Hi,
the bug is present in 5.0.11, 5.0.13 et 5.0.14 (rawhide).
Please see :
https://bugzilla.redhat.com/show_bug.cgi?id=1708315
I guess it will be a tough one, since it's seems clearly linked to the
gcc version, since the same code works under Fedora 29 (gcc 8), and
fails under Fedora 30 (gcc 9).
Regards,
Pierre
Le 12/05/2019 à 19:11, Coly Li a écrit :
On 2019/5/12 1:30 上午, Pierre JUHEN wrote:
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.
On my development machine the GCC is still v7.3.1, for now I don't know
how to upgrade to GCC 9.1 yet.
>From the dmesg.lis file, it seems fc30 uses 5.0.11-300, so what is the
kernel version of fc29 ?
(And from dmesg.lis I don't see anything suspicious on bcache message,
no clue yet).
Coly Li
