Comment 2 for bug 1861941

root@ubuntu:~# bash -x ./test-bcache-byuuid-links.sh
+ mountpoint /mnt
/mnt is a mountpoint
+ umount -f /mnt
+ '[' -e /dev/bcache0 ']'
+ wipefs -a /dev/bcache0
/dev/bcache0: 2 bytes were erased at offset 0x00000438 (ext4): 53 ef
+ true
++ ls /sys/class/block/bcache0/bcache/stop
+ bdev_stop=/sys/class/block/bcache0/bcache/stop
+ '[' -n /sys/class/block/bcache0/bcache/stop -a -e /sys/class/block/bcache0/bcache/stop ']'
+ echo 'writing 1 to /sys/class/block/bcache0/bcache/stop'
writing 1 to /sys/class/block/bcache0/bcache/stop
+ echo 1
+ udevadm settle
+ sleep 1
+ true
++ ls /sys/class/block/bcache0/bcache/stop
ls: cannot access '/sys/class/block/bcache0/bcache/stop': No such file or directory
+ bdev_stop=
+ '[' -n '' -a -e '' ']'
+ break
+ true
++ ls /sys/fs/bcache/06727454-1020-4b7b-99ef-14789f7f7f3b/stop
+ cdev_stop=/sys/fs/bcache/06727454-1020-4b7b-99ef-14789f7f7f3b/stop
+ '[' -n /sys/fs/bcache/06727454-1020-4b7b-99ef-14789f7f7f3b/stop -a -e /sys/fs/bcache/06727454-1020-4b7b-99ef-14789f7f7f3b/stop ']'
+ echo 'writing 1 to /sys/fs/bcache/06727454-1020-4b7b-99ef-14789f7f7f3b/stop'
writing 1 to /sys/fs/bcache/06727454-1020-4b7b-99ef-14789f7f7f3b/stop
+ echo 1
+ udevadm settle
+ sleep 1
+ true
++ ls '/sys/fs/bcache/*-*-*-*/stop'
ls: cannot access '/sys/fs/bcache/*-*-*-*/stop': No such file or directory
+ cdev_stop=
+ '[' -n '' -a -e '' ']'
+ break
+ (( x=0 ))
+ (( x<50 ))
+ wipefs -a /dev/sdc
/dev/sdc: 16 bytes were erased at offset 0x00001018 (bcache): c6 85 73 f6 4e 1a 45 ca 82 65 f5 7f 48 ba 6d 81
+ rc=0
+ '[' 0 = 0 ']'
+ break
+ '[' 0 '!=' 0 ']'
+ (( x=0 ))
+ (( x<50 ))
+ wipefs -a /dev/sdb
/dev/sdb: 16 bytes were erased at offset 0x00001018 (bcache): c6 85 73 f6 4e 1a 45 ca 82 65 f5 7f 48 ba 6d 81
+ rc=0
+ '[' 0 = 0 ']'
+ break
+ '[' 0 '!=' 0 ']'
+ make-bcache --wipe-bcache -C /dev/sdc -B /dev/sdb
UUID: 59306fe6-b5fd-439b-bea3-df7ee65d0b8d
Set UUID: 89103ca3-a773-4fca-a456-f10bd3ea17b2
version: 0
nbuckets: 20480
block_size: 1
bucket_size: 1024
nr_in_set: 1
nr_this_dev: 0
first_bucket: 1
UUID: 8b8fb68a-8f3c-46ba-b656-0442b511bfe7
Set UUID: 89103ca3-a773-4fca-a456-f10bd3ea17b2
version: 1
block_size: 1
data_offset: 16
+ udevadm settle --exit-if-exists /dev/bcache0
+ '[' '!' -e /dev/bcache/by-uuid ']'
+ ls -al /dev/bcache/by-uuid/
total 0
drwxr-xr-x 2 root root 60 Feb 4 23:30 .
drwxr-xr-x 3 root root 60 Feb 4 23:30 ..
lrwxrwxrwx 1 root root 13 Feb 4 23:30 8b8fb68a-8f3c-46ba-b656-0442b511bfe7 -> ../../bcache0
+ echo 'Creating filesystems on bcache0'
Creating filesystems on bcache0
+ mkfs.ext4 /dev/bcache0
mke2fs 1.45.3 (14-Jul-2019)
Discarding device blocks: done
Creating filesystem with 2621438 4k blocks and 655360 inodes
Filesystem UUID: 48988989-b276-42c1-b999-e29928353796
Superblock backups stored on blocks:
 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done

+ echo 'mounting bcache0 to /mnt'
mounting bcache0 to /mnt
+ mount /dev/bcache0 /mnt
+ udevadm settle --exit-if-exists /dev/bcache0
+ '[' '!' -e /dev/bcache/by-uuid ']'
+ echo 'bcache0 mounted and /dev/bcache/by-uuid does not exist!'
bcache0 mounted and /dev/bcache/by-uuid does not exist!
+ exit 2