vfs: documentation and a few minor changes

ableos/src/filesystem/errors.rs

@@ -5,8 +5,9 @@
  */
 
 pub enum FsError {
-    UnsupportedOperation,
+    InodeNotFound,
     InvalidDevice,
+    UnsupportedOperation,
 }
 
 impl Into<FsError> for ext2::error::Error {
@@ -15,9 +16,16 @@ impl Into<FsError> for ext2::error::Error {
             ext2::error::Error::Other(_) => todo!(),
             ext2::error::Error::BadMagic { magic: _ } => todo!(),
             ext2::error::Error::OutOfBounds { index: _ } => todo!(),
-            ext2::error::Error::AddressOutOfBounds { sector: _, offset: _, size: _ } => todo!(),
+            ext2::error::Error::AddressOutOfBounds {
-            ext2::error::Error::BadBlockGroupCount { by_blocks: _, by_inodes: _ } => todo!(),
+                sector: _,
-            ext2::error::Error::InodeNotFound { inode: _ } => todo!(),
+                offset: _,
+                size: _,
+            } => todo!(),
+            ext2::error::Error::BadBlockGroupCount {
+                by_blocks: _,
+                by_inodes: _,
+            } => todo!(),
+            ext2::error::Error::InodeNotFound { inode: _ } => FsError::InodeNotFound,
             ext2::error::Error::NotADirectory { inode: _, name: _ } => todo!(),
             ext2::error::Error::NotAbsolute { name: _ } => todo!(),
             ext2::error::Error::NotFound { name: _ } => todo!(),

ableos/src/filesystem/ext2.rs

@@ -4,10 +4,11 @@
  * SPDX-License-Identifier: MPL-2.0
  */
 
-use ext2::fs::Ext2;
+use ext2::fs::{sync::Synced, Ext2};
 use ext2::sector::SectorSize;
 use ext2::volume::Volume;
 
+use super::errors::FsError;
 use super::{FsResult as Result, StorageDevice};
 
 pub struct Ext2StorageDevice<S, V>
@@ -15,7 +16,7 @@ where
     S: SectorSize,
     V: Volume<u8, S>,
 {
-    fs: Ext2<S, V>,
+    fs: Synced<Ext2<S, V>>,
 }
 
 impl<S, V> Ext2StorageDevice<S, V>
@@ -25,7 +26,7 @@ where
 {
     pub fn new(volume: V) -> Result<Self> {
         Ok(Self {
-            fs: Ext2::new(volume).map_err(|e| e.into())?,
+            fs: Synced::new(volume).map_err(|e| e.into())?,
         })
     }
 }
@@ -36,6 +37,11 @@ where
     V: Volume<u8, S> + Send,
 {
     fn open(&self, node: &super::FsNode /* TODO: flags */) -> Result<crate::handle::Handle> {
+        let inode = self
+            .fs
+            .inode_nth(node.inode as usize)
+            .ok_or_else(|| FsError::InodeNotFound)?;
+
         todo!()
     }
 

ableos/src/filesystem/mod.rs

@@ -30,14 +30,19 @@ where
 }
 
 /// A VFS node, that can either be a file or a directory.
+///
+/// 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.
 pub struct FsNode {
     flags: FsNodeFlags,
-    length: u32, // in bytes
+    length: u32,           // in bytes
-    inode: u32, // implementation specific identifier for the node
+    fd_count: u32,         // count of open file descriptors
+    inode: u32,            // implementation specific identifier for the node
     device_handle: Handle, // uniquely assigned device handle
-    ptr: Weak<FsNode>, // used by mountpoints and symlinks
+    ptr: Weak<FsNode>,     // used by mountpoints and symlinks
-    // todo: permissions mask
+                           // todo: permissions mask
-    // todo: owning user/group
+                           // todo: owning user/group
 }
 
 impl FsNode {
@@ -51,12 +56,14 @@ impl FsNode {
         Self {
             flags,
             length,
+            fd_count: 0,
             inode,
             device_handle,
             ptr,
         }
     }
 
+    /// This method opens a new file descriptor for this VFS node.
     // TODO: make this take flags
     pub fn open(&self) -> Result<Handle> {
         let state = KERNEL_STATE.lock();
@@ -67,6 +74,8 @@ impl FsNode {
         device.open(self)
     }
 
+    /// This method is for closing the VFS node, which is done when no open file
+    /// descriptors for this file are left.
     pub fn close(&self) -> Result<()> {
         let state = KERNEL_STATE.lock();
         let device = state
@@ -76,6 +85,9 @@ impl FsNode {
         device.close(self)
     }
 
+    /// This method reads from the VFS node without opening a new file
+    /// descriptor. This is intended to be used internally, if you're trying to
+    /// read a file then you probably want to read from a file descriptor.
     pub fn read(&self, offset: u32, size: u32) -> Result<Box<[u8]>> {
         let state = KERNEL_STATE.lock();
         let device = state
@@ -85,6 +97,9 @@ impl FsNode {
         device.read(self, offset, 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: u32, buffer: Box<[u8]>) -> Result<()> {
         let state = KERNEL_STATE.lock();
         let device = state
@@ -115,7 +130,7 @@ impl FsNode {
 
 bitflags! {
     /// Flags associated with VFS nodes.
-    /// 
+    ///
     /// 0x00000MST
     /// T is set to 0 for files, 1 for directories
     /// S is set when the node is a symbolic link
@@ -128,6 +143,9 @@ bitflags! {
     }
 }
 
+/// A file descriptor.
+pub struct FileDescriptor {}
+
 pub struct DirectoryEntry {
     name: String,
     inode: u32,

ableos/src/kernel_state.rs

@@ -1,7 +1,10 @@
 use hashbrown::HashMap;
 use spin::Lazy;
 
-use crate::{handle::{Handle, HandleResource}, filesystem::StorageDevice};
+use crate::{
+    filesystem::StorageDevice,
+    handle::{Handle, HandleResource},
+};
 
 pub static KERNEL_STATE: Lazy<spin::Mutex<KernelInternalState>> =
     Lazy::new(|| spin::Mutex::new(KernelInternalState::new()));
@@ -26,7 +29,8 @@ impl KernelInternalState {
     }
 
     pub fn add_storage_device(&mut self, device: impl StorageDevice + Send + 'static) {
-        self.storage_devices.insert(Handle::new(HandleResource::StorageDevice), Box::new(device));
+        self.storage_devices
+            .insert(Handle::new(HandleResource::StorageDevice), Box::new(device));
     }
 
     pub fn get_storage_device(&self, handle: Handle) -> Option<&dyn StorageDevice> {

ableos/src/scratchpad.rs

@@ -11,7 +11,9 @@ use crate::systeminfo::{KERNEL_VERSION, RELEASE_TYPE};
 use crate::time::fetch_time;
 use crate::KERNEL_STATE;
 use crate::{
-    arch::shutdown, rhai_shell::KEYBUFF, vterm::Term,
+    arch::shutdown,
+    rhai_shell::KEYBUFF,
+    vterm::Term,
     // wasm_jumploader::run_program,
 };
 
@@ -231,19 +233,12 @@ pub fn command_parser(user: String, command: String) {
         //     }
         // }
 
-<<<<<<< HEAD
+        // "echo" => match conf_args.1.arguments.get("p") {
-        "echo" => match conf_args.1.arguments.get("p") {
+        //     Some(path) => echo_file(path.to_string(), fs),
-            Some(path) => echo_file(path.to_string(), fs),
 
-            None => println!("No path provided"),
+        //     None => println!("No path provided"),
-        },
-        "test" => {}
-=======
-        // "echo" => {
-        //     echo_file(iter.next().unwrap().to_string(), fs);
         // }
->>>>>>> 5149f26... vfs: move operations into trait StorageDevice, hold StorageDevices in KERNEL_STATE
+        "test" => {}
-
         "quit" => shutdown(),
 
         _ => {
@@ -263,23 +258,8 @@ pub fn command_parser(user: String, command: String) {
             //                 Ok(file) => file,
             //                 Err(error) => {
             //                     trace!("{:?}", error);
-                                println!("No such binary: {}", bin_name);
+            println!("No such binary: {}", bin_name);
-                                error!("No such binary: {}", bin_name);
+            error!("No such binary: {}", bin_name);
-                                return;
-<<<<<<< HEAD
-                            }
-                        }
-                    }
-                }
-            };
-
-            let mut binary = vec![];
-            file.read_to_end(&mut binary).unwrap();
-
-            // let args = iter.collect::<Vec<&str>>();
-            // println!("{:?}", args);
-            run_program(&binary);
-=======
             //                 }
             //             }
             //         }
@@ -292,7 +272,6 @@ pub fn command_parser(user: String, command: String) {
             // let args = iter.collect::<Vec<&str>>();
             // println!("{:?}", args);
             // run_program(&binary);
->>>>>>> 5149f26... vfs: move operations into trait StorageDevice, hold StorageDevices in KERNEL_STATE
         }
     }
 }