It looks that we're trying to register /dev/vdg multiple times as a backing device (make-bcache -B). I'm not getting this message during my tests, so that might be required to reproduce that particular deadlock.
I'll modify my test case to trigger these errors and see if I can reproduce the hung task timeout issue.
Thanks Ryan, this is very interesting:
[ 259.411486] bcache: register_bcache() error /dev/vdg: device already registered (emitting change event)
[ 259.537070] bcache: register_bcache() error /dev/vdg: device already registered (emitting change event)
[ 259.797830] bcache: register_bcache() error /dev/vdg: device already registered (emitting change event)
[ 259.900392] bcache: register_bcache() error /dev/vdg: device already registered (emitting change event)
It looks that we're trying to register /dev/vdg multiple times as a backing device (make-bcache -B). I'm not getting this message during my tests, so that might be required to reproduce that particular deadlock.
I'll modify my test case to trigger these errors and see if I can reproduce the hung task timeout issue.