Crash with ZFS between r296491 and r296548

[Ed Maste]

On 9 March 2016 at 01:39, Ed Maste <emaste at freebsd.org> wrote:
> On 8 March 2016 at 18:52, Jean-Sébastien Pédron
> <jean-sebastien.pedron at dumbbell.fr> wrote:
>> Hi!
>>
>> I use Root on ZFS and my laptop doesn't boot with a kernel from r296548
>> and world from r296491 (so older than kernel). Ed hits a similar crash.
>>
>> Here are the dmesg and backtrace of zfs(8):
>> https://gist.github.com/dumbbell/c9978ad4ac70214f0f47
>>
>> With a kernel and world from r296491, everything is ok.
>>
>> I didn't have the time to bisect the bad commit yet, so this is mostly a
>> warning for other. Maybe someone will know what's wrong :)
>
> The error's coming from namespace_reload() in libzfs_util.c,
> ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_CONFIGS, &zc)
>
> I haven't had a chance to bisect yet either. There are 9 or so commits
> between r296491 and r296548 -- I hope mav@ has some insight.

I still haven't been able to bisect, but in a local tree I've reverted
recent ZFS changes and the issue is gone.

Reverted commits: r296510, r296512, r296514, r296516, r296519,
r296521, r296523, r296528, r296530