ksud: Don't umount stock bind mount, just bind it again after overlay.

userspace/ksud/src/event.rs

@@ -20,16 +20,10 @@ fn mount_partition(partition: &str, lowerdir: &mut Vec<String>) -> Result<()> {
     }
 
     // handle stock mounts under /partition, we should restore the mount point after overlay
+    // because the overlayfs mount will "overlay" the bind mount such as /vendor/bt_firmware, /vendor/dsp
+    // which will cause the system bootloop or bluetooth/dsp not working
     let stock_mount = mount::StockMount::new(&format!("/{partition}/"))
         .with_context(|| format!("get stock mount of partition: {partition} failed"))?;
-    let result = stock_mount.umount();
-    if result.is_err() {
-        let remount_result = stock_mount.remount();
-        if let Err(e) = remount_result {
-            log::error!("remount stock failed: {:?}", e);
-        }
-        bail!("umount stock mount of failed: {:?}", result);
-    }
 
     // add /partition as the lowerest dir
     let lowest_dir = format!("/{partition}");

userspace/ksud/src/mount.rs

@@ -284,21 +284,6 @@ impl StockMount {
         mounts
     }
 
-    pub fn umount(&self) -> Result<()> {
-        let mounts = self.get_target_mounts();
-        log::info!("umount stock for {} : {:?}", self.mnt, mounts);
-        for m in mounts {
-            let dst = m
-                .dest
-                .to_str()
-                .ok_or(anyhow::anyhow!("Failed to get dst"))?;
-            umount_dir(dst)?;
-            log::info!("umount: {:?}", m);
-        }
-        log::info!("umount stock succeed!");
-        Ok(())
-    }
-
     pub fn remount(&self) -> Result<()> {
         let mut mounts = self.get_target_mounts();
         mounts.reverse(); // remount it in order
@@ -342,10 +327,6 @@ impl StockMount {
         })
     }
 
-    pub fn umount(&self) -> Result<()> {
-        unimplemented!()
-    }
-
     pub fn remount(&self) -> Result<()> {
         unimplemented!()
     }