Wrong id and gid running /system/bin/sdcard

Question

I am trying to use my ext4 sdcard properly in Stock rooted Android 4.4.4. For this, I run

mount -rw -t ext4 /dev/block/mmcblk1p1 /mnt/media_rw/sdcard1

and then

/system/bin/sdcard -u 1023 -g 1023 -w 1023 /mnt/media_rw/sdcard1 /storage/sdcard1

I also tried

/system/bin/sdcard /mnt/media_rw/sdcard1 /storage/sdcard1 1023 1023

The problem is that the ownership of the tree created in /storage/sdcard1 is then 0.1015 instead of 1023.1023 (??), so I have permission problems...

Any idea why the /system/bin/sdcard command is not obeying the ownership flags?

Thanks!

Answer 1

Edit: The solution is here: https://source.android.com/devices/storage/config.html

"For Android releases 4.3 and later, the various fstab files used by init, vold and recovery were unified in the /fstab. file. For external storage volumes that are managed by vold, the entries should have the following format:"

 <src> <mnt_point> <type> <mnt_flags> <fs_mgr_flags>

"...Devices may provide external storage by emulating a case-insensitive, permissionless filesystem backed by internal storage. One possible implementation is provided by the FUSE daemon in system/core/sdcard, which can be added as a device-specific init.rc service:"

# virtual sdcard daemon running as media_rw (1023)
service sdcard /system/bin/sdcard <source_path> <dest_path> 1023 1023
    class late_start