vfs+ext2: full implementation of FsNode::open()

This commit is contained in:
TheOddGarlic 2022-08-03 21:16:18 +03:00
parent aa3667714b
commit cdb6632f98
3 changed files with 66 additions and 35 deletions

View file

@ -9,7 +9,7 @@ use ext2::sector::SectorSize;
use ext2::volume::Volume;
use super::errors::FsError;
use super::{FsResult as Result, StorageDevice};
use super::{FsResult as Result, StorageDevice, DirectoryEntry, FsNode, FileDescriptor};
pub struct Ext2StorageDevice<S, V>
where
@ -36,32 +36,32 @@ where
S: SectorSize + Send,
V: Volume<u8, S> + Send,
{
fn open(&self, node: &super::FsNode /* TODO: flags */) -> Result<crate::handle::Handle> {
fn open(&self, node: &super::FsNode /* TODO: flags */) -> Result<FileDescriptor> {
let inode = self
.fs
.inode_nth(node.inode as usize)
.ok_or_else(|| FsError::InodeNotFound)?;
todo!()
Ok(FileDescriptor::new(node.flags, inode.size(), node.inode))
}
fn close(&self, node: &super::FsNode) -> Result<()> {
todo!()
}
fn read(&self, node: &super::FsNode, offset: u32, size: u32) -> Result<Box<[u8]>> {
fn read(&self, node: &super::FsNode, offset: usize, size: usize) -> Result<Box<[u8]>> {
todo!()
}
fn write(&self, node: &super::FsNode, offset: u32, buffer: Box<[u8]>) -> Result<()> {
fn write(&self, node: &super::FsNode, offset: usize, buffer: Box<[u8]>) -> Result<()> {
todo!()
}
fn read_dir(&self, node: &super::FsNode, index: u32) -> Result<super::DirectoryEntry> {
fn read_dir(&self, node: &super::FsNode, index: usize) -> Result<DirectoryEntry> {
todo!()
}
fn find_dir(&self, node: &super::FsNode, name: &str) -> Result<super::FsNode> {
fn find_dir(&self, node: &super::FsNode, name: &str) -> Result<FsNode> {
todo!()
}
}

View file

@ -21,11 +21,11 @@ pub trait StorageDevice
where
Self: Send,
{
fn open(&self, node: &FsNode /* TODO: flags */) -> Result<Handle>;
fn open(&self, node: &FsNode /* TODO: flags */) -> Result<FileDescriptor>;
fn close(&self, node: &FsNode) -> Result<()>;
fn read(&self, node: &FsNode, offset: u32, size: u32) -> Result<Box<[u8]>>;
fn write(&self, node: &FsNode, offset: u32, buffer: Box<[u8]>) -> Result<()>;
fn read_dir(&self, node: &FsNode, index: u32) -> Result<DirectoryEntry>;
fn read(&self, node: &FsNode, offset: usize, size: usize) -> Result<Box<[u8]>>;
fn write(&self, node: &FsNode, offset: usize, buffer: Box<[u8]>) -> Result<()>;
fn read_dir(&self, node: &FsNode, index: usize) -> Result<DirectoryEntry>;
fn find_dir(&self, node: &FsNode, name: &str) -> Result<FsNode>;
}
@ -35,21 +35,21 @@ where
/// 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
fd_count: u32, // count of open file descriptors
inode: u32, // implementation specific identifier for the node
flags: FsFlags,
length: usize, // in bytes
fd_count: usize, // count of open file descriptors
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
// TODO: permissions mask
// TODO: owning user/group
}
impl FsNode {
pub fn new(
flags: FsNodeFlags,
length: u32,
inode: u32,
flags: FsFlags,
length: usize,
inode: usize,
device_handle: Handle,
ptr: Weak<FsNode>,
) -> Self {
@ -65,13 +65,16 @@ impl FsNode {
/// This method opens a new file descriptor for this VFS node.
// TODO: make this take flags
pub fn open(&self) -> Result<Handle> {
pub fn open(&mut self) -> Result<Handle> {
let state = KERNEL_STATE.lock();
let device = state
.get_storage_device(self.device_handle)
.ok_or_else(|| FsError::InvalidDevice)?;
let fd = device.open(self)?;
let mut kernel_state = KERNEL_STATE.lock();
let handle = kernel_state.add_file_descriptor(fd);
device.open(self)
Ok(handle)
}
/// This method is for closing the VFS node, which is done when no open file
@ -88,7 +91,7 @@ impl FsNode {
/// 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]>> {
pub fn read(&self, offset: usize, size: usize) -> Result<Box<[u8]>> {
let state = KERNEL_STATE.lock();
let device = state
.get_storage_device(self.device_handle)
@ -100,7 +103,7 @@ impl FsNode {
/// 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<()> {
pub fn write(&self, offset: usize, buffer: Box<[u8]>) -> Result<()> {
let state = KERNEL_STATE.lock();
let device = state
.get_storage_device(self.device_handle)
@ -109,7 +112,7 @@ impl FsNode {
device.write(self, offset, buffer)
}
pub fn read_dir(&self, index: u32) -> Result<DirectoryEntry> {
pub fn read_dir(&self, index: usize) -> Result<DirectoryEntry> {
let state = KERNEL_STATE.lock();
let device = state
.get_storage_device(self.device_handle)
@ -129,13 +132,13 @@ impl FsNode {
}
bitflags! {
/// Flags associated with VFS nodes.
/// Flags associated with VFS nodes and file descriptors
///
/// 0x00000MST
/// T is set to 0 for files, 1 for directories
/// S is set when the node is a symbolic link
/// M is set if the node is an active mount point
pub struct FsNodeFlags: u8 {
/// 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;
@ -144,9 +147,28 @@ bitflags! {
}
/// A file descriptor.
pub struct FileDescriptor {}
pub struct FileDescriptor {
flags: FsFlags,
length: usize, // in bytes
inode: usize, // implementation specific identifier for the node
// TODO: permissions mask
// TODO: owning user/group
// TODO: read file position?
// FIXME: I'm not sure if this needs to have a ptr to the VFS node,
// figure that out.
}
impl FileDescriptor {
fn new(flags: FsFlags, length: usize, inode: usize) -> Self {
Self {
flags,
length,
inode,
}
}
}
pub struct DirectoryEntry {
name: String,
inode: u32,
inode: usize,
}

View file

@ -2,7 +2,7 @@ use hashbrown::HashMap;
use spin::Lazy;
use crate::{
filesystem::StorageDevice,
filesystem::{StorageDevice, FileDescriptor},
handle::{Handle, HandleResource},
};
@ -12,6 +12,7 @@ pub static KERNEL_STATE: Lazy<spin::Mutex<KernelInternalState>> =
pub struct KernelInternalState {
pub hostname: String,
storage_devices: HashMap<Handle, Box<dyn StorageDevice>>,
fd_table: HashMap<Handle, FileDescriptor>,
should_shutdown: bool,
}
@ -20,6 +21,7 @@ impl KernelInternalState {
Self {
should_shutdown: false,
storage_devices: HashMap::new(),
fd_table: HashMap::new(),
hostname: "".to_string(),
}
}
@ -28,15 +30,22 @@ impl KernelInternalState {
self.hostname = hostname;
}
pub fn add_storage_device(&mut self, device: impl StorageDevice + Send + 'static) {
self.storage_devices
.insert(Handle::new(HandleResource::StorageDevice), Box::new(device));
pub fn add_storage_device(&mut self, device: impl StorageDevice + Send + 'static) -> Handle {
let handle = Handle::new(HandleResource::StorageDevice);
self.storage_devices.insert(handle, Box::new(device));
handle
}
pub fn get_storage_device(&self, handle: Handle) -> Option<&dyn StorageDevice> {
self.storage_devices.get(&handle).map(|d| &**d)
}
pub fn add_file_descriptor(&mut self, fd: FileDescriptor) -> Handle {
let handle = Handle::new(HandleResource::FileDescriptor);
self.fd_table.insert(handle, fd);
handle
}
pub fn shutdown(&mut self) {
self.should_shutdown = true;
}