feat: 虚拟媒体支持同时挂载多个镜像

src/hid/backend.rs

@@ -83,6 +83,10 @@ pub trait HidBackend: Send + Sync {
 
     async fn reset(&self) -> Result<()>;
 
+    async fn prepare_rebuild(&self) -> Result<()> {
+        self.shutdown().await
+    }
+
     async fn shutdown(&self) -> Result<()>;
 
     fn runtime_snapshot(&self) -> HidBackendRuntimeSnapshot;

src/hid/mod.rs

@@ -234,6 +234,30 @@ impl HidController {
         Ok(())
     }
 
+    pub async fn prepare_otg_rebuild(&self) -> Result<()> {
+        if !matches!(*self.backend_type.read().await, HidBackendType::Otg) {
+            return Ok(());
+        }
+
+        info!("Preparing OTG HID backend for gadget rebuild");
+        self.backend_available.store(false, Ordering::Release);
+        self.stop_runtime_worker().await;
+
+        if let Some(backend) = self.backend.write().await.take() {
+            backend.prepare_rebuild().await?;
+        }
+
+        let current = self.runtime_state.read().await.clone();
+        let rebuilding_state = HidRuntimeState::with_error(
+            &HidBackendType::Otg,
+            &current,
+            "OTG gadget is rebuilding",
+            "rebuilding",
+        );
+        self.apply_runtime_state(rebuilding_state).await;
+        Ok(())
+    }
+
     pub async fn send_keyboard(&self, event: KeyboardEvent) -> Result<()> {
         if !self.backend_available.load(Ordering::Acquire) {
             return Err(AppError::BadRequest(

src/hid/otg.rs

@@ -894,6 +894,19 @@ impl HidBackend for OtgBackend {
         Ok(())
     }
 
+    async fn prepare_rebuild(&self) -> Result<()> {
+        self.stop_runtime_worker();
+        *self.keyboard_dev.lock() = None;
+        *self.mouse_rel_dev.lock() = None;
+        *self.mouse_abs_dev.lock() = None;
+        *self.consumer_dev.lock() = None;
+        self.initialized.store(false, Ordering::Relaxed);
+        self.online.store(false, Ordering::Relaxed);
+        self.notify_runtime_changed();
+        info!("OTG backend prepared for gadget rebuild");
+        Ok(())
+    }
+
     async fn shutdown(&self) -> Result<()> {
         self.stop_runtime_worker();
 
@@ -948,6 +961,7 @@ impl Drop for OtgBackend {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::io::{Seek, SeekFrom, Write};
 
     #[test]
     fn test_led_state() {
@@ -964,4 +978,22 @@ mod tests {
         let kb_report = KeyboardReport::default();
         assert_eq!(kb_report.to_bytes().len(), 8);
     }
+
+    #[tokio::test]
+    async fn prepare_rebuild_closes_devices_without_writing_reset_reports() {
+        let mut file = tempfile::tempfile().unwrap();
+        file.write_all(b"sentinel").unwrap();
+        file.seek(SeekFrom::Start(0)).unwrap();
+
+        let backend = OtgBackend::from_handles(HidDevicePaths::default()).unwrap();
+        *backend.keyboard_dev.lock() = Some(file);
+        backend.initialized.store(true, Ordering::Relaxed);
+        backend.online.store(true, Ordering::Relaxed);
+
+        backend.prepare_rebuild().await.unwrap();
+
+        assert!(backend.keyboard_dev.lock().is_none());
+        assert!(!backend.initialized.load(Ordering::Relaxed));
+        assert!(!backend.online.load(Ordering::Relaxed));
+    }
 }