5.4.20: cannot mount device that blipped off the bus: duplicate device fsid:devid for

[Marc MERLIN <marc@merlins.org>]

/dev/sde blipped off the bus (hardware issue?) and came
back as /dev/sdq.
Except btrfs won't let me scan or mount it.

I was able to btrfs check it though and that came back clean.

gargamel:~# ls -l /dev/sde
ls: cannot access '/dev/sde': No such file or directory


gargamel:~# mount /dev/sdq1 /mnt/mnt
mount: /mnt/mnt: mount(2) system call failed: File exists.
gargamel:~# dmesg |tail -1
[2560371.195249] BTRFS warning (device sde1): duplicate device fsid:devid for 727c7ba3-f6f9-462a-8472-453dd7d46d8a:1 old:/dev/sde1 new:/dev/sdq1

gargamel:~# btrfs device scan
Scanning for Btrfs filesystems
ERROR: device scan failed on '/dev/sdq1': File exists
ERROR: there are 1 errors while registering devices
gargamel:~# dmesg |tail -1
[2560416.434529] BTRFS warning (device sde1): duplicate device fsid:devid for 727c7ba3-f6f9-462a-8472-453dd7d46d8a:1 old:/dev/sde1 new:/dev/sdq1

gargamel:~# grep sde /proc/mounts 
cgroup2 /sys/fs/cgroup/unified cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate 0 0
gargamel:~# 

gargamel:~# lsblk -f |grep 727c7ba3-f6f9-462a-8472-453dd7d46d8a
└─sdq1                            btrfs             btrfs_space                 727c7ba3-f6f9-462a-8472-453dd7d46d8a   
gargamel:~# 

So, that FS isn't a duplicate anymore and I see to have no way out except reboot
which I'll do now.

Was there another way around it? Obviously this is not desirable
behaviour, in the past, I was able to remount the device when it came
back.

Thanks,
Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
 
Home page: http://marc.merlins.org/                       | PGP 7F55D5F27AAF9D08