Note to self: The commit being backported to 3.19 and 3.13 has to contain this race fix:
commit dcc909d90ccdbb73226397ff6d298f7af35b0e11 Author: Markus Pargmann <[email protected]> Date: Tue Oct 6 20:03:54 2015 +0200 nbd: Add locking for tasks The timeout handling introduced in 7e2893a16d3e (nbd: Fix timeout detection) introduces a race condition which may lead to killing of tasks that are not in nbd context anymore. This was not observed or reproducable yet. This patch adds locking to critical use of task_recv and task_send to avoid killing tasks that already left the NBD thread functions. This lock is only acquired if a timeout occures or the nbd device starts/stops. Reported-by: Ben Hutchings <[email protected]> Signed-off-by: Markus Pargmann <[email protected]> Reviewed-by: Ben Hutchings <[email protected]> Fixes: 7e2893a16d3e ("nbd: Fix timeout detection") Signed-off-by: Jens Axboe <[email protected]> Also. ** Patch removed: "trusty-nbd-restructure-debugging-prints.patch" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1505564/+attachment/4524366/+files/trusty-nbd-restructure-debugging-prints.patch ** Patch removed: "trusty-nbd-fix-timeout-detection.patch" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1505564/+attachment/4524367/+files/trusty-nbd-fix-timeout-detection.patch -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1505564 Title: Soft lockup with "block nbdX: Attempted send on closed socket" spam To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1505564/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
