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/* Copyright (c) [2023] [Syswonder Community]
* [Rukos] is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
* http://license.coscl.org.cn/MulanPSL2
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
* See the Mulan PSL v2 for more details.
*/
//! Device filesystem used by [ArceOS](https://github.com/rcore-os/arceos).
//!
//! The implementation is based on [`axfs_vfs`].
#![cfg_attr(not(test), no_std)]
extern crate alloc;
mod dir;
mod null;
mod zero;
#[cfg(test)]
mod tests;
pub use self::dir::DirNode;
pub use self::null::NullDev;
pub use self::zero::ZeroDev;
use alloc::sync::Arc;
use axfs_vfs::{VfsNodeRef, VfsOps, VfsResult};
use spin::once::Once;
/// A device filesystem that implements [`axfs_vfs::VfsOps`].
pub struct DeviceFileSystem {
parent: Once<VfsNodeRef>,
root: Arc<DirNode>,
}
impl DeviceFileSystem {
/// Create a new instance.
pub fn new() -> Self {
Self {
parent: Once::new(),
root: DirNode::new(None),
}
}
/// Create a subdirectory at the root directory.
pub fn mkdir(&self, name: &'static str) -> Arc<DirNode> {
self.root.mkdir(name)
}
/// Add a node to the root directory.
///
/// The node must implement [`axfs_vfs::VfsNodeOps`], and be wrapped in [`Arc`].
pub fn add(&self, name: &'static str, node: VfsNodeRef) {
self.root.add(name, node);
}
}
impl VfsOps for DeviceFileSystem {
fn mount(&self, _path: &str, mount_point: VfsNodeRef) -> VfsResult {
if let Some(parent) = mount_point.parent() {
self.root.set_parent(Some(self.parent.call_once(|| parent)));
} else {
self.root.set_parent(None);
}
Ok(())
}
fn root_dir(&self) -> VfsNodeRef {
self.root.clone()
}
}
impl Default for DeviceFileSystem {
fn default() -> Self {
Self::new()
}
}