mobile

Hello. I wanna change a file's permission in sdcard/android/data but when i try this,root explorer gives "permissions change was not succesfull. Please note that some filesystems (e. G. Sd card) don't allow permission changes." I tried a lot of things to fix it. Tried fix permissions in android, add a line to platform.xml. It didin't work. I'm on cyanogenmod 12 with stock kernel. Shall i change my kernel or migrate my filesystem to f2fs? Thank u