XFS locking issues in 3.18-rc3+

[Dave Chinner]

On Thu, Nov 13, 2014 at 04:57:11PM -0800, Andy Lutomirski wrote:
> I'm running a kernel somewhere between 3.18-rc3 and 3.18-rc4.  I got
> the warnings below.  Is this a known issue?

Yup, false positive. shmem is instantiating an inode under the
mmap_sem and in doing so taking inode locks under the mmap_sem,
which triggers other filesystems to issue false warnings about
mmap_sem <-> inode lock order.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com