Comment 25 for bug 1793901

For documentation purposes, this is the block device setup
configured in the system to debug/test/fix/verify the bug.

disk partitioning:

# fdisk /dev/sdb # create sdb1 and sbd2, 100G each.

bcache backing device: LVM volume in partition 1

# pvcreate /dev/sdb1
# vgcreate vg-test /dev/sdb1
# lvcreate vg-test -n lv-test --size 99G

bcache caching device: partition 2

# make-bcache -B /dev/mapper/vg--test-lv--test
# make-bcache -C /dev/sdb2

bcache attach:

# bcache-super-show /dev/sdb2 | grep cset.uuid
cset.uuid 73f95583-561c-408f-a93a-4cbd2498f5c8

# echo 73f95583-561c-408f-a93a-4cbd2498f5c8 > /sys/block/bcache0/bcache/attach

bcache writeback mode (important):

# echo writeback > /sys/block/bcache0/bcache/cache_mode

block device topology:

# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 931.5G 0 disk
├─sdb2 8:18 0 100G 0 part
│ └─bcache0 252:0 0 99G 0 disk /test
└─sdb1 8:17 0 100G 0 part
└─vg--test-lv--test 253:0 0 99G 0 lvm
└─bcache0 252:0 0 99G 0 disk /test
sda 8:0 0 931.5G 0 disk
├─sda2 8:2 0 931G 0 part /
└─sda1 8:1 0 512M 0 part /boot/efi

filesystem

# mkfs.ext4 /dev/bcache0