From a08191c7193293308348dc5c7e35932082bb330d Mon Sep 17 00:00:00 2001
From: LoGin <longjin@DragonOS.org>
Date: Wed, 1 Jan 2025 23:36:37 +0800
Subject: [PATCH] =?UTF-8?q?feat(fs/syscall):=20=E5=AE=9E=E7=8E=B0fchdir?=
 =?UTF-8?q?=E7=B3=BB=E7=BB=9F=E8=B0=83=E7=94=A8=20(#1081)?=
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Signed-off-by: longjin <longjin@DragonOS.org>
---
 kernel/src/filesystem/vfs/syscall.rs | 16 ++++++++++++++++
 kernel/src/syscall/mod.rs            |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/kernel/src/filesystem/vfs/syscall.rs b/kernel/src/filesystem/vfs/syscall.rs
index 795469bd4..f9ca9528f 100644
--- a/kernel/src/filesystem/vfs/syscall.rs
+++ b/kernel/src/filesystem/vfs/syscall.rs
@@ -740,6 +740,22 @@ impl Syscall {
         }
     }
 
+    pub fn fchdir(fd: i32) -> Result<usize, SystemError> {
+        let pcb = ProcessManager::current_pcb();
+        let file = pcb
+            .fd_table()
+            .read()
+            .get_file_by_fd(fd)
+            .ok_or(SystemError::EBADF)?;
+        let inode = file.inode();
+        if inode.metadata()?.file_type != FileType::Dir {
+            return Err(SystemError::ENOTDIR);
+        }
+        let path = inode.absolute_path()?;
+        pcb.basic_mut().set_cwd(path);
+        return Ok(0);
+    }
+
     /// @brief 获取当前进程的工作目录路径
     ///
     /// @param buf 指向缓冲区的指针
diff --git a/kernel/src/syscall/mod.rs b/kernel/src/syscall/mod.rs
index f9f7db29c..c904cd90f 100644
--- a/kernel/src/syscall/mod.rs
+++ b/kernel/src/syscall/mod.rs
@@ -238,6 +238,10 @@ impl Syscall {
                 let r = args[0] as *const u8;
                 Self::chdir(r)
             }
+            SYS_FCHDIR => {
+                let fd = args[0] as i32;
+                Self::fchdir(fd)
+            }
 
             #[allow(unreachable_patterns)]
             SYS_GETDENTS64 | SYS_GETDENTS => {