We have confirmed that the patchwork.kernel.org patch originally requested was not the right one.
This set of four patches from mainline (applied to bionic) supplies the needed functionality, and a test backport to bionic has been confirmed to work as expected: bdaeedc1bea9 scsi: tcmu: add module wide block/reset_netlink support 9de3a1ef032a scsi: tcmu: simplify nl interface 3228691ffec1 scsi: tcmu: track nl commands 0297e962907d scsi: tcmu: delete unused __wait ** Description changed: With the 4.15.0 kernel version used in bionic GCP/GKE, if the tcmu user space code crashes while handling a netlink message from the kernel, the kernel module will be stuck waiting for the response. This situation can only be resolved with a server reboot. === SRU Justification === [Impact] With this particular user-space crash in the current Ubuntu image it results in a hang hobbles the entire physical server. [Fix] - The request is for Canonical to backport the patch https://patchwork.kernel.org/patch/10319623/ to the bionic 4.15.0 kernel + The request is for Canonical to backport the patch https://patchwork.kernel.org/patch/10319623/ to the bionic 4.15.0 kernel [** CORRECTED: See comment #2 ***] There were a number of mainline upstream commits to apply as part of the backport [Test] unavailable [Regression Potential] Low. it's all mainline commits, and affects only that driver. ** Description changed: With the 4.15.0 kernel version used in bionic GCP/GKE, if the tcmu user space code crashes while handling a netlink message from the kernel, the kernel module will be stuck waiting for the response. This situation can only be resolved with a server reboot. === SRU Justification === [Impact] With this particular user-space crash in the current Ubuntu image it results in a hang hobbles the entire physical server. [Fix] - The request is for Canonical to backport the patch https://patchwork.kernel.org/patch/10319623/ to the bionic 4.15.0 kernel [** CORRECTED: See comment #2 ***] + The request is for Canonical to backport the patch https://patchwork.kernel.org/patch/10319623/ to the bionic 4.15.0 kernel [** CORRECTION: See comment #2 ***] There were a number of mainline upstream commits to apply as part of the backport [Test] unavailable [Regression Potential] Low. it's all mainline commits, and affects only that driver. ** Changed in: linux (Ubuntu Bionic) Importance: Undecided => High -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-gcp in Ubuntu. https://bugs.launchpad.net/bugs/1819504 Title: tcmu user space crash results in kernel module hang. Status in linux package in Ubuntu: Incomplete Status in linux-gcp package in Ubuntu: Invalid Status in linux source package in Bionic: In Progress Status in linux-gcp source package in Bionic: In Progress Bug description: With the 4.15.0 kernel version used in bionic GCP/GKE, if the tcmu user space code crashes while handling a netlink message from the kernel, the kernel module will be stuck waiting for the response. This situation can only be resolved with a server reboot. === SRU Justification === [Impact] With this particular user-space crash in the current Ubuntu image it results in a hang hobbles the entire physical server. [Fix] The request is for Canonical to backport the patch https://patchwork.kernel.org/patch/10319623/ to the bionic 4.15.0 kernel [** CORRECTION: See comment #2 ***] There were a number of mainline upstream commits to apply as part of the backport [Test] unavailable [Regression Potential] Low. it's all mainline commits, and affects only that driver. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1819504/+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
