The following patches sent on 2019/12/18 have been removed from the Eoan/Disco/Bionic kernels:
https://lists.ubuntu.com/archives/kernel-team/2019-December/106461.html Therefore I'm setting the linux tasks back to 'In Progress'. ** Changed in: linux (Ubuntu Bionic) Status: Fix Committed => In Progress ** Changed in: linux (Ubuntu Disco) Status: Fix Committed => In Progress ** Changed in: linux (Ubuntu Eoan) Status: Fix Committed => In Progress -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1850540 Title: multi-zone raid0 corruption Status in Release Notes for Ubuntu: New Status in linux package in Ubuntu: Confirmed Status in mdadm package in Ubuntu: Fix Released Status in linux source package in Precise: New Status in mdadm source package in Precise: New Status in linux source package in Trusty: Confirmed Status in mdadm source package in Trusty: Confirmed Status in linux source package in Xenial: Confirmed Status in mdadm source package in Xenial: Confirmed Status in linux source package in Bionic: In Progress Status in mdadm source package in Bionic: Fix Committed Status in linux source package in Disco: In Progress Status in mdadm source package in Disco: Fix Committed Status in linux source package in Eoan: In Progress Status in mdadm source package in Eoan: Fix Committed Status in linux source package in Focal: Confirmed Status in mdadm source package in Focal: Fix Released Status in mdadm package in Debian: Fix Released Bug description: Bug 1849682 tracks the temporarily revert of the fix for this issue, while this bug tracks the re-application of that fix once we have a full solution. [Impact] (cut & paste from https://marc.info/?l=linux-raid&m=157360088014027&w=2) An unintentional RAID0 layout change was introduced in the v3.14 kernel. This effectively means there are 2 different layouts Linux will use to write data to RAID0 arrays in the wild - the “pre-3.14” way and the “3.14 and later” way. Mixing these layouts by writing to an array while booted on these different kernel versions can lead to corruption. Note that this only impacts RAID0 arrays that include devices of different sizes. If your devices are all the same size, both layouts are equivalent, and your array is not at risk of corruption due to this issue. Unfortunately, the kernel cannot detect which layout was used for writes to pre-existing arrays, and therefore requires input from the administrator. This input can be provided via the kernel command line with the raid0.default_layout=<N> parameter, or by setting the default_layout module parameter when loading the raid0 module. With a new enough version of mdadm (>= 4.2, or equivalent distro backports), you can set the layout version when assembling a stopped array. For example: mdadm --stop /dev/md0 mdadm --assemble -U layout-alternate /dev/md0 /dev/sda1 /dev/sda2 See the mdadm manpage for more details. Once set in this manner, the layout will be recorded in the array and will not need to be explicitly specified in the future. (The mdadm part of this SRU is for the above support ^) [Test Case] = mdadm = Confirm that a multi-zone raid0 created w/ older mdadm is able to be started on a fixed kernel by setting a layout. 1) Ex: w/ old kernel/mdadm: mdadm --create /dev/md0 --run --metadata=default \ --level=0 --raid-devices=2 /dev/vdb1 /dev/vdc1 2) Reboot onto fixed kernel & update mdadm 3) sudo mdadm --stop /dev/md0 && sudo mdadm --assemble -U layout-alternate \ /dev/md0 /dev/vdb1 /dev/vdc1 4) Confirm that the array autostarts on reboot 5) Confirm that w/ new kernel & new mdadm, a user can create and start an array in a backwards-compatible fashion (i.e. w/o an explicit layout). 6) Verify that 'mdadm --detail /dev/md0' displays the layout = linux = Similar to above, but using kernel command line options. [Regression Risk] The kernel side of things will break starting pre-existing arrays. That's intentional. The mdadm side will cause a regression in functionality where a user can no longer create multi-zone raid0s on kernels that do not yet have the raid0 layout patches. This is intentional, as such RAID arrays present a corruption risk. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-release-notes/+bug/1850540/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp