jfs: possible irq lock inversion dependency detected

This just happend on a PowerPC (32 bit) box running Debian/stable and a 
vanilla 4.6.0-rc7 kernel:

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
4.6.0-rc7 #2 Not tainted
---------------------------------------------------------
kswapd0/272 just changed the state of lock:
 (&jfs_ip->rdwrlock#2){++++-.}, at: [<c01f0840>] jfs_get_block+0x50/0x370
but this lock took another, RECLAIM_FS-unsafe lock in the past:
 (&jfs_ip->commit_mutex){+.+.+.}

Full dmesg & .config: http://nerdbynature.de/bits/4.6.0-rc7/

The system is still up & running and I didn't notice any ill effects so 
far. The box has its root disk formatted with with JFS for a long time
now and this has never happened and I suspect an ongoing compile job must
have triggered the lockdep warning, as the box isn't normally doing much 
compilation.

I found a similar report[0] from 2009 and also one in the kernel 
bugzilla[1], but both are really old.

Thanks,
Christian.

[0] http://lkml.iu.edu/hypermail/linux/kernel/0910.2/01271.html
[1] https://bugzilla.kernel.org/show_bug.cgi?id=13613
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