VFS+Ext2: many simplifications and filesystem initialisation

ableos/src/filesystem/errors.rs

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: MPL-2.0
  */
 
+#[derive(Copy, Clone, Debug)]
 pub enum FsError {
     EndOfFile,
     InodeNotFound,

ableos/src/filesystem/ext2.rs

@@ -4,16 +4,17 @@
  * SPDX-License-Identifier: MPL-2.0
  */
 
-use alloc::sync::Weak;
+use alloc::sync::{Arc, Weak};
 use ext2::fs::{sync::Synced, Ext2};
 use ext2::sector::SectorSize;
 use ext2::sys::inode::TypePerm;
 use ext2::volume::Volume;
 
-use crate::handle::Handle;
+use crate::handle::{Handle, HandleResource};
 
 use super::errors::FsError;
-use super::{DirectoryEntry, FsFlags, FsNode, FsResult as Result, StorageDevice};
+use super::vfs::{add_fs_node, find_fs_node, DirectoryEntry, FsFlags};
+use super::{FsNode, FsResult as Result, StorageDevice};
 
 pub struct Ext2StorageDevice<S, V>
 where
@@ -22,6 +23,7 @@ where
 {
     fs: Synced<Ext2<S, V>>,
     device_handle: Handle,
+    root: Arc<FsNode>,
 }
 
 impl<S, V> Ext2StorageDevice<S, V>
@@ -29,10 +31,24 @@ where
     S: SectorSize,
     V: Volume<u8, S>,
 {
-    pub fn new(volume: V, device_handle: Handle) -> Result<Self> {
+    pub fn new(volume: V) -> Result<Self> {
-        Ok(Self {
+        let fs = Synced::new(volume).map_err(|e| e.into())?;
-            fs: Synced::new(volume).map_err(|e| e.into())?,
+        let root_inode = fs.root_inode();
+        let device_handle = Handle::new(HandleResource::StorageDevice);
+        let root = Arc::new(FsNode::new(
+            FsFlags::DIRECTORY,
+            root_inode.size(),
+            2,
             device_handle,
+            Weak::new(),
+        ));
+
+        add_fs_node(root.clone());
+
+        Ok(Self {
+            fs,
+            device_handle,
+            root,
         })
     }
 }
@@ -45,7 +61,7 @@ where
     fn read(&self, node: &FsNode, offset: usize, size: usize, buffer: &mut Vec<u8>) -> Result<()> {
         let inode = self
             .fs
-            .inode_nth(node.inode as usize)
+            .inode_nth(node.inode() as usize)
             .ok_or_else(|| FsError::InodeNotFound)?;
 
         // FIXME: I don't really know how Ext2 works, so for now we don't
@@ -66,21 +82,38 @@ where
     fn read_dir(&self, node: &FsNode, index: usize) -> Result<DirectoryEntry> {
         let inode = self
             .fs
-            .inode_nth(node.inode as usize)
+            .inode_nth(node.inode() as usize)
             .ok_or_else(|| FsError::InodeNotFound)?;
         let mut dir = inode.directory().ok_or_else(|| FsError::NotADirectory)?;
         let entry = dir
             .nth(index)
             .ok_or_else(|| FsError::InodeNotFound)?
             .map_err(|e| e.into())?;
+        let entry_inode = self
+            .fs
+            .inode_nth(entry.inode)
+            .ok_or_else(|| FsError::InodeNotFound)?;
+        let entry_node_handle =
+            find_fs_node(entry.inode, self.device_handle).unwrap_or_else(|| {
+                add_fs_node(Arc::new(FsNode::new(
+                    ext2_type_to_fs_flags(entry_inode.type_perm()),
+                    inode.size(),
+                    entry.inode,
+                    self.device_handle,
+                    Weak::new(),
+                )))
+            });
 
-        Ok(DirectoryEntry::new(entry.file_name_string(), entry.inode))
+        Ok(DirectoryEntry::new(
+            entry.file_name_string(),
+            entry_node_handle,
+        ))
     }
 
-    fn find_dir(&self, node: &FsNode, name: &str) -> Result<FsNode> {
+    fn find_dir(&self, node: &FsNode, name: &str) -> Result<Handle> {
         let inode = self
             .fs
-            .inode_nth(node.inode as usize)
+            .inode_nth(node.inode() as usize)
             .ok_or_else(|| FsError::InodeNotFound)?;
         let dir = inode.directory().ok_or_else(|| FsError::NotADirectory)?;
         let mut found_node = Err(FsError::NotFound);
@@ -91,23 +124,30 @@ where
 
             let entry = entry.unwrap();
             if entry.file_name_string() == name {
-                let inode = self
+                found_node = Ok(
-                    .fs
+                    find_fs_node(entry.inode, self.device_handle).unwrap_or_else(|| {
-                    .inode_nth(entry.inode as usize)
+                        add_fs_node(Arc::new(FsNode::new(
-                    .ok_or_else(|| FsError::InodeNotFound)?;
+                            ext2_type_to_fs_flags(inode.type_perm()),
-                let flags = ext2_type_to_fs_flags(inode.type_perm());
-                found_node = Ok(FsNode::new(
-                    flags,
                             inode.size(),
                             entry.inode,
                             self.device_handle,
                             Weak::new(),
-                ))
+                        )))
+                    }),
+                );
             }
         }
 
         found_node
     }
+
+    fn root_node(&self) -> Arc<FsNode> {
+        self.root.clone()
+    }
+
+    fn device_handle(&self) -> Handle {
+        self.device_handle
+    }
 }
 
 fn ext2_type_to_fs_flags(type_perm: TypePerm) -> FsFlags {
@@ -127,13 +167,6 @@ fn ext2_type_to_fs_flags(type_perm: TypePerm) -> FsFlags {
     t | s
 }
 
-// fn load_fs() -> Arc<Mutex<Ext2<Size1024, Vec<u8>>>> {
-//     let mut volume = Vec::new();
-//     volume.extend_from_slice(include_bytes!("../../../userland/root_fs/ext2.img"));
-
-//     Arc::<Ext2<Size1024, _>>::new(volume).unwrap()
-// }
-
 // pub fn walk<S: SectorSize, V: Volume<u8, S>>(
 //     fs: &Synced<Ext2<S, V>>,
 //     inode: Inode<S, V>,

ableos/src/filesystem/mod.rs

@@ -6,15 +6,18 @@
 
 pub mod errors;
 pub mod ext2;
+pub mod vfs;
 
-use core::cmp;
+use ::ext2::sector::Size1024;
-
+use alloc::sync::Arc;
-use alloc::sync::{Arc, Weak};
-use bitflags::bitflags;
 
 use crate::{handle::Handle, KERNEL_STATE};
 
-use self::errors::FsError;
+use self::{
+    errors::FsError,
+    ext2::Ext2StorageDevice,
+    vfs::{DirectoryEntry, FsNode},
+};
 use FsResult as Result;
 
 pub type FsResult<T> = core::result::Result<T, FsError>;
@@ -27,138 +30,22 @@ where
     fn read(&self, node: &FsNode, offset: usize, size: usize, buffer: &mut Vec<u8>) -> Result<()>;
     fn write(&self, node: &FsNode, offset: usize, buffer: &[u8]) -> Result<()>;
     fn read_dir(&self, node: &FsNode, index: usize) -> Result<DirectoryEntry>;
-    fn find_dir(&self, node: &FsNode, name: &str) -> Result<FsNode>;
+    fn find_dir(&self, node: &FsNode, name: &str) -> Result<Handle>;
     // TODO: flush to disk
+
+    fn root_node(&self) -> Arc<FsNode>;
+    fn device_handle(&self) -> Handle;
 }
 
-/// A VFS node, that can either be a file or a directory.
+pub fn init() -> Result<()> {
-///
-/// VFS nodes are created whenever a file that doesn't have an open VFS node is
-/// opened. When there are no open file descriptors to a file, the associated
-/// VFS node is dropped.
-#[derive(Debug)]
-pub struct FsNode {
-    flags: FsFlags,
-    length: usize,         // in bytes
-    inode: usize,          // implementation specific identifier for the node
-    device_handle: Handle, // uniquely assigned device handle
-    ptr: Weak<FsNode>,     // used by mountpoints and symlinks
-                           // TODO: permissions mask
-                           // TODO: owning user/group
-}
-
-impl FsNode {
-    pub fn new(
-        flags: FsFlags,
-        length: usize,
-        inode: usize,
-        device_handle: Handle,
-        ptr: Weak<FsNode>,
-    ) -> Self {
-        Self {
-            flags,
-            length,
-            inode,
-            device_handle,
-            ptr,
-        }
-    }
-
-    /// This method opens a new file descriptor for this VFS node.
-    // TODO: make this take flags
-    pub fn open(self: Arc<Self>) -> Result<Handle> {
     let mut state = KERNEL_STATE.lock();
-        let handle = state.open_file_descriptor(self);
+    state.add_storage_device(load_fs()?);
-
+    Ok(())
-        Ok(handle)
 }
 
-    /// This method reads from the VFS node without opening a new file
+fn load_fs() -> Result<Ext2StorageDevice<Size1024, Vec<u8>>> {
-    /// descriptor. This is intended to be used internally, if you're trying to
+    let mut volume = Vec::new();
-    /// read a file then you probably want to read from a file descriptor.
+    volume.extend_from_slice(include_bytes!("../../../userland/root_fs/ext2.img"));
-    pub fn read(&self, offset: usize, size: usize, buffer: &mut Vec<u8>) -> Result<usize> {
-        let state = KERNEL_STATE.lock();
-        let device = state
-            .get_storage_device(self.device_handle)
-            .ok_or_else(|| FsError::InvalidDevice)?;
 
-        if self.is_dir() {
+    Ext2StorageDevice::new(volume)
-            Err(FsError::IsDirectory)?;
-        }
-
-        if offset > self.length {
-            Err(FsError::EndOfFile)?;
-        }
-
-        let readable_size = cmp::min(size, self.length - offset);
-        device.read(self, offset, readable_size, buffer)?;
-        Ok(readable_size)
-    }
-
-    /// This method writes to the VFS node without opening a new file
-    /// descriptor. This is intended to be used internally, if you're trying to
-    /// write to a file then you probably want to write to a file descriptor.
-    pub fn write(&self, offset: usize, buffer: &[u8]) -> Result<()> {
-        let state = KERNEL_STATE.lock();
-        let device = state
-            .get_storage_device(self.device_handle)
-            .ok_or_else(|| FsError::InvalidDevice)?;
-
-        device.write(self, offset, buffer)
-    }
-
-    pub fn read_dir(&self, index: usize) -> Result<DirectoryEntry> {
-        let state = KERNEL_STATE.lock();
-        let device = state
-            .get_storage_device(self.device_handle)
-            .ok_or_else(|| FsError::InvalidDevice)?;
-
-        device.read_dir(self, index)
-    }
-
-    pub fn find_dir(&self, name: &str) -> Result<FsNode> {
-        let state = KERNEL_STATE.lock();
-        let device = state
-            .get_storage_device(self.device_handle)
-            .ok_or_else(|| FsError::InvalidDevice)?;
-
-        device.find_dir(self, name)
-    }
-
-    pub fn is_dir(&self) -> bool {
-        (self.flags & FsFlags::DIRECTORY) == FsFlags::DIRECTORY
-    }
-}
-
-impl Drop for FsNode {
-    fn drop(&mut self) {
-        trace!("dropping VFS node: {self:#?}");
-        // TODO: flush to disk here
-    }
-}
-
-bitflags! {
-    /// Flags associated with VFS nodes and file descriptors
-    ///
-    /// 0x00000MST \
-    /// T is set to 0 for files, 1 for directories \
-    /// S is set when the file is a symbolic link \
-    /// M is set if the file is an active mount point
-    pub struct FsFlags: u8 {
-        const FILE = 0b00000000;
-        const DIRECTORY = 0b00000001;
-        const SYMBOLIC_LINK = 0b00000010;
-        const MOUNT_POINT = 0b00000100;
-    }
-}
-
-pub struct DirectoryEntry {
-    name: String,
-    inode: usize,
-}
-
-impl DirectoryEntry {
-    fn new(name: String, inode: usize) -> Self {
-        Self { name, inode }
-    }
 }

ableos/src/handle.rs

@@ -23,6 +23,7 @@ pub enum HandleResource {
     BinaryData,
     StorageDevice,
     FileDescriptor,
+    FsNode,
 }
 
 #[derive(Debug, Eq, Hash, PartialEq, Clone, Copy)]
@@ -40,6 +41,7 @@ impl Display for Handle {
             HandleResource::Socket => write!(f, "-Socket")?,
             HandleResource::StorageDevice => write!(f, "-StorageDevice")?,
             HandleResource::FileDescriptor => write!(f, "-FileDescriptor")?,
+            HandleResource::FsNode => write!(f, "-FsNode")?,
         }
 
         Ok(())

ableos/src/kernel_state.rs

@@ -1,9 +1,15 @@
+/*
+ * Copyright (c) 2022, Umut İnan Erdoğan <umutinanerdogan@pm.me>
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
 use alloc::sync::Arc;
 use hashbrown::HashMap;
 use spin::Lazy;
 
 use crate::{
-    filesystem::{FsNode, StorageDevice},
+    filesystem::{vfs::FsNode, StorageDevice},
     handle::{Handle, HandleResource},
 };
 
@@ -32,13 +38,12 @@ impl KernelInternalState {
         self.hostname = hostname;
     }
 
-    pub fn add_storage_device(&mut self, device: impl StorageDevice + Send + 'static) -> Handle {
+    pub fn add_storage_device(&mut self, device: impl StorageDevice + Send + 'static) {
-        let handle = Handle::new(HandleResource::StorageDevice);
+        let device = Box::new(device);
-        self.storage_devices.insert(handle, Box::new(device));
+        self.storage_devices.insert(device.device_handle(), device);
-        handle
     }
 
-    pub fn get_storage_device(&self, handle: Handle) -> Option<&dyn StorageDevice> {
+    pub fn storage_device(&self, handle: Handle) -> Option<&dyn StorageDevice> {
         self.storage_devices.get(&handle).map(|d| &**d)
     }
 
@@ -49,7 +54,7 @@ impl KernelInternalState {
         handle
     }
 
-    pub fn get_file_descriptor(&self, handle: Handle) -> Option<&FileTableEntry> {
+    pub fn file_descriptor(&self, handle: Handle) -> Option<&FileTableEntry> {
         self.file_table.get(&handle)
     }
 
@@ -83,4 +88,8 @@ impl FileTableEntry {
     fn new(fs_node: Arc<FsNode>) -> Self {
         Self { fs_node }
     }
+
+    pub fn fs_node(&self) -> Arc<FsNode> {
+        self.fs_node.clone()
+    }
 }

ableos/src/kmain.rs

@@ -1,13 +1,19 @@
+/*
+ * Copyright (c) 2022, Umut İnan Erdoğan <umutinanerdogan@pm.me>
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
 #![allow(clippy::empty_loop)]
 
 use core::sync::atomic::AtomicU64;
 
 use crate::arch::{drivers::sysinfo::master, init, sloop};
-use crate::hardware;
 use crate::relib::network::socket::{SimpleSock, Socket};
 use crate::{
     boot_conf::KernelConfig, scratchpad, systeminfo::RELEASE_TYPE, TERM,
 };
+use crate::{filesystem, hardware};
 use kernel::KERNEL_VERSION;
 use spin::Lazy;
 
@@ -36,6 +42,9 @@ pub fn kernel_main() -> ! {
     x86_64::instructions::interrupts::without_interrupts(|| {
         hardware::init_mouse();
     });
+
+    filesystem::init().unwrap();
+
     /*
 
     // println!("abc");

ableos/src/lib.rs

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2022, Able <able@ablecorp.us>
+ * Copyright (c) 2022, Umut İnan Erdoğan <umutinanerdogan@pm.me>
  *
  * SPDX-License-Identifier: MPL-2.0
  */
@@ -25,6 +26,9 @@
 #[macro_use]
 pub extern crate log;
 
+#[macro_use]
+pub extern crate bitflags;
+
 pub extern crate alloc;
 pub extern crate externc_libm as libm;
 

ext2-rs/src/fs/sync.rs

@@ -393,8 +393,6 @@ impl<S: SectorSize, V: Volume<u8, S>> Inode<S, V> {
     }
     /// Determine if an inode is a directory
     pub fn is_dir(&self) -> bool {
-        use sys::inode::TypePerm;
-
         { self.inner.type_perm }.contains(TypePerm::DIRECTORY)
         // self.inner.type_perm.contains(TypePerm::DIRECTORY)
     }