isize */) => (*offset as isize)
                 .checked_add(off)
                 .ok_or_else(|| Error::with_message(Errno::EOVERFLOW, "file offset overflow"))?,
         };
         if new_offset < 0 {
             return_errno_with_message!(Errno::EINVAL, "file offset must not be negative");
         }
-        // Invariant: 0 <= new_offset <= i64::max_value()
+        // Invariant: 0 <= new_offset <= isize::max_value()
         let new_offset = new_offset as usize;
         *offset = new_offset;
         Ok(new_offset)

src/services/libs/jinux-std/src/fs/file_handle/mod.rs

@@ -3,7 +3,7 @@
 mod file;
 mod inode_handle;
 
-use crate::fs::utils::Metadata;
+use crate::fs::utils::{Metadata, SeekFrom};
 use crate::prelude::*;
 use crate::rights::{ReadOp, WriteOp};
 use alloc::sync::Arc;
@@ -74,6 +74,13 @@ impl FileHandle {
         }
     }
 
+    pub fn seek(&self, seek_from: SeekFrom) -> Result<usize> {
+        match &self.inner {
+            Inner::File(file) => file.seek(seek_from),
+            Inner::Inode(inode_handle) => inode_handle.seek(seek_from),
+        }
+    }
+
     pub fn clean_for_close(&self) -> Result<()> {
         match &self.inner {
             Inner::Inode(inode_handle) => {

src/services/libs/jinux-std/src/fs/stdio.rs

@@ -3,7 +3,7 @@ use crate::tty::{get_n_tty, Tty};
 
 use super::file_handle::File;
 use super::file_table::FileDescripter;
-use super::utils::{InodeMode, InodeType, IoEvents, Metadata};
+use super::utils::{InodeMode, InodeType, IoEvents, Metadata, SeekFrom};
 
 pub const FD_STDIN: FileDescripter = 0;
 pub const FD_STDOUT: FileDescripter = 1;
@@ -46,6 +46,11 @@ impl File for Stdin {
         }
     }
 
+    fn seek(&self, seek_from: SeekFrom) -> Result<usize> {
+        // TODO: do real seek
+        Ok(0)
+    }
+
     fn metadata(&self) -> Metadata {
         Metadata {
             dev: 0,
@@ -82,6 +87,11 @@ impl File for Stdout {
         }
     }
 
+    fn seek(&self, seek_from: SeekFrom) -> Result<usize> {
+        // TODO: do real seek
+        Ok(0)
+    }
+
     fn metadata(&self) -> Metadata {
         Metadata {
             dev: 0,
@@ -119,6 +129,11 @@ impl File for Stderr {
         }
     }
 
+    fn seek(&self, seek_from: SeekFrom) -> Result<usize> {
+        // TODO: do real seek
+        Ok(0)
+    }
+
     fn metadata(&self) -> Metadata {
         Metadata {
             dev: 0,

src/services/libs/jinux-std/src/fs/utils/mod.rs

@@ -32,9 +32,9 @@ mod vnode;
 
 #[derive(Copy, PartialEq, Eq, Clone, Debug)]
 pub enum SeekFrom {
-    Start(u64),
-    End(i64),
-    Current(i64),
+    Start(usize),
+    End(isize),
+    Current(isize),
 }
 
 /// Maximum bytes in a path

src/services/libs/jinux-std/src/syscall/lseek.rs

@@ -1,12 +1,27 @@
+use crate::fs::{file_table::FileDescripter, utils::SeekFrom};
 use crate::log_syscall_entry;
-use crate::{fs::file_table::FileDescripter, prelude::*};
+use crate::prelude::*;
 
 use super::SyscallReturn;
 use super::SYS_LSEEK;
 
-pub fn sys_lseek(fd: FileDescripter, offset: usize, whence: u32) -> Result<SyscallReturn> {
+pub fn sys_lseek(fd: FileDescripter, offset: isize, whence: u32) -> Result<SyscallReturn> {
     log_syscall_entry!(SYS_LSEEK);
     debug!("fd = {}, offset = {}, whence = {}", fd, offset, whence);
-    // TODO: do lseek
-    Ok(SyscallReturn::Return(0))
+    let seek_from = match whence {
+        0 => {
+            if offset < 0 {
+                return_errno!(Errno::EINVAL);
+            }
+            SeekFrom::Start(offset as usize)
+        }
+        1 => SeekFrom::Current(offset),
+        2 => SeekFrom::End(offset),
+        _ => return_errno!(Errno::EINVAL),
+    };
+    let current = current!();
+    let file_table = current.file_table().lock();
+    let file = file_table.get_file(fd)?;
+    let offset = file.seek(seek_from)?;
+    Ok(SyscallReturn::Return(offset as _))
 }