Comment 6 for bug 1729145

Mainline kernel does not help; it fails the same way and also has a bug that's fixed in the Ubuntu kernel:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1667078

Here's the details from the mainline test:

ubuntu@a-unsolar-melonie:~$ dpkg --list | grep linux-image
ii linux-image-4.13.0-16-generic 4.13.0-16.19 amd64 Linux kernel image for version 4.13.0 on 64 bit x86 SMP
ii linux-image-4.14.0-041400rc7-generic 4.14.0-041400rc7.201710292231 amd64 Linux kernel image for version 4.14.0 on 64 bit x86 SMP
ii linux-image-virtual 4.13.0.16.17 amd64 Virtual Linux kernel image
ubuntu@a-unsolar-melonie:~$ uname -r
4.14.0-041400rc7-generic
ubuntu@a-unsolar-melonie:~$ uname -a
Linux a-unsolar-melonie 4.14.0-041400rc7-generic #201710292231 SMP Sun Oct 29 22:32:07 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@a-unsolar-melonie:~$ ls -al /dev/bcache*
brw-rw---- 1 root disk 251, 0 Nov 1 14:45 /dev/bcache0
brw-rw---- 1 root disk 251, 16 Nov 1 14:45 /dev/bcache16
brw-rw---- 1 root disk 251, 32 Nov 1 14:45 /dev/bcache32
ubuntu@a-unsolar-melonie:~$ dmesg | grep bcache
[ 3.099823] bcache: register_bdev() registered backing device vdb4
[ 3.159769] bcache: bch_journal_replay() journal replay done, 0 keys in 1 entries, seq 2
[ 3.170818] bcache: register_cache() registered cache device vdb1
[ 3.173682] bcache: register_bdev() registered backing device vdb3
[ 3.183034] bcache: register_bdev() registered backing device vdb2
[ 8.271351] bcache: register_bcache() error opening /dev/vdb1: device already registered
[ 8.296933] bcache: register_bcache() error opening /dev/vdb2: device already registered
[ 8.345949] bcache: register_bcache() error opening /dev/vdb3: device already registered
[ 8.353927] bcache: register_bcache() error opening /dev/vdb4: device already registered