Comment 20 for bug 1867916

Ryan,

Good progress with your crashdump; thanks!

I could root cause the source of the BUG() / NULL pointer address 0x8,
and its relation to the offending commit you identified.

Could you please provide another crashdump, with the _working_ kernel 4.15.0-88,
with the bcache device _mounted_? I'd like to check a few values in its structs.

You should be able to force/trigger a crashdump in a working system with:
$ echo c | sudo tee /proc/sysrq-trigger

Please make sure you run 'sync' before triggering it, so commit any data to disk, and avoid losing it.

Thank you!
Mauricio