Failed to mount sdcardfs on DragonBoard 845c

I build and flash by referring to this site ( AOSP/db845c - Linaro Wiki )
But failed to mount sdcardfs
when I use this image, device is normal operation
http://snapshots.linaro.org/96boards/dragonboard845c/linaro/aosp-master/408/
Is there anything else to check?

--------- beginning of system
08-31 05:32:17.572 1199 1199 W sdcard : Device explicitly enabled sdcardfs
08-31 05:32:17.572 1199 1199 W sdcard : Failed to mount sdcardfs with options fsuid=1023,fsgid=1023,multiuser,derive_gid,default_normal,unshared_obb,mask=6,userid=0,gid=1015: No such device
08-31 05:32:17.572 1199 1199 W sdcard : Failed to mount sdcardfs with options fsuid=1023,fsgid=1023,multiuser,derive_gid,default_normal,mask=6,userid=0,gid=1015: No such device
08-31 05:32:17.573 1199 1199 W sdcard : Failed to mount sdcardfs with options fsuid=1023,fsgid=1023,multiuser,derive_gid,mask=6,userid=0,gid=1015: No such device
08-31 05:32:17.573 1199 1199 W sdcard : Failed to mount sdcardfs with options fsuid=1023,fsgid=1023,multiuser,mask=6,userid=0,gid=1015: No such device
08-31 05:32:17.573 1199 1199 W sdcard : Failed to mount sdcardfs with options fsuid=1023,fsgid=1023,mask=6,userid=0,gid=1015: No such device
08-31 05:32:17.573 1199 1199 F sdcard : sdcard.cpp:190] failed to sdcardfs_setup
--------- beginning of crash
08-31 05:32:17.573 1199 1199 F libc : Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 1199 (sdcard), pid 1199 (sdcard)

Which kernel version failed to mount sdcardfs? sdcardfs is discontinued since android-mainline-5.7. So if you are booting v5.7 or newer there is no sdcardfs support.

Linaro Snapshots prebuilt images boot with v5.4.y, hence you don’t see this sdcardfs mount problem there.

Thanks,
Amit Pundir

Which kernel version failed to mount sdcardfs?
→ 5.4 kernel

using this command for source download
Already sdcardfs has been deleted in common-android11-5.4
Therefore, this problem still occurs in db845c

repo init -u kernel/manifest - Git at Google -b common-android11-5.4

commit c6d419d9ff6ee687a83dc4798e0e0be46fa3050a
Author: Greg Kroah-Hartman gregkh@google.com
Date: Fri May 29 09:37:57 2020 +0200

ANDROID: sdcardfs: remove sdcardfs from system

It's no longer needed on Android devices, so remove sdcardfs core code,
and a bunch of exports that were only added so that it could be built as
a module.

Bug: 157700134
Cc: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I2b5c1103a79c07dcbd7273b42ac4b7ddf4615d38

Argh… I forgot about android11-5.4. Any reason you want to stick to android11-5.4? android12-5.4 still has sdcardfs support. If you want to stick to android11-5.4, I suggest you revert this commit (c6d419d9ff6ee6 ANDROID: sdcardfs: remove sdcardfs from system), since you are building your kernel from source anyway.

FWIW Android11 and beyond is not using sdcardfs. They have switched to a new feature called “scoped storage”, https://developer.android.com/preview/privacy/storage, implemented using Fuse and ext4/f2fs case folding. Scoped storage code has not landed in AOSP yet, so you have to live with sdcardfs till then.