diff --git a/kernel/Cargo.lock b/kernel/Cargo.lock
index b4870cf0..f95c60c6 100644
--- a/kernel/Cargo.lock
+++ b/kernel/Cargo.lock
@@ -409,7 +409,7 @@ dependencies = [
 [[package]]
 name = "rcore-fs"
 version = "0.1.0"
-source = "git+https://github.com/rcore-os/rcore-fs#585eb6197aa687320618ee8c3c550a4e32aa9d15"
+source = "git+https://github.com/rcore-os/rcore-fs#ee0d0b31a1cea4c905100cef501a3bc522ded00d"
 dependencies = [
  "spin 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -417,7 +417,7 @@ dependencies = [
 [[package]]
 name = "rcore-fs-sfs"
 version = "0.1.0"
-source = "git+https://github.com/rcore-os/rcore-fs#585eb6197aa687320618ee8c3c550a4e32aa9d15"
+source = "git+https://github.com/rcore-os/rcore-fs#ee0d0b31a1cea4c905100cef501a3bc522ded00d"
 dependencies = [
  "bitvec 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/kernel/src/drivers/bus/pci.rs b/kernel/src/drivers/bus/pci.rs
index 48a254fa..c1226469 100644
--- a/kernel/src/drivers/bus/pci.rs
+++ b/kernel/src/drivers/bus/pci.rs
@@ -175,9 +175,7 @@ pub fn init_driver(dev: &PCIDevice) {
                 assert!(len as usize <= PAGE_SIZE);
                 let vaddr = phys_to_virt(addr as usize);
                 if let Some(driver) = ahci::init(irq, vaddr, len as usize) {
-                    PCI_DRIVERS
-                        .lock()
-                        .insert(dev.loc, driver);
+                    PCI_DRIVERS.lock().insert(dev.loc, driver);
                 }
             }
         }
diff --git a/kernel/src/fs/file.rs b/kernel/src/fs/file.rs
index 538b53c3..1f409a07 100644
--- a/kernel/src/fs/file.rs
+++ b/kernel/src/fs/file.rs
@@ -50,21 +50,23 @@ impl FileHandle {
             return Err(FsError::InvalidParam); // FIXME: => EBADF
         }
         let mut len: usize = 0;
-        /*
         if !self.options.nonblock {
             // block
             loop {
-                len = self.inode.read_at(offset, buf)?;
-                if len > 0 {
-                    break;
+                match self.inode.read_at(offset, buf) {
+                    Ok(read_len) => {
+                        len = read_len;
+                        break;
+                    }
+                    Err(FsError::Again) => {}
+                    Err(err) => {
+                        return Err(err);
+                    }
                 }
             }
         } else {
             len = self.inode.read_at(offset, buf)?;
         }
-        */
-        // TODO: handle block/nonblock correctly
-        len = self.inode.read_at(offset, buf)?;
         Ok(len)
     }
 
diff --git a/kernel/src/fs/file_like.rs b/kernel/src/fs/file_like.rs
index d489e01b..bd45dc8e 100644
--- a/kernel/src/fs/file_like.rs
+++ b/kernel/src/fs/file_like.rs
@@ -32,7 +32,7 @@ impl FileLike {
     }
     pub fn ioctl(&mut self, request: usize, arg1: usize, arg2: usize, arg3: usize) -> SysResult {
         match request {
-            // TODO: place flags & path in FileLike in stead of FileHandle/Socket
+            // TODO: place flags & path in FileLike instead of FileHandle/Socket
             FIOCLEX => Ok(0),
             FIONBIO => Ok(0),
             _ => {
diff --git a/kernel/src/fs/pseudo.rs b/kernel/src/fs/pseudo.rs
index fdcc5358..273a200e 100644
--- a/kernel/src/fs/pseudo.rs
+++ b/kernel/src/fs/pseudo.rs
@@ -72,6 +72,7 @@ impl INode for Pseudo {
             nlinks: 0,
             uid: 0,
             gid: 0,
+            rdev: 0,
         })
     }
     impl_inode!();
diff --git a/kernel/src/fs/stdio.rs b/kernel/src/fs/stdio.rs
index fae5dc74..a3f84a1d 100644
--- a/kernel/src/fs/stdio.rs
+++ b/kernel/src/fs/stdio.rs
@@ -95,7 +95,7 @@ impl INode for Stdin {
             buf[0] = self.pop() as u8;
             Ok(1)
         } else {
-            Ok(0)
+            Err(FsError::Again)
         }
     }
     fn write_at(&self, _offset: usize, _buf: &[u8]) -> Result<usize> {
diff --git a/kernel/src/fs/vga.rs b/kernel/src/fs/vga.rs
index b3faa6b2..3f34116f 100755
--- a/kernel/src/fs/vga.rs
+++ b/kernel/src/fs/vga.rs
@@ -64,6 +64,7 @@ impl INode for Vga {
             nlinks: 0,
             uid: 0,
             gid: 0,
+            rdev: 0,
         })
     }
     fn io_control(&self, cmd: u32, data: usize) -> Result<()> {
diff --git a/kernel/src/syscall/fs.rs b/kernel/src/syscall/fs.rs
index 5e3c46fd..27f8464f 100644
--- a/kernel/src/syscall/fs.rs
+++ b/kernel/src/syscall/fs.rs
@@ -948,6 +948,9 @@ impl From<FsError> for SysError {
             FsError::DirNotEmpty => SysError::ENOTEMPTY,
             FsError::WrongFs => SysError::EINVAL,
             FsError::DeviceError => SysError::EIO,
+            FsError::IOCTLError => SysError::EINVAL,
+            FsError::NoDevice => SysError::EINVAL,
+            FsError::Again => SysError::EAGAIN,
         }
     }
 }
diff --git a/user b/user
index bf02e72b..4f90dd04 160000
--- a/user
+++ b/user
@@ -1 +1 @@
-Subproject commit bf02e72b85784af3555c7abe6b985aefc215023e
+Subproject commit 4f90dd042bacdb7eee61ae35ab60b9e17bc70cf7