failed to rollback from 15.04 alpha #4 to #3

[Leo Arias]

I flashed snappy 15.04 alpha #3 in my beaglebone black. Today there's a new image on that channel, so I updated.
I rebooted and got into alpha #4. Then I tried to rollback to #3, but after the reboot, it fails to boot and I end up in #4 again. So it's no possible for me to rollback.

My test log with the steps to reproduce: http://paste.ubuntu.com/11873826/
This is the serial console after the reboot: http://paste.ubuntu.com/11873742/

[Ricardo Salveti (rsalveti)]

(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ ls -l a/
total 19616
drwxr-xr-x 2 root root 512 Jul 13 16:02 dtbs
-rwxr-xr-x 1 root root 114 Jul 13 16:02 hardware.yaml
-rwxr-xr-x 1 root root 13574238 Jul 13 16:02 initrd.img
-rwxr-xr-x 1 root root 6510264 Jul 13 16:02 vmlinuz

(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ md5sum a/vmlinuz
baae473daca1d9fa2c2e998aab1c0bcc a/vmlinuz
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ md5sum a/initrd.img
c42761096016a6a8813a3f718b24f777 a/initrd.img
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ sudo md5sum /boot/vmlinuz-3.19.0-18-generic
baae473daca1d9fa2c2e998aab1c0bcc /boot/vmlinuz-3.19.0-18-generic
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ md5sum /boot/initrd.img-3.19.0-18-generic
c42761096016a6a8813a3f718b24f777 /boot/initrd.img-3.19.0-18-generic

After updating to image 4 and booting again:
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ ls -l a/
total 19616
drwxr-xr-x 2 root root 512 Jul 13 16:02 DTBS
-rwxr-xr-x 1 root root 114 Jul 13 16:02 HARDWA~1.YAM
-rwxr-xr-x 1 root root 13574238 Jul 13 16:02 INITRD.IMG
-rwxr-xr-x 1 root root 6510264 Jul 13 16:02 VMLINUZ
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ md5sum a/VMLINUZ
26e74d8bbae82f6eb9055ffde9c9c5ec a/VMLINUZ
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot$ md5sum a/INITRD.IMG
f52e6affb21728251d6de9ab520635af a/INITRD.IMG

So it did end up modifying the kernel (maybe via fsck?).

[Ricardo Salveti (rsalveti)]

(BeagleBoneBlack)ubuntu@localhost:~$ sudo snappy rollback ubuntu-core 3
Setting ubuntu-core to version 3
Name Date Version Developer
ubuntu-core 2015-06-10 3 ubuntu!
Reboot to use the new ubuntu-core.

(BeagleBoneBlack)ubuntu@localhost:/boot/uboot/a$ sudo md5sum /writable/cache/system/boot/vmlinuz-3.19.0-18-generic
baae473daca1d9fa2c2e998aab1c0bcc /writable/cache/system/boot/vmlinuz-3.19.0-18-generic
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot/a$ sudo md5sum /writable/cache/system/boot/initrd.img-3.19.0-18-generic
c42761096016a6a8813a3f718b24f777 /writable/cache/system/boot/initrd.img-3.19.0-18-generic
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot/a$ sudo cp /writable/cache/system/boot/vmlinuz-3.19.0-18-generic VMLINUZ
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot/a$ sudo cp /writable/cache/system/boot/initrd.img-3.19.0-18-generic INITRD.IMG
(BeagleBoneBlack)ubuntu@localhost:/boot/uboot/a$ sync
(BeagleBoneBlack)ubuntu@localhost:~$ sync
(BeagleBoneBlack)ubuntu@localhost:~$ sudo reboot

Then I was able to successfully boot image 3 again (partition a), which clearly shows that the kernel and initrd were indeed corrupted.

[Ricardo Salveti (rsalveti)]

Now the question is why the vfat partition is getting into this weird/broken state, maybe not unmounted properly during reboot?

[Oliver Grawert (ogra)]

probably fatwrite does something to it when it re-writes the snappy stamp file during first boot after update ...

[Michael Vogt (mvo)]

We are almost ready to replace the broken fatwrite with using a uboot environment file for the state handling.