xfs: possible deadlock warning

[Dave Chinner]

On Wed, May 28, 2014 at 01:19:16PM +0800, Gu Zheng wrote:
> Hi all,
> When running the latest Linus' tree, the following possible deadlock warning occurs.

false positive. There isn't a deadlock between inode locks on
different filesystems. i.e. there is no dependency between shmem
inodes and xfs inodes, nor on their security contexts.  Nor can you
take a page fault on a directory inode, which is the XFS inode lock
class it's complaining about.

Fundamentally, the problem here is shmem instantiating a new inode
with the mmap_sem held. That's just plain wrong...


Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com