Implements VFile read (obhq#789)

SuchAFuriousDeath · Mar 31, 2024 · 01c1a5d · 01c1a5d
1 parent 807686a
commit 01c1a5d
Show file tree

Hide file tree

Showing 13 changed files with 193 additions and 126 deletions.
diff --git a/src/kernel/src/fs/dev/cdev.rs b/src/kernel/src/fs/dev/cdev.rs
@@ -116,7 +116,7 @@ impl FileBackend for CharacterDevice {
         file: &VFile,
         buf: &mut UioMut,
         td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         todo!()
     }
 
@@ -126,7 +126,7 @@ impl FileBackend for CharacterDevice {
         file: &VFile,
         buf: &mut Uio,
         td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         todo!()
     }
 

diff --git a/src/kernel/src/fs/dev/vnode.rs b/src/kernel/src/fs/dev/vnode.rs
@@ -172,7 +172,7 @@ impl crate::fs::VnodeBackend for VnodeBackend {
         #[allow(unused_variables)] vn: &Arc<Vnode>,
         #[allow(unused_variables)] buf: &mut UioMut,
         #[allow(unused_variables)] td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         todo!()
     }
 
@@ -181,7 +181,7 @@ impl crate::fs::VnodeBackend for VnodeBackend {
         #[allow(unused_variables)] vn: &Arc<Vnode>,
         #[allow(unused_variables)] buf: &mut Uio,
         #[allow(unused_variables)] td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         todo!()
     }
 }

diff --git a/src/kernel/src/fs/file.rs b/src/kernel/src/fs/file.rs
@@ -10,7 +10,7 @@ use crate::shm::SharedMemory;
 use bitflags::bitflags;
 use macros::Errno;
 use std::fmt::Debug;
-use std::io::{Read, Seek, SeekFrom, Write};
+use std::io::{ErrorKind, Read, Seek, SeekFrom};
 use std::sync::Arc;
 use thiserror::Error;
 
@@ -62,13 +62,7 @@ impl VFile {
 
         // TODO: consider implementing ktrace.
 
-        let res = self.read(&mut uio, td);
-
-        if let Err(ref e) = res {
-            todo!()
-        }
-
-        res
+        todo!()
     }
 
     /// See `dofilewrite` on the PS4 for a reference.
@@ -81,16 +75,10 @@ impl VFile {
         // TODO: consider implementing ktrace.
         // TODO: implement bwillwrite.
 
-        let res = self.write(&mut uio, td);
-
-        if let Err(ref e) = res {
-            todo!()
-        }
-
-        res
+        todo!()
     }
 
-    fn read(&self, buf: &mut UioMut, td: Option<&VThread>) -> Result<usize, Box<dyn Errno>> {
+    fn read(&self, buf: &mut UioMut, td: Option<&VThread>) -> Result<(), Box<dyn Errno>> {
         match &self.ty {
             VFileType::Vnode(vn) => FileBackend::read(vn, self, buf, td),
             VFileType::Socket(so) | VFileType::IpcSocket(so) => so.read(self, buf, td),
@@ -101,7 +89,7 @@ impl VFile {
         }
     }
 
-    fn write(&self, buf: &mut Uio, td: Option<&VThread>) -> Result<usize, Box<dyn Errno>> {
+    fn write(&self, buf: &mut Uio, td: Option<&VThread>) -> Result<(), Box<dyn Errno>> {
         match &self.ty {
             VFileType::Vnode(vn) => FileBackend::write(vn, self, buf, td),
             VFileType::Socket(so) | VFileType::IpcSocket(so) => so.write(self, buf, td),
@@ -152,9 +140,27 @@ impl VFile {
 }
 
 impl Seek for VFile {
-    #[allow(unused_variables)] // TODO: Remove when implementing.
-    fn seek(&mut self, _pos: SeekFrom) -> std::io::Result<u64> {
-        todo!()
+    fn seek(&mut self, pos: SeekFrom) -> std::io::Result<u64> {
+        self.seekable_vnode().ok_or(ErrorKind::Other)?;
+
+        // Negative seeks should not be allowed here
+        let offset: u64 = match pos {
+            SeekFrom::Start(offset) => offset,
+            SeekFrom::Current(_) => {
+                todo!()
+            }
+            SeekFrom::End(_) => {
+                todo!()
+            }
+        };
+
+        self.offset = if let Ok(offset) = offset.try_into() {
+            offset
+        } else {
+            todo!()
+        };
+
+        Ok(offset as u64)
     }
 
     fn rewind(&mut self) -> std::io::Result<()> {
@@ -174,14 +180,20 @@ impl Seek for VFile {
 
 impl Read for VFile {
     fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        let total = buf.len();
+
         let ref mut iovec = IoVec::from_slice(buf);
 
-        let mut uio = UioMut::from_single_vec(iovec);
+        let mut uio = UioMut::from_single_vec(iovec, self.offset);
+
+        if let Err(e) = VFile::read(self, &mut uio, None) {
+            println!("Error: {:?}", e);
 
-        let Ok(read) = VFile::read(self, &mut uio, None) else {
             todo!()
         };
 
+        let read = total - uio.bytes_left;
+
         if let Ok(read) = TryInto::<i64>::try_into(read) {
             self.offset += read;
         } else {
@@ -192,17 +204,6 @@ impl Read for VFile {
     }
 }
 
-impl Write for VFile {
-    #[allow(unused_variables)] // TODO: Remove when implementing.
-    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
-        todo!()
-    }
-
-    fn flush(&mut self) -> std::io::Result<()> {
-        todo!()
-    }
-}
-
 /// Type of [`VFile`].
 #[derive(Debug)]
 pub enum VFileType {
@@ -233,7 +234,7 @@ pub trait FileBackend: Debug + Send + Sync + 'static {
         file: &VFile,
         buf: &mut UioMut,
         td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         Err(Box::new(DefaultFileBackendError::ReadNotSupported))
     }
 
@@ -244,7 +245,7 @@ pub trait FileBackend: Debug + Send + Sync + 'static {
         file: &VFile,
         buf: &mut Uio,
         td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         Err(Box::new(DefaultFileBackendError::WriteNotSupported))
     }
 

diff --git a/src/kernel/src/fs/host/file.rs b/src/kernel/src/fs/host/file.rs
@@ -209,7 +209,7 @@ impl HostFile {
         use std::ptr::null_mut;
         use windows_sys::Wdk::{
             Foundation::OBJECT_ATTRIBUTES,
-            Storage::FileSystem::{NtCreateFile, FILE_CREATE, FILE_DIRECTORY_FILE},
+            Storage::FileSystem::{NtCreateFile, FILE_DIRECTORY_FILE, FILE_OPEN},
         };
         use windows_sys::Win32::{
             Foundation::{RtlNtStatusToDosError, STATUS_SUCCESS, UNICODE_STRING},
@@ -256,7 +256,7 @@ impl HostFile {
                 null_mut(),
                 FILE_ATTRIBUTE_DIRECTORY,
                 FILE_SHARE_READ | FILE_SHARE_WRITE,
-                FILE_CREATE,
+                FILE_OPEN,
                 FILE_DIRECTORY_FILE,
                 null_mut(),
                 0,
@@ -274,13 +274,89 @@ impl HostFile {
     }
 
     #[cfg(unix)]
-    pub(super) fn read(&self, buf: &mut UioMut) -> Result<usize, Error> {
-        todo!()
+    pub(super) fn read(&self, buf: &mut UioMut) -> Result<(), Error> {
+        use libc::pread;
+
+        buf.write_with::<Error>(|iov, mut offset| {
+            let nbytes = if let Ok(nbytes) = iov.len().try_into() {
+                nbytes
+            } else {
+                todo!()
+            };
+
+            let nread = unsafe { pread(self.raw, iov.ptr().cast(), nbytes, offset) };
+
+            match nread {
+                0.. if nread == nbytes as isize => Ok(nread as u64),
+                0.. => todo!(),
+                _ => todo!(),
+            }
+        })?;
+
+        Ok(())
     }
 
     #[cfg(windows)]
-    pub(super) fn read(&self, buf: &mut UioMut) -> Result<usize, Error> {
-        todo!()
+    pub(super) fn read(&self, buf: &mut UioMut) -> Result<(), Error> {
+        use std::ptr::null_mut;
+        use windows_sys::{
+            Wdk::Storage::FileSystem::NtReadFile,
+            Win32::{
+                Foundation::{STATUS_END_OF_FILE, STATUS_PENDING},
+                System::{
+                    Threading::{WaitForSingleObject, INFINITE},
+                    IO::{IO_STATUS_BLOCK, IO_STATUS_BLOCK_0},
+                },
+            },
+        };
+
+        buf.write_with::<Error>(|iov, mut offset| {
+            let nbytes = if let Ok(nbytes) = iov.len().try_into() {
+                nbytes
+            } else {
+                todo!()
+            };
+
+            let mut io_status = IO_STATUS_BLOCK {
+                Anonymous: IO_STATUS_BLOCK_0 {
+                    Status: STATUS_PENDING,
+                },
+                Information: 0,
+            };
+
+            let status = unsafe {
+                NtReadFile(
+                    self.raw,
+                    0,
+                    None,
+                    null_mut(),
+                    &mut io_status,
+                    iov.ptr().cast(),
+                    nbytes,
+                    &mut offset,
+                    null_mut(),
+                )
+            };
+
+            let status = if status == STATUS_PENDING {
+                unsafe {
+                    WaitForSingleObject(self.raw, INFINITE);
+                    io_status.Anonymous.Status
+                }
+            } else {
+                status
+            };
+
+            match status {
+                STATUS_PENDING => todo!(),
+                STATUS_END_OF_FILE => todo!(),
+                0.. if io_status.Information == nbytes as usize => Ok(io_status.Information as u64),
+                0.. => todo!(),
+                _ => todo!(),
+            }
+        })?;
+
+        Ok(())
     }
 
     #[cfg(unix)]

diff --git a/src/kernel/src/fs/host/vnode.rs b/src/kernel/src/fs/host/vnode.rs
@@ -129,7 +129,7 @@ impl crate::fs::VnodeBackend for VnodeBackend {
         _: &Arc<Vnode>,
         buf: &mut UioMut,
         _: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         let read = self.file.read(buf).map_err(ReadError::ReadFailed)?;
 
         Ok(read)
@@ -140,7 +140,7 @@ impl crate::fs::VnodeBackend for VnodeBackend {
         #[allow(unused_variables)] vn: &Arc<Vnode>,
         #[allow(unused_variables)] buf: &mut Uio,
         #[allow(unused_variables)] td: Option<&VThread>,
-    ) -> Result<usize, Box<dyn Errno>> {
+    ) -> Result<(), Box<dyn Errno>> {
         todo!()
     }
 }