CURRENT r331284: crashing with USB

[Hans Petter Selasky]

On 03/21/18 12:07, Hartmann, O. wrote:
> Hello.
> 
> Incident: CURRENT r331284 can be brought down reliably with an USB
> flash drive plugged in and out without mounting or doing anything with
> it.
> 
> I first recognized the incident with a ZFS on a SanDisk 32GB USB 3.0
> flash drive. Plugging the USB flash and typing "zpool import" revealed
> the very first time I issue this command the existence of the ZFS
> fielsystem. Usually, I import then this USB drive for maintenance
> purposes. Now, typing "zpool import" a second time, nothing is shown at
> all. I see that umass0 has been destroyed - although the USB drive is
> still plugged in.
> 
> Pulling the USB flash drive without having actually imported the
> ZFS makes CURRENT crash and reboot.
> 
> I tried different USB flash drives, 3.0, 2.0, different boxes running
> CURRENT, different hardware (Notebooks, Fujitsu workstations, HP
> servers). It seems that the USB subsystem does have a serious problem -
> not the ZFS. I can plugin the USB and then unplug it and after two or
> three times doing this, the box goes down.
> 
> 
> Does anyone else observe this bug?
> 
> By the way: all ZFS USB drives I use or all other USB flash drives
> cause no problem on FreeBSD 11.1-RELENG-p7!
> 

I've seen something similar, but I thought the issue was fixed by:

https://reviews.freebsd.org/D14456

--HPS