Public bug reported: SRU justification:
Impact: The flashcache DKMS module is building but due to an incomplete adaptation for the bi_op/bi_opf split the resulting device-mapper logical volume is not properly writing back data to the backing device. !!! It is possible to write to the volume but the data is LOST !!! Fix: When setting up internal device-mapper IO structures we *must* also initialize bi_op_flags. At least when the structure is on the stack and is set up with individual assignments. Maybe it would not be required for the { ... } form but better be explicit in all cases. Testcase: - prereq: two block devices (disks or partitions), for testing this can also be loop devices. also need flashcache-utils and flashcache-dkms - run "sudo flashcache-create -p back <name> <cache-dev> <backing-dev>" - run "sudo mkfs.ext4 /dev/mapper/<name>" - run "sudo fsck -f /dev/mapper/<name>" - run "sudo dmsetup remove <name>" (this can take a bit) - run "sudo fsck -f <backing-dev>" ** Affects: flashcache (Ubuntu) Importance: High Assignee: Stefan Bader (smb) Status: In Progress ** Patch added: "init-bi-op-flags.patch" https://bugs.launchpad.net/bugs/1714185/+attachment/4941783/+files/init-bi-op-flags.patch -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1714185 Title: flashcache is not usable on kernel version 4.8 and later To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flashcache/+bug/1714185/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs