- fix a livelock when we cause a huge number of cache misses
- Add a cond_resched() call to gc
- clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing device
- fix a leak in bch_cached_dev_run()
- unregister reboot notifier if bcache fails to unregister device
- allows use of register in udev to avoid "device_busy" error.
- prevent crash on changing writeback_running
- Change refill_dirty() to always scan entire disk if necessary
As requested in
https://lists.debian.org/debian-backports/2016/01/msg00067.html
Ben Hutchings