Bug#903838: Unable to mount ext4 filesystem with meta_bg flag

[debian@heinopeters.de]

Package: linux-image-4.9.0-7-amd64
Version: 4.9.110-1

Mounting ext4 filesystem with meta_bg set fails with "structure needs cleaning".
Mounting the same filesystem with the kernel from linux-image-4.9.0-6-amd64
works as expected.

root@mini:/home/peters# mkfs.ext4 -O meta_bg,^resize_inode /dev/sdb1
mke2fs 1.43.4 (31-Jan-2017)
Creating filesystem with 10485504 4k blocks and 2621440 inodes
Filesystem UUID: 5400c937-1062-4cc2-8c4c-94dcf8ec2f57
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000, 7962624

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (65536 blocks): done
Writing superblocks and filesystem accounting information: done   

root@mini:/home/peters# mount -v /dev/sdb1 /mnt
mount: mount /dev/sdb1 on /mnt failed: Structure needs cleaning
root@mini:/home/peters# tail -3 /var/log/syslog 
Jul 15 11:42:44 mini kernel: [   28.425654]  sdb: sdb1
Jul 15 11:48:26 mini kernel: [  370.639747] EXT4-fs (sdb1): ext4_check_descriptors: Block bitmap for group 0 overlaps block group descriptors
Jul 15 11:48:26 mini kernel: [  370.640447] EXT4-fs (sdb1): group descriptors corrupted!
root@mini:/home/peters# uname -a
Linux mini 4.9.0-7-amd64 #1 SMP Debian 4.9.110-1 (2018-07-05) x86_64 GNU/Linux
root@mini:/home/peters#