Hi,
I use bcache extensively on 3 PC, and I lost data on 2 of them after an
attempt to migrate to Fedora 30.
My configuration is almost the same on the 3 PCs :
/boot/efi and /boot are native on the SSD, and there is a bache frontend.
bcache backend is on a HDD or on a raid1 array.
bcache device is the physical volume of an LVM volume group.
Here is how to reproduce the problem :
1/ Create the storage configuration as explained above.
2/ Install Fedora 29 on a logical volume (ext4) and a swap logical volume.
3/ Update the installation (dnf update --refresh)
4/ Migrate to Fedora 30 in download mode (dnf system-upgrade
--releasever=30 --allowerasing donwnload, then dnf system-upgrade reboot)
5/ try to prevent automatic reboot in Fedora 30 (for example in
commenting out /boot/efi in /etc/fstab)
6/ reboot using Fedora 29 kernel and initramfs -> Everything is fine
7/ reboot using Fedora 30 kernel and initramfs -> Everything is
corrupted, even unmounted volumes of the volume group
I did the test case twice, the second time in downgrading bcache-tools
to Fedora 29 -> same issue
This means that's the problem is located in the bcache kernel module ;
but since I guess it's the same code, the problem is probably linked to
the building environment (gcc version ?)
I reported the bug : https://bugzilla.redhat.com/show_bug.cgi?id=1707822
But I thought it was not a kernel problem.
Thanks
Regards,
Pierre Juhen
