The problem is likely caused by: [trusty] 5d2f571 bcache: allows use of register in udev to avoid "device_busy" error. ... which introduces a code path that calls mutex_unlock(&bch_register_lock) twice.
Another mainline commit (added in Linux v3.15, but not marked cc: stable) removes one of the unlocks, and is likely the fix we need for trusty and 3.13-stable: [mainline] 4fa0340 bcache: Fix a lockdep splat in an error path -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1551327 Title: [regression] task bcache_register blocked To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1551327/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
