XFS locking issues in 3.18-rc3+

[Dave Chinner]

On Fri, Nov 14, 2014 at 01:02:59PM -0800, Andy Lutomirski wrote:
> On Thu, Nov 13, 2014 at 9:25 PM, Dave Chinner <david at fromorbit.com> wrote:
> > 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.
> 
> I still have an enormous flood of warnings even if
> CONFIG_PROVE_LOCKING=n.  This one is repeated at high frequency:
> 
> [   70.969118] ------------[ cut here ]------------
> [   70.969121] WARNING: CPU: 8 PID: 653 at mm/truncate.c:758
> pagecache_isize_extended+0x105/0x110()

Fixed in 3.18-rc4.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com