• topjohnwu's avatar
    Use /data as tmpfs mount point in 2SI setup · 810d27a6
    topjohnwu authored
    Design credit to @yujincheng08
    Close #5146. Fix #5491, fix #3752
    
    Previously, Magisk changes the mount point from /system to /system_root
    by patching fstab to prevent the original init from changing root.
    The reason why we want to prevent the original init from switching the
    root directory is because it will then be read-only, making patching
    and injecting magiskinit into the boot chain difficult.
    
    This commit (ab)uses the fact that the /data folder will never be part
    of early mount (because it is handled very late in the boot by vold),
    so that we can use it as the mount point of tmpfs to store files.
    
    Some advantages of this method:
    
    - No need to switch root manually
    - No need to modify fstab, which significantly improves compatibility
      e.g. avoid hacks for weird devices like those using oplus.fstab,
      and avoid hacking init to bypass fstab in device trees
    - Supports skip_mount.cfg
    - Support DSU
    810d27a6
mount.cpp 11.7 KB