refactor(vfs): 将read和readv系统调用提取到独立模块

Signed-off-by: longjin <[email protected]>

kernel/src/filesystem/vfs/syscall/mod.rs

@@ -21,7 +21,6 @@ use crate::{
     time::{syscall::PosixTimeval, PosixTimeSpec},
 };
 
-use super::iov::{IoVec, IoVecs};
 use super::stat::{do_newfstatat, do_statx, PosixKstat};
 use super::vcore::do_symlinkat;
 use super::{
@@ -36,6 +35,8 @@ use super::{
     VFS_MAX_FOLLOW_SYMLINK_TIMES,
 };
 
+mod sys_read;
+mod sys_readv;
 mod sys_write;
 mod sys_writev;
 
@@ -501,28 +502,6 @@ impl Syscall {
         return r;
     }
 
-    /// @brief 根据文件描述符，读取文件数据。尝试读取的数据长度与buf的长度相同。
-    ///
-    /// @param fd 文件描述符编号
-    /// @param buf 输出缓冲区
-    ///
-    /// @return Ok(usize) 成功读取的数据的字节数
-    /// @return Err(SystemError) 读取失败，返回posix错误码
-    pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> {
-        let binding = ProcessManager::current_pcb().fd_table();
-        let fd_table_guard = binding.read();
-
-        let file = fd_table_guard.get_file_by_fd(fd);
-        if file.is_none() {
-            return Err(SystemError::EBADF);
-        }
-        // drop guard 以避免无法调度的问题
-        drop(fd_table_guard);
-        let file = file.unwrap();
-
-        return file.read(buf.len(), buf);
-    }
-
     /// @brief 调整文件操作指针的位置
     ///
     /// @param fd 文件描述符编号
@@ -1405,19 +1384,6 @@ impl Syscall {
         return Ok(0);
     }
 
-    pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> {
-        // IoVecs会进行用户态检验
-        let iovecs = unsafe { IoVecs::from_user(iov as *const IoVec, count, true) }?;
-
-        let mut data = vec![0; iovecs.total_len()];
-
-        let len = Self::read(fd, &mut data)?;
-
-        iovecs.scatter(&data[..len]);
-
-        return Ok(len);
-    }
-
     pub fn readlink_at(
         dirfd: i32,
         path: *const u8,

kernel/src/filesystem/vfs/syscall/sys_read.rs

@@ -0,0 +1,105 @@
+use system_error::SystemError;
+
+use crate::arch::syscall::nr::SYS_READ;
+use crate::process::ProcessManager;
+use crate::syscall::table::FormattedSyscallParam;
+use crate::syscall::table::Syscall;
+use crate::syscall::user_access::UserBufferWriter;
+
+use alloc::string::ToString;
+use alloc::vec::Vec;
+
+/// System call handler for the `read` syscall
+///
+/// This handler implements the `Syscall` trait to provide functionality for reading data from a file descriptor.
+pub struct SysReadHandle;
+
+impl Syscall for SysReadHandle {
+    /// Returns the number of arguments expected by the `read` syscall
+    fn num_args(&self) -> usize {
+        3
+    }
+
+    /// Handles the `read` system call
+    ///
+    /// Reads data from the specified file descriptor into a user buffer.
+    ///
+    /// # Arguments
+    /// * `args` - Array containing:
+    ///   - args[0]: File descriptor (i32)
+    ///   - args[1]: Pointer to user buffer (*mut u8)
+    ///   - args[2]: Length of data to read (usize)
+    /// * `from_user` - Indicates if the call originates from user space
+    ///
+    /// # Returns
+    /// * `Ok(usize)` - Number of bytes successfully read
+    /// * `Err(SystemError)` - Error code if operation fails
+    fn handle(&self, args: &[usize], from_user: bool) -> Result<usize, SystemError> {
+        let fd = Self::fd(args);
+        let buf_vaddr = Self::buf(args);
+        let len = Self::len(args);
+
+        let mut user_buffer_writer = UserBufferWriter::new(buf_vaddr, len, from_user)?;
+
+        let user_buf = user_buffer_writer.buffer(0)?;
+        do_read(fd, user_buf)
+    }
+
+    /// Formats the syscall parameters for display/debug purposes
+    ///
+    /// # Arguments
+    /// * `args` - The raw syscall arguments
+    ///
+    /// # Returns
+    /// Vector of formatted parameters with descriptive names
+    fn entry_format(&self, args: &[usize]) -> Vec<FormattedSyscallParam> {
+        vec![
+            FormattedSyscallParam::new("fd", Self::fd(args).to_string()),
+            FormattedSyscallParam::new("buf", format!("{:#x}", Self::buf(args) as usize)),
+            FormattedSyscallParam::new("len", Self::len(args).to_string()),
+        ]
+    }
+}
+
+impl SysReadHandle {
+    /// Extracts the file descriptor from syscall arguments
+    fn fd(args: &[usize]) -> i32 {
+        args[0] as i32
+    }
+
+    /// Extracts the buffer pointer from syscall arguments
+    fn buf(args: &[usize]) -> *mut u8 {
+        args[1] as *mut u8
+    }
+
+    /// Extracts the buffer length from syscall arguments
+    fn len(args: &[usize]) -> usize {
+        args[2]
+    }
+}
+
+syscall_table_macros::declare_syscall!(SYS_READ, SysReadHandle);
+
+/// Internal implementation of the read operation
+///
+/// # Arguments
+/// * `fd` - File descriptor to read from
+/// * `buf` - Buffer to store read data
+///
+/// # Returns
+/// * `Ok(usize)` - Number of bytes successfully read
+/// * `Err(SystemError)` - Error code if operation fails
+pub(super) fn do_read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> {
+    let binding = ProcessManager::current_pcb().fd_table();
+    let fd_table_guard = binding.read();
+
+    let file = fd_table_guard.get_file_by_fd(fd);
+    if file.is_none() {
+        return Err(SystemError::EBADF);
+    }
+    // drop guard 以避免无法调度的问题
+    drop(fd_table_guard);
+    let file = file.unwrap();
+
+    return file.read(buf.len(), buf);
+}

kernel/src/filesystem/vfs/syscall/sys_readv.rs

@@ -0,0 +1,65 @@
+use system_error::SystemError;
+
+use crate::arch::syscall::nr::SYS_READV;
+use crate::filesystem::vfs::iov::IoVec;
+use crate::filesystem::vfs::iov::IoVecs;
+use crate::syscall::table::FormattedSyscallParam;
+use crate::syscall::table::Syscall;
+
+use alloc::string::ToString;
+use alloc::vec::Vec;
+
+use super::sys_read::do_read;
+
+/// System call handler for `readv` operation
+///
+/// The `readv` system call reads data into multiple buffers from a file descriptor.
+/// It is equivalent to multiple `read` calls but is more efficient.
+pub struct SysReadVHandle;
+
+impl Syscall for SysReadVHandle {
+    fn num_args(&self) -> usize {
+        3
+    }
+
+    fn handle(&self, args: &[usize], _from_user: bool) -> Result<usize, SystemError> {
+        let fd = Self::fd(args);
+        let iov = Self::iov(args);
+        let count = Self::count(args);
+
+        // IoVecs会进行用户态检验
+        let iovecs = unsafe { IoVecs::from_user(iov, count, true) }?;
+
+        let mut data = vec![0; iovecs.total_len()];
+
+        let len = do_read(fd, &mut data)?;
+
+        iovecs.scatter(&data[..len]);
+
+        return Ok(len);
+    }
+
+    fn entry_format(&self, args: &[usize]) -> Vec<FormattedSyscallParam> {
+        vec![
+            FormattedSyscallParam::new("fd", Self::fd(args).to_string()),
+            FormattedSyscallParam::new("iov", format!("{:#x}", Self::iov(args) as usize)),
+            FormattedSyscallParam::new("count", Self::count(args).to_string()),
+        ]
+    }
+}
+
+impl SysReadVHandle {
+    fn fd(args: &[usize]) -> i32 {
+        args[0] as i32
+    }
+
+    fn iov(args: &[usize]) -> *const IoVec {
+        args[1] as *const IoVec
+    }
+
+    fn count(args: &[usize]) -> usize {
+        args[2]
+    }
+}
+
+syscall_table_macros::declare_syscall!(SYS_READV, SysReadVHandle);

kernel/src/filesystem/vfs/syscall/sys_write.rs

@@ -37,7 +37,7 @@ impl Syscall for SysWriteHandle {
     fn handle(&self, args: &[usize], from_user: bool) -> Result<usize, SystemError> {
         let fd = Self::fd(args);
         let buf_vaddr = Self::buf(args);
-        let len = Self::count(args);
+        let len = Self::len(args);
 
         let user_buffer_reader = UserBufferReader::new(buf_vaddr, len, from_user)?;
 
@@ -57,7 +57,7 @@ impl Syscall for SysWriteHandle {
         vec![
             FormattedSyscallParam::new("fd", Self::fd(args).to_string()),
             FormattedSyscallParam::new("buf", format!("{:#x}", Self::buf(args) as usize)),
-            FormattedSyscallParam::new("count", Self::count(args).to_string()),
+            FormattedSyscallParam::new("len", Self::len(args).to_string()),
         ]
     }
 }
@@ -74,7 +74,7 @@ impl SysWriteHandle {
     }
 
     /// Extracts the buffer length from syscall arguments
-    fn count(args: &[usize]) -> usize {
+    fn len(args: &[usize]) -> usize {
         args[2]
     }
 }

kernel/src/syscall/mod.rs

@@ -169,17 +169,6 @@ impl Syscall {
                 let fd = args[0];
                 Self::close(fd)
             }
-            SYS_READ => {
-                let fd = args[0] as i32;
-                let buf_vaddr = args[1];
-                let len = args[2];
-                let from_user = frame.is_from_user();
-                let mut user_buffer_writer =
-                    UserBufferWriter::new(buf_vaddr as *mut u8, len, from_user)?;
-
-                let user_buf = user_buffer_writer.buffer(0)?;
-                Self::read(fd, user_buf)
-            }
 
             SYS_LSEEK => {
                 let fd = args[0] as i32;
@@ -784,8 +773,6 @@ impl Syscall {
                 return ret;
             }
 
-            SYS_READV => Self::readv(args[0] as i32, args[1], args[2]),
-
             SYS_SET_TID_ADDRESS => Self::set_tid_address(args[0]),
 
             #[cfg(target_arch = "x86_64")]